WorldWideScience

Sample records for iron alloy targets

  1. Iron-nickel-chromium alloys

    International Nuclear Information System (INIS)

    Karenko, M.K.

    1981-01-01

    A specification is given for iron-nickel-chromium age-hardenable alloys suitable for use in fast breeder reactor ducts and cladding, which utilize the gamma-double prime strengthening phase and are characterized in having a delta or eta phase distributed at or near grain boundaries. A range of compositions is given. (author)

  2. Progress in development of iron base alloys

    International Nuclear Information System (INIS)

    Zackay, V.V.; Parker, E.R.

    1980-01-01

    The ways of development of new iron base high-strength alloys are considered. Perspectiveness of ferritic steel strengthening with intermetallides (TaFe 2 , for instance) is shown. Favourable combination of plasticity, strength and fracture toughness in nickel-free iron-manganese alloys (16-20%) is also pointed out. A strength level of alloyed maraging steels can be achieved by changes in chemical composition and by proper heat treatments of low- and medium-alloyed steels

  3. Iron-based amorphous alloys and methods of synthesizing iron-based amorphous alloys

    Science.gov (United States)

    Saw, Cheng Kiong; Bauer, William A.; Choi, Jor-Shan; Day, Dan; Farmer, Joseph C.

    2016-05-03

    A method according to one embodiment includes combining an amorphous iron-based alloy and at least one metal selected from a group consisting of molybdenum, chromium, tungsten, boron, gadolinium, nickel phosphorous, yttrium, and alloys thereof to form a mixture, wherein the at least one metal is present in the mixture from about 5 atomic percent (at %) to about 55 at %; and ball milling the mixture at least until an amorphous alloy of the iron-based alloy and the at least one metal is formed. Several amorphous iron-based metal alloys are also presented, including corrosion-resistant amorphous iron-based metal alloys and radiation-shielding amorphous iron-based metal alloys.

  4. X-ray target with substrate of molybdenum alloy

    International Nuclear Information System (INIS)

    Hirsch, H.H.

    1980-01-01

    Rotary targets for x-ray tubes are provided comprising a molybdenum base body alloyed with a stabilizing proportion of iron, silicon, cobalt, tantalum, niobium, hafnium, stable metal oxide, or a mixture of the preceding

  5. Iron-titanium-mischmetal alloys for hydrogen storage

    Science.gov (United States)

    Sandrock, Gary Dale

    1978-01-01

    A method for the preparation of an iron-titanium-mischmetal alloy which is used for the storage of hydrogen. The alloy is prepared by air-melting an iron charge in a clay-graphite crucible, adding titanium and deoxidizing with mischmetal. The resultant alloy contains less than about 0.1% oxygen and exhibits a capability for hydrogen sorption in less than half the time required by vacuum-melted, iron-titanium alloys.

  6. Microcapillary Features in Silicon Alloyed High-Strength Cast Iron

    Directory of Open Access Journals (Sweden)

    R.K. Hasanli

    2017-04-01

    Full Text Available Present study explores features of silicon micro capillary in alloyed high-strength cast iron with nodular graphite (ductile iron produced in metal molds. It identified the nature and mechanism of micro liquation of silicon in a ductile iron alloyed with Nickel and copper, and demonstrated significant change of structural-quality characteristics. It was concluded that the matrix of alloyed ductile iron has a heterogeneous structure with cross reinforcement and high-silicon excrement areas.

  7. Aluminium alloys containing iron and nickel

    International Nuclear Information System (INIS)

    Coriou, H.; Fournier, R.; Grall, L.; Hure, J.; Herenguel, J.; Lelong, P.

    1958-01-01

    The first part of this report addresses mechanism, kinetics and structure factors of aluminium alloys containing iron and nickel in water and high temperature steam. The studied alloys contain from 0.3 to 0.7 per cent of iron, and 0.2 to 1.0 per cent of nickel. Corrosion resistance and corrosion structure have been studied. The experimental installation, process and samples are presented. Corrosion structures in water at 350 C are identified and discussed (structure of corrosion products, structure of metal-oxide interface), and then in steam at different temperatures (350-395 C). Corrosion kinetics is experimentally studied (weight variation in time) in water at 350 C and in steam at different temperatures. Reactions occurring at over-heated steam (more than 400 C) are studied, and the case of welded alloys is also addressed. The second part addresses the metallurgical mechanism and processes influencing aluminium alloy resistance to corrosion by high temperature water as it appeared that separated phases protect the solid solution through a neighbourhood action. In order to avoid deep local corrosions, it seems necessary to multiply protective phases in an as uniform as possible way. Some processes enabling this result are described. They belong to conventional metallurgy or to powder metallurgy (with sintering and extrusion)

  8. Studies on neutron irradiation effects of iron alloys and nickel-base heat resistant alloys

    International Nuclear Information System (INIS)

    Watanabe, Katsutoshi

    1987-09-01

    The present paper describes the results of neutron irradiation effects on iron alloys and nickel-base heat resistant alloys. As for the iron alloys, irradiation hardening and embrittlement were investigated using internal friction measurement, electron microscopy and tensile testings. The role of alloying elements was also investigated to understand the irradiation behavior of iron alloys. The essential factors affecting irradiation hardening and embrittlement were thus clarified. On the other hand, postirradiation tensile and creep properties were measured of Hastelloy X alloy. Irradiation behavior at elevated temperatures is discussed. (author)

  9. ANALYSIS OF KINETICS OF CAST IRON ALLOYING THROUGH SLAG PHASE

    Directory of Open Access Journals (Sweden)

    O. S. Komarov

    2012-01-01

    Full Text Available The mechanism of cast iron alloying through slag phase due to use of nickel and copper oxides is considered and the analysis of kinetics regularity of alloying in case of absence of fuse in the form of milled cast-iron chips in slag and at their presence in it is carried out.

  10. Spatial Bimetallic Castings Manufactured from Iron Alloys

    Directory of Open Access Journals (Sweden)

    M. Cholewa

    2007-07-01

    Full Text Available In this paper a conception for manufacturing method of skeleton castings with composite features was shown. Main application of such castings are the working organs of machines subjected to intensive abrasive and erosive wear. Skeleton geometry was based on three-dimensional cubic net consisting of circular connectors and nodes joining 6 connectors according to Cartesian co-ordinate system. Dimension of an elementary cell was equal to 10 mm and diameter of single connector was equal to 5 mm. For bimetallic castings preparation two Fe based alloys were used: L25SHMN cast steel for skeleton substrate and ZlCr15NiMo cast iron for working part of the casting. In presented work obtained structure was analyzed with indication of characteristic regions. Authors described phenomena occurring at the alloys interface and phases in transition zone. A thesis was formulated concerning localization of transition zone at the cast iron matrix – cast steel reinforcement interface. Direction of further studies were indicated.

  11. Study of the pyrophoric characteristics of uranium-iron alloys

    International Nuclear Information System (INIS)

    Duplessis, X.

    2000-01-01

    The objective of the study is to understand the pyrophoric characteristics of uranium-iron alloys. In order to carry out this research we have elected to use uranium-iron alloy powder with granules of 200 μm and 1000 μm diameter with 4%, 10.8% and 14% iron content. The experiments were performed on small samples of few milligrams and on larger quantities of few hundred grams. The main conclusions obtained are the followings: -The reaction start at 453 K (180 deg. C) and the ignition at 543 K (270 deg. C) - The influence of the specific area seems more important than the iron concentration in the alloys - When the alloy ignites, the fire spreads quickly and the alloy rapidly consumes. (author)

  12. Effect of diluted alloying elements on mechanical properties of iron

    International Nuclear Information System (INIS)

    Hassan, A.A.S.

    1996-01-01

    Iron and its alloys have extensive applications. The effect of solute additions on mechanical properties of iron was investigated to check the efficiency of solute atoms on strength and surface e life. Additions in the range of 0.1 wt.% and 0.3 wt.% of alloying elements of Cu,Ni and Si were used. Samples of grains size ranged from 6-40 m which have been prepared by annealing followed by furnace cooling. The recrystallization temperature increases with alloying addition (475 degree C for Fe-0.3 wt. % C alloy compared to 375 degree C for pure iron). Si and Cu additions inhibit grain growth of iron whereas Ni addition enhances it.Addition of Si or Ni to iron induced softening below room temperature whereas addition of Cu caused hardening. The work hardening parameters decreased due to alloying additions. The strength coefficient K was 290 M N/m2 for Fe-03 wt % Ni compared to 340 M N/m2 for pure iron. The work hardening exponent n is 0.12 for fe-0.3 wt. Cu alloy compared to 0.17 for pure iron. All the investigated alloys fulfilled the Hall-Petch relation at liquid Nitrogen and at room temperature. Alloying addition which caused softening addition which caused hardening increased the Half-Petch parameters. Ni addition favors ductility of iron whereas Cu addition reduces it. Alloying additions generally lead to brittle fracture and decrease the crack resistance of iron. 9 tabs., 55 figs., 103 refs

  13. Elimination of Iron Based Particles in Al-Si Alloy

    Directory of Open Access Journals (Sweden)

    Bolibruchová D.

    2015-03-01

    Full Text Available This paper deals with influence on segregation of iron based phases on the secondary alloy AlSi7Mg0.3 microstructure by chrome. Iron is the most common and harmful impurity in aluminum casting alloys and has long been associated with an increase of casting defects. In generally, iron is associated with the formation of Fe-rich phases. It is impossible to remove iron from melt by standard operations, but it is possible to eliminate its negative influence by addition some other elements that affect the segregation of intermetallics in less harmful type. Realization of experiments and results of analysis show new view on solubility of iron based phases during melt preparation with higher iron content and influence of chrome as iron corrector of iron based phases. By experimental work were used three different amounts of AlCr20 master alloy a three different temperature of chill mold. Our experimental work confirmed that chrome can be used as an iron corrector in Al-Si alloy, due to the change of intermetallic phases and shortening their length.

  14. Effect of iron and silicon in aluminium and its alloys

    International Nuclear Information System (INIS)

    Kovacs, I.

    1990-01-01

    The iron and silicon are the main impurities in aluminium, they are always present in alloys made from commercially pure base material. The solid solubility of iron in aluminium is very low, therefore its largest amount forms intermetallic compounds the kind of which depends strongly on the other impurities of alloying elements. Although the solid solubility of silicon is much larger than that of the iron, it is the constituent of both the primary and the secondary particles, the structure of which depends in general on the iron-silicon concentration ratio. These Fe and Si containing particles can cause various and basic changes in the macroscopic properties of the alloy. Since commercially pure aluminium has extensive consumer and industrial use, it is very important to know, not only from scientific but also from practical point of view, the effect of iron and silicon on the physical and mechanical properties of aluminium and its alloys. The aim of the ''International Workshop on the Effect of Iron and Silicon in Aluminium and its Alloys'' was to clarify the present knowledge on this subject. The thirty papers presented at the Workshop and collected in this Proceedings cover many important fields of the subject. I hope that they will contribute to both the deeper understanding of the related phenomena and the improvement of technologies for producing better aluminium alloys

  15. Textural and morphological studies on zinc-iron alloy electrodeposits

    Indian Academy of Sciences (India)

    Zinc-iron alloy electrodeposits have industrial significance, since they provide better corrosion resistance and with improved mechanical properties when compared to pure zinc coatings. This is due to the unique phase structure of the alloy formed. But this deposition belongs to anomalous deposition, where the ...

  16. Roentgenoelectronic investigation into oxidation of iron-chromium and iron-chromium-nickel alloys

    International Nuclear Information System (INIS)

    Akimov, A.G.; Rozenfel'd, I.L.; Kazanskij, L.P.; Machavariani, G.V.

    1978-01-01

    Kinetics of iron-chromium and iron-chromium-nickel alloy oxidation (of the Kh13 and Kh18N10T steels) in oxygen was investigated using X-ray electron spectroscopy. It was found that according to X-ray electron spectra chromium oxidation kinetics in the iron-chromium alloy differs significantly from oxidation kinetics of chromium pattern. Layer by layer X-ray electron analysis showed that chromium is subjected to a deeper oxidation as compared to iron, and accordingly, Cr 2 O 3 layer with pure iron impregnations is placed between the layer of mixed oxide (Fe 3 O 4 +Cr 2 O 3 ) and metal. A model of the iron-chromium alloy surface is suggested. The mixed oxide composition on the steel surface is presented as spinel Fesub(2+x)Crsub(1-x)Osub(y)

  17. Influence of Iron in AlSi10MgMn Alloy

    Directory of Open Access Journals (Sweden)

    Žihalová M.

    2014-12-01

    Full Text Available Presence of iron in Al-Si cast alloys is common problem mainly in secondary (recycled aluminium alloys. Better understanding of iron influence in this kind of alloys can lead to reduction of final castings cost. Presented article deals with examination of detrimental iron effect in AlSi10MgMn cast alloy. Microstructural analysis and ultimate tensile strength testing were used to consider influence of iron to microstructure and mechanical properties of selected alloy.

  18. STRUCTURE FORMATION OF ALLOYS ON IRON BASIS AFTER LASER ALLOYING

    Directory of Open Access Journals (Sweden)

    О. V. Diachenko

    2016-01-01

    Full Text Available The paper is devoted to investigations on influence of laser treatment regimes of gas-thermal and adhesive coatings from self-fluxing powders on iron basis and after melting with modifying plaster on their roughness and phase composition. One of mathematical planning methods that is a complete factor experiment method has been used for investigation of parameters’ influence on micro-geometry of coatings. The executed investigations have made it possible to observe a general regularity which does not depend on a type of alloying plaster: while increasing speed of laser beam relatively to treated part, beam diameter value of Ra parameter is becoming less. Decrease in height of surface irregularities in case of increasing laser beam speed is related with intensification of evaporation processes. An increase in beam diameter diminishes Ra parameter of the surface. This is due to the fact that decrease in power density occurs at high rate of beam defocusing. Overlapping coefficient does not exert a pronounced effect on Ra parameter of fused coatings. While increasing the speed of laser beam relatively to the part structure is transferred from dendrite into supersaturated one with carbide and boride precipitations. It has been established that technological parameters of laser treatment and particularly speed of laser beam influence on coating composition. While increasing the speed up to v5 = 5 × 10–3 m/s amount of chromium has become larger by 1.5-fold that resulted in increase of micro-hardness of the coating from 9.5–10.1 GPa up to 11.04–15.50 GPa.

  19. Constitution and magnetism of iron and its alloys

    CERN Document Server

    Pepperhoff, Werner

    2001-01-01

    Iron played an important role in the development of the industrial society and has not lost any of its significance since today. This book provides the foundations of understanding the physical nature of iron and its alloys. Basics and recent developments concerning its constitution and magnetism are presented as well as its thermal properties. The exceptional role of iron with its wide spectrum of most different technological and physical properties relies on its versatility, its polymorphism of its crystal structure and its magnetism. Therefore it is the aim of the book to link together the constitution and magnetism of iron.

  20. Solid - solid and solid - liquid phase transitions of iron and iron alloys under laser shock compression

    Science.gov (United States)

    Harmand, M.; Krygier, A.; Appel, K.; Galtier, E.; Hartley, N.; Konopkova, Z.; Lee, H. J.; McBride, E. E.; Miyanishi, K.; Nagler, B.; Nemausat, R.; Vinci, T.; Zhu, D.; Ozaki, N.; Fiquet, G.

    2017-12-01

    An accurate knowledge of the properties of iron and iron alloys at high pressures and temperatures is crucial for understanding and modelling planetary interiors. While Earth-size and Super-Earth Exoplanets are being discovered in increasingly large numbers, access to detailed information on liquid properties, melting curves and even solid phases of iron and iron at the pressures and temperatures of their interiors is still strongly limited. In this context, XFEL sources coupled with high-energy lasers afford unique opportunities to measure microscopic structural properties at far extreme conditions. Also the achievable time resolution allows the shock history and phase transition mechanisms to be followed during laser compression, improving our understanding of the high pressure and high strain experiments. Here we present recent studies devoted to investigate the solid-solid and solid-liquid transition in laser-shocked iron and iron alloys (Fe-Si, Fe-C and Fe-O alloys) using X-ray diffraction and X-ray diffuse scattering. Experiment were performed at the MEC end-station of the LCLS facility at SLAC (USA). Detection of the diffuse scattering allowed the identification of the first liquid peak position along the Hugoniot, up to 4 Mbar. The time resolution shows ultrafast (between several tens and several hundreds of picoseconds) solid-solid and solid-liquid phase transitions. Future developments at XFEL facilities will enable detailed studies of the solid and liquid structures of iron and iron alloys as well as out-of-Hugoniot studies.

  1. Improvement of magnetocaloric properties of Gd-Ge-Si alloys by alloying with iron

    Directory of Open Access Journals (Sweden)

    Erenc-Sędziak T.

    2013-01-01

    Full Text Available The influence of annealing of Gd5Ge2Si2Fex alloys at 1200°C and of alloying with various amount of iron on structure as well as thermal and magnetocaloric properties is investigated. It was found that annealing for 1 to 10 hours improves the entropy change, but reduces the temperature of maximum magnetocaloric effect by up to 50 K. Prolonged annealing of the Gd5Ge2Si2 alloy results in the decrease of entropy change due to the reduction of Gd5Ge2Si2 phase content. Addition of iron to the ternary alloy enhances the magnetocaloric effect, if x = 0.4 – 0.6, especially if alloying is combined with annealing at 1200°C: the peak value of the isothermal entropy change from 0 to 2 T increases from 3.5 to 11 J/kgK. Simultaneously, the temperature of maximum magnetocaloric effect drops to 250 K. The changes in magnetocaloric properties are related to the change in phase transformation from the second order for arc molten ternary alloy to first order in the case of annealed and/or alloyed with iron. The results of this study indicate that the minor addition of iron and heat treatment to Gd-Ge-Si alloys may be useful in improving the materials’ magnetocaloric properties..

  2. Investigation of sulphides in iron alloys of high purity

    International Nuclear Information System (INIS)

    Wyjadlowski, T.

    1973-01-01

    This research thesis reports the study of the morphology and composition of sulphides in iron alloys with respect to metal composition and to the nature of impurities. In order to understand the specific action of each addition on inclusion morphology, this work has started with high-purity alloys (binary alloys and then ternary alloys). The author studied whether solubility variations would entail either intergranular or intragranular or hybrid iron sulphide precipitation. He examined whether sulphide morphology is depending on thermal treatment, and whether equilibrium precipitates were different in terms of morphology and composition at high and room temperature. He studied the influence of addition elements on sulphide morphology and composition, an important issue as some elements may reduce brittleness. These elements are classified in terms of affinity with sulphur

  3. Iron titanium manganase alloy hydrogen storage

    Science.gov (United States)

    Reilly, James J.; Wiswall, Jr., Richard H.

    1979-01-01

    A three component alloy capable of reversible sorption of hydrogen having the chemical formula TiFe.sub.1-x Mn.sub.x where x is in the range of about 0.02 to 0.5 and the method of storing hydrogen using said alloy.

  4. Solubility of nitrogen in iron alloys with vanadium and niobium

    International Nuclear Information System (INIS)

    Pomarin, Yu.M.; Grigorenko, G.M.; Lakomskij, V.I.

    1975-01-01

    The solubility of nitrogen in the concentration range under study in Fe-N-V and Fe-N-Nb systems is in compliance with Syverts' law. An equation has been set up so as to estimate the nitrogen solubility in the iron alloys containing up to 10 per cent of vanadium and niobium in the wide temperature range

  5. Moessbauer effect studies of magnetic interactions in iron and dilute iron alloys

    International Nuclear Information System (INIS)

    Woude, F. van der; Schurer, P.J.; Sawatzky, G.A.

    1975-01-01

    A temperature-dependent Moessbauer study was conducted in FeX alloys, where X = Al, Si, Ti, V, Cr, Mn, Co, and Ni, aimed at solving the problem of 'what is localized and what is itinerant in iron ferromagnetism'. The experimental results are interpreted using a phenomenological model based on a modified Zener-Vonsovskij theory. Absorption spectra of FeX alloys were measured as a function of temperature. It was found that the 3d magnetic moments in iron were mainly localized while exchange coupling was provided by partly itinerant 3d electrons. (L.D.)

  6. Salt Fog Testing Iron-Based Amorphous Alloys

    International Nuclear Information System (INIS)

    Rebak, Raul B.; Aprigliano, Louis F.; Day, S. Daniel; Farmer, Joseph C.

    2007-01-01

    Iron-based amorphous alloys are hard and highly corrosion resistant, which make them desirable for salt water and other applications. These alloys can be produced as powder and can be deposited as coatings on any surface that needs to be protected from the environment. It was of interest to examine the behavior of these amorphous alloys in the standard salt-fog testing ASTM B 117. Three different amorphous coating compositions were deposited on 316L SS coupons and exposed for many cycles of the salt fog test. Other common engineering alloys such as 1018 carbon steel, 316L SS and Hastelloy C-22 were also tested together with the amorphous coatings. Results show that amorphous coatings are resistant to rusting in salt fog. Partial devitrification may be responsible for isolated rust spots in one of the coatings. (authors)

  7. Method for producing dysprosium-iron-boron alloy powder

    International Nuclear Information System (INIS)

    Camp, F.E.; Wooden, S.A.

    1989-01-01

    A method for producing a dysprosium-iron alloy adapted for use in the manufacture of rare-earth element containing, iron-boron permanent magnets, the method including providing a particle mixture comprising dysprosium oxide, iron and calcium, compacting the particle mixture to produce a consolidated article, heating the article for a time at temperature to form a metallic compound comprising dysprosium and iron and to form calcium oxide, producing a particle mass of -35 mesh from the compact, washing the particle mass with water at a temperature no greater than 10 0 C to react to the calcium and to the calcium oxide therewith to form a calcium hydroxide, while preventing oxidation of the particle mass, and removing the calcium hydroxide from the particle mass

  8. Preparing rare earth-silicon-iron-aluminum alloys

    International Nuclear Information System (INIS)

    Marchant, J.D.; Morrice, E.; Herve, B.P.; Wong, M.M.

    1980-01-01

    As part of its mission to assure the maximum recovery and use of the Nation's mineral resources, the Bureau of Mines, investigated an improved procedure for producing rare earth-silicon alloys. For example, a charge consisting of 681 grams of mixed rare-earth oxides, 309 grams of ferrosilicon (75 wt-pct Si), and 182 grams of aluminum metal along with a flux consisting of 681 grams of CaO and 45 grams of MgO was reacted at 1500 0 C in an induction furnace. Good slag-metal separation was achieved. The alloy product contained, in weight-percent, 53 RE, 28 Si, 11 Fe, and 4 Al with a rare earth recovery of 80 pct. In current industrial practice rare earth recoveries are usually about 60 pct in alloy products that contain approximately 30 wt-pct each of rare earths and silicon. Metallurgical evaluations showed the alloys prepared in this investigation to be as effective in controlling the detrimental effect of sulfur in steel and cast iron as the commercial rare earth-silicon-iron alloys presently used in the steel industry

  9. Fractography of hydrogen-embrittled iron-chromium-nickel alloys

    International Nuclear Information System (INIS)

    Caskey, G.R. Jr.

    1980-01-01

    Tensile specimens of iron-chromium-nickel base alloys were broken in either a hydrogen environment or in air following thermal charging with hydrogen. Fracture surfaces were examined by scanning electron microscopy. Fracture morphology of hydrogen-embrittled specimens was characterized by: changed dimple size, twin-boundary parting, transgranular cleavage, and intergranular separation. The nature and extent of the fracture mode changes induced by hydrogen varied systematically with alloy composition and test temperature. Initial microstructure developed during deformation processing and heat treating had a secondary influence on fracture mode

  10. Alkaline stress corrosion of iron-nickel-chromium austenitic alloys

    International Nuclear Information System (INIS)

    Hocquellet, Dominique

    1984-01-01

    This research thesis reports the study of the behaviour in stress corrosion of austenitic iron-nickel-chromium alloys by means of tensile tests at imposed strain rate, in a soda solution at 50 pc in water and 350 degrees C. The author shows that the mechanical-chemical model allows the experimental curves to be found again, provided the adjustment of characteristic parameters, on the one hand, of corrosion kinetics, and on the other hand, of deformation kinetics. A classification of the studied alloys is proposed [fr

  11. A TEM Study on the Ti-Alloyed Grey Iron

    DEFF Research Database (Denmark)

    Moumeni, Elham; Tiedje, Niels Skat; Grumsen, Flemming Bjerg

    2014-01-01

    The microstructure of graphite flakes in titanium alloyed cast iron is studied using electron microscopy techniques. Dual beam SEM/FIB has been used for TEM sample preparation. A TEM study has been carried out on graphite flakes in grey cast iron using selected area electron diffraction. Based...... and that there is a high proportion of twins in the fine grained graphite. It appears that twinning and stacking faults are involved in the fine grained structure of the graphite. It is discussed how Ti addition affect crystal growth and may lead to formation of superfine graphite....

  12. Identification of a cast iron alloy containing nonstrategic elements

    Science.gov (United States)

    Cooper, C. V.; Anton, D. L.; Lemkey, F. D.; Nowotny, H.; Bailey, R. S.; Favrow, L. H.; Smeggil, J. G.; Snow, D. B.

    1989-01-01

    A program was performed to address the mechanical and environmental needs of Stirling engine heater head and regenerator housing components, while reducing the dependence on strategic materials. An alloy was developed which contained no strategic elemental additions per se. The base is iron with additions of manganese, molybdenum, carbon, silicon, niobium, and ferro-chromium. Such an alloy should be producible on a large scale at very low cost. The resulting alloy, designated as NASAUT 4G-Al, contained 15 Mn, 15 Cr, 2 Mo, 1.5 C, 1.0 Si, 1.0 Nb (in weight percent) with a balance of Fe. This alloy was optimized for chemistry, based upon tensile strength, creep-rupture strength, fracture behavior, and fatigue resistance up to 800 C. Alloys were also tested for environmental compatibility. The microstructure and mechanic properties (including hardness) were assessed in the as-cast condition and following several heat treatments, including one designed to simulate a required braze cycle. The alloy was fabricated and characterized in the form of both equiaxed and columnar-grained castings. The columnar grains were produced by directional solidification, and the properties were characterized in both the longitudinal and transverse orientations. The NASAUT 4G-Al alloy was found to be good in cyclic-oxidation resistance and excellent in both hydrogen and hot-corrosion resistance, especially in comparison to the baseline XF-818 alloy. The mechanical properties of yield strength, stress-rupture life, high-cycle-fatigue resistance, and low-cycle-fatigue resistance were good to excellent in comparison to the current alloy for this application, HS-31 (X-40), with precise results depending in a complex manner on grain orientation and temperature. If required, the ductility could be improved by lowering the carbon content.

  13. Acceptability and use of iron and iron-alloy cooking pots: implications for anaemia control programmes.

    Science.gov (United States)

    Tripp, Katherine; Mackeith, Nancy; Woodruff, Bradley A; Talley, Leisel; Mselle, Laurent; Mirghani, Zahra; Abdalla, Fathia; Bhatia, Rita; Seal, Andrew J

    2010-01-01

    To evaluate the acceptability of iron and iron-alloy cooking pots prior to an intervention trial and to investigate factors affecting retention and use. Pre-trial research was conducted on five types of iron and iron-alloy pots using focus group discussions and a laboratory evaluation of Fe transfer during cooking was undertaken. Usage and retention during the subsequent intervention trial were investigated using focus group discussions and market monitoring. Three refugee camps in western Tanzania. Refugee health workers were selected for pre-trial research. Mothers of children aged 6-59 months participated in the investigation of retention and use. Pre-trial research indicated that the stainless steel pot would be the only acceptable type for use in this population due to excessive rusting and/or the high weight of other types. Cooking three typical refugee dishes in stainless steel pots led to an increase in Fe content of 3.2 to 17.1 mg/100 g food (P basic acceptability criteria. The relatively low usage reported during the trial highlights the limitations of using high-value iron-alloy cooking pots as an intervention in populations where poverty and the availability of other pots may lead to selling.

  14. Criticality of iron and its principal alloying elements.

    Science.gov (United States)

    Nuss, Philip; Harper, E M; Nassar, N T; Reck, Barbara K; Graedel, T E

    2014-04-01

    Because modern technology depends on reliable supplies of a wide variety of materials and because of increasing concern about those supplies, a comprehensive methodology was created to quantify the degree of criticality of the metals of the periodic table. In this paper, we apply this methodology to iron and several of its main alloying elements (i.e., vanadium, chromium, manganese, and niobium). These elements represent the basic metals of any industrial society and are vital for national security and economic well-being. Assessments relating to the dimensions of criticality - supply risk, vulnerability to supply restriction, and environmental implications - for 2008 are made on the global level and for the United States. Evaluations of each of the multiple indicators are presented, with aggregate results plotted in "criticality space", together with Monte Carlo simulation-derived "uncertainty cloud" estimates. Iron has the lowest supply risk, primarily because of its widespread geological occurrence. Vanadium displays the highest cradle-to-gate environmental implications, followed by niobium, chromium, manganese, and iron. Chromium and manganese, both essential in steel making, display the highest vulnerability to supply restriction, largely because substitution or substitution at equal performance is not possible for all end-uses. From a comprehensive perspective, we regard the overall criticality as low for iron and modest for the alloying elements we evaluated.

  15. TEM investigation of ductile iron alloyed with vanadium.

    Science.gov (United States)

    Dymek, S; Blicharski, M; Morgiel, J; Fraś, E

    2010-03-01

    This article presents results of the processing and microstructure evolution of ductile cast iron, modified by an addition of vanadium. The ductile iron was austenitized closed to the solidus (1095 degrees C) for 100 h, cooled down to 640 degrees C and held on at this temperature for 16 h. The heat treatment led to the dissolution of primary vanadium-rich carbides and their subsequent re-precipitation in a more dispersed form. The result of mechanical tests indicated that addition of vanadium and an appropriate heat treatment makes age hardening of ductile iron feasible. The precipitation processes as well as the effect of Si content on the alloy microstructure were examined by scanning and transmission electron microscopy. It was shown that adjacent to uniformly spread out vanadium-rich carbides with an average size of 50 nm, a dispersoid composed of extremely small approximately 1 nm precipitates was also revealed.

  16. Mineralogical issues in long-term corrosion of iron and iron-nickel alloys

    International Nuclear Information System (INIS)

    VanOrden, A.C.; McNeil, M.B.

    1988-01-01

    Prediction of very long term corrosion behavior of buried objects in general requires taking into account that the corrosion processes themselves after the local conditions. Recent work has analyzed corrosion processes in terms of trajectories on Pourbaix diagrams and appears to offer the prospect for using short-term corrosion tests to project corrosion behavior over very long periods. Two different classes of materials are considered here: essentially pure iron, which is an analogue to the carbon steel design overpacks for the salt and basalt sites (on which work has been suspended at present, and iron-nickel alloys, which are the best analogues available for some of the alloys being considered on the tuff site. There are a number of sources of data on corrosion of iron over archaeological times; the data used in this paper are from the recent National Bureau of Standards work on Roman iron nails for Inchtuthill in Scotland, which can be dated fairly precisely to about 70 A.D. and whose method of production is understood. The only available source of natural-analogue data on Fe-Ni alloys is the corrosion of meteorites

  17. Oxygen stabilized zirconium-vanadium-iron alloy

    International Nuclear Information System (INIS)

    Gruen, D.M.; Mendelsohn, M.H.

    1982-01-01

    An oxygen stabilized intermetallic compound having the formula (Zrsub(1-x)Tisub(x))sub(2-u)(Vsub(1-y)Fesub(y))Osub(z) where x = 0.0 to 0.9, y = 0.01 to 0.9, z = 0.25 to 0.5 and u = 0 to 1. The compound is capable of reversibly sorbing hydrogen at temperatures from -196 deg C to 200 deg C at pressures down to 10 - 6 torr. The compound is suitable for use as a hydrogen getter in low pressure, high temperature applications such as magnetic confinement fusion devices, and the iron content may be substituted by nickel, cobalt or manganese. (author)

  18. Oxygen stabilized zirconium-vanadium-iron alloy

    International Nuclear Information System (INIS)

    Gruen, D.M.; Mendelsohn, M.H.

    1982-01-01

    An oxygen stabilized intermetallic compound having the formula (Zrsub(1-x)Tisub(x))sub(2-u)(Vsub(1-y)Fesub(y))Osub(z) where x=0.0 to 0.9, y=0.01 to 0.9, z=0.25 to 0.5 and u=0 to 1. The compound is capable of reversibly sorbing hydrogen at temperatures from -196 0 C to 200 0 C at pressures down to 10 - 6 torr. The compound is suitable for use as a hydrogen getter in low pressure, high temperature applications such as magnetic confinement fusion devices, and the iron content may be substituted by nickel, cobalt or manganese. (author)

  19. Thermodynamic Properties of Alloys of Iron and Silicon

    International Nuclear Information System (INIS)

    Vecher, R.A.; Gejderih, V.A.; Gerasimov, Ja.I.

    1966-01-01

    The Fe-Si phase diagram is complex. At 1000°K there are FeSi 2 (β) and FeSi phases and solid solutions of silicon in α and α' iron. EMF measurements were made on the electrochemical cells: Fe|Fe 2+ , KI + Nal|Fe-Si at 600-800°C molten The alloys were prepared from particularly pure components by powder metallurgy and protracted annealing. Studies were made of ten alloys with silicon content between 85 and 4% in all the phase fields in the diagram section at 1000°K. We calculated the integral thermodynamic quantities ΔG, ΔH and ΔS for the formation of the silicides FeSi 2 (β), FeSi and Fe 3 Si at the mean temperature for the experimental range (1000°K), and also (using the thermal capacity of the silicides, the iron and the silicon) at 298, 1188 and 1798°K. The heats of formation of the silicides mentioned at 298°K (kcal/mole) are -19.4, -17.6 and -22.4 respectively. The data existing in the literature enable us to calculate the heat of formation of FeSi 2.33 (α-leboite) at 298°K and this is found to be -14.4 kcal/mole. The heats calculated by us are 1.5-3 kcal higher than the experimental values of Corber and Olsen. The heats of mixing calculated by us for liquid alloys agree well with data in the literature. The data obtained can be regarded as due to the change in the character of the bond in silicides from metallic to covalent when the silicon content is increased. From the data for alloy solutions of silicon in a-iron, the iron activities were calculated. It was found that the α ⇌ α' transformation observed is a real phase transformation. The two-phase range is wider than shown in the phase diagram (from data in the literature). Conversion of the iron activities in solid solution to liquid solution gives good agreement with the data of Chipman. (author) [fr

  20. Model of the Alphinising Coating Crystallisation on Iron Alloys

    Directory of Open Access Journals (Sweden)

    S. Pietrowski

    2007-07-01

    Full Text Available The study presents a hypothetical model of crystallisation of the alphinising coating produced on iron alloys by immersion in the bath of silumin. Basing on a wide-range of experiments and investigations, the effect of the type of inserted material (“armco” iron, C45 steel, grey cast iron and nodular graphite cast iron and of the technological regime of the alphinising process (chemical composition of silumin bath, its temperature, the time of holding an insert in the bath, and the insert surface roughness height “Rz” on the coating structure was determined. The type of the coating structure was established by metallographic examinations carried out by optical microscopy, electron transmission microsopy and scanning electron microscopy, using additionally an X-ray microanalyser and X-ray diffraction patterns. The results of these investigations were described in [1÷7]. Basing on the obtained results, a probable model of the crystallisation of an alphi-nising coating on iron alloys, produced by immersion in the alphinising bath, was developed. It has been stated that, most probably, the alphinising process begins when the insert reaches its contact temperature “ts”.. Since that moment, due to the wetting process and convec-tion movement of bath around the insert surface, an intense process of the dissolution starts. A reactive diffusion of the atoms of Fe and Si from the insert to the bath and of the atoms of Al and Si from the bath to the insert takes place. An intermetallic Al3Fe phase is crystallis-ing on the steel, while on the cast iron, a silicon carbide Fe4CSi is growing, probably due to carbon diffusion from graphite. Then, on the steel, as an effect of the peritectic reaction, are successively crystallising the phases of Al12Fe3Si2 and Al9Fe3Si2. The Al3Fe phase probably crystallises on the cast iron to be transformed later, due to peritectic reaction, into an Al12Fe3Si2 phase on which the Al9Fe3Si2 phase will be growing

  1. Corrosion of iron-base alloys by lithium

    International Nuclear Information System (INIS)

    Selle, J.E.

    1976-01-01

    A review of corrosion mechanisms operating in lithium-iron-base alloy systems is presented along with data obtained with thermal-convection loops of niobium-stabilized 2 1 / 4 percent Cr-1 percent Mo steel and types 304L and 321 stainless steels. A corrosion rate of 2.3 μm/year (0.09 mil/year) was obtained on the 2 1 / 4 percent Cr-1 percent Mo steel at 600 0 C. Considerably more mass transport of alloying constituents and a maximum corrosion rate of about 14 μm/year (0.55 mil/year) was obtained with the austenitic stainless steels. Results of metallography, x-ray fluorescence analysis, scanning electron microscopy, and weight-change data are presented and discussed

  2. Contribution to the study of iron-manganese alloy oxidation in oxygen at high temperatures

    International Nuclear Information System (INIS)

    Olivier, Francoise

    1972-01-01

    This research thesis reports a systematic investigation of the oxidation of three relatively pure iron-manganese alloys in oxygen, under atmospheric pressure, and between 400 and 1000 C, these alloys being annealed as well as work-hardened. It also compares their behaviour with that of non-alloyed iron oxidized under the same conditions. The author describes the experimental techniques and installations, discusses the morphology of oxide films formed under the experimental conditions, discusses the film growth kinetics which is studied by thermogravimetry, proposes interpretations of results, and outlines the influence of manganese addition to iron on iron oxidation

  3. low temperature irradiation effects in iron-alloys and ceramics

    International Nuclear Information System (INIS)

    Kuramoto, Eiichi; Abe, Hironobu; Tanaka, Minoru; Nishi, Kazuya; Tomiyama, Noriyuki.

    1991-01-01

    Electron beam irradiation at 77K and neutron irradiation at 20K were carried out on Fe-Cr and Fe-Cr-Ni alloys and ZnO and graphite system ceramics, and by measuring positron annihilation lifetime, the micro-information about irradiation-introduced defects was obtained. The temperature of the movement of atomic vacancies in pure iron is about 200K, but it was clarified that by the addition of Cr, it was not much affected. However, in the case of high concentration Cr alloys, the number of atomic vacancies which take part in the formation of micro-voids decreased as compared with the case of pure iron. It is considered that among the irradiation defects of ZnO, O-vac. restored below 300degC. It is considered that in the samples without irradiation, the stage of restoration exists around 550degC, which copes with structural defects. By the measurement of graphite without irradiation, the positron annihilation lifetime corresponding with the interface of matrix and crystal grains, grain boundaries and internal surfaces was almost determined. The materials taken up most actively in the research and development of nuclear fusion reactor materials are austenitic and ferritic stainless steels, and their irradiation defects have been studied. (K.I.)

  4. Analysis of iron-base alloys by low-wattage glow discharge emission spectrometry

    International Nuclear Information System (INIS)

    Wagatsuma, K.; Hirokawa, K.

    1984-01-01

    Several iron-base alloys were investigated by low-wattage glow discharge emission spectrometry. The emission intensity principally depended on the sputtering parameters of constituent elements in the alloy. However, in the case of chromium, stable and firm oxides formed on the surface influencing the yield of ejected atoms. This paper discusses the relation between the sputtering parameters in Fe-Ni, Fe-Cr, and Fe-Co alloys and their relative emission intensities. Additionally, quantitative analysis was performed for some ternary iron-base alloys and commercial stainless steels with the calibration factors of binary alloy systems

  5. Phosphorus effect on structure and physical properties of iron-nickel alloys

    International Nuclear Information System (INIS)

    Berseneva, F.N.; Kalinin, V.M.; Rybalko, O.F.

    1982-01-01

    The structure and properties of iron-nickel alloys (30-50 % Ni) containing from 0.02 to 0.5 wt. % P have been investigated. It has been found that phosphorus solubility in iron-nickel alloys at most purified from impurities exceeds limiting solubility values usually observed for commercial alloys. Phosphide eutectics precipitation over the grain boundaries of studied alloys occurs but with phosphorus content equal 0.45 wt. %. The 0.4 wt. % P addition in invar alloys increases saturation magnetization and the Curie point and leads to a more homogeneous structure

  6. Effect of cerium addition on microstructures of carbon-alloyed iron ...

    Indian Academy of Sciences (India)

    All the alloys exhibited a typical two-phase microstructure consisting of Fe3AlC carbides in an iron aluminide matrix. In the alloy without Ce addition, large bulky carbides were equally distributed throughout the matrix with many smaller precipitates interspersed in between. In the alloy with Ce addition, the carbide grain sizes ...

  7. RF plasma nitriding of severely deformed iron-based alloys

    International Nuclear Information System (INIS)

    Ferkel, H.; Glatzer, M.; Estrin, Y.; Valiev, R.Z.; Blawert, C.; Mordike, B.L.

    2003-01-01

    The effect of severe plastic deformation by cold high pressure torsion (HPT) on radio frequency (RF) plasma nitriding of pure iron, as well as St2K50 and X5CrNi1810 steels was investigated. Nitriding was carried out for 3 h in a nitrogen atmosphere at a pressure of 10 -5 bar and temperatures of 350 and 400 deg. C. Nitrided specimens were analysed by scanning electron microscopy (SEM), X-ray diffraction and micro hardness measurements. It was found that HPT enhances the effect of nitriding leading almost to doubling of the thickness of the nitrided layer for pure iron and the high alloyed steel. The largest increase in hardness was observed when HPT was combined with RF plasma nitriding at 350 deg. C. In the case of pure iron, the X-ray diffraction spectra showed the formation of ε and γ' nitrides in the compound layer, with a preferential formation of γ' at the expense of the α-phase at the higher nitriding temperature. The corresponding surface hardness was up to 950 HV0.01. While the HPT-processed St2K50 exhibits both nitride phases after nitriding at 350 deg. C, only the γ'-phase was observed after nitriding at 400 deg. C. A surface hardness of up to 1050 HV0.01 was measured for this steel. The high alloyed steel X5CrNi1810 exhibited the highest increase in surface hardness when HPT was combined with nitriding at 350 deg. C. The surface hardness of this steel was greater than 1400 HV0.025. The XRD analyses indicate the formation of the expanded austenite (S-phase) in the surface layer as a result of RF plasma nitriding. Furthermore, after HPT X5CrNi1810 was transformed completely into deformation martensite which did not transform back to austenite under thermochemical treatment. However, in the case of nitriding of the HPT-processed high alloyed steel at 400 deg. C, the formation of the S-phase was less pronounced. In view of the observed XRD peak broadening, the formation of nitrides, such as e.g. CrN, cannot be ruled out

  8. Low temperature irradiation effects on iron-boron based amorphous metallic alloys

    International Nuclear Information System (INIS)

    Audouard, Alain.

    1983-01-01

    Three iron-boron amorphous alloys and the crystalline Fe 3 B alloy have been irradiated at liquid hydrogen temperature. 2,4 MeV electron irradiation induces the creation of point defects in the amorphous alloys as well as in the crystalline Fe 3 B alloy. These point defects can be assimilated to iron ''Frenkel pairs''. They have been characterized by determining their intrinsic electrical resistivity and their formation volume. The displacement threshold energy of iron atoms has also been determined. 10 B fission fragments induce, in these amorphous alloys, displacement cascades which lead to stable vacancy rich zones. This irradiation also leads to a structural disorder in relation with the presence of defects. 235 U fission fragments irradiation modifies drastically the structure of the amorphous alloys. The results have been interpreted on the basis of the coexistence of two opposite processes which induce local disorder and crystallisation respectively [fr

  9. Bubble formation upon crystallization of high nitrogen iron base alloys

    International Nuclear Information System (INIS)

    Svyazhin, A.G.; Sivka, E.; Skuza, Z.

    2000-01-01

    A study is made into the conditions of nitrogen bubble formation during crystallization of unalloyed iron, alloys of Fe-O, Fe-O-S systems, steels 1Kh13, 0Kh18N9 and a two-phase Fe-11%Cr-1%Mo-0.2%V steel. It is revealed that the amount of bubbles in a high nitrogen steel casting increases with a degree of nitrogen supersaturation and decreases with a cooling rate growth and with a rise of surfactant concentration in the metal. In sound castings a nitrogen content can be increased due to a cooling rate growth, nitrogen dilution with inert gas, an increase of nitrogen pressure during crystallization as well as due to the introduction of such surfactants as sulphur, selenium, tellurium, tin [ru

  10. Iron addiction: a novel therapeutic target in ovarian cancer

    International Nuclear Information System (INIS)

    Basuli, D.

    2017-01-01

    Ovarian cancer is a lethal malignancy that has not seen a major therapeutic advance in over 30 years. We demonstrate that ovarian cancer exhibits a targetable alteration in iron metabolism. Ferroportin (FPN), the iron efflux pump, is decreased, and transferrin receptor (TFR1), the iron importer, is increased in tumor tissue from patients with high grade but not low grade serous ovarian cancer. A similar profile of decreased FPN and increased TFR1 is observed in a genetic model of ovarian cancer tumor-initiating cells (TICs). The net result of these changes is an accumulation of excess intracellular iron and an augmented dependence on iron for proliferation. A forced reduction in intracellular iron reduces the proliferation of ovarian cancer TICs in vitro, and inhibits both tumor growth and intraperitoneal dissemination of tumor cells in vivo. Some mechanistic studies demonstrate that iron increases metastatic spread by facilitating invasion through expression of matrix metalloproteases and synthesis of interleukin 6 (IL-6). Here, we show that the iron dependence of ovarian cancer TICs renders them exquisitely sensitive in vivo to agents that induce iron-dependent cell death (ferroptosis) as well as iron chelators, and thus creates a metabolic vulnerability that can be exploited therapeutically.

  11. Elastic properties of magnetostrictive rare-earth-iron alloys

    International Nuclear Information System (INIS)

    Cullen, J.R.; Blessing, G.; Rinaldi, S.

    1978-01-01

    The elastic properties of certain magnetostrictive rare-earth-iron alloys, namely polycrystalline Tbsub(0.3)Dysub(0.7)Fesub(2), Smsub(0.88)Dysub(0.12)Fesub(2)and amorphous TbFesub(2), were investigated ultrasonically. In all cases two shear waves were observed propagating simultaneously when a magnetic field was applied perpendicular to the direction of propagation. A model to explain this behaviour, based on magnetic-elastic coupling within local regions of these disordered materials, is developed and discussed in two limiting cases: (i) strongly coupled regions for which an effective isotropic magneto-elastic coupling is appropriate, and (ii) materials for which the elastic properties of the conglomerate are determined by averaging over those of independent regions. Experimental results up to fields of 25 kOe on the alloys mentioned above are exhibited and compared with the limiting cases (i) and (ii). In the case of polycrystalline Tbsub(0.3)Dysub(0.7)Fesub(2) further comparison is made between the determination of the magneto-elastic coupling constants using this model and the determination by using the results of a previous single-crystal study. (author)

  12. Field Induced Magnetic Moments in a Metastable Iron-Mercury Alloy

    DEFF Research Database (Denmark)

    Pedersen, M.S.; Mørup, Steen; Linderoth, Søren

    1996-01-01

    The magnetic properties of a metastable iron-mercury alloy have been investigated in the temperature range from 5 to 200 K by Mossbauer spectroscopy and magnetization measurements. At low temperature the magnetic moment per iron atom is larger than af alpha-Fe. The effective spontaneous magnetic ....... It was found that the field-induced increase of the magnetic moment in the metastable iron-mecury alloy was about 0.06 Bohr magnetons per iron atom in the temperature range from 5 to 200 K for a field change from 6 to 12 T....

  13. INFLUENCE OF IMPULSE MAGNETIC FIELD ON GRAPHITE MORPHOLOGY OF HIGH-ALLOY IRON

    Directory of Open Access Journals (Sweden)

    A. G. Anisovich

    2011-01-01

    Full Text Available The results of researches of change of microstructure of heavily alloyed austenitic cast-iron ChN1507 subjected to magnetoimpulse processing are given. It is established that microhardness rises on all section of the sample.

  14. Void swelling in fast reactor irradiated high purity binary iron-chromium alloys

    International Nuclear Information System (INIS)

    Little, E.A.; Stow, D.A.

    The void swelling characteristics of a series of high purity binary iron-chromium alloys containing 0 - 615 0 C. The void swelling behaviour can be qualitatively rationalized in terms of point defect trapping and precipitation processes involving chromium atoms

  15. Iron-niobium-aluminum alloy having high-temperature corrosion resistance

    Science.gov (United States)

    Hsu, Huey S.

    1988-04-14

    An alloy for use in high temperature sulfur and oxygen containing environments, having aluminum for oxygen resistance, niobium for sulfur resistance and the balance iron, is discussed. 4 figs., 2 tabs.

  16. Iron Deprivation Affects Drug Susceptibilities of Mycobacteria Targeting Membrane Integrity

    Directory of Open Access Journals (Sweden)

    Rahul Pal

    2015-01-01

    Full Text Available Multidrug resistance (MDR acquired by Mycobacterium tuberculosis (MTB through continuous deployment of antitubercular drugs warrants immediate search for novel targets and mechanisms. The ability of MTB to sense and become accustomed to changes in the host is essential for survival and confers the basis of infection. A crucial condition that MTB must surmount is iron limitation, during the establishment of infection, since iron is required by both bacteria and humans. This study focuses on how iron deprivation affects drug susceptibilities of known anti-TB drugs in Mycobacterium smegmatis, a “surrogate of MTB.” We showed that iron deprivation leads to enhanced potency of most commonly used first line anti-TB drugs that could be reverted upon iron supplementation. We explored that membrane homeostasis is disrupted upon iron deprivation as revealed by enhanced membrane permeability and hypersensitivity to membrane perturbing agent leading to increased passive diffusion of drug and TEM images showing detectable differences in cell envelope thickness. Furthermore, iron seems to be indispensable to sustain genotoxic stress suggesting its possible role in DNA repair machinery. Taken together, we for the first time established a link between cellular iron and drug susceptibility of mycobacteria suggesting iron as novel determinant to combat MDR.

  17. Method of forming magnetostrictive rods from rare earth-iron alloys

    Science.gov (United States)

    McMasters, O. Dale

    1986-09-02

    Rods of magnetrostructive alloys of iron with rare earth elements are formed by flowing a body of rare earth-iron alloy in a crucible enclosed in a chamber maintained under an inert gas atmosphere, forcing such molten rare-earth-iron alloy into a hollow mold tube of refractory material positioned with its lower end portion within the molten body by means of a pressure differential between the chamber and mold tube and maintaining a portion of the molten alloy in the crucible extending to a level above the lower end of the mold tube so that solid particles of higher melting impurities present in the alloy collect at the surface of the molten body and remain within the crucible as the rod is formed in the mold tube.

  18. High temperature cathodic charging of hydrogen in zirconium alloys and iron and nickel base alloys

    International Nuclear Information System (INIS)

    John, J.T.; De, P.K.; Gadiyar, H.S.

    1990-01-01

    These investigations lead to the development of a new technique for charging hydrogen into metals and alloys. In this technique a mixture of sulfates and bisulfates of sodium and potassium is kept saturated with water at 250-300degC in an open pyrex glass beaker and electrolysed using platinum anode and the material to be charged as the cathode. Most of the studies were carried out on Zr alloys. It is shown that because of the high hydrogen flux available at the surface and the high diffusivity of hydrogen in metals at these temperatures the materials pick up hydrogen faster and more uniformly than the conventional electrolytic charging at room temperature and high temperature autoclaving in LiOH solutions. Chemical analysis, metallographic examination and XRD studies confirm this. This technique has been used to charge hydrogen into many iron and nickel base austentic alloys, which are very resistant to hydrogen pick up and to H-embrittlement. Since this involved a novel method of electrolysing water, the hydrogen/deuterium isotopic ratio has been studied. At this temperatures the D/H ratio in the evolved hydrogen gas was found to be closer to the value in the liquid water, which means a smaller separation factor. This confirm the earlier observation that separation factor decreases with increase of temperature. (author). 16 refs., 21 fi gs., 6 tabs

  19. Corrosion resistance and electrochemical potentiokinetic reactivation testing of some iron-base hardfacing alloys

    International Nuclear Information System (INIS)

    Cockeram, B.V.

    1999-01-01

    Hardfacing alloys are weld deposited on a base material to provide a wear resistant surface. Commercially available iron-base hardfacing alloys are being evaluated for replacement of cobalt-base alloys to reduce nuclear plant activation levels. Corrosion testing was used to evaluate the corrosion resistance of several iron-base hardfacing alloys in highly oxygenated environments. The corrosion test results indicate that iron-base hardfacing alloys in the as-deposited condition have acceptable corrosion resistance when the chromium to carbon ratio is greater than 4. Tristelle 5183, with a high niobium (stabilizer) content, did not follow this trend due to precipitation of niobium-rich carbides instead of chromium-rich carbides. This result indicates that iron-base hardfacing alloys containing high stabilizer contents may possess good corrosion resistance with Cr:C < 4. NOREM 02, NOREM 01, and NoCo-M2 hardfacing alloys had acceptable corrosion resistance in the as-deposited and 885 C/4 hour heat treated condition, but rusting from sensitization was observed in the 621 C/6 hour heat treated condition. The feasibility of using an Electrochemical Potentiokinetic Reactivation (EPR) test method, such as used for stainless steel, to detect sensitization in iron-base hardfacing alloys was evaluated. A single loop-EPR method was found to provide a more consistent measurement of sensitization than a double loop-EPR method. The high carbon content that is needed for a wear resistant hardfacing alloy produces a high volume fraction of chromium-rich carbides that are attacked during EPR testing. This results in inherently lower sensitivity for detection of a sensitized iron-base hardfacing alloy than stainless steel using conventional EPR test methods

  20. A review of ordering phenomena in iron-silicon alloys

    Directory of Open Access Journals (Sweden)

    González, F.

    2013-06-01

    Full Text Available Silicon steel is an industrially-desired alloy of iron and silicon, characterised by soft magnetic properties, low eddy-current losses, and low magnetostriction. Silicon steels have narrow hysteresis cycles, making them particularly advantageous in applications using electromagnetic fields, such as transformers, generators, electric motor cores, and few other components in industry. Despite its incontestable industrial value, there is not much agreement on the atomic structure of silicon steel. Gaining better understanding of e.g. ordering processes in Fe-Si alloys could not only explain their magnetic properties, but also open opportunities to reduce their weaker characteristics, such as brittleness that adversely affects silicon steel workability and its associated high production costs. This review summarises the state-of-the-art knowledge about ordering in silicon steel and describes the most relevant experimental techniques used for studying its microstructure. In addition, the process of building the iron rich part of the Fe-Si phase diagram is explained. Lastly, the influence of order on the alloy’s magnetic and mechanical properties is illustrated.El acero al silicio es una aleación de importancia industrial, caracterizada por propiedades magnéticas blandas, bajas pérdidas por corrientes de Foucault y baja magnetostricción. Los aceros al silicio tienen ciclo de histéresis estrecho, lo que es una ventaja en aplicaciones con campos electromagnéticos, como transformadores, generadores, núcleos de motores eléctricos y otros componentes industriales. A pesar de su incomparable valor industrial, no hay convenio sobre la estructura atómica del acero al silicio. Obtener mayor conocimiento sobre los procesos de orden no sólo podría explicar las propiedades magnéticas sino que también podría abrir vías para la reducción de sus características más débiles, como su fragilidad, la cual afecta negativamente a la fabricación del

  1. Effect of Ternary Addition of Iron on Shape Memory Characteristics of Cu-Al Alloys

    Science.gov (United States)

    Raju, T. N.; Sampath, V.

    2011-07-01

    The effect of alloying Cu-Al alloys with Fe on their transformation temperatures and shape memory properties was investigated by differential scanning calorimetry and bend test. It was found that the minor additions of iron resulted in change of transformation temperatures and led to excellent shape memory properties of the alloys. Since the transformation temperatures are high, they are an ideal choice for high-temperature applications.

  2. Study of solubility of akaline earth metals in liquid iron and in alloys on its base

    International Nuclear Information System (INIS)

    Ageev, Yu.A.; Archugov, S.A.

    1985-01-01

    Solubility of magnesium, calcium, strontium and barium in liquid iron and its alloys with aluminium, silicon, nickel, chromium and carbon at 1600 deg C has been measured. Interaction parameters taking account of the effect of added elements on alkaline earth metal solubility in liquid iron have been estimated

  3. Contribution to the study of the electrodeposition of iron-nickel alloys

    International Nuclear Information System (INIS)

    Valignat, J.

    1968-01-01

    Using a coulometric technique based upon the anodic intentiostatic dissolution, we studied the potentiostatic, deposition of nickel, iron and nickel iron alloys. We have shown that the minimum of the curve I = f (t) (deposition current versus time) is probably due to the transitory blocking of the surface by hydrogen and that the syn-crystallisation of nickel and iron is responsible for the anomalous co-deposition of these two elements. (author) [fr

  4. Elastic characteristics and microplastic deformation of amorphous alloys on iron base

    International Nuclear Information System (INIS)

    Pol'dyaeva, G.P.; Zakharov, E.K.; Ovcharov, V.P.; Tret'yakov, B.N.

    1983-01-01

    Investigation results of elasticity and microplasticity properties (modulus of normal elasticity E, elasticity limit σsub(0.01) and yield limit σsub(0.2)) of three amorphous alloys on iron base Fe 80 B 20 , Fe 70 Cr 10 B 20 and Fe 70 Cr 5 Ni 5 B 20 are given. Amorphous band of the alloys is obtained using the method of melt hardening. It is shown that amorphous alloys on iron base possess high elasticity and yield limits and hardness and are very perspective for the use as spring materials

  5. Preparation and Characterization of Nicke-iron Alloy Film as Freestanding Electrode for Oxygen Evolution Reaction

    Directory of Open Access Journals (Sweden)

    Yao Mengqi

    2018-01-01

    Full Text Available This work reports the porous nicke-iron alloy film supported on stainless steel mesh as freestanding electrode for enhanced oxygen evolution reaction (OER catalyst prepared from an one step electrodeposition method. Results indicated that the porous nickle-iron alloy film exhibits a low overpotential of 270 mV at 10 mA cm-2 and excellent electroconductibility. The superior OER properties can be attributed to its novel synthetic process, conductive substrate and porous structure. This work will provide a new strategy to fabricate alloy film for OER electrocatalyst.

  6. Elastic characteristics and microplastic deformation of amorphous alloys on iron base

    Energy Technology Data Exchange (ETDEWEB)

    Pol' dyaeva, G.P.; Zakharov, E.K.; Ovcharov, V.P.; Tret' yakov, B.N. (Tsentral' nyj Nauchno-Issledovatel' skij Inst. Chernoj Metallurgii, Moscow (USSR))

    1983-01-01

    Investigation results of elasticity and microplasticity properties (modulus of normal elasticity E, elasticity limit sigmasub(0.01) and yield limit sigmasub(0.2)) of three amorphous alloys on iron base Fe/sub 80/B/sub 20/, Fe/sub 70/Cr/sub 10/B/sub 20/ and Fe/sub 70/Cr/sub 5/Ni/sub 5/B/sub 20/ are given. Amorphous band of the alloys is obtained using the method of melt hardening. It is shown that amorphous alloys on iron base possess high elasticity and yield limits and hardness and are very perspective for the use as spring materials.

  7. Effect of Iron and Magnesium on Alloy AL9M Structure and Properties

    Science.gov (United States)

    Bazhenov, V. E.; Koltygin, A. V.; Belov, V. D.

    2017-09-01

    The effect of iron impurity on the structure and properties of aluminum alloy AL9M, especially its action on magnesium distribution within the structure, is studied. The microstructure of a cast component of this alloy broken during operation is analyzed. It is shown that iron impurity has an unfavorable effect on structure and mechanical properties of a casting due to appearance of Al9Fe2Si and Al18Fe2Mg7Si10 intermetallics. Formation of these intermetallics consumes a considerable amount of magnesium and lowers the content of the Q(Al5Cu2Mg8Si6) strengthening phase in the alloy structure.

  8. Structure and growth of oxide on iron-chromium alloys

    International Nuclear Information System (INIS)

    Cox, M.G.C.; McEnaney, B.; Scott, V.D.

    1974-01-01

    Several oxides form during the initial stages of oxidation of iron-chromium alloys at 400 to 600 0 C in CO 2 -1%CO gas. The nature of the oxidation product depends upon crystallographic orientation and composition of the substrate, and can be explained by considering the maximum solubility of chromium in different oxide phases together with interfacial and strain energy factors. Kinetics of oxidation together with micrographic observations indicate that, as oxidation proceeds spinel oxide M 3 O 4 nucleates at sites on the substrate surface associated with asperities. The spinel nuclei grow laterally and vertically until they coalesce and the scale subsequently thickens according to a parabolic rate law. The duplex structure of scales is interpreted in terms of an outward diffusion of cations together with simultaneous growth of an inner layer in the space created by this outward movement. Scale porosity provides a route for gas-phase transport of oxidant to support the growth of the inner layer. Regularly spaced lamellar voids which may form in the inner layer are believed to be associated with a cyclic vacancy condensation process. Enrichment of the inner layer in chromium is explained by analysis of the possible diffusion path networks in close-packed oxides. Some comments are made concerning possible practical applications of these data. (author)

  9. The hyperfine properties of iron-gallium alloys

    Energy Technology Data Exchange (ETDEWEB)

    Elzain, M., E-mail: elzain@squ.edu.om; Gismelseed, A.; Al-Rawas, A.; Yousif, A.; Widatallah, H.; Al-Azri, Maya [Sultan Qaboos University, Department of Physics (Oman); Al-Barwani, M. [NYU Abu Dhabi (United Arab Emirates)

    2016-12-15

    The hyperfine properties at Fe site in iron-gallium alloy are calculated using the full-potential linear-augmented-plane-waves method. We have calculated the Fermi contact field (B{sub hf}) and isomer shift (δ) at the Fe site versus the number of neighbouring Ga atoms. We found that B{sub hf} decrease whereas δ increases with increasing number of neighbouring G atom. In addition we have calculated the hyperfine properties of FeGa system with DO{sub 3} structure, where various distributions of 4 the Ga atoms in the conventional unit cell are considered (including the regular DO{sub 3} structure). We found that the DO{sub 3} structure has the lowest energy as compared to the other configurations. The two distinct A and D sites of the ordered DO{sub 3} conventional unit cell have two distinct values for B{sub hf} and δ. On changing the atomic arrangement of the Ga atoms within the conventional unit cell, the configuration of the A site is maintained whereas that of the D site becomes imperfect. The contact magnetic hyperfine fields of the D-like sites in the imperfect structures are lower than that of the DO{sub 3}D site.

  10. Oxidation influence on crystallisation in iron-based amorphous alloys

    Energy Technology Data Exchange (ETDEWEB)

    Gloriant, T.; Surinach, S.; Munoz, J.S.; Baro, M.D. [Universitat Autonoma de Barcelona (Spain). Dept. de Fisica; Inoue, A. [Tohoku Univ., Sendai (Japan). Inst. for Materials Research

    2001-07-01

    The partially crystalline iron-based nanophase composites elaborated by rapid solidification techniques are very attractive for their excellent soft magnetic properties and their potential for industrial applications. In these nanocomposite materials a control of both the structure (size, shape and distribution of the nanoparticles in the amorphous matrix) and the kinetic behaviour (nucleation and growth mechanism) is essential in order to obtain the best properties and to be able to produce them at the industrial scale. Our group has been working in this research area for a long time and the investigation presented here is the result of an international collaboration. This study deals with the effect of cobalt addition in Fe-Nb-B melt-spun amorphous alloys on the devitrification/crystallisation processes induced by thermal treatments and characterised by X-ray diffraction analysis (XRD), thermomagnetic analysis (TMG) and transmission electron microscopy observations (TEM). The transformation sequences, from the initial amorphous phase to the fully crystallised final state, were carried out using different annealing experiments (under vacuum and in air) and have revealed a strong influence of the environmental atmosphere during devitrification. It is shown that oxidation can greatly affect the crystallisation behaviour as a result of the high metastable state of the initial amorphous phase. The results and observations of this phenomenon will be presented. (orig.)

  11. Procedure of identification of fullerenes isolated from iron-carbon alloys

    International Nuclear Information System (INIS)

    Zakirnichnaya, M.M.

    2001-01-01

    A method of fullerenes isolation from the structure of iron-carbon alloys and their identification using physical methods which provide determination of the different parameters of nanoobjects is developed. Qualitative (mass-spectrometry of positive and negative ions, small angle X-ray scattering) and quantitative (IR-spectrometry, liquid chromatography) evaluation of fullerenes in the samples obtained from iron-carbon alloys and their visual observation using scanning tunnel microscopy are performed. It is found that the method provides isolation and identification of fullerenes present in the structure of steels and irons [ru

  12. Determination of trace impurities in iron-based alloy using neutron activation analysis

    International Nuclear Information System (INIS)

    Zaidi, J.H.; Waheed, S.; Ahmad, S.

    2000-01-01

    A radiochemical neutron activation analysis procedure has been developed and applied to investigate 40 major, minor, and trace impurities in iron-based alloy. A comparison of RNAA and INAA indicated a significant improvement in the detection limits. The extensive use of these alloys in the heavy mechanical industry, manufacturing of aircraft engines, nuclear applications, medical devices and chemical equipment requires their precise characterization. The concentration of iron in the iron-based alloy was found to be 86.7%, whereas Ca, Cr, K, Mg, Mn, V and W were the other constituents of the alloy, which constituted to around 12.89%. The rest of the elements were present in minor or trace levels. Most of the rare earth elements were also present in trace amounts. (orig.)

  13. Vanadium Influence on Iron Based Intermetallic Phases in AlSi6Cu4 Alloy

    Directory of Open Access Journals (Sweden)

    Bolibruchová D.

    2014-10-01

    Full Text Available Negative effect of iron in Al-Si alloys mostly refers with iron based intermetallic phases, especially Al5FeSi phases. These phases are present in platelet-like forms, which sharp edges are considered as main cracks initiators and also as contributors of porosity formation. In recent times, addition of some elements, for example Mn, Co, Cr, Ni, V, is used to reduce influence of iron. Influence of vanadium in aluminium AlSi6Cu4 alloy with intentionally increased iron content is presented in this article. Vanadium amount has been graduated and chemical composition of alloy has been analysed by spectral analysis. Vanadium influence on microstructural changes was evaluated by microstructural analysis and some of intermetallic particles were reviewed by EDX analysis.

  14. Alloying behavior of iron, gold and silver in AlCoCrCuNi-based equimolar high-entropy alloys

    International Nuclear Information System (INIS)

    Hsu, U.S.; Hung, U.D.; Yeh, J.W.; Chen, S.K.; Huang, Y.S.; Yang, C.C.

    2007-01-01

    High-entropy alloys are newly developed alloys that are composed, by definition, of at least five principal elements with concentrations in the range of 5-35 at.%. Therefore, the alloying behavior of any given principal element is significantly affected by all the other principal elements present. In order to elucidate this further, the influence of iron, silver and gold addition on the microstructure and hardness of AlCoCrCuNi-based equimolar alloys has been examined. The as-cast AlCoCrCuNi base alloy is found to have a dendritic structure, of which only solid solution FCC and BCC phases can be observed. The BCC dendrite has a chemical composition close to that of the nominal alloy, with a deficiency in copper however, which is found to segregate and form a FCC Cu-rich interdendrite. The microstructure of the iron containing alloys is similar to that of the base alloy. It is found that both of these aforementioned alloys have hardnesses of about 420 HV, which is equated to their similar microstructures. The as-cast ingot forms two layers of distinct composition with the addition of silver. These layers, which are gold and silver in color, are determined to have a hypoeutectic Ag-Cu composition and a multielement mixture of the other principal elements, respectively. This indicates the chemical incompatibility of silver with the other principal elements. The hardnesses of the gold (104 HV) and silver layers (451 HV) are the lowest and highest of the alloy systems studied. This is attributed to the hypoeutectic Ag-Cu composition of the former and the reduced copper content of the latter. Only multielement mixtures, i.e. without copper segregation, form in the gold containing alloy. Thus, it may be said that gold acts as a 'mixing agent' between copper and the other elements. Although several of the atom pairs in the gold containing alloy have positive enthalpies, thermodynamic considerations show that the high entropy contribution is sufficient to counterbalance

  15. Low temperature irradiation effects on iron boron based amorphous metallic alloys

    International Nuclear Information System (INIS)

    Audouard, A.

    1982-09-01

    Three Fe-B amorphous alloys (Fe 80 B 20 , Fe 27 Mo 2 B 20 and Fe 75 B 25 ) and the crystallized Fe 3 B alloy have been irradiated at the temperature of liquid hydrogen. Electron irradiation and irradiation by 10 B fission fragments induce point defects in amorphous alloys. These defects are characterized by an intrinsic resistivity and a formation volume. The threshold energy for the displacement of iron atoms has also been calculated. Irradiation by 235 U fission fragments induces some important structural modifications in the amorphous alloys [fr

  16. Microstructural study and wear behavior of ductile iron surface alloyed by Inconel 617

    International Nuclear Information System (INIS)

    Arabi Jeshvaghani, R.; Jaberzadeh, M.; Zohdi, H.; Shamanian, M.

    2014-01-01

    Highlights: • The Ni-base alloy was deposited on the surface of ductile iron by TIG welding process. • Microstructure of alloyed layer consisted of carbides embedded in Ni-rich dendrite. • Hardness and wear resistance of coated sample greatly improved. • The formation of oxide layer and delamination were dominant mechanisms of wear. - Abstract: In this research, microstructure and wear behavior of Ni-based alloy is discussed in detail. Using tungsten inert gas welding process, coating of nearly 1–2 mm thickness was deposited on ductile iron. Optical and scanning electron microscopy, as well as X-ray diffraction analysis and electron probe microanalysis were used to characterize the microstructure of the surface alloyed layer. Micro-hardness and wear resistance of the alloyed layer was also studied. Results showed that the microstructure of the alloyed layer consisted of M 23 C 6 carbides embedded in Ni-rich solid solution dendrites. The partial melted zone (PMZ) had eutectic ledeburit plus martensite microstructure, while the heat affected zone (HAZ) had only a martensite structure. It was also noticed that hardness and wear resistance of the alloyed layer was considerably higher than that of the substrate. Improvement of wear resistance is attributed to the solution strengthening effect of alloying elements and also the presence of hard carbides such as M 23 C 6 . Based on worn surface analysis, the dominant wear mechanisms of alloyed layer were found to be oxidation and delamination

  17. The effect of microstructure of low-alloy spheroidal cast iron on impact strength

    Directory of Open Access Journals (Sweden)

    T. Szykowny

    2010-01-01

    Full Text Available The study presents an evaluation of the effect of microstructure of low-alloy spheroidal cast iron on impact strength within the temperature range from –60 to 100°C. Analyses were conducted on one type of cast iron containing 0.51% Cu and 0.72% Ni. Cast iron was austempered or normalized. Values of KCV and static mechanical properties were determined. Structural and fractographic analyses were based on light and scanning microscopy as well as X-ray diffraction. It was found that thermal processing considerably improves impact strength in relation to cast iron after casting. At the same time static mechanical properties are enhanced.

  18. FEATURES OF SPHEROIDIZING MODIFICATION OF HIGH-STRENGTH CAST IRON WITH MASTER ALLOYS BASED ON COPPER

    Directory of Open Access Journals (Sweden)

    A. S. Kalinichenko

    2016-01-01

    Full Text Available The increase of efficiency of modification process for ductile iron is topically, thereby increasing its mechanical and operational properties. For these purposes, in practice, various magnesium containing alloys are used, including «heavy» ones on the basis of Copper and Nickel. The analysis has shown that the application of bulk inoculating alloys based on copper basis were not effectively due to long dissolution period. From this point of view, the interest is high-speed casting, allowing the production of inoculating alloys in the form of strips – chips that are characterized by a low dissolution time and low piroeffekt. The aim of this work is to study the features of structure formation in nodular cast iron using different spheroidizing alloys based on copper. Studies have shown that the transition from the use of briquetted form alloys based on copper and magnesium to the «chips-inoculating alloys» allowed increasing the efficiency of the spheroidizing process. Further improvement in the quality of ductile iron can be achieved by the use in «chip-inoculating alloys» additives of nanosized yttrium oxide powder. 

  19. Fiber laser cladding of nickel-based alloy on cast iron

    Energy Technology Data Exchange (ETDEWEB)

    Arias-González, F., E-mail: felipeag@uvigo.es [Applied Physics Dpt., University of Vigo, EEI, Lagoas-Marcosende, Vigo E-36310 (Spain); Val, J. del [Applied Physics Dpt., University of Vigo, EEI, Lagoas-Marcosende, Vigo E-36310 (Spain); Comesaña, R. [Materials Engineering, Applied Mechanics and Construction Dpt., University of Vigo, EEI, Lagoas-Marcosende, Vigo E-36310 (Spain); Penide, J.; Lusquiños, F.; Quintero, F.; Riveiro, A.; Boutinguiza, M.; Pou, J. [Applied Physics Dpt., University of Vigo, EEI, Lagoas-Marcosende, Vigo E-36310 (Spain)

    2016-06-30

    Highlights: • Fiber laser cladding of Ni-based alloy on cast iron was experimentally studied. • Two different types of cast iron have been analyzed: gray and ductile cast iron. • Suitable processing parameters to generate a Ni-based coating were determined. • Dilution is higher in gray cast iron samples than in ductile cast iron. • Ni-based coating presents higher hardness than cast iron but similar Young's modulus. - Abstract: Gray cast iron is a ferrous alloy characterized by a carbon-rich phase in form of lamellar graphite in an iron matrix while ductile cast iron presents a carbon-rich phase in form of spheroidal graphite. Graphite presents a higher laser beam absorption than iron matrix and its morphology has also a strong influence on thermal conductivity of the material. The laser cladding process of cast iron is complicated by its heterogeneous microstructure which generates non-homogeneous thermal fields. In this research work, a comparison between different types of cast iron substrates (with different graphite morphology) has been carried out to analyze its impact on the process results. A fiber laser was used to generate a NiCrBSi coating over flat substrates of gray cast iron (EN-GJL-250) and nodular cast iron (EN-GJS-400-15). The relationship between processing parameters (laser irradiance and scanning speed) and geometry of a single laser track was examined. Moreover, microstructure and composition were studied by Scanning Electron Microscopy (SEM), Energy Dispersive X-Ray Spectroscopy (EDS) and X-Ray Diffraction (XRD). The hardness and elastic modulus were analyzed by means of micro- and nanoindentation. A hardfacing coating was generated by fiber laser cladding. Suitable processing parameters to generate the Ni-based alloy coating were determined. For the same processing parameters, gray cast iron samples present higher dilution than cast iron samples. The elastic modulus is similar for the coating and the substrate, while the Ni

  20. Thin wall ductile iron casting as a substitute for aluminum alloy casting in automotive industry

    Directory of Open Access Journals (Sweden)

    M. Górny

    2009-01-01

    Full Text Available In paper it is presented thin wall ductile iron casting (TWDI as a substitute of aluminium alloy casting. Upper control arm made of ductile iron with wall thickness ranging from 2 – 3.7 mm was produced by inmold process. Structure, mechanical properties and computer simulations were investigated. Structural analysis of TWDI shows pearlitic-ferritic matrix free from chills and porosity. Mechanical testing disclose superior ultimate tensile strength (Rm, yield strength (Rp0,2 and slightly lower elongation (E of TWDI in comparison with forged control arm made of aluminium alloy (6061-T6. Moreover results of computer simulation of static loading for tested control arms are presented. Analysis show that the light-weight ductile iron casting can be loaded to similar working conditions as the forged Al alloy without any potential failures.

  1. The GENIALL process for generation of nickel-iron alloys from nickel ores or mattes

    International Nuclear Information System (INIS)

    Diaz, G.; Frias, C.; Palma, J.

    2001-01-01

    A new process, called GENIALL (acronym of Generation of Nickel Alloys), for nickel recovery as ferronickel alloys from ores or mattes without previous smelting is presented in this paper. Its core technology is a new electrolytic concept, the ROSEL cell, for electrowinning of nickel-iron alloys from concentrated chloride solutions. In the GENIALL Process the substitution of iron-based solid wastes as jarosite, goethite or hematite, by saleable ferronickel plates provides both economic and environmental attractiveness. Another advantage is that no associated sulfuric acid plant is required. The process starts with leaching of the raw material (ores or mattes) with a solution of ferric chloride. The leachate liquor is purified by conventional methods like cementation or solvent extraction, to remove impurities or separate by-products like copper and cobalt. The purified solution, that contains a mixture of ferrous and nickel chlorides is fed to the cathodic compartment of the electrowinning cell, where nickel and ferrous ions are reduced together to form an alloy. Simultaneously, ferrous chloride is oxidized to ferric chloride in the anodic compartment, from where it is recycled to the leaching stage. The new electrolytic equipment has been developed and scaled up from laboratory to pilot prototypes with commercial size electrodes of 1 m 2 . Process operating conditions have been established in continuous runs at bench and pilot plant scale. The technology has shown a remarkable capacity to produce nickel-iron alloys of a wide range of compositions, from 10% to 80% nickel, just by adjusting the operating parameters. This emerging technology could be implemented in many processes in which iron and other non-ferrous metals are harmful impurities to be removed, or valuable metals to be recovered as a marketable iron alloy. Other potential applications of this technology are regeneration of spent etching liquors, and iron removal from aqueous effluents. (author)

  2. The pupylation machinery is involved in iron homeostasis by targeting the iron storage protein ferritin.

    Science.gov (United States)

    Küberl, Andreas; Polen, Tino; Bott, Michael

    2016-04-26

    The balance of sufficient iron supply and avoidance of iron toxicity by iron homeostasis is a prerequisite for cellular metabolism and growth. Here we provide evidence that, in Actinobacteria, pupylation plays a crucial role in this process. Pupylation is a posttranslational modification in which the prokaryotic ubiquitin-like protein Pup is covalently attached to a lysine residue in target proteins, thus resembling ubiquitination in eukaryotes. Pupylated proteins are recognized and unfolded by a dedicated AAA+ ATPase (Mycobacterium proteasomal AAA+ ATPase; ATPase forming ring-shaped complexes). In Mycobacteria, degradation of pupylated proteins by the proteasome serves as a protection mechanism against several stress conditions. Other bacterial genera capable of pupylation such as Corynebacterium lack a proteasome, and the fate of pupylated proteins is unknown. We discovered that Corynebacterium glutamicum mutants lacking components of the pupylation machinery show a strong growth defect under iron limitation, which was caused by the absence of pupylation and unfolding of the iron storage protein ferritin. Genetic and biochemical data support a model in which the pupylation machinery is responsible for iron release from ferritin independent of degradation.

  3. Method for determining the hardness of strain hardening articles of tungsten-nickel-iron alloy

    International Nuclear Information System (INIS)

    Wallace, S.A.

    1984-01-01

    The present invention is directed to a rapid nondestructive method for determining the extent of strain hardening in an article of tungsten-nickel-iron alloy. The method comprises saturating the article with a magnetic field from a permanent magnet, measuring the magnetic flux emanating from the article, comparing the measurements of the magnetic flux emanating from the article with measured magnetic fluxes from similarly shaped standards of the alloy with known amounts of strain hardening to determine the hardness

  4. Relation between feeding mechanisms and solidification mode in 380 aluminium alloy with different iron contents

    International Nuclear Information System (INIS)

    Tovio, D. O.; Gonzalez, A.C.; Mugica, G. W.; Cuyas, J. C.

    2003-01-01

    In the present work the effect of iron (0.15, 0.42 and 0.86%) content in feeding mechanisms for 380 aluminium alloy has been studied. The feeding capacity has been evaluated by a device that produces a barrier removable to allowing the movement of the inter dendritic liquid. The results show the flow of different quantity of liquid, it depends of the temperature of operating the device and of the iron content. For minimum and maximum iron content, the inter dendritic and bursts feeding mechanisms are fundamentally involved, for 0.42% of iron the feeding mechanisms was the inter dendritic. The authors establish this behavior by the solidification mode of alloy, which promotes the presence of particles of Si or plates of b-Al 3 FeDi phase, in the inter dendritic channels and produce the different feeding mechanisms. (Author) 15 refs

  5. Adhesive wear of iron chromium nickel silicon manganese molybdenum niobium alloys with duplex structure

    International Nuclear Information System (INIS)

    Lugscheider, E.; Deppe, E.; Ambroziak, A.; Melzer, A.

    1991-01-01

    Iron nickel chromium manganese silicon and iron chromium nickel manganese silicon molybdenum niobium alloys have a so-called duplex structure in a wide concentration range. This causes an excellent resistance to wear superior in the case of adhesive stress with optimized concentrations of manganese, silicon, molybdenum and niobium. The materials can be used for welded armouring structures wherever cobalt and boron-containing alloy systems are not permissible, e.g. in nuclear science. Within the framework of pre-investigations for manufacturing of filling wire electrodes, cast test pieces were set up with duplex structure, and their wear behavior was examined. (orig.) [de

  6. Chemical interaction silicon nitride ceramics and iron alloys

    Directory of Open Access Journals (Sweden)

    Oliveira, F. J.

    2000-12-01

    Full Text Available Metal/ceramic diffusion experiments are helpful to study bonding mechanisms or the effect of metal composition on the chemical wear of ceramic cutting tools. The reaction kinetics of Fe alloys/Si3 N4 ceramic diffusion couples was investigated in the temperature range 1050ºC-1250ºC, for 0.5h to 80h, under inert atmosphere. Optical microscopy, SEM and EPMA were carried out in cross sections of the reacted pairs. Si3N4 decomposes into Si and N that dissolve and diffuse through the metal. Both the diffusion zone on the metal side and the reaction zone on the ceramic side obey parabolic growth laws of time, with activation energies in the range Q=310-460kJmol-1. The amount of dissolved Si, the length of the diffusion zone and thus the reactivity of the ceramic increase as the alloy carbon content decreases. Due to Si accumulation, the α-Fe solid solution is stabilised at the reaction temperature and a steep decrease in the Si concentration is observed beyond the diffusion zone. The reinforcement of the Si3N4 composites with A12O3 platelets enhances the chemical resistance of the ceramic due to the inertness of this oxide and to the partial crystallisation of the intergranular phase. Other dispersoids such as HfN, BN and TiN do not improve the chemical resistance of the matrix by iron attack.

    Los experimentos de difusión metal/cerámica permiten estudiar mecanismos de unión y analizar el efecto de la composición del metal en el desgaste químico de herramientas de corte cerámicas. En este trabajo se investigó la cinética de reacción en pares de difusión aleaciones de Fe/Si3N4 a temperaturas entre 1050ºC-1250ºC, tiempos entre 0.5h a 80h, en atmósfera inerte. Las secciones transversales de los pares de difusión se analizaron mediante microscopía óptica, SEM y microsonda electrónica. El Si3N4 se descompone en Si y N que se disuelven y difunden en el metal. Tanto la zona de difusión en el metal como la zona de reacción en la cer

  7. Effect of Iron Impurity on the Phase Composition, Structure and Properties of Magnesium Alloys Containing Manganese and Aluminum

    Science.gov (United States)

    Volkova, E. F.

    2017-07-01

    Results of a study of the interaction between iron impurity and manganese and aluminum alloying elements during formation of phase composition in alloys of the Mg - Mn, Mg - Al, Mg - Al - Mn, and Mg - Al - Zn - Mn systems are presented. It is proved that this interaction results in introduction of Fe into the intermetallic phase. The phase compositions of model magnesium alloys and commercial alloys MA2-1 and MA5 are studied. It is shown that both manganese and aluminum may bind the iron impurity into phases. Composite Fe-containing intermetallic phases of different compositions influence differently the corrosion resistance of magnesium alloys.

  8. Influence of iron and beryllium additions on heat resistance of silicide coatings on TsMB-30 molybdenum alloy

    International Nuclear Information System (INIS)

    Zajtseva, A.L.; Fedorchuk, N.M.; Lazarev, Eh.M.; Korotkov, N.A.

    1985-01-01

    Alloying of titanium modified silicide coatings on TsMB-30 molybdenum alloy with iron or beryllium is stated to improve their protective properties. Coatings with low content of alloying elements have the best protective properties. Service life of coatings is determined by the formed oxide film and phase transformations taking place in the coating

  9. Effects of iron on intermetallic compound formation in scandium modified Al–Si–Mg Alloys

    Energy Technology Data Exchange (ETDEWEB)

    Patakham, Ussadawut [National Metal and Materials Technology Center, National Science and Technology Development Agency, 114 Thailand Science Park, Klong Nueng, Klong Luang, Pathumthani 12120 (Thailand); Limmaneevichitr, Chaowalit, E-mail: chaowalit.lim@mail.kmutt.ac.th [Production Engineering Department, Faculty of Engineering, King Mongkut’s University of Technology Thonburi, 126 Pracha-Utid Rd., Bangmod, Tungkhru, Bangkok 10140 (Thailand)

    2014-12-15

    Highlights: • Iron reduces the modification effects of scandium in Al–Si–Mg alloys. • Morphologies of Sc-rich intermetallic phases vary with Fe and Sc contents and the cooling rates. • Sc neutralizes effects of Fe by changing Fe-rich intermetallic phases from platelets to more cubic. - Abstract: In general, iron has a strong tendency to dissolve in molten aluminum. Iron has very low solid solubility in aluminum–silicon casting alloys, so it will form intermetallic compounds that cause detrimental effects on mechanical properties. In this work, the effects of iron on intermetallic compound formations in scandium modified Al–Si–Mg alloys were studied. There were two levels of iron addition (0.2 and 0.4 wt.%) and two levels of scandium addition (0.2 and 0.4 wt.%). We found that the effects of scandium modification decreased with increasing iron addition. The morphologies of the complex intermetallic compounds were characterized by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and electron backscatter diffraction (EBSD) techniques. It was found that scandium changes the morphology of Fe-rich intermetallic compounds from β-phase (plate-like) to α-phase, which reduces the harmful effects of β-phase.

  10. Method of fabricating thin-walled articles of tungsten-nickel-iron alloy

    Science.gov (United States)

    Hovis, Jr., Victor M.; Northcutt, Jr., Walter G.

    1982-01-01

    The present invention relates to a method for fabricating thin-walled high-density structures oftungsten-nickel-iron alloys. A powdered blend of the selected alloy constituents is plasma sprayed onto a mandrel having the desired article configuration. The sprayed deposit is removed from the mandrel and subjected to liquid phase sintering to provide the alloyed structure. The formation of the thin-walled structure by plasma spraying significantly reduces shrinkage, and cracking while increasing physical properties of the structure over that obtainable by employing previously known powder metallurgical procedures.

  11. Interstitial-phase precipitation in iron-base alloys: a comparative study

    International Nuclear Information System (INIS)

    Pelton, A.R.

    1982-06-01

    Recent developments have elucidated the atomistic mechanisms of precipitation of interstitial elements in simple alloy systems. However, in the more technologically important iron base alloys, interstitial phase precipitation is generally not well understood. The present experimental study was therefore designed to test the applicability of these concepts to more complex ferrous alloys. Hence, a comparative study was made of interstitial phase precipitation in ferritic Fe-Si-C and in austenitic phosphorus-containing Fe-Cr-Ni steels. These systems were subjected to a variety of quench-age thermal treatments, and the microstructural development was subsequently characterized by transmission electron microscopy

  12. The influence of various cooling rates during laser alloying on nodular iron surface layer

    Science.gov (United States)

    Paczkowska, Marta; Makuch, Natalia; Kulka, Michał

    2018-06-01

    The results of research referring to modification of the nodular iron surface layer by laser alloying with cobalt were presented. The aim of this study was to analyze the possibilities of cobalt implementation into the surface layer of nodular iron in various laser heat treatment conditions (by generating different cooling rates of melted surface layer). The modified surface layer of nodular iron was analyzed with OM, SEM, TEM, XRD, EDS and Vickers microhardness tester. The modified surface layer of nodular iron after laser alloying consisted of: the alloyed zone (melted with cobalt), the transition zone and the hardened zone from solid state. The alloyed zone was characterized by higher microstructure homogeneity - in contrast to the transition and the hardened zones. All the alloyed zones contained a dendritic microstructure. Dendrites consisted of martensite needles and retained austenite. Cementite was also detected. It was stated, that due to similar dimension of iron and cobalt atoms, their mutual replacement in the crystal lattice could occur. Thus, formation of phases based on α solution: Co-Fe (44-1433) could not be excluded. Although cobalt should be mostly diluted in solid solutions (because of its content in the alloyed zone), the other newly formed phases as Co (ε-hex.), FeC and cobalt carbides: Co3C, CoC0.25 could be present in the alloyed zones as a result of unique microstructure creation during laser treatment. Pearlite grains were observed in the zone, formed using lower power density of the laser beam and its longer exposition time. Simply, such conditions resulted in the cooling rate which was lower than critical cooling rate. The alloyed zones, produced at a higher cooling rate, were characterized by better microstructure homogeneity. Dendrites were finer in this case. This could result from a greater amount of crystal nuclei appearing at higher cooling rate. Simultaneously, the increased amount of γ-Fe and Fe3C precipitates was expected in

  13. Modification of fuel performance code to evaluate iron-based alloy behavior under LOCA scenario

    Energy Technology Data Exchange (ETDEWEB)

    Giovedi, Claudia; Martins, Marcelo Ramos, E-mail: claudia.giovedi@labrisco.usp.br, E-mail: mrmartin@usp.br [Laboratorio de Analise, Avaliacao e Gerenciamento de Risco (LabRisco/POLI/USP), São Paulo, SP (Brazil); Abe, Alfredo; Muniz, Rafael O.R.; Gomes, Daniel de Souza; Silva, Antonio Teixeira e, E-mail: ayabe@ipen.br, E-mail: dsgomes@ipen.br, E-mail: teixiera@ipen.br [Instituto de Pesquisas Energéticas e Nucleares (IPEN/CNEN-SP), São Paulo, SP (Brazil)

    2017-07-01

    Accident tolerant fuels (ATF) has been studied since the Fukushima Daiichi accident in the research efforts to develop new materials which under accident scenarios could maintain the fuel rod integrity for a longer period compared to the cladding and fuel system usually utilized in Pressurized Water Reactors (PWR). The efforts have been focused on new materials applied as cladding, then iron-base alloys appear as a possible candidate. The aim of this paper is to implement modifications in a fuel performance code to evaluate the behavior of iron based alloys under Loss-of-Coolant Accident (LOCA) scenario. For this, initially the properties related to the thermal and mechanical behavior of iron-based alloys were obtained from the literature, appropriately adapted and introduced in the fuel performance code subroutines. The adopted approach was step by step modifications, where different versions of the code were created. The assessment of the implemented modification was carried out simulating an experiment available in the open literature (IFA-650.5) related to zirconium-based alloy fuel rods submitted to LOCA conditions. The obtained results for the iron-based alloy were compared to those obtained using the regular version of the fuel performance code for zircaloy-4. The obtained results have shown that the most important properties to be changed are those from the subroutines related to the mechanical properties of the cladding. The results obtained have shown that the burst is observed at a longer time for fuel rods with iron-based alloy, indicating the potentiality of this material to be used as cladding with ATF purposes. (author)

  14. Modification of fuel performance code to evaluate iron-based alloy behavior under LOCA scenario

    International Nuclear Information System (INIS)

    Giovedi, Claudia; Martins, Marcelo Ramos; Abe, Alfredo; Muniz, Rafael O.R.; Gomes, Daniel de Souza; Silva, Antonio Teixeira e

    2017-01-01

    Accident tolerant fuels (ATF) has been studied since the Fukushima Daiichi accident in the research efforts to develop new materials which under accident scenarios could maintain the fuel rod integrity for a longer period compared to the cladding and fuel system usually utilized in Pressurized Water Reactors (PWR). The efforts have been focused on new materials applied as cladding, then iron-base alloys appear as a possible candidate. The aim of this paper is to implement modifications in a fuel performance code to evaluate the behavior of iron based alloys under Loss-of-Coolant Accident (LOCA) scenario. For this, initially the properties related to the thermal and mechanical behavior of iron-based alloys were obtained from the literature, appropriately adapted and introduced in the fuel performance code subroutines. The adopted approach was step by step modifications, where different versions of the code were created. The assessment of the implemented modification was carried out simulating an experiment available in the open literature (IFA-650.5) related to zirconium-based alloy fuel rods submitted to LOCA conditions. The obtained results for the iron-based alloy were compared to those obtained using the regular version of the fuel performance code for zircaloy-4. The obtained results have shown that the most important properties to be changed are those from the subroutines related to the mechanical properties of the cladding. The results obtained have shown that the burst is observed at a longer time for fuel rods with iron-based alloy, indicating the potentiality of this material to be used as cladding with ATF purposes. (author)

  15. Review of lithium iron-base alloy corrosion studies

    International Nuclear Information System (INIS)

    DeVan, J.H.; Selle, J.E.; Morris, A.E.

    1976-01-01

    An extensive literature search was conducted on the compatibility of ferrous alloys with lithium, with the emphasis on austenitic stainless steels. The information is summarized and is divided into two sections. The first section gives a brief summary and the second is an annotated bibliography. Comparisons of results are complicated by differences in lithium purity, alloy composition, alloy treatment, flow rates, and lithium handling procedures. For long-term application, austenitic stainless steels appear to be limited to about 500 0 C. While corrosion can probably not be decreased to zero, a considerable reduction to tolerable and predictable amounts appears possible

  16. Low alloy additions of iron, silicon, and aluminum to uranium: a literature survey

    International Nuclear Information System (INIS)

    Ludwig, R.L.

    1980-01-01

    A survey of the literature has been made on the experimental results of small additions of iron, silicon, and aluminum to uranium. Information is also included on the constitution, mechanical properties, heat treatment, and deformation of various binary and ternary alloys. 42 references, 24 figures, 13 tables

  17. An electron-microscope study of alpha to gamma transformation in an iron-nickel alloy

    Science.gov (United States)

    Lobodyuk, V. A.; Khandros, L. G.; Fedas, N. P.

    1980-01-01

    Procedures used to study the alpha to gamma conversion in thin foils of an iron alloy with 32% nickel concentration and initial martensite conversion temperature of -60 C are described. Photomicrographs show deformation twinning as well as changes in samples after they were heated. Reverse conversion is discussed and results are examined.

  18. Standard specification for Nickel-Chromium-Iron alloys (UNS N06600, N06601, N06603, N06690, N06693, N06025, N06045, and N06696), Nikel-Chromium-Cobalt-Molybdenum alloy (UNS N06617), and Nickel-Iron-Chromium-Tungsten alloy (UNS N06674) seamless pipe and tube

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2011-01-01

    Standard specification for Nickel-Chromium-Iron alloys (UNS N06600, N06601, N06603, N06690, N06693, N06025, N06045, and N06696), Nikel-Chromium-Cobalt-Molybdenum alloy (UNS N06617), and Nickel-Iron-Chromium-Tungsten alloy (UNS N06674) seamless pipe and tube

  19. Standard specification for Nickel-Chromium-Iron alloys (UNS N06600, N06601, N06603, N06690, N06693, N06025, N06045 and N06696), Nickel-Chromium-Cobalt-Molybdenum alloy (UNS N06617), and Nickel-Iron-Chromium-Tungsten alloy (UNS N06674) plate, sheet and strip

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2011-01-01

    Standard specification for Nickel-Chromium-Iron alloys (UNS N06600, N06601, N06603, N06690, N06693, N06025, N06045 and N06696), Nickel-Chromium-Cobalt-Molybdenum alloy (UNS N06617), and Nickel-Iron-Chromium-Tungsten alloy (UNS N06674) plate, sheet and strip

  20. Standard specification for Nickel-Chromium-Iron alloys (UNS N06600, N06601, N06603, N06690, N06693, N06025, N06045, and N06696), Nickel-Chromium-Cobalt-Molybdenum alloy (UNS N06617), and Nickel-Iron-Chromium-Tungsten alloy (UNS N06674) rod, bar, and wire

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2011-01-01

    Standard specification for Nickel-Chromium-Iron alloys (UNS N06600, N06601, N06603, N06690, N06693, N06025, N06045, and N06696), Nickel-Chromium-Cobalt-Molybdenum alloy (UNS N06617), and Nickel-Iron-Chromium-Tungsten alloy (UNS N06674) rod, bar, and wire

  1. Diffusion Coefficient in the Zinc Coating Shaped on the Surface of Cast Iron and Steel Alloys

    Directory of Open Access Journals (Sweden)

    Kopyciński D.

    2015-06-01

    Full Text Available The article presents the method to assess the diffusion coefficient D in the sub-layer of intermetallic phases formed during hot-dip galvanizing “Armco” iron and ductile cast iron EN-GJS-500-7. Hot-dip galvanizing is one of the most popular forms of long-term protection of Fe-C alloys against corrosion. The process for producing a protective layer of sufficient quality is closely related to diffusion of atoms of zinc and iron. The simulation consist in performed a hot-dip galvanizing in laboratory condition above Fe-C alloys, in the Department of Engineering of Cast Alloys and Composites. Galvanizing time ranged from 15 to 300 seconds. Then metallographic specimens were prepared, intermetallic layers were measured and diffusion coefficient (D were calculated. It was found that the diffusion coefficient obtained during hot-dip galvanizing “Armco” iron and zinc is about two orders of magnitude less than the coefficient obtained on ductile cast iron EN-GJS-500-7.

  2. Study of the pyrophoric characteristics of uranium-iron alloys; Etude du caractere pyrophorique des alliages uranium fer

    Energy Technology Data Exchange (ETDEWEB)

    Duplessis, X

    2000-02-23

    The objective of the study is to understand the pyrophoric characteristics of uranium-iron alloys. In order to carry out this research we have elected to use uranium-iron alloy powder with granules of 200 {mu}m and 1000 {mu}m diameter with 4%, 10.8% and 14% iron content. The experiments were performed on small samples of few milligrams and on larger quantities of few hundred grams. The main conclusions obtained are the followings: -The reaction start at 453 K (180 deg. C) and the ignition at 543 K (270 deg. C) - The influence of the specific area seems more important than the iron concentration in the alloys - When the alloy ignites, the fire spreads quickly and the alloy rapidly consumes. (author)

  3. Effect of alloying elements on characteristics of iron passive state in sulfuric acid

    International Nuclear Information System (INIS)

    Rejes Jola, O.; Mustafa-Zade, F.M.; Sukhotin, A.M.; Tchannikova, O.A.

    1981-01-01

    The curves of anodic polarization of iron binary alloys with Cr, Mo, W, Ni, Si, Co, Mn, Re, Ti, Al, Cu, Bi, Zn, In, V, Sb, Ta, Hf, Pb, Sn, Zr, Nb, Ce, B, P, S in 0.5 MH 2 SO 4 are studied. Passivation potentials, potentials of total passivation, transpassivity and current density are determined in the passivity region. All alloys had alpha-structure, the content of alloying elements was close to solubility in solid solution. Elements are classified according to the type of their effect on passive state of iron. Character of this effect does not have a direct connection with passivation ability the elements themselves, it is determined, probably, by a possibility to form stable passivating ruixed oxides of the ferrospinel type [ru

  4. Iron-nickel alloys as canister material for radioactive waste disposal in underground repositories

    International Nuclear Information System (INIS)

    Apps, J.A.

    1982-01-01

    Canisters containing high-level radioactive waste must retain their integrity in an underground waste repository for at least one thousand years after burial (Nuclear Regulatory Commission, 1981). Since no direct means of verifying canister integrity is plausible over such a long period, indirect methods must be chosen. A persuasive approach is to examine the natural environment and find a suitable material which is thermodynamically compatible with the host rock under the environmental conditions with the host rock under the environmental conditions expected in a waste repository. Several candidates have been proposed, among them being iron-nickel alloys that are known to occur naturally in altered ultramafic rocks. The following review of stability relations among iron-nickel alloys below 350 0 C is the initial phase of a more detailed evaluation of these alloys as suitable canister materials

  5. In vitro evaluation of iron solubility and dialyzability of various iron fortificants and of iron-fortified milk products targeted for infants and toddlers.

    Science.gov (United States)

    Kapsokefalou, Maria; Alexandropoulou, Isidora; Komaitis, Michail; Politis, Ioannis

    2005-06-01

    The objectives of the present study were: to compare the solubility and dialyzability of various iron fortificants (iron pyrophosphate, ferrous bis-glycinate, ferrous gluconate, ferrous lactate, ferrous sulfate) added, in the presence of ascorbic acid, to pasteurized milk samples produced under laboratory conditions; and to compare the solubility and dialyzability of iron in commercial pasteurized, UHT and condensed milk products available in the Greek market fortified with various vitamins and minerals including iron and targeted towards infants (6-12 months old) and toddlers. Iron solubility and dialyzability were determined using a simulated gastrointestinal digestive system. Ferrous dialyzable iron (molecular weight lower than 8000) was used as an index for prediction of iron bioavailability. Ferrous dialyzable iron in pasteurized milk samples fortified with iron pyrophosphate, ferrous lactate and ferrous bis-glycinate was higher (P iron in products fortified with ferrous lactate was not different (P > 0.05) from those fortified with ferrous sulfate. Ferrous dialyzable iron in four condensed commercial milk products was higher (P iron was higher (P iron source, milk processing and the overall product composition affect formation of ferrous dialyzable iron and may determine the success and effectiveness of iron fortification of milk.

  6. Microstructural characteristics of Al-alloyed austempered ductile irons

    International Nuclear Information System (INIS)

    Kiani-Rashid, A.R.; Edmonds, D.V.

    2009-01-01

    Microstructural development after austempering ductile irons containing 0.48% and 4.88%Al has been studied by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The experimental irons were made by green sand casting and gravity die casting. After austenitising at 920 deg. C for 90 min, an austempering treatment at 400 deg. C for times up to 100 min resulted in microstructures consisting of carbide-free bainitic ferrite with considerable amounts of high carbon retained austenite.

  7. Production of rare earth-silicon-iron alloys

    International Nuclear Information System (INIS)

    Mehra, O.K.; Bose, D.K.; Gupta, C.K.

    1987-01-01

    At Metallurgy Division, BARC, improved procedures for producing rare earth-silicon alloys have been investigated. In these methods, reduction of mixed rare earth oxide by a ferro-silicon and aluminium mixture in combination with CaO-MgO flux/CaO-CaF 2 flux have been tried to prepare an alloy product with a higher rare earth recovery at a higher rare earth content than the present commercial production method. The rare earth recovery using CaO-CaF 2 was 85 per cent while in the case of CaO-MgO flux it was 76 per cent. The corresponding rare earth contents in the alloy correspond to 40 per cent and 55 per cent by weight respectively. (author)

  8. Development of weldable, corrosion-resistant iron-aluminide alloys

    Energy Technology Data Exchange (ETDEWEB)

    Maziasz, P.J.; Goodwin, G.M.; Wang, X.L. [Oak Ridge National Laboratory, TN (United States)

    1995-05-01

    Corrosion-resistant, weldable FeAl alloys have been developed with improved high-temperature strength industrial applications. Previous processing difficulties with these alloys led to their evaluation as weld-overlay claddings on conventional structural steels to take advantage of their good properties now. Simplified and better processing methods for monolithic FeAl components are also currently being developed so that components for industrial testing can be made. Other avenues for producing FeAl coatings are currently being explored. Neutron scattering experiments residual stress distributions in the FeAl weld-overlay cladding began in FY 1993 and continued this year.

  9. On aging of iron-nickel-titanium alloys

    International Nuclear Information System (INIS)

    Vintajkin, E.Z.; Dmitriev, V.B.; Udovenko, V.A.

    1978-01-01

    The mechanism of structural transformations on the initial stages of aging of Fe-(26-29) at. % Ni-(2.5-5.75) at. % Ti alloys was studied by neutron radiography. It was shown that at the earliest aging stages at 550 deg C there appear ordered areas which are FCC nuclei of the Ni 3 Ti phase. The rate of nucleation depends on the content of titanium in the all. In alloys with more than 3% Ti, nuclei appear even at the hardening stage. During the subsequent aging, the nuclei are enriched with nickel and titanium

  10. Iron-based alloy and nitridation treatment for PEM fuel cell bipolar plates

    Science.gov (United States)

    Brady, Michael P [Oak Ridge, TN; Yang, Bing [Oak Ridge, TN; Maziasz, Philip J [Oak Ridge, TN

    2010-11-09

    A corrosion resistant electrically conductive component that can be used as a bipolar plate in a PEM fuel cell application is composed of an alloy substrate which has 10-30 wt. % Cr, 0.5 to 7 wt. % V, and base metal being Fe, and a continuous surface layer of chromium nitride and vanadium nitride essentially free of base metal. A oxide layer of chromium vanadium oxide can be disposed between the alloy substrate and the continuous surface nitride layer. A method to prepare the corrosion resistant electrically conductive component involves a two-step nitridization sequence by exposing the alloy to a oxygen containing gas at an elevated temperature, and subsequently exposing the alloy to an oxygen free nitrogen containing gas at an elevated temperature to yield a component where a continuous chromium nitride layer free of iron has formed at the surface.

  11. Preparation of Iron-nickel Alloy Nanostructures via Two Cationic Pyridinium Derivatives as Soft Templates

    Directory of Open Access Journals (Sweden)

    Jingxin Zhou

    2015-09-01

    Full Text Available In this paper, crystalline iron-nickel alloy nanostructures were successfully prepared from two cationic pyridinium derivatives as soft templates in solution. The crystal structure and micrograph of FeNi alloy nanostructures were characterized by X-ray diffraction, scanning electron microscopy and transmission electron microscopy, and the content was confirmed by energy-dispersive spectrometry. The results indicated that the as-prepared nanostructures showed slightly different diameter ranges with the change of cationic pyridinium derivatives on the surface. The experimental data indicated that the adsorption of cationic pyridinium compounds on the surface of particles reduces the surface charge, leading to an isotropic distribution of the residual surface charges. The magnetic behaviours of as-prepared FeNi alloy nanostructures exhibited disparate behaviours, which could be attributed to their grain sizes and distinctive structures. The present work may give some insight into the synthesis and character of new alloy nanomaterials with special nanostructures using new soft templates.

  12. SOFTWARE FOR IMAGE PROCESSING OF IRON-CARBONACEOUS ALLOY MICROSTRUCTURES

    Directory of Open Access Journals (Sweden)

    A. N. Chichko

    2011-01-01

    Full Text Available The paper proposes a mathematical apparatus for image processing of a cast-iron microstructure of a pearlite class that has casually distributed graphite inclusions in the structure the software has been developed and it allows to determine statistical functions concerning distribution of graphite inclusion characteristics according to areas, perimeters and distances between inclusions. The paper shows that computer processing of gray pig-iron microstructure image makes it possible to classify microstructures on the basis of statistical distribution of a graphite phase which are considered as indiscernible while applying conventional metallographic methods and it has practical significance for investigation of the interrelations – «workability – cast iron microstructure».

  13. A chemical approach toward low temperature alloying of immiscible iron and molybdenum metals

    Energy Technology Data Exchange (ETDEWEB)

    Nazir, Rabia [Department of Chemistry, Quaid-i-Azam University, Islamabad 45320 (Pakistan); Applied Chemistry Research Centre, Pakistan Council of Scientific and Industrial Research Laboratories Complex, Lahore 54600 (Pakistan); Ahmed, Sohail [Department of Chemistry, Quaid-i-Azam University, Islamabad 45320 (Pakistan); Mazhar, Muhammad, E-mail: mazhar42pk@yahoo.com [Department of Chemistry, University of Malaya, Lembah Pantai, 50603 Kuala Lumpur (Malaysia); Akhtar, Muhammad Javed; Siddique, Muhammad [Physics Division, PINSTECH, P.O. Nilore, Islamabad (Pakistan); Khan, Nawazish Ali [Material Science Laboratory, Department of Physics, Quaid-i-Azam University, Islamabad 45320 (Pakistan); Shah, Muhammad Raza [HEJ Research Institute of Chemistry, University of Karachi, Karachi 75270 (Pakistan); Nadeem, Muhammad [Physics Division, PINSTECH, P.O. Nilore, Islamabad (Pakistan)

    2013-11-15

    Graphical abstract: - Highlights: • Low temperature pyrolysis of [Fe(bipy){sub 3}]Cl{sub 2} and [Mo(bipy)Cl{sub 4}] homogeneous powder. • Easy low temperature alloying of immiscible metals like Fe and Mo. • Uniform sized Fe–Mo nanoalloy with particle size of 48–68 nm. • Characterization by EDXRF, AFM, XRPD, magnetometery, {sup 57}Fe Mössbauer and impedance. • Alloy behaves as almost superparamagnetic obeying simple –R(CPE)– circuit. - Abstract: The present research is based on a low temperature operated feasible method for the synthesis of immiscible iron and molybdenum metals’ nanoalloy for technological applications. The nanoalloy has been synthesized by pyrolysis of homogeneous powder precipitated, from a common solvent, of the two complexes, trisbipyridineiron(II)chloride, [Fe(bipy){sub 3}]Cl{sub 2}, and bipyridinemolybedenum(IV) chloride, [Mo(bipy)Cl{sub 4}], followed by heating at 500 °C in an inert atmosphere of flowing argon gas. The resulting nanoalloy has been characterized by using EDXRF, AFM, XRD, magnetometery, {sup 57}Fe Mössbauer and impedance spectroscopies. These results showed that under provided experimental conditions iron and molybdenum metals, with known miscibility barrier, alloy together to give (1:1) single phase material having particle size in the range of 48–66 nm. The magnetism of iron is considerably reduced after alloy formation and shows its trend toward superparamagnetism. The designed chemical synthetic procedure is equally feasible for the fabrication of other immiscible metals.

  14. A chemical approach toward low temperature alloying of immiscible iron and molybdenum metals

    International Nuclear Information System (INIS)

    Nazir, Rabia; Ahmed, Sohail; Mazhar, Muhammad; Akhtar, Muhammad Javed; Siddique, Muhammad; Khan, Nawazish Ali; Shah, Muhammad Raza; Nadeem, Muhammad

    2013-01-01

    Graphical abstract: - Highlights: • Low temperature pyrolysis of [Fe(bipy) 3 ]Cl 2 and [Mo(bipy)Cl 4 ] homogeneous powder. • Easy low temperature alloying of immiscible metals like Fe and Mo. • Uniform sized Fe–Mo nanoalloy with particle size of 48–68 nm. • Characterization by EDXRF, AFM, XRPD, magnetometery, 57 Fe Mössbauer and impedance. • Alloy behaves as almost superparamagnetic obeying simple –R(CPE)– circuit. - Abstract: The present research is based on a low temperature operated feasible method for the synthesis of immiscible iron and molybdenum metals’ nanoalloy for technological applications. The nanoalloy has been synthesized by pyrolysis of homogeneous powder precipitated, from a common solvent, of the two complexes, trisbipyridineiron(II)chloride, [Fe(bipy) 3 ]Cl 2 , and bipyridinemolybedenum(IV) chloride, [Mo(bipy)Cl 4 ], followed by heating at 500 °C in an inert atmosphere of flowing argon gas. The resulting nanoalloy has been characterized by using EDXRF, AFM, XRD, magnetometery, 57 Fe Mössbauer and impedance spectroscopies. These results showed that under provided experimental conditions iron and molybdenum metals, with known miscibility barrier, alloy together to give (1:1) single phase material having particle size in the range of 48–66 nm. The magnetism of iron is considerably reduced after alloy formation and shows its trend toward superparamagnetism. The designed chemical synthetic procedure is equally feasible for the fabrication of other immiscible metals

  15. Carbon Dissolution Using Waste Biomass—A Sustainable Approach for Iron-Carbon Alloy Production

    Directory of Open Access Journals (Sweden)

    Irshad Mansuri

    2018-04-01

    Full Text Available This paper details the characterisation of char obtained by high-temperature pyrolysis of waste macadamia shell biomass and its application as carbon source in iron-carbon alloy production. The obtained char was characterised by ultimate and proximate analysis, X-ray diffraction (XRD, Raman spectroscopy, Fourier-transform infrared spectroscopy (FTIR, X-ray photon spectroscopy (XPS, Brunauer-Emmett-Teller (BET surface area via N2 isothermal adsorption and scanning electron microscopy (SEM. The results indicated that obtained char is less porous, low in ash content, and high in carbon content. Investigation of iron-carbon alloy formation through carbon dissolution at 1550 °C was carried out using sessile drop method by using obtained char as a carbon source. Rapid carbon pickup by iron was observed during first two minutes of contact and reached a saturation value of ~5.18 wt % of carbon after 30 min. The carbon dissolution rate using macadamia char as a source of carbon was comparatively higher using than other carbonaceous materials such as metallurgical coke, coal chars, and waste compact discs, due to its high percentage of carbon and low ash content. This research shows that macadamia shell waste, which has a low content of ash, is a valuable supplementary carbon source for iron-carbon alloy industries.

  16. Iron Intermetallic Phases in the Alloy Based on Al-Si-Mg by Applying Manganese

    Directory of Open Access Journals (Sweden)

    Podprocká R.

    2017-09-01

    Full Text Available Manganese is an effective element used for the modification of needle intermetallic phases in Al-Si alloy. These particles seriously degrade mechanical characteristics of the alloy and promote the formation of porosity. By adding manganese the particles are being excluded in more compact shape of “Chinese script” or skeletal form, which are less initiative to cracks as Al5FeSi phase. In the present article, AlSi7Mg0.3 aluminium foundry alloy with several manganese content were studied. The alloy was controlled pollution for achieve higher iron content (about 0.7 wt. % Fe. The manganese were added in amount of 0.2 wt. %, 0.6 wt. %, 1.0 wt. % and 1.4 wt. %. The influence of the alloying element on the process of crystallization of intermetallic phases were compared to microstructural observations. The results indicate that increasing manganese content (> 0.2 wt. % Mn lead to increase the temperature of solidification iron rich phase (TAl5FeSi and reduction this particles. The temperature of nucleation Al-Si eutectic increase with higher manganese content also. At adding 1.4 wt. % Mn grain refinement and skeleton particles were observed.

  17. Targeted magnetic iron oxide nanoparticles for tumor imaging and therapy

    Directory of Open Access Journals (Sweden)

    Xiang-Hong Peng

    2008-10-01

    Full Text Available Xiang-Hong Peng1,4, Ximei Qian2,4, Hui Mao3,4, Andrew Y Wang5, Zhuo (Georgia Chen1,4, Shuming Nie2,4, Dong M Shin1,4*1Department of Medical Oncology/Hematology; 2Department of Biomedical Engineering; 3Department of Radiology; 4Winship Cancer Institute, Emory University School of Medicine, Atlanta, GA, USA; 5Ocean Nanotech, LLC, Fayetteville, AR, USAAbstract: Magnetic iron oxide (IO nanoparticles with a long blood retention time, biodegradability and low toxicity have emerged as one of the primary nanomaterials for biomedical applications in vitro and in vivo. IO nanoparticles have a large surface area and can be engineered to provide a large number of functional groups for cross-linking to tumor-targeting ligands such as monoclonal antibodies, peptides, or small molecules for diagnostic imaging or delivery of therapeutic agents. IO nanoparticles possess unique paramagnetic properties, which generate significant susceptibility effects resulting in strong T2 and T*2 contrast, as well as T1 effects at very low concentrations for magnetic resonance imaging (MRI, which is widely used for clinical oncology imaging. We review recent advances in the development of targeted IO nanoparticles for tumor imaging and therapy.Keywords: iron oxide nanoparticles, tumor imaging, MRI, therapy

  18. Identification of fullerenes in iron-carbon alloys structure.

    Directory of Open Access Journals (Sweden)

    KUZEEV Iskander Rustemovich

    2017-11-01

    Full Text Available Steels of various purposes are used in the construction industry, for example, as the reinforcement material in reinforced concrete structures. In the oil and gas industry, steel structures are used for storage and transportation of explosive toxic media. In this case the catastrophic damages might take place, that points at insufficiently deep knowledge about the processes running in structural materials when load is applied. Recent studies show that many properties of steel are set at the nanoscale level during crystallization from the molten metal and thermal treatment. To detect and identify fullerenes С60 and С70, which are independent nanoscale objects in steel structure, by various methods requires studying of how these objects influence on formation of steel properties. Iron atoms can serve as a catalyst and, interacting with large aromatic structures or fragments of the graphite planes, they form voluminous fullerene-type structures. The inverse phenomenon, i.e. influence of the formed nanoscale objects on structuring of the iron atoms, is also possible, as fullerene size is comparable with the size of the stable nucleus of the iron crystalline phase. The article discusses the issue of mechanisms of fullerenes formation in steels and cast irons. The most complicated issue in the study is the fullerenes identification by spectral methods as the quantity of released molecules is small. In order to increase the sensitivity of the fullerenes IR-spectrometry method, potassium bromide has been proposed to use. Dried and reduced sediment obtained as a result of dissolving iron matrix in steels is mixed with potassium bromide, the mixture becomes bright-orange. This fact points to presence of bromic fullerenes and to presence of fullerenes in the studied specimens. It is shown that the offered specimen preparation algorithm significantly increases sensitivity of the method.

  19. A Study on Zinc-Iron Alloy Electrodeposition from a Chloride Electrolyte

    DEFF Research Database (Denmark)

    Jensen, Jens Dahl

    1998-01-01

    The electrodeposition of zinc-iron alloys from a chloride-based electrolyte has been studied using electrochemical polarisation techniques, Auger Electron Spectroscopy (AES), Scanning Electron Microscopy (SEM), Energy Dispersive X-ray Analysis (EDXA) and Computer Assisted Pulse Plating (CAPP...... this system ideal for production of compositional modulated alloy (CMA) electrodeposits. Chloride content, pH and agitation of the electrolyte have been observed to have a strong influence on the reaction at the cathode surface, just as the use of pulse reversal current during electrodeposition. A theory...

  20. Internal friction in iron-aluminium alloys having a high aluminium content

    International Nuclear Information System (INIS)

    Hillairet, J.; Delaplace, J.; Silvent, A.

    1966-01-01

    By using a torsion pendulum to measure the internal friction of iron-aluminium alloys containing between 25 and 50 atom per cent of aluminium, it has been possible to show the existence of three damping peaks due to interstitial carbon. Their evolution is followed as a function of the carbon content, of the thermal treatment and of the aluminium content. A model based on the preferential occupation of tetrahedral sites is proposed as an interpretation of the results. A study of the Zener peak in these substitution alloys shows also that a part of the short distance disorder existing at high temperatures can be preserved by quenching. (author) [fr

  1. Process for fabricating articles of tungsten-nickel-iron alloy

    Science.gov (United States)

    Northcutt, Jr., Walter G.; Snyder, Jr., William B.

    1976-01-01

    A high density W--Ni--Fe alloy of composition 85-96% by weight W and the remainder Ni and Fe in a wt. ratio of 5:5-8:2 having enhanced mechanical properties is prepared by compacting the mixed powders, sintering the compact in reducing atmosphere to near theoretical density followed by further sintering at a temperature where a liquid phase is present, vacuum annealing, and cold working to achieve high uniform hardness.

  2. Thermal behaviour in dynamic recrystallisation. Application for iron base alloys

    International Nuclear Information System (INIS)

    Belkebir, A.; Kobylanski, A.

    1995-01-01

    A constitutive relationship for predicting the flow stress with dynamic recrystallization were proposed. The approach is based on a phenomenological formalism of the law θ-ε where θ correspond to the work-hardening rate at constant strain rate and temperature. The equations proposed were justified by the experimental data collected by hot compression test of low-alloy steels. The model can be used to estimate the critical strain for the onset of dynamic recrystallization. (orig.)

  3. Process for fabricating articles of tungsten--nickel--iron alloy

    International Nuclear Information System (INIS)

    Northcutt, W.G. Jr.; Snyder, W.B. Jr.

    1976-01-01

    A high density W--Ni--Fe alloy of composition 85 to 96 percent by weight W and the remainder Ni and Fe in a wt. ratio of 5:5 to 8:2 having enhanced mechanical properties is prepared by compacting the mixed powders, sintering the compact in reducing atmosphere to near theoretical density followed by further sintering at a temperature where a liquid phase is present, vacuum annealing, and cold working to achieve high uniform hardness. 7 claims

  4. Spectrophotometric determination of phosphorus in iron alloys employing a flow injection system

    OpenAIRE

    Gervasio,Ana P. G.; Miranda,Carlos E. S.; Luca,Gilmara C.; Tumang,Cristiane A.; Campos,Luis F. P.; Reis,Boaventura F.

    2001-01-01

    A flow-injection procedure for spectrophotometric determination of phosphorus in electrolytic iron and iron alloys is proposed. The method is based on the ammonium molybdate reaction followed by stannous chloride reduction in acidic medium. In order to circumvent the severe interference caused by the major constituents such as Fe(III) and Cr(III), a mini-column packed with AG50W-X8 resin was coupled to the manifold. A sample throughput of 40 determinations per hour, a dynamical range from P 0...

  5. Transmission electron microscopy characterization of laser-clad iron-based alloy on Al-Si alloy

    International Nuclear Information System (INIS)

    Mei, Z.; Wang, W.Y.; Wang, A.H.

    2006-01-01

    Microstructure characterization is important for controlling the quality of laser cladding. In the present work, a detailed microstructure characterization by transmission electron microscopy was carried out on the iron-based alloy laser-clad on Al-Si alloy and an unambiguous identification of phases in the coating was accomplished. It was found that there is austenite, Cr 7 C 3 and Cr 23 C 6 in the clad region; α-Al, NiAl 3 , Fe 2 Al 5 and FeAl 2 in the interface region; and α-Al and silicon in the heat-affected region. A brief discussion was given for their existence based on both kinetic and thermodynamic principles

  6. Equation for calculation of nitrogen solubility in iron alloys

    International Nuclear Information System (INIS)

    Pomarin, Yu.M.; Grigorenko, G.M.

    1989-01-01

    Equation for calculating nitrogen solubility in multicomponent iron melts in a wide range of partial pressures (1-1600 kPa), of doping component concentrations and temperatures (1773-2373 K) is proposed. Comparative analysis of experimental and calculated values of nitrogen solubility has demonstrated a principle possibility of applying the equation proposed for evaluating absorption ability to nitrogen of industrial nitrogen containing steels and ferroalloys subjected to melting or remelting in plasma or other melting devices

  7. Nanocrystalline Iron-Cobalt Alloys for High Saturation Indutance

    Science.gov (United States)

    2016-02-24

    film deposited just like the pick-up of a turn-table music player. The contact pads provide the electrical contacts to the starting and end point of...anisotropy using the geometry of the thin toroid. We have shown experimentally that the thin film toroid calculations may be applicable to up to millimeter...thin film as well as bulk devices. 15. SUBJECT TERMS Micromagnetic Calculations, Nanocrystalline cobalt-iron, Thin Film Toroids 16. SECURITY

  8. Precipitation hardenable iron-nickel-chromium alloy having good swelling resistance and low neutron absorbence

    International Nuclear Information System (INIS)

    Korenko, M.K.; Merrick, H.F.; Gibson, R.C.

    1982-01-01

    An iron-nickel-chromium age-hardenable alloy suitable for use in fast breeder reactor ducts and cladding utilizes the gamma-double prime strengthening phase and has a morphology of the gamma-double prime phase enveloping the gamma-prime phase and delta phase distributed at or near the grain boundaries. The alloy consists essentially of about 40-50 percent nickel, 7.5-14 percent chromium, 1.5-4 percent niobium, .25-.75 percent silicon, 1-3 percent titanium, .1-.5 percent aluminum, .02-1 percent carbon, .002-.015 percent boron, and the balance iron. Up to 2 percent manganese and up to .01 percent magnesium may be added to inhibit trace element effects; up to .1 percent zirconium may be added to increase radiation swelling resistance; and up to 3 percent molybdenum may be added to increase strength

  9. Effect of chromium and phosphorus on the physical properties of iron and titanium-based amorphous metallic alloy films

    Science.gov (United States)

    Distefano, S.; Rameshan, R.; Fitzgerald, D. J.

    1991-01-01

    Amorphous iron and titanium-based alloys containing various amounts of chromium, phosphorus, and boron exhibit high corrosion resistance. Some physical properties of Fe and Ti-based metallic alloy films deposited on a glass substrate by a dc-magnetron sputtering technique are reported. The films were characterized using differential scanning calorimetry, stress analysis, SEM, XRD, SIMS, electron microprobe, and potentiodynamic polarization techniques.

  10. Comparison of low cycle fatigue of ductile cast irons with different matrix alloyed with nickel

    Czech Academy of Sciences Publication Activity Database

    Petrenec, Martin; Tesařová, H.; Beran, Přemysl; Šmíd, Miroslav; Roupcová, Pavla

    2010-01-01

    Roč. 2, č. 1 (2010), s. 2307-2316 E-ISSN 1877-7058. [ Fatigue 2010. Praha, 06.06.2010-11.06.2010] R&D Projects: GA ČR GAP108/10/2371 Institutional research plan: CEZ:AV0Z20410507; CEZ:AV0Z10480505 Keywords : Low cycle fatigue * ferritic ductile cast iron * ADI * nickel alloying * neutron diffraction Subject RIV: JL - Materials Fatigue , Friction Mechanics

  11. Electroerosion formation and technology of cast iron coatings on aluminum alloys

    Directory of Open Access Journals (Sweden)

    Smolentsev Vladislav P.

    2017-01-01

    Full Text Available At present in the course of designing basic production parts and industrial equipment designers pay more and more attention to aluminum alloys having a number of properties compared favorably with other materials. In particular, technological aluminum tool electrodes without coating in the presence of products of processing with alkali in the composition of operation environment are being destroyed at the expense of intensified material dissolution. It is shown in the paper that the method offered by the authors and covered by the patents on cast iron coating of products made of aluminum alloys, allows obtaining on a product surface the layers with high adhesion durability ensuring a high protection against destruction in the friction units including operation in hostile environment. Thereupon, aluminum, as compared with iron-based alloys used at manufacturing technological equipment for electrical methods of processing, has a high electrical and thermal conduction, its application will allow achieving considerable energy-saving in the course of parts production. A procedure for the design of a technological process of qualitative cast iron coatings upon aluminum tool electrodes and parts of basic production used in different branches of mechanical engineering is developed.

  12. Anodic behaviours, dissolution and passivation of iron-nickel alloys in sulphuric environment. Influence of friction

    International Nuclear Information System (INIS)

    Ponthiaux, Pierre

    1990-01-01

    This research thesis reports the study of anodic dissolution and passivation of iron-nickel alloys (10, 20 and 31 pc nickel) in a sulphuric environment, with or without friction, by using anodic polarization curves. Without friction, the three alloys have a similar behaviour as pure iron. The analysis reveals different dissolution and passivation mechanisms with pure iron, and highlights the influence of nickel content on corresponding kinetics. The influence of cyclic plane-on-plane friction has been studied for the 31 pc nickel alloy which has an unsteady austenitic structure. Fretting results in some modifications of polarization curves. These modifications are analysed with respect to fretting parameters (relative speed of antagonist surfaces, contact pressure). They reveal the specific influence of the following phenomena: material strain hardening, martensitic transformation induced by strain hardening, partial destruction of adsorbates and/or of the passive film. Modifications of polarization curves give also information on the evolution of friction characteristics with respect to speed (a phenomenon of lubrication by the electrolyte occurs) [fr

  13. Effect of cerium addition on the corrosion behaviour of carbon-alloyed iron aluminides

    International Nuclear Information System (INIS)

    Sriram, S.; Balasubramaniam, R.; Mungole, M.N.; Bharagava, S.; Baligidad, R.G.

    2006-01-01

    The effect of Ce addition on the microstructure and corrosion behavior of carbon-alloyed iron aluminides Fe-20.0Al-2.0C, Fe-18.5Al-3.6C and Fe-19.2Al-3.3C-0.07Ce (in at.%) has been studied. The potentiodynamic polarization behaviour of the alloys was evaluated in freely aerated 0.25 mol/l H 2 SO 4 . A 0.05% C steel was used for comparison purposes. All the alloys exhibited active-passive behaviour in the acidic solution. The addition of Ce destroyed passivity as indicated by lower breakdown potentials in polarization studies. This has been related to the finer distribution of the carbides in the microstructure. Corrosion rates were evaluated by immersion testing. The iron aluminide with Ce addition exhibited a lower corrosion rate compared to the aluminides without Ce addition. This has been attributed to modifications in surface film with Ce addition. Scanning electron microscopy of corroded surfaces indicated that the carbon-alloyed intermetallics were susceptible to localized galvanic corrosion due to the presence of carbides in the microstructure

  14. Aluminium alloys containing iron and nickel; Alliages d'aluminium contenant du fer et du nickel

    Energy Technology Data Exchange (ETDEWEB)

    Coriou, H.; Fournier, R.; Grall, L.; Hure, J. [Commissariat a l' Energie atomique, Centre d' Etudes Nucleaires de Saclay, Departement de Metallurgie et de Chimie Appliquee (France); Herenguel, J.; Lelong, P. [Centre de Recherches d' Antony, des Trefileries et Laminoirs du Havre (France)

    1958-07-01

    The first part of this report addresses mechanism, kinetics and structure factors of aluminium alloys containing iron and nickel in water and high temperature steam. The studied alloys contain from 0.3 to 0.7 per cent of iron, and 0.2 to 1.0 per cent of nickel. Corrosion resistance and corrosion structure have been studied. The experimental installation, process and samples are presented. Corrosion structures in water at 350 C are identified and discussed (structure of corrosion products, structure of metal-oxide interface), and then in steam at different temperatures (350-395 C). Corrosion kinetics is experimentally studied (weight variation in time) in water at 350 C and in steam at different temperatures. Reactions occurring at over-heated steam (more than 400 C) are studied, and the case of welded alloys is also addressed. The second part addresses the metallurgical mechanism and processes influencing aluminium alloy resistance to corrosion by high temperature water as it appeared that separated phases protect the solid solution through a neighbourhood action. In order to avoid deep local corrosions, it seems necessary to multiply protective phases in an as uniform as possible way. Some processes enabling this result are described. They belong to conventional metallurgy or to powder metallurgy (with sintering and extrusion)

  15. Corrosion modelling of iron based alloy in nuclear waste repository

    Energy Technology Data Exchange (ETDEWEB)

    Bataillon, C., E-mail: christian.bataillon@cea.f [CEA, DEN, DPC, SCCME, F-91191 Gif sur Yvette (France); Bouchon, F.; Chainais-Hillairet, C. [Clermont Universite, Universite Blaise Pascal, Laboratoire de Mathematiques, BP10448, F-63000 Clermont-Ferrand (France); CNRS, UMR 6620, Laboratoire de Mathematiques, F-63177 Aubiere (France); Desgranges, C. [CEA, DEN, DPC, SCCME, F-91191 Gif sur Yvette (France); Hoarau, E. [ANDRA/DS, 92298 Chatenay-Malabry Cedex (France); Martin, F.; Perrin, S. [CEA, DEN, DPC, SCCME, F-91191 Gif sur Yvette (France); Tupin, M. [CEA, DEN, DMN, SEMI, LM2E, F-91191 Gif sur Yvette (France); Talandier, J. [ANDRA/DS, 92298 Chatenay-Malabry Cedex (France)

    2010-06-01

    The Diffusion Poisson Coupled Model (DPCM) is presented to modelling the oxidation of a metal covered by an oxide layer. This model is similar to the Point Defect Model and the Mixed Conduction Model except for the potential profile which is not assumed but calculated in solving the Poisson equation. This modelling considers the motions of two moving interfaces linked through the ratio of Pilling-Bedworth. Their locations are unknowns of the model. Application to the case of iron in neutral or slightly basic solution is discussed. Then, DPCM has been first tested in a simplified situation where the locations of interfaces were fixed. In such a situation, DPCM is in agreement with Mott-Schottky model when iron concentration profile is homogeneous. When it is not homogeneous, deviation from Mott-Schottky model has been observed and is discussed. The influence of the outer and inner interfacial structures on the kinetics of electrochemical reactions is illustrated and discussed. Finally, simulations for the oxide layer growth are presented. The expected trends have been obtained. The steady-state thickness is a linear function of the applied potential and the steady-state current density is potential independent.

  16. Transmission electron microscope study of fusion-environment radiation damage in iron and iron-chromium alloys

    Energy Technology Data Exchange (ETDEWEB)

    Horton, L.L.S.

    1982-07-01

    A transmission electron microscopy study of radiation damage microstructures in iron and iron-chromium alloys has been performed. This study consisted of both qualitative and quantitative characterization of the dislocation and cavity microstructures, including determination of vacancy/interstitial character and Burgers vectors for dislocation loops and analysis of the cavity morphology. The effects of irradiation temperature, fluence, helium implantation, and chromium content were investigated. Neutron irradiation (iron specimens, 1 dpa, 455 to 1000 K) and triple-beam ion irradiation (Fe-10% Cr specimens, 10 dpa, 725 to 950 K; Fe-10% Cr specimens, 850 K, 0.3 to 100 dpa; and Fe, Fe-5% Cr, Fe-10% Cr specimens, 850 K, 10 dpa) were employed. In the triple-beam ion irradiation procedure, simultaneous bombardment with 4 MeV Fe/sup + +/ ions and energetic He/sup +/ and D/sub 2//sup +/ ions was used to simulate the fusion environment (10 at. ppM He/dpa and 41 at. ppM D/dpa). In addition, single-beam 4 MeV Fe/sup + +/ ion irradiations of Fe-10% Cr both with and without pre-injection of helium and deuterium were performed.

  17. Transmission electron microscope study of fusion-environment radiation damage in iron and iron-chromium alloys

    International Nuclear Information System (INIS)

    Horton, L.L.S.

    1982-07-01

    A transmission electron microscopy study of radiation damage microstructures in iron and iron-chromium alloys has been performed. This study consisted of both qualitative and quantitative characterization of the dislocation and cavity microstructures, including determination of vacancy/interstitial character and Burgers vectors for dislocation loops and analysis of the cavity morphology. The effects of irradiation temperature, fluence, helium implantation, and chromium content were investigated. Neutron irradiation (iron specimens, 1 dpa, 455 to 1000 K) and triple-beam ion irradiation (Fe-10% Cr specimens, 10 dpa, 725 to 950 K; Fe-10% Cr specimens, 850 K, 0.3 to 100 dpa; and Fe, Fe-5% Cr, Fe-10% Cr specimens, 850 K, 10 dpa) were employed. In the triple-beam ion irradiation procedure, simultaneous bombardment with 4 MeV Fe ++ ions and energetic He + and D 2 + ions was used to simulate the fusion environment (10 at. ppM He/dpa and 41 at. ppM D/dpa). In addition, single-beam 4 MeV Fe ++ ion irradiations of Fe-10% Cr both with and without pre-injection of helium and deuterium were performed

  18. Dry sliding wear of Ni alloyed austempered ductile iron

    Directory of Open Access Journals (Sweden)

    E. Akbarzadeh Chiniforush

    2016-09-01

    Full Text Available Measurements of dry sliding wear are presented for ductile irons with composition Fe-3.56C-2.67Si-0.25Mo-0.5Cu and Ni contents of 0.8 and 1.5 in wt.% with applied loads of 50, 100 and 150 N for austempering temperatures of 270, 320, and 370 °C after austenitizing at 870 °C for 120 min. The mechanical property measurements show that the grades of the ASTM 897M: 1990 Standard can be satisfied for the selected austempering conditions. The results show that wear resistance is independent of austempering temperature with an applied load of 50 N, but there is a strong dependence at higher austempering temperatures with applied loads of 100 and 150 N. Observations indicate that wear is due to subsurface fatigue with cracks nucleated at deformed graphite nodules.

  19. B2-ordered iron-aluminium alloys strengthening. Influence of additions (Ni and B) and microstructure

    International Nuclear Information System (INIS)

    Colas, David

    2004-01-01

    We study the effects of additions (Ni and B) and microstructure on the mechanical behaviour of 40 at. % Al iron-aluminium alloys. From a macroscopic point of view, we show that nickel reinforces FeAl alloys over the whole temperature range, but that it simultaneously leads to emphasize the room temperature brittleness of these alloys through a cleavage stress decrease. We confirm powder metallurgy grain refining interest to enhance yield stress as well as fracture resistance. We show that nickel-induced yield stress effect is additive to 'Hall-Petch' one. Also, we point out that the strengthening phenomena (nickel or grain size) cause the yield stress anomaly, which these alloys usually present, to be hidden. Through a dislocation structures analysis of deformed materials we precise that low temperature nickel-induced solid solution hardening (SSH) cannot be explained on the basis of classical SSH theories but more probably through nickel influence upon the Peierls stress. Moreover, we show that the APB tubes dragging model may be compatible with our microscopic and macroscopic results about the anomaly. Eventually, we put into relation a dynamic super-dislocations multiplication process observation (in situ transmission microscopy) with the nickel-containing alloys tendency to cleavage. (author) [fr

  20. Characteristics of Iron-Palladium alloy thin films deposited by magnetron sputtering

    Science.gov (United States)

    Chiu, Y.-J.; Shen, C.-Y.; Chang, H.-W.; Jian, S.-R.

    2018-06-01

    The microstructural features, magnetic, nanomechanical properties and wettability behaviors of Iron-Palladium (FePd) alloy thin films are investigated by using X-ray diffraction (XRD), atomic force microscopy (AFM), vibrating sample magnetometer (VSM), nanoindentation and water contact angle (CA) techniques, respectively. The FePd alloy thin films were deposited on glass substrates using a magnetron sputtering system. The post-annealing processes of FePd alloy thin films were carried out at 400 °C and 750 °C and resulted in a significant increase of both the average grain size and surface roughness. The XRD analysis showed that FePd alloy thin films exhibited a predominant (1 1 1) orientation. The magnetic field dependence of magnetization of all FePd thin films are measured at room temperature showed the ferromagnetic characteristics. The nanoindentation with continuous stiffness measurement (CSM) is used to measure the hardness and Young's modulus of present films. The contact angle (θCA) increased with increasing surface roughness. The maximum θCA of 75° was achieved for the FePd alloy thin film after annealing at 750 °C and a surface roughness of 4.2 nm.

  1. Segregation and precipitation in iron-chromium alloys during thermal ageing and irradiation

    International Nuclear Information System (INIS)

    Senninger, O.

    2013-01-01

    Iron-Chromium alloys have a peculiar thermodynamic and diffusion behavior which is due to their magnetic properties. The alloy decomposition under thermal ageing has been studied in this thesis. An atomistic kinetic model has been performed in this aim in which we have modeled in details the chemical species thermodynamic and diffusion properties. In particular, the evolution of elements diffusion properties which the ferro-paramagnetic transition has been introduced in the model. Simulated decompositions have been compared with experiments for a large range of concentrations and temperatures. A good agreement between simulations and experiments was observed and these comparisons have highlighted the ferro to paramagnetic transition key role in the concentrated alloys kinetic decomposition. This study has also evidenced that the elements diffusion at phases interfaces is responsible for the alloy decomposition kinetic in long lasting.We have also started a study of the alloy radiation induced segregation. For that purpose, atomistic kinetic model has been performed modeling defects migration through a perfect planar sink. It have been shown, I agreement with former studies, that chromium tends to segregate in the vicinity of sinks at low temperatures and deplete at high temperature. (author) [fr

  2. EFFECT OF ALLOYING ON TEMPERATURE OF TRANSFORMATION «PEARLITE – AUSTENITE» IN COMPLEX-ALLOYED WHITE CAST IRONS

    Directory of Open Access Journals (Sweden)

    T. V. Pastukhova

    2014-11-01

    Full Text Available Purpose. Pearlite is not accepted in the microstructure of wear resistant steels and cast irons. To prevent the pearlite by means of appropriate selection of mode of quenching requires the knowledge of the temperature of the critical points Ac1 and Ac3 for various steels and cast irons. Purpose of work is determine the effect of V (5-10% and Cr (up to 9% on the temperature range of the phase-structural transformation "pearlite®austenite in the complex-alloyed V-Cr-Mn-Ni white cast irons with spheroidal vanadium carbides. Methodology. Nine Mg-treated cast irons smelted in laboratory furnace were used for investigation. The metallographic and optical dilatometric analysis methods as well as energy-dispersive spectroscopy were used. Findings. It is shown that in irons studied the critical point Ac1 is in a temperature range from 710-780 °C (lower limit up to 730-850 °C (upper limit. The data on the concentrations of chromium and vanadium in a matrix of iron are presented, the regression equation describing the effect of vanadium and chromium on the temperature limits of the transformation «pearlite ® austenite» are obtained. Originality. It is shown that increase the chromium content leads to growth of lower and upper limits of the temperature interval of transformation "pearlite ® austenite"; vanadium increases only the upper limit of the range. It was found that the effect of chromium on the critical point Ac1 is attributed to its solubility in the metallic matrix (concentration of Cr in the austenite reaches 7%; vanadium, due to its slight dissolution in the matrix (vanadium content does not exceed 1.75%, affects the critical point indirectly by increasing of chromium concentration in the matrix due to enhanced carbon sequestration in VC carbides. Practical value. The temperature ranges of heating for quenching of V-Cr-Mn-Ni cast irons with spheroidal vanadium carbides, which provides the formation of austenitic-martensitic matrix without

  3. Preparation of hard magnetic materials based on nitrogenated rare-earth iron alloys

    International Nuclear Information System (INIS)

    Guilherme, Eneida da Graca

    1999-01-01

    Nd Fe 11 Ti, Nd Fe 10.5 Mo 1.5 and Nd Fe 10.75 Mo 1.25 alloys were synthesized by reduction-diffusion calciothermic process (RDC) from neodymium chloride (NdCl 3 ), iron, titanium, molybdenum and reduction agent (metallic calcium). The effect of process variables, like temperature, time, excess amount of NdCl 3 , heating rate, and composition variation of the Nd Fe 12-x Mo x (1 ≥ x ≥ 2). Mother alloys in which 1:12 phase is major were nitrogenated by gas-solid reaction with N 2 and by chemical reaction with sodium zide (Na N 3 ). In addition, the influence of reducing particle size of the powdered mother alloys in the nitrogenation step with Na N 3 were studied. As prepared and interstitially modified Nd Fe 11 Ti, Nd Fe 10.5 Mo 1.5 and Nd Fe 10.75 Mo 1.25 alloys with nitrogen , were characterized by X-ray diffraction, Moessbauer spectroscopy, thermomagnetic, SEM and EDS. Nitrogenation by gas-solid reaction with N 2 is found to be not promising, since resulted Curie temperatures (Tc) were lower than literature values. However, nitrogenation by chemical reaction with Na N 3 was efficient with higher or same Tc than previous reported results. The average increases on Tc and volumetric expansion were 200 deg C and 4%, respectively. Milling of the mother alloys before nitrogenation at 330 deg C is preferred because reaction kinetics is enhanced. Nevertheless, at 450 deg C, a competition between the interstitially modified compound formation (alloy + N) and alloy dissociation has occurred, resulting in a Fe-α phase increase. (author)

  4. Self-assembled Targeting of Cancer Cells by Iron(III)-doped, Silica Nanoparticles

    OpenAIRE

    Mitchell, K.K. Pohaku; Sandoval, S.; Cortes-Mateos, M. J.; Alfaro, J.G.; Kummel, A. C.; Trogler, W.C.

    2014-01-01

    Iron(III)-doped silica nanoshells are shown to possess an in vitro cell-receptor mediated targeting functionality for endocytosis. Compared to plain silica nanoparticles, iron enriched ones are shown to be target-specific, a property that makes them potentially better vehicles for applications, such as drug delivery and tumor imaging, by making them more selective and thereby reducing the nanoparticle dose. Iron(III) in the nanoshells can interact with endogenous transferrin, a serum protein ...

  5. Hydrogen solubility in iron, platinum and their alloys under pressure up to 67 kbars

    International Nuclear Information System (INIS)

    Belash, I.T.; Antonov, V.E.; Ponyatovskij, E.G.

    1979-01-01

    The solubility of hydrogen was studied in iron, nickel and Fe-Pt-H alloy at a high pressure. It was shown that at T=250 deg C and psub(Hsub(2))=67 kbar, the solubility hy of hydrogen in α-iron and platinum is below the sensitivity threshold of the employed method of chemical analysis, deltasub(n) approximately 0.05 (n - atomic ratio hydrogen metal). At this pressure and at a temperature of T=150 deg C, the equilibrium concentration of hydrogen in non-ordered Fe-Pt alloys with a FCC lattice, containing 25 and 32 at. % Pt, attains, respectively, n = (5+-2)x10 -2 and (2+-5)x10 -2 . Ordering of the alloy with 25 at. % Pt produces no substantial change in the solubility of hydrogen. In a hydrogen atmosphere, the dependence of the Curie point Tsub(c)(psub(Hsub(2)) deviates from Tsub(c)(p). In an inert medium, at p=67 kbar, ΔTsub(c)=Tsub(c)(psub(Hsub(2)) - Tsub(c)(p) = 35+-10 deg C

  6. Microstructural evolution of ferritic steel powder during mechanical alloying with iron oxide

    Energy Technology Data Exchange (ETDEWEB)

    Wen, Yuren; Liu, Yong; Liu, Donghua; Tang, Bei [Central South Univ., State Key Lab. of Powder Metallurgy, Changsha (China); Liu, C.T. [The Hong Kong Polytechnic Univ., Dept. of Mechanical Engineering, Hong Kong (China)

    2011-02-15

    Mechanical alloying of mixed powders is of great importance for preparing oxide dispersion strengthened ferritic steels. In this study, the microstructural evolution of ferritic steel powder mixed with TiH{sub x}, YH{sub 2} and Fe{sub 2}O{sub 3} in the process of mechanical alloying is systematically investigated by using X-ray diffraction analysis, scanning electron microscopy, transmission electron microscopy and microhardness tests. It is found that titanium, yttrium hydrides and iron oxide are completely dissolved during milling, and homogeneous element distribution can be achieved after milling for 12 h. The disintegration of the composite powder particles occurs at 24 h and reaches the balance of welding and fracturing after 36 h. The oxygen content increases sharply with the disintegration of powder particles due to the absorption of oxygen at the solid/gas interface from the milling atmosphere, which is the main source of extra oxygen in the milled powder. Grain refinement down to nanometer level occurs due to the severe plastic deformation of particles; however, the grain size does not change much with further disintegration of particles. The hardness increases with milling time and then becomes stable during further milling. The study indicates that the addition of iron oxide and hydrides may be more beneficial for the dispersion and homogenization of chemical compositions in the powder mixture, thus shortening the mechanical alloying process. (orig.)

  7. Effect of alloying elements on solidification of primary austenite in Ni-Mn-Cu cast iron

    Directory of Open Access Journals (Sweden)

    A. Janus

    2011-04-01

    Full Text Available Within the research, determined were direction and intensity of alloying elements influence on solidification way (directional orvolumetric of primary austenite dendrites in hypoeutectic austenitic cast iron Ni-Mn-Cu. 50 cast shafts dia. 20 mm were analysed.Chemical composition of the alloy was as follows: 1.7 to 3.3 % C, 1.4 to 3.1 % Si, 2.8 to 9.9 % Ni, 0.4 to 7.7 % Mn, 0 to 4.6 % Cu, 0.14 to0.16 % P and 0.03 to 0.04 % S. The discriminant analysis revealed that carbon influences solidification of primary austenite dendrites most intensively. It clearly increases the tendency to volumetric solidification. Influence of the other elements is much weaker. This means that the solidification way of primary austenite dendrites in hypoeutectic austenitic cast iron Ni-Mn-Cu does not differ from that in an unalloyed cast iron.

  8. Iron -chromium alloys and free surfaces: from ab initio calculations to thermodynamic modeling

    International Nuclear Information System (INIS)

    Levesque, M.

    2010-11-01

    Ferritic steels possibly strengthened by oxide dispersion are candidates as structural materials for generation IV and fusion nuclear reactors. Their use is limited by incomplete knowledge of the iron-chromium phase diagram at low temperatures and of the phenomena inducing preferential segregation of one element at grain boundaries or at surfaces. In this context, this work contributes to the multi-scale study of the model iron-chromium alloy and their free surfaces by numerical simulations. This study begins with ab initio calculations of properties related to the mixture of atoms of iron and chromium. We highlight complex dependency of the magnetic moments of the chromium atoms on their local chemical environment. Surface properties are also proving sensitive to magnetism. This is the case of impurity segregation of chromium in iron and of their interactions near the surface. In a second step, we construct a simple energy model for high numerical efficiency. It is based on pair interactions on a rigid lattice to which are given local chemical environment and temperature dependencies. With this model, we reproduce the ab initio results at zero temperature and experimental results at high temperature. We also deduce the solubility limits at all intermediate temperatures with mean field approximations that we compare to Monte Carlo simulations. The last step of our work is to introduce free surfaces in our model. We then study the effect of ab initio calculated bulk and surface properties on surface segregation.Finally, we calculate segregation isotherms. We therefore propose an evolution model of surface composition of iron-chromium alloys as a function of bulk composition. which are given local chemical environment and temperature dependencies. With this model, we reproduce the ab initio results at zero temperature and experimental results at high temperature. We also deduce the solubility limits at all intermediate temperatures with mean field approximations that

  9. First-principles investigations of iron-based alloys and their properties

    Science.gov (United States)

    Limmer, Krista Renee

    Fundamental understanding of the complex interactions governing structure-property relationships in iron-based alloys is necessary to advance ferrous metallurgy. Two key components of alloy design are carbide formation and stabilization and controlling the active deformation mechanism. Following a first-principles methodology, understanding on the electronic level of these components has been gained for predictive modeling of alloys. Transition metal carbides have long played an important role in alloy design, though the complexity of their interactions with the ferrous matrix is not well understood. Bulk, surface, and interface properties of vanadium carbide, VCx, were calculated to provide insight for the carbide formation and stability. Carbon vacancy defects are shown to stabilize the bulk carbide due to increased V-V bonding in addition to localized increased V-C bond strength. The VCx (100) surface energy is minimized when carbon vacancies are at least two layers from the surface. Further, the Fe/VC interface is stabilized through maintaining stoichiometry at the Fe/VC interface. Intrinsic and unstable stacking fault energy, gammaisf and gamma usf respectively, were explicitly calculated in nonmagnetic fcc Fe-X systems for X = Al, Si, P, S, and the 3d and 4d transition elements. A parabolic relationship is observed in gamma isf across the transition metals with minimums observed for Mn and Tc in the 3d and 4d periods, respectively. Mn is the only alloying addition that was shown to decrease gamma isf in fcc Fe at the given concentration. The effect of alloying on gammausf also has a parabolic relationship, with all additions decreasing gammaisf yielding maximums for Fe and Rh.

  10. High temperature Moessbauer study of order-disorder transformation in iron-aluminum alloys

    International Nuclear Information System (INIS)

    Oki, Kensuke; Yamamura, Akihiko; Kudo, Kazunao; Eguchi, Tetsuo

    1979-01-01

    Ordering process of iron rich Fe-Al alloys has been investigated at elevated temperatures by mean of Moessbauer spectroscopy. The observed spectra are analyzed to obtain the temperature dependences of the internal field, isomer shift and line width, and the results are discussed in connection with the ordering process. The alloy with 24.7 at% Al exhibits spectra, which are characteristic of the superposition of a single-line spectrum and a six-line one, originating from the ordered paramagnetic B2 or DO 3 state and disordered ferromagnetic α, respectively, and the results confirm the coexistence of α phase with B2 or DO 3 . The isomer shift of the paramagnetic component of the spectra shows discontinuous changes at the temperatures of transformation α reversible B2 and B2 reversible DO 3 . (author)

  11. Estimation of the effect of molybdenum on chemical and electrochemical stability of iron-based alloys

    International Nuclear Information System (INIS)

    Tyurin, A.G.

    2003-01-01

    The E-pH diagram for Mo-H 2 O system is made more precise. It is shown that a passivating film on molybdenum in weakly acid, neutral and alkali solutions may constitute MoO 2 only. In strongly acid solutions at anodic polarization the film should transform according to the following scheme: MoO 2 → Mo 4 O 11 → Mo 9 O 26 → MoO 3 . Sections of a Fe-Mo-O system phase diagram and a Fe-Mo-H 2 O system E-pH diagram at 25 deg C are plotted. MoO 2 is found to be a product of iron-molybdenum alloy oxidation in the air and in water. For the system of alloy Kh17N13M2-H 2 O the section of a E-pH diagram is plotted at 25 deg C [ru

  12. Corrosion-resistant amorphous alloy ribbons for electromagnetic filtration of iron rusts from water

    International Nuclear Information System (INIS)

    Kawashima, Asahi; Asami, Katsuhiko; Sato, Takeaki; Hashimoto, Koji

    1985-01-01

    An attempt was made to use corrosion-resistant amorphous Fe-9Cr-13P-7C alloy ribbons as an electromagnetic filter material for trapping various iron rusts suspended in water at 40 0 C. The ferrimagnetic Fe 3 O 4 rust was trapped with the 100 % efficiency and paramagnetic rusts such as α-Fe 2 O 3 , α-FeOOH and amorphous ferric oxyhydroxide were trapped with certain efficiencies at the magnetic field strength of 0.5-10 kOe. The regeneration of the filter by back-washing was easy. The trapping capacity of electromagnetic filter was proportional to the edge length of the filter material where the high magnetic field strength existed. Therefore, melt-spun thin and narrow amorphous alloy ribbons having the high corrosion resistance have the potential utility as electromagnetic filter material. (author)

  13. Role of samarium additions on the shape memory behavior of iron based alloys

    International Nuclear Information System (INIS)

    Shakoor, R.A.; Khalid, F. Ahmad; Kang, Kisuk

    2011-01-01

    Research highlights: → The effect of samarium contents on shape memory behavior has been studied. → Addition of samarium increases the strength, c/a ratio and ε (hcp martensite). → Addition of samarium retards the nucleation of α (bcc martensite). → Improvement in shape memory effect with the increase in samarium contents. - Abstract: The effect of samarium contents on shape memory behavior of iron based shape memory alloys has been studied. It is found that the strength of the alloys increases with the increase in samarium contents. This effect can be attributed to the solid solution strengthening of austenite by samarium addition. It is also noticed that the shape memory effect increases with the increase in samarium contents. This improvement in shape memory effect presumably can be regarded as the effect of improvement in strength, increase in c/a ratio and obstruction of nucleation of α in the microstructure.

  14. Development of the white cast iron with niobium alloy, heat treating, to wear of the abrasive resistance

    International Nuclear Information System (INIS)

    Farah, Alessandro Fraga

    1997-01-01

    This work presents the heat treatment and abrasion tests results of a white cast iron with niobium alloy. The hardening heat treatment were made 950, 1000, 1050 e 110 deg C temperatures cooled by forced air. The tempering treatment were made at 450, 500 e 550 deg C temperatures. The heat treating alloy were compared, in the abrasive tests, with commercial alloys used as hardfacing by welding process in wear pieces. The abrasion tests was realized in pin on disk test. Additional tests were carried out for microstructural characterization to identify the different phases presents in the alloys. In a general way, the alloy studies showed the best wear rate for the heat treatments that results in higher hardness. It performance was superior than that of the commercial alloys. (author)

  15. Evolution of Iron-containing Compounds in Al-Cu Alloys during Heat Treatment

    Directory of Open Access Journals (Sweden)

    Liu Kun

    2016-01-01

    Full Text Available The evolution of iron-containing compounds in Al-Cu 206 cast alloy during solution treatment has been investigated. Results show that platelet β-Fe and Chinese script α-Fe are the two iron-containing compounds in as-cast condition. Little change is observed on β-Fe during solution treatment. However, fine blocky post β-Fe begins to form on α-Fe when solution treated at 520°C for 8hrs. When soaking time is extended to 24 hrs, α–Fe is found to decompose to fine branches while post β-Fe present as clusters on these branches. Al-Cu-Mg-Si Q phase is observed to form at the edge of decomposed α-Fe, possibly the result of Si from decomposed α-Fe.

  16. Anxiety and ironic effects in aiming at a far target

    NARCIS (Netherlands)

    Bakker, F.C.; Binsch, O.

    2011-01-01

    In far aiming the negative intention not to miss may ironically increase the tendency to do precisely that. Although cognitive constraints enhance the occurrence of ironic effects in the perceptual-motor domain the role of anxiety in inducing such effects has rarely been investigated while anxiety

  17. Investigation into iron moessbauer atom state in a deformed iron-manganese alloys

    International Nuclear Information System (INIS)

    Mints, R.I.; Semenkin, V.A.; Shevchenko, Yu.A.

    1977-01-01

    A plastically deformed Fe + 12 at. %. Mn alloy was investigated by the method of nuclear gamma-resonance on Fe 57 nuclei. The specimens were deformed by 5 to 57 %. The obtained nuclear gamma-resonance spectra, which are a superposition of the paramagnetic single line (ν-phase) and the Zeeman splitting line (α-phase), were statistically processed with the aid of a computer. The behaviour of the values of Moessbauer parameters possessing a least dispersion, such as isomer chemical shift, quadrupolar reaction constant, effectiveness of magnetic field and of area of the nuclear gamma-resonance spectrum, points to their connection with the degree of the deformation disintegration of the initial solid solution

  18. Properties of grain boundaries in BCC iron and iron-based alloys

    International Nuclear Information System (INIS)

    Terentyev, D.; He, Xinfu

    2010-01-01

    The report contains a summary of work done within the collaboration established between SCK-CEN and CIEA, performed during the internship of Xinfu He (CIAE) in the period of September 2009 to June 2010. In this work, we have carried out an atomistic study addressing the properties of grain boundaries in BCC Fe and Fe-Cr alloys. Throughout this work we report on the structural and cohesive properties of grain boundaries; thermal stability; interaction of grain boundaries with He and diffusivity of He in the core of the grain boundaries; equilibrium segregation of Cr near the grain boundary zone; cleavage fracture of grain boundaries; influence of the Cr precipitates, voids and He bubbles on the structure and strength of grain boundaries.

  19. Properties of grain boundaries in BCC iron and iron-based alloys

    Energy Technology Data Exchange (ETDEWEB)

    Terentyev, D.; He, Xinfu

    2010-08-15

    The report contains a summary of work done within the collaboration established between SCK-CEN and CIEA, performed during the internship of Xinfu He (CIAE) in the period of September 2009 to June 2010. In this work, we have carried out an atomistic study addressing the properties of grain boundaries in BCC Fe and Fe-Cr alloys. Throughout this work we report on the structural and cohesive properties of grain boundaries; thermal stability; interaction of grain boundaries with He and diffusivity of He in the core of the grain boundaries; equilibrium segregation of Cr near the grain boundary zone; cleavage fracture of grain boundaries; influence of the Cr precipitates, voids and He bubbles on the structure and strength of grain boundaries.

  20. The kinetics of phase transformations of undercooled austenite of the Mn-Ni iron based model alloy

    OpenAIRE

    E. Rożniata; R. Dziurka; J. Pacyna

    2011-01-01

    Purpose: Present work corresponds to the research on the kinetics of phase transformations of undercooled austenite of Mn-Ni iron based model alloy. The kinetics of phase transformations of undercooled austenite of investigated alloy was presented on CCT diagram (continuous cooling transformation). Also the methodology of a dilatometric samples preparation and the method of the critical points determination were described.Design/methodology/approach: The austenitising temperature was defined ...

  1. A Powerful Mitochondria-Targeted Iron Chelator Affords High Photoprotection against Solar Ultraviolet A Radiation

    OpenAIRE

    Reelfs, Olivier; Abbate, Vincenzo; Hider, Robert C.; Pourzand, Charareh

    2016-01-01

    Mitochondria are the principal destination for labile iron, making these organelles particularly susceptible to oxidative damage on exposure to ultraviolet A (UVA, 320?400 nm), the oxidizing component of sunlight. The labile iron-mediated oxidative damage caused by UVA to mitochondria leads to necrotic cell death via adenosine triphosphate depletion. Therefore, targeted removal of mitochondrial labile iron via highly specific tools from these organelles may be an effective approach to protect...

  2. Investigation of americium-241 metal alloys for target applications

    International Nuclear Information System (INIS)

    Conner, W.V.; Rockwell International Corp., Golden, CO

    1982-01-01

    Several 241 Am metal alloys have been investigated for possible use in the Lawrence Livermore National Laboratory Radiochemical Diagnostic Tracer Program. Several properties were desired for an alloy to be useful for tracer program applications. A suitable alloy would have a fairly high density, be ductile, homogeneous and easy to prepare. Alloys investigated have included uranium-americium, aluminium-americium, and cerium-americium. Uranium-americium alloys with the desired properties proved to be difficult to prepare, and work with this alloy was discontinued. Aluminium-americium alloys were much easier to prepare, but the alloy consisted of an aluminium-americium intermetallic compound (AmAl 4 ) in an aluminum matrix. This alloy could be cast and formed into shapes, but the low density of aluminum, and other problems, made the alloy unsuitable for the intended application. Americium metal was found to have a high solid solubility in cerium and alloys prepared from these two elements exhibited all of the properties desired for the tracer program application. Cerium-americium alloys containing up to 34 wt% americium have been prepared using both co-melting and co-reduction techniques. The latter technique involves co-reduction of cerium tetrafluoride and americium tetrafluoride with calcium metal in a sealed reduction vessel. Casting techniques have been developed for preparing up to eight 2.2 cm (0.87 in) diameter disks in a single casting, and cerium-americium metal alloy disks containing from 10 to 25 wt% 241 Am have been prepared using these techniques. (orig.)

  3. Effects of Alloying Elements (Mo, Ni, and Cu on the Austemperability of GGG-60 Ductile Cast Iron

    Directory of Open Access Journals (Sweden)

    Erkan Konca

    2017-08-01

    Full Text Available The interest in austempered ductile irons (ADI is continuously increasing due to their various advantageous properties over conventional ductile irons and some steels. This study aimed to determine the roles of alloying elements Ni, Cu, and Mo, on the austemperability of GGG-60 ductile cast iron. Two different sets of GGG-60 (EN-GJS-600-3 samples, one set alloyed with Ni and Cu and the other set alloyed with Mo, Ni, and Cu, were subjected to austempering treatments at 290 °C, 320 °C, and 350 °C. A custom design heat treatment setup, consisting of two units with the top unit (furnace serving for austenitizing and the 200 L capacity bottom unit (stirred NaNO2-KNO3 salt bath serving for isothermal treatment, was used for the experiments. It was found that austempering treatment at 290 °C increased the hardness of the Ni-Cu alloyed GGG-60 sample by about 44% without causing a loss in its ductility. In the case of the Mo-Ni-Cu alloyed sample, the increase in hardness due to austempering reached to almost 80% at the same temperature while some ductility was lost. Here, the microstructural investigation and mechanical testing results of the austempered samples are presented and the role of alloying elements (Mo, Ni, and Cu on the austemperability of GGG-60 is discussed.

  4. Effects of alloying elements on the microstructure and fatigue properties of cast iron for internal combustion engine exhaust manifolds

    Science.gov (United States)

    Eisenmann, David J.

    In the design of exhaust manifolds for internal combustion engines the materials used must exhibit resistance to corrosion at high temperatures while maintaining a stable microstructure. Cast iron has been used for manifolds for many years by auto manufacturers due to a combination of suitable mechanical properties, low cost, and ease of casting. Over time cast iron is susceptible to microstructural changes, corrosion, and oxidation which can result in failure due to fatigue. This thesis seeks to answer the question: "Can observed microstructural changes and measured high temperature fatigue life in cast iron alloys be used to develop a predictive model for fatigue life?" the importance of this question lies in the fact that there is little data for the behavior of cast iron alloys at high temperature. For this study two different types of cast iron, 50HS and HSM will be examined. Of particular concern for the high Si+C cast irons (and Mo in the case of the HSM cast iron) are subsurface microstructural changes that result due to heat treatment including (1) decarburization, (2) ferrite formation, (3) graphitization, (4) internal oxidation of the Si, (5) high temperature fatigue resistance, and (6) creep potential. Initial results obtained include microstructure examination after being exposed to high temperatures, grain size, nodule size, and hardness measurements. The initial examinations concluded that both cast irons performed fairly similarly, although the microstructure of the HSM samples did show slightly better resistance to high temperature as compared to that of the 50HS. Follow on work involved high temperature fatigue testing of these two materials in order to better determine if the newer alloy, HSM is a better choice for exhaust manifolds. Correlations between fatigue performance and microstructure were made and discussed, with the results examined in light of current and proposed models for predicting fatigue performance based on computational methods

  5. Swelling of austenitic iron-nickelchromium ternary alloys during fast neutron irradiation

    International Nuclear Information System (INIS)

    Garner, F.A.; Brager, H.R.

    1984-01-01

    Swelling data are now available for 15 iron-nickel-chromium ternary alloys irradiated to exposures as high as 110 displacements per atom (dpa) in Experimental Breeder Reactor-II (EBR-II) between 400 and 650 0 C. These data confirm trends observed at lower exposure levels and extend the generality of earlier conclusions to cover a broader range of composition and temperature. It appears that all austenitic iron-nickel-chromium ternary alloys eventually approach an intrinsic swelling rate of about1%/dpa over a range of temperature even wider than studied in this experiment. The duration of the transient regime that precedes the attainment of this rate is quite sensitive to nickel and chromium content, however. At nickel and chromium levels typical of 300 series steels, swelling does not saturate at engineering-relevant levels. However, there appears to be a tendency toward saturation that increases with declining temperature, increasing nickel and decreasing chromium levels. Comparisons of these results are made with those of similar studies conducted with charged particles. Conclusions are then drawn concerning the validity of charged particle simulation studies to determine the compositional and temperature dependence of swelling

  6. High density tungsten-nickel-iron-cobalt alloys having improved hardness and method for making same

    International Nuclear Information System (INIS)

    Penrice, T.W.; Bost, J.

    1988-01-01

    This patent describes the process of making high density alloy containing about 85 to 98 weight percent tungsten and the balance of the alloy being essentially a binder of nickel, iron and cobalt, and wherein the cobalt is present in an amount within the range of about 5 to 47.5 weight percent of the binder, comprising: blending powders of the tungsten, nickel, iron and cobalt into a homogeneous composition, compacting the homogeneous composition into a shaped article, heating the shaped article to a temperature and for a time sufficient to sinter the article, subjecting the sintered article to a temperature sufficient to enable the intermetallic phase formed at the matrix to tungsten interface to diffuse into the gamma austenitic phase whereby the alpha tungsten/gamma austenite boundaries are essentially free of such intermetallic phase, quenching the article, and swaging the article to a reduction in area of about 5 to 40 percent, the article having improved mechanical properties, including improved tensile strength and hardness while maintaining suitable ductility for subsequent working thereof

  7. Targeted Iron Chelation Will Improve Recovery after Spinal Cord Injury

    Science.gov (United States)

    2014-10-01

    NAME OF RESPONSIBLE PERSON USAMRMC a. REPORT U b. ABSTRACT U c. THIS PAGE U 19b. TELEPHONE NUMBER (include area code) Standard Form 298 (Rev. 8-98...contusions were performed using standardized proto- cols as previously described (Almad et al., 2011; Almad and McTigue, 2010). All procedures conformed to...excluded. Urinalysis Iron content in the urine was assayed using the liquid ferrozine method (Iron Reagents Kit, Thermo Scientific). Urine

  8. Composition tunable cobalt–nickel and cobalt–iron alloy nanoparticles below 10 nm synthesized using acetonated cobalt carbonyl

    International Nuclear Information System (INIS)

    Schooneveld, Matti M. van; Campos-Cuerva, Carlos; Pet, Jeroen; Meeldijk, Johannes D.; Rijssel, Jos van; Meijerink, Andries; Erné, Ben H.; Groot, Frank M. F. de

    2012-01-01

    A general organometallic route has been developed to synthesize Co x Ni 1−x and Co x Fe 1−x alloy nanoparticles with a fully tunable composition and a size of 4–10 nm with high yield. In contrast to previously reported synthesis methods using dicobalt octacarbonyl (Co 2 (CO) 8 ), here the cobalt–cobalt bond in the carbonyl complex is first broken with anhydrous acetone. The acetonated compound, in the presence of iron carbonyl or nickel acetylacetonate, is necessary to obtain small composition tunable alloys. This new route and insights will provide guidelines for the wet-chemical synthesis of yet unmade bimetallic alloy nanoparticles.

  9. Iron-chrome-aluminum alloy cladding for increasing safety in nuclear power plants

    Science.gov (United States)

    Rebak, Raul B.

    2017-12-01

    After a tsunami caused plant black out at Fukushima, followed by hydrogen explosions, the US Department of Energy partnered with fuel vendors to study safer alternatives to the current UO2-zirconium alloy system. This accident tolerant fuel alternative should better tolerate loss of cooling in the core for a considerably longer time while maintaining or improving the fuel performance during normal operation conditions. General electric, Oak ridge national laboratory, and their partners are proposing to replace zirconium alloy cladding in current commercial light water power reactors with an iron-chromium-aluminum (FeCrAl) cladding such as APMT or C26M. Extensive testing and evaluation is being conducted to determine the suitability of FeCrAl under normal operation conditions and under severe accident conditions. Results show that FeCrAl has excellent corrosion resistance under normal operation conditions and FeCrAl is several orders of magnitude more resistant than zirconium alloys to degradation by superheated steam under accident conditions, generating less heat of oxidation and lower amount of combustible hydrogen gas. Higher neutron absorption and tritium release effects can be minimized by design changes. The implementation of FeCrAl cladding is a near term solution to enhance the safety of the current fleet of commercial light water power reactors.

  10. Phase composition of iron-rich R-Fe-Si (R=Dy, Ho, Er) alloys

    International Nuclear Information System (INIS)

    Ivanova, G.V.; Makarova, G.M.; Shcherbakova, E.V.; Belozerov, E.V.

    2005-01-01

    Phase composition is studied in iron-rich alloys of R-Fe-Si (R=Dy, Ho, Er). In the as-cast state R 2 (Fe, Si) 17 of type Th 2 Ni 17 and R(Fe, Si) 12 compounds are observed; in the alloys of rated composition of R(Fe 0.85 Si 0.15 ) 8.5 (R=Dy, Er) a compound R 2 (Fe, Si) 17 of Th 2 Zn 17 -type is revealed as well. The annealing at 1273 K results in formation of Dy 3 (Fe, Si) 29 and also the compounds with the presumed composition of Dy 4 (Fe, Si) 41 and Ho 4 (Fe, Si) 41 . As this takes place the alloys contain a transition structure as well that represents a set of small-sized areas with various type short-range order in mutual displacement of Fe-Fe(Si) dumpbell chains. The process of phase formation at 1273 K is faced with difficulties. Even the annealing for 1000 h does not result in the state of equilibrium [ru

  11. Method of simultaneous continuous determination of transfer rates of iron and chromium into solution during Fe-Cr alloys dissolution

    International Nuclear Information System (INIS)

    Shirinov, T.I.; Florianovich, G.M.; Skuratnik, Ya.B.

    1978-01-01

    Radiometry method of simultaneous continuous registration of transfer rates of iron and chromium into solution from Fe-Cr alloys with various composition has been developed. Using gamma-spectrometer components of Fe-Cr alloys can be determined with high sensitivity in separate samples according to Fe 59 and Cr 51 radioactive labels, obtained by neutron activation. The above method is applied to estimate Fe and Cr transfer rates into H 2 SO 4 solution at the temperature of 50 deg from Fe - 28% Cr alloy during its active dissolution. It is established, that beginning with some seconds of alloy and solution contact, its components transfer into the solution in the same composition, as in the alloy. The method enables to determine Fe with the accuracy of up to 5% and Cr with that of up to 10%

  12. Neutralization of the negative influence of iron and silicon on the mechanical properties of aluminium casting alloys

    International Nuclear Information System (INIS)

    Zolotorevsky, V.S.; Axenov, A.A.; Belov, N.A.

    1990-01-01

    In most of casting aluminium alloys iron is a harmful impurity due to the appearance of rough particles with needle, plate or sceleton shapes of intermetallic compounds during crystallization. As a result of it the plasticity, fracture toughness and sometimes the strength are decreased

  13. PERSPECTIVE SOURCES OF METALS RESOURCES (CU, NI FOR CAST IRON ALLOYING, ARISING ON THE TERRITORY OF THE REPUBLIC OF BELARUS

    Directory of Open Access Journals (Sweden)

    V. L. Tribushevski

    2005-01-01

    Full Text Available The article is dedicated to the practical foundation of combined resources-economy technologies of the alloyed cast iron melting using wastes of galvanic productions, containing sulfates and hydroxides of these metals, instead of metallic nickel and copper.

  14. EVALUATION OF MACHINABILITY OF DUCTILE IRONS ALLOYED WITH Ni AND Cu IN TERMS OF CUTTING FORCES AND SURFACE QUALITY

    Directory of Open Access Journals (Sweden)

    Yücel AŞKUN

    2003-02-01

    Full Text Available Due to the enhanced strength, ductility and thoughness of Ductile Iron (DI when compared to the other types cast iron, its machinability is relatively poor. When a steel part is replaced with ductile iron, however, better machinability is considered to be the most important gain. This study presents the results of machining tests of ductile irons alloyed with Ni and Cu at various contents to determine the effect of their microstructure and mechanical properties on cutting forces and surface roughness. Six different specimen groups of ductile iron alloyed with various amounts of nickel and copper were subjected to machining tests and their machinabilities were investigated based on cutting forces and surface roughness criteria. The results were evaluated according to microstructure and mechanical properties of specimens determined before. In terms of both criterion, the best result obtained was specimen added 0.7 % Ni and 0.7 % Cu. When the specimens were evaluated according to their mechanical properties, the specimens alloyed 1 % Ni and 0.65 % Cu seemed promising.

  15. Targeting iron acquisition blocks infection with the fungal pathogens Aspergillus fumigatus and Fusarium oxysporum.

    Science.gov (United States)

    Leal, Sixto M; Roy, Sanhita; Vareechon, Chairut; Carrion, Steven deJesus; Clark, Heather; Lopez-Berges, Manuel S; Di Pietro, Antonio; diPietro, Antonio; Schrettl, Marcus; Beckmann, Nicola; Redl, Bernhard; Haas, Hubertus; Pearlman, Eric

    2013-01-01

    Filamentous fungi are an important cause of pulmonary and systemic morbidity and mortality, and also cause corneal blindness and visual impairment worldwide. Utilizing in vitro neutrophil killing assays and a model of fungal infection of the cornea, we demonstrated that Dectin-1 dependent IL-6 production regulates expression of iron chelators, heme and siderophore binding proteins and hepcidin in infected mice. In addition, we show that human neutrophils synthesize lipocalin-1, which sequesters fungal siderophores, and that topical lipocalin-1 or lactoferrin restricts fungal growth in vivo. Conversely, we show that exogenous iron or the xenosiderophore deferroxamine enhances fungal growth in infected mice. By examining mutant Aspergillus and Fusarium strains, we found that fungal transcriptional responses to low iron levels and extracellular siderophores are essential for fungal growth during infection. Further, we showed that targeting fungal iron acquisition or siderophore biosynthesis by topical application of iron chelators or statins reduces fungal growth in the cornea by 60% and that dual therapy with the iron chelator deferiprone and statins further restricts fungal growth by 75%. Together, these studies identify specific host iron-chelating and fungal iron-acquisition mediators that regulate fungal growth, and demonstrate that therapeutic inhibition of fungal iron acquisition can be utilized to treat topical fungal infections.

  16. Targeting iron acquisition blocks infection with the fungal pathogens Aspergillus fumigatus and Fusarium oxysporum.

    Directory of Open Access Journals (Sweden)

    Sixto M Leal

    Full Text Available Filamentous fungi are an important cause of pulmonary and systemic morbidity and mortality, and also cause corneal blindness and visual impairment worldwide. Utilizing in vitro neutrophil killing assays and a model of fungal infection of the cornea, we demonstrated that Dectin-1 dependent IL-6 production regulates expression of iron chelators, heme and siderophore binding proteins and hepcidin in infected mice. In addition, we show that human neutrophils synthesize lipocalin-1, which sequesters fungal siderophores, and that topical lipocalin-1 or lactoferrin restricts fungal growth in vivo. Conversely, we show that exogenous iron or the xenosiderophore deferroxamine enhances fungal growth in infected mice. By examining mutant Aspergillus and Fusarium strains, we found that fungal transcriptional responses to low iron levels and extracellular siderophores are essential for fungal growth during infection. Further, we showed that targeting fungal iron acquisition or siderophore biosynthesis by topical application of iron chelators or statins reduces fungal growth in the cornea by 60% and that dual therapy with the iron chelator deferiprone and statins further restricts fungal growth by 75%. Together, these studies identify specific host iron-chelating and fungal iron-acquisition mediators that regulate fungal growth, and demonstrate that therapeutic inhibition of fungal iron acquisition can be utilized to treat topical fungal infections.

  17. Effect of shot peening process on fatigue behavior of an alloyed austempered ductile iron

    Directory of Open Access Journals (Sweden)

    Amir Sadighzadeh Benam

    2011-08-01

    Full Text Available Shot peening is one of the most common surface treatments to improve the fatigue behavior of metallic parts. In this study the effect of shot peening process on the fatigue behavior of an alloyed austempered ductile iron (ADI has been studied. Austempering heat treatment consisted of austenitizing at 875℃ for 90 min followed by austempering at three different temperatures of 320, 365 and 400℃. Rotating-bending fatigue test was carried out on samples after shot peening by 0.4 – 0.6 mm shots. XRD and SEM analysis, micro hardness and roughness tests were carried out to study the fatigue behavior of the samples. Results indicate that the fatigue strengths of samples austempered at 320, 365 and 400℃ are increased by 27.3%, 33.3% and 48.4%, respectively, after shot peening process.

  18. Oxidation behavior of austenitic iron-base ODS alloy in supercritical water

    Energy Technology Data Exchange (ETDEWEB)

    Behnamian, Y.; Dong, Z.; Zahiri, R.; Kohandehghan, A.; Mitlin, D., E-mail: behnamia@ualberta.ca, E-mail: zdong@ualberta.ca, E-mail: kohandeh@ualberta.ca, E-mail: rzahiris@ualberta.ca, E-mail: dave.mitlin@ualberta.ca [Univ. of Alberta, Edmondon, AB (Canada); Zhou, Z., E-mail: zhouzhj@mater.ustb.edu.cn [Univ. of Science and Tech. Beijing, Beijing (China); Chen, W.; Luo, J., E-mail: weixing.chen@ualberta.ca, E-mail: Jingli.luo@ualberta.ca [Univ. of Alberta, Edmonton, AB (Canada); Zheng, W., E-mail: wenyue@nrcan.gc.ca [Natural Resources Canada, Canmet MATERIALS, Hamilton, ON (Canada); Guzonas, D. [Atomic Energy of Canada Limited, Chalk River, ON (Canada)

    2014-07-01

    In this study, the effect of exposure time on the corrosion of the 304 stainless steel based oxide dispersion strengthened alloy, SS304ODS, in supercritical water was investigated at 650 {sup o}C with constant dissolved oxygen concentration. The results show that the oxidation of SS304ODS in supercritical water followed a parabolic law at 650 {sup o}C. Discontinuous oxide scale with two distinct layers has formed after 550 hours. The inner layer was chromium-rich while the outer layer was iron-rich (Magnetite). The oxide islands grow with increasing the exposure time. With increasing exposure time, the quantity of oxide islands increased in which major preferential growth along oxide-substrate interface was observed. The possible mechanism of SS304ODS oxidation in supercritical water was also discussed. (author)

  19. A new high-strength iron base austenitic alloy with good toughness and corrosion resistance (GE-EPRI alloy-TTL)

    International Nuclear Information System (INIS)

    Ganesh, S.

    1989-01-01

    A new high strength, iron based, austenitic alloy has been successfully developed by GE-EPRI to satisfy the strength and corrosion resistance requirements of large retaining rings for high capacity generators (>840Mw). This new alloy is a modified version of the EPRI alloy-T developed by the University of California, Berkeley, in an earlier EPRI program. It is age hardenable and has the nominal composition (weight %): 34.5 Ni, 5Cr, 3Ti, 1Nb, 1Ta, 1Mo, .5Al, .3V, .01B. This composition was selected based on detailed metallurgical and processing studies on modified versions of alloy-T. These studies helped establish the optimum processing conditions for the new alloy and enabled the successful scale-up production of three large (50-52 inch dia) test rings from a 5,000 lb VIM-VAR billet. The rings were metallurgically sound and exhibited yield strength capabilities in the range 145 to 220 ksi depending on the extent of hot/cold work induced. The test rings met or exceeded all the property goals. The above alloy can provide a good combination of strength, toughness and corrosion resistance and, through an suitable modification of chemistry or processing conditions, could be a viable candidate for high strength LWR internal applications. 3 figs

  20. Spectrophotometric determination of phosphorus in iron alloys employing a flow injection system

    Directory of Open Access Journals (Sweden)

    Gervasio Ana P. G.

    2001-01-01

    Full Text Available A flow-injection procedure for spectrophotometric determination of phosphorus in electrolytic iron and iron alloys is proposed. The method is based on the ammonium molybdate reaction followed by stannous chloride reduction in acidic medium. In order to circumvent the severe interference caused by the major constituents such as Fe(III and Cr(III, a mini-column packed with AG50W-X8 resin was coupled to the manifold. A sample throughput of 40 determinations per hour, a dynamical range from P 0.25 to 6.00 mg L-1, a reagent consumption of 25 mg ammonium molybdate and 2 mg stannous chloride per determination, and a relative standard deviation < 1% (n = 10 for a typical sample with 2.20 mg L-1 P were achieved. Three different types of samples were used to evaluate system performance. Accuracy was assessed by comparing the results with certified values and no significant difference at 95 % confidence level was observed.

  1. In vitro and in vivo corrosion properties of new iron-manganese alloys designed for cardiovascular applications.

    Science.gov (United States)

    Drynda, Andreas; Hassel, Thomas; Bach, Friedrich Wilhelm; Peuster, Matthias

    2015-04-01

    The principle of biodegradation for the production of temporary implant materials (e.g. stents) plays an important role in the treatment of congenital heart defects. In the last decade several attempts have been made with different alloy materials-mainly based on iron and magnesium. None of the currently available materials in this field have demonstrated satisfying results and have therefore not found entry into broad clinical practice. While magnesium or magnesium alloy systems corrode too fast, the corrosion rate of pure iron-stents is too slow for cardiovascular applications. In the last years FeMn alloy systems were developed with the idea that galvanic effects, caused by different electrochemical properties of Fe and Mn, would increase the corrosion rate. In vitro tests with alloys containing up to 30% Mn showed promising results in terms of biocompatibility. This study deals with the development of new FeMn alloy systems with lower Mn concentrations (FeMn 0.5 wt %, FeMn 2.7 wt %, FeMn 6.9 wt %) to avoid Mn toxicity. Our results show, that these alloys exhibit good mechanical features as well as suitable in vitro biocompatibility and corrosion properties. In contrast, the evaluation of these alloys in a mouse model led to unexpected results-even after 9 months no significant corrosion was detectable. Preliminary SEM investigations showed that passivation layers (FeMn phosphates) might be the reason for corrosion resistance. If this can be proved in further experiments, strategies to prevent or dissolve those layers need to be developed to expedite the in vivo corrosion of FeMn alloys. © 2014 Wiley Periodicals, Inc.

  2. Iron

    Science.gov (United States)

    Iron is a mineral that our bodies need for many functions. For example, iron is part of hemoglobin, a protein which carries ... It helps our muscles store and use oxygen. Iron is also part of many other proteins and ...

  3. Elastic and plastic properties of iron-aluminium alloys. Special problems raised by the brittleness of alloys of high aluminium content

    International Nuclear Information System (INIS)

    Mouturat, P.

    1966-06-01

    The present study embodies the results obtained with iron-aluminium alloys whose composition runs from 0 to nearly 50 atoms per cent aluminium. Conditions of elaboration and transformation have been studied successively, as well as the Young's modulus and the flow stress; the last chapter embodies, a study of the Portevin-le-Chatelier effect in alloys of 40 atoms per cent of aluminium. I) The principal difficulty to clear up consisted in the intergranular brittleness of ordered alloys; this brittleness has been considerably reduced with appropriate conditions of elaboration and transformation. II) The studies upon the Young's modulus are in connection with iron-aluminium alloys; transformation temperatures are well shown up. The formation of covalent bonds on and after 25 atoms per cent show the highest values of the modulus. III) The analysis of variations of the flow stress according to the temperature show some connection with ordered structures, the existence of antiphase domains and the existence of sur-structure dislocations. IV) In the ordered Fe Al domain the kinetics of the Portevin-le-Chatelier effect could be explained by a mechanism of diffusion of vacancies. The role they play has been specified by the influence they exert upon the dislocations; this has led us to the inhomogeneous Rudman order; this inhomogeneous order could explain the shape of the traction curves. (author) [fr

  4. Formulation design for target delivery of iron nanoparticles to TCE zones.

    Science.gov (United States)

    Wang, Ziheng; Acosta, Edgar

    2013-12-01

    Nanoparticles of zero-valent iron (NZVI) are effective reducing agents for some dense non-aqueous phase liquid (DNAPL) contaminants such as trichloroethylene (TCE). However, target delivery of iron nanoparticles to DNAPL zones in the aquifer remains an elusive feature for NZVI technologies. This work discusses three strategies to deliver iron nanoparticles to DNAPL zones. To this end, iron oxide nanoparticles coated with oleate (OL) ions were used as stable analogs for NZVI. The OL-coated iron oxide nanoparticles are rendered lipophilic via (a) the addition of CaCl2, (b) acidification, or (c) the addition of a cationic surfactant, benzethonium chloride (BC). Mixtures of OL and BC show promise as a target delivery strategy due to the high stability of the nanoparticles in water, and their preferential partition into TCE in batch experiments. Column tests show that while the OL-BC coated iron oxide nanoparticles remain largely mobile in TCE-free columns, a large fraction of these particles are retained in TCE-contaminated columns, confirming the effectiveness of this target delivery strategy. © 2013.

  5. A Powerful Mitochondria-Targeted Iron Chelator Affords High Photoprotection against Solar Ultraviolet A Radiation.

    Science.gov (United States)

    Reelfs, Olivier; Abbate, Vincenzo; Hider, Robert C; Pourzand, Charareh

    2016-08-01

    Mitochondria are the principal destination for labile iron, making these organelles particularly susceptible to oxidative damage on exposure to ultraviolet A (UVA, 320-400 nm), the oxidizing component of sunlight. The labile iron-mediated oxidative damage caused by UVA to mitochondria leads to necrotic cell death via adenosine triphosphate depletion. Therefore, targeted removal of mitochondrial labile iron via highly specific tools from these organelles may be an effective approach to protect the skin cells against the harmful effects of UVA. In this work, we designed a mitochondria-targeted hexadentate (tricatechol-based) iron chelator linked to mitochondria-homing SS-like peptides. The photoprotective potential of this compound against UVA-induced oxidative damage and cell death was evaluated in cultured primary skin fibroblasts. Our results show that this compound provides unprecedented protection against UVA-induced mitochondrial damage, adenosine triphosphate depletion, and the ensuing necrotic cell death in skin fibroblasts, and this effect is fully related to its potent iron-chelating property in the organelle. This mitochondria-targeted iron chelator has therefore promising potential for skin photoprotection against the deleterious effects of the UVA component of sunlight. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  6. Comparative study of crystallized melt-spun iron-boron alloys by Moessbauer effect and resistivity measurements

    International Nuclear Information System (INIS)

    Arshad, M.; Siddique, M.; Anwar-ul-Islam, M.; Butt, N.M.; Ashfaq, A.; Shamim, A.

    1993-01-01

    Moessbauer study of two as-quenched, melt-spun iron-boron completely crystallized alloys, Fe/sub 72/01/B/sub 28/ and Fe/sub 88/01/B/sub 12/, indicates the presence of alpha-Fe, Fe/sub 2/B and Fe/sub 3/B. The percentage of these phases is different in the two alloys. Resistivity measurements show to phase transformation of Fe/sub 3/B and Fe/sub 2/B, respectively. (author)

  7. Sliding wear and corrosion behaviour of alloyed austempered ductile iron subjected to novel two step austempering treatment

    Science.gov (United States)

    Sethuram, D.; Srisailam, Shravani; Rao Ponangi, Babu

    2018-04-01

    Austempered Ductile Iron(ADI) is an exciting alloy of iron which offers the design engineers the best combination high strength-to-weight ratio, low cost design flexibility, good toughness, wear resistance along with fatigue strength. The two step austempering procedure helps in simultaneously improving the tensile strength as-well as the ductility to more than that of the conventional austempering process. Extensive literature survey reveals that it’s mechanical and wear behaviour are dependent on heat treatment and alloy additions. Current work focuses on characterizing the two-step ADI samples (TSADI) developed by novel heat treatment process for resistance to corrosion and wear. The samples of Ductile Iron were austempered by the two-Step Austempering process at temperatures 300°C to 450°C in the steps of 50°C.Temperaturesare gradually increased at the rate of 14°C/Hour. In acidic medium (H2SO4), the austempered samples showed better corrosive resistance compared to conventional ductile iron. It has been observed from the wear studies that TSADI sample at 350°C is showing better wear resistance compared to ductile iron. The results are discussed in terms of fractographs, process variables and microstructural features of TSADI samples.

  8. Effect of performance of Zr-Y alloy target on thin film deposition technology

    International Nuclear Information System (INIS)

    Pan Qianfu; Liu Chaohong; Jiang Mingzhong; Yin Changgeng

    2011-01-01

    Yttria-stabilized zirconia (YSZ) films are synthesized on corrosion resistant plates by pulsed bias arc ion plating. The arc starting performance and the stability of thin film deposition is explored by improving the uniformity and compactibility of Zr-Y alloy target. The property of Zr-Y alloy target and depositional thin films were measured with the optical microscope, scanning electron microscope, X-ray diffractometer. The result shows that the target with hot rolling and annealing has a good arc starting performance and stability of thin film deposition, and the depositional thin films made of Yttria and amorphous zirconia are homogeneous and compact. (authors)

  9. Deformation mechanism maps for pure iron, corrosion resistant austenitic steels and a low-alloy carbon steel

    International Nuclear Information System (INIS)

    Frost, H.Y.; Ashby, M.F.

    1980-01-01

    Principles of construction of deformation mechanisms charts for iron base alloys are presented. Deformation mechanisms charts for pure iron, 316 and 314 stainless steels, a ferritic steel with 1% Cr, Mo, V are given, examples of the charts application being provided. The charts construction is based, when it is possible, on the state equations, deduced from theoretical models and satisfying experimental data. The charts presented should be considered as an attempt to unite the main regularities of the theory of dislocations and diffusion with the observed experimental picture of plastic deformation and creep of commercial steels [ru

  10. Investigation of effects of boron additives and heat treatment on carbides and phase transition of highly alloyed duplex cast iron

    International Nuclear Information System (INIS)

    Tasgin, Yahya; Kaplan, Mehmet; Yaz, Mehmet

    2009-01-01

    The effect of boron additives and heat treatment on the microstructural morphology of the transition zone in a duplex cast iron, which has an outer shell of white cast iron (with a high Cr-content and containing boron additives) and an inner side composed of normal gray cast iron, has been investigated. For this purpose, two experimental materials possessing different compositions of white-gray duplex cast iron were produced. Subsequently, metallographic investigations were carried out to study the effect of heat treatment applied to the experimental materials by using the scanning electron microscopy technique, along with optical microscopy and energy dispersive X-ray spectroscopy. Moreover, the formation of various phases and carbide composites in the samples and their effects on the hardness were also investigated using X-ray diffraction techniques. The results of investigations, and hardness showed that addition of the elements Cr and B to high-alloyed white cast iron affected carbide formation significantly, while simultaneously hardening the microstructure, and consequently the carbide present in the transition area of white-gray cast iron was spread out and became thinner. However, B additives and heat treatment did not cause any damage to the transition region of high Cr-content duplex cast iron.

  11. Superparamagnetic iron oxide nanoparticles (SPIONs) for targeted drug delivery

    Science.gov (United States)

    Garg, Vijayendra K.; Kuzmann, Erno; Sharma, Virender K.; Kumar, Arun; Oliveira, Aderbal C.

    2016-10-01

    Studies of superparamagnetic iron oxide nanoparticles (SPIONs) have been extensively carried out. Since the earlier work on Mössbauer studies on SPIONs in 1970s, many biomedical applications and their uses in innovative methods to produce new materials with improved performance have appeared. Applications of SPIONs in environmental remediation are also forthcoming. Several different methods of synthesis and coating of the magnetic particles have been described in the literature, and Mössbauer spectroscopy has been an important tool in the characterization of these materials. It is quite possible that the interpretation of the Mössbauer spectra might not be entirely correct because the possible presence of maghemite in the end product of SPIONs might not have been taken into consideration. Nanotechnology is an emerging field that covers a wide range of new technologies under development in nanoscale (1 to 100 nano meters) to produce new products and methodology.

  12. Studies of plutonium-iron and uranium-plutonium-iron alloys; Etudes d'alliages plutonium-fer et d'alliages uranium-plutonium-fer

    Energy Technology Data Exchange (ETDEWEB)

    Avivi, Ehud [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

    1964-01-15

    We study the plutonium-iron system, by means of dilatometry, X rays and metallography, especially in the domain between PuFe{sub 2} and Fe. We determine the solubilities of Fe in PuFe{sub 2} and of Pu in Fe. We show the presence of an hexagonal PuFe{sub 2} phase and we propose a modification in the Pu-Fe phase diagram. Some low iron concentration U-Pu-Fe alloys have also been investigated. We characterise the different phases. We confirm that adding some iron lowers the quantity of the zeta U-Pu phase. We emphasize some characteristics of the alloys having the global concentration (U, Pu){sub 6} Fe. (authors) [French] On etudie par dilatometrie, rayons X et micrographie le systeme plutonium-fer, principalement dans la region comprise entre PuFe{sub 2} et Fe, On determine les solubilites du fer dans PuFe{sub 2}, et de Pu dans Fe. On met en evidence une phase PuFe{sub 2} hexagonale et on propose une modification du diagramme d'equilibre Pu-Fe. Certains alliages U-Pu-Fe a faibles concentrations en fer sont egalement etudies. On caracterise les phases en presence. On confirme que l'addition de fer diminue rapidement la quantite de phase U-Pu zeta. Enfin on revele certaines caracteristiques des alliages de composition globale (U, Pu){sub 6} Fe. (auteurs)

  13. Wear Resistant Thermal Sprayed Composite Coatings Based on Iron Self-Fluxing Alloy and Recycled Cermet Powders

    Directory of Open Access Journals (Sweden)

    Heikki SARJAS

    2012-03-01

    Full Text Available Thermal spray and WC-Co based coatings are widely used in areas subjected to abrasive wear. Commercial  cermet thermal spray powders for HVOF are relatively expensive. Therefore applying these powders in cost-sensitive areas like mining and agriculture are hindered. Nowadays, the use of cheap iron based self-fluxing alloy powders for thermal spray is limited. The aim of this research was to study properties of composite powders based on self-fluxing alloys and recycled cermets and to examine the properties of thermally sprayed (HVOF coatings from composite powders based on iron self-fluxing alloy and recycled cermet powders (Cr3C2-Ni and WC-Co. To estimate the properties of  recycled cermet powders, the sieving analysis, laser granulometry and morphology were conducted. For deposition of coatings High Velocity Oxy-Fuel spray was used. The structure and composition of powders and coatings were estimated by SEM and XRD methods. Abrasive wear performance of coatings was determined and compared with wear resistance of coatings from commercial powders. The wear resistance of thermal sprayed coatings from self-fluxing alloy and recycled cermet powders at abrasion is comparable with wear resistance of coatings from commercial expensive spray powders and may be an alternative in tribological applications in cost-sensitive areas.DOI: http://dx.doi.org/10.5755/j01.ms.18.1.1338

  14. DEVELOPMENT OF TREAD ON THE BASIS OF COLOR ALLOYS RECYCLED IRON-CARBON ALLOYS PROTECTION FROM CORROSION

    Directory of Open Access Journals (Sweden)

    A. A. Pivovarchyk

    2016-01-01

    Full Text Available The results of development of the compositions of protectors for the corrosion protection low-carbon alloys used in the automotive industry, using as the raw material of the secondary aluminum raw materials. The results of research on the effectiveness of the tread designed to protect the alloy composition.

  15. Effects of alloying elements (Mn, Co, Al, W, Sn, B, C and S) on biodegradability and in vitro biocompatibility of pure iron.

    Science.gov (United States)

    Liu, B; Zheng, Y F

    2011-03-01

    Pure iron was determined to be a valid candidate material for biodegradable metallic stents in recent animal tests; however, a much faster degradation rate in physiological environments was desired. C, Mn, Si, P, S, B, Cr, Ni, Pb, Mo, Al, Ti, Cu, Co, V and W are common alloying elements in industrial steels, with Cr, Ni, Mo, Cu, Ti, V and Si being acknowledged as beneficial in enhancing the corrosion resistance of iron. The purpose of the present work (using Fe-X binary alloy models) is to explore the effect of the remaining alloying elements (Mn, Co, Al, W, B, C and S) and one detrimental impurity element Sn on the biodegradability and biocompatibility of pure iron by scanning electron microscopy, X-ray diffraction, metallographic observation, tensile testing, microhardness testing, electrochemical testing, static (for 6 months) and dynamic (for 1 month with various dissolved oxygen concentrations) immersion testing, cytotoxicity testing, hemolysis and platelet adhesion testing. The results showed that the addition of all alloying elements except for Sn improved the mechanical properties of iron after rolling. Localized corrosion of Fe-X binary alloys was observed in both static and dynamic immersion tests. Except for the Fe-Mn alloy, which showed a significant decrease in corrosion rate, the other Fe-X binary alloy corrosion rates were close to that of pure iron. It was found that compared with pure iron all Fe-X binary alloys decreased the viability of the L929 cell line, none of experimental alloying elements significantly reduced the viability of vascular smooth muscle cells and all the elements except for Mn increased the viability of the ECV304 cell line. The hemolysis percentage of all Fe-X binary alloy models were less than 5%, and no sign of thrombogenicity was observed. In vitro corrosion and the biological behavior of these Fe-X binary alloys are discussed and a corresponding mechanism of corrosion of Fe-X binary alloys in Hank's solution proposed. As a

  16. Preliminary neutronic assessment for ATF (Accident Tolerant Fuel) based on iron alloy

    International Nuclear Information System (INIS)

    Abe, Alfredo; Carluccio, Thiago; Piovezan, Pamela; Giovedi, Claudia; Martins, Marcelo R.

    2015-01-01

    After Fukushima Daiichi nuclear accident in 2011, the nuclear fuel performance under accident condition became a very important issue and currently different research and development program are in progress toward to reliability and withstand under accident condition. These initiatives are known as ATF (Accident Tolerant Fuel) R and D program, which many countries with different research institutes, fuel vendors and others are nowadays involved. Accident Tolerant Fuel (ATF) can be defined as enhanced fuel which can tolerate loss of active cooling system capability for a considerably longer time period and the fuel/cladding system can be maintained without significant degradation and can also improve the fuel performance during normal operations and transients, as well as design-basis accident (DBA) and beyond design-basis (BDBA) accident. Different materials have being proposed as fuel cladding candidates considering thermo-mechanical properties and lower reaction kinetic with steam and slower hydrogen production. The aim of this work is to perform a neutronic assessment for several cladding candidates based on iron alloy considering a standard PWR fuel rod (fuel pellet and dimension). The purpose of the assessment is to address different parameters that might contribute for possible neutronic reactivity gain in order to overcome the penalty due to increase of neutron absorption in the cladding materials. All the neutronic assessment is performed using MCNP, Monte Carlo code. (author)

  17. Statistical study to determine the effect of carbon, silicon, nickel and other alloying elements on the mechanical properties of as-cast ferritic ductile irons

    International Nuclear Information System (INIS)

    Lacaze, J.; Sertucha, J.; Larranaga, P.; Suarez, R.

    2016-01-01

    There is a great interest in fully ferritic ductile irons due to their structural homogeneity, remarkable ductility and good response when machining. On the other hand the wide variety of raw materials available in foundry plants becomes a problem when controlling the chemical composition of the manufactured alloys. The present work shows a statistical study about the effect of different C, Si, Ni contents and other minor elements on structural and mechanical properties of a group of ferritic ductile iron alloys. A set of equations are finally presented to predict room temperature mechanical properties of ferritic ductile irons by means of their chemical composition and pearlite content. (Author)

  18. Statistical study to determine the effect of carbon, silicon, nickel and other alloying elements on the mechanical properties of as-cast ferritic ductile irons

    Energy Technology Data Exchange (ETDEWEB)

    Lacaze, J.; Sertucha, J.; Larranaga, P.; Suarez, R.

    2016-10-01

    There is a great interest in fully ferritic ductile irons due to their structural homogeneity, remarkable ductility and good response when machining. On the other hand the wide variety of raw materials available in foundry plants becomes a problem when controlling the chemical composition of the manufactured alloys. The present work shows a statistical study about the effect of different C, Si, Ni contents and other minor elements on structural and mechanical properties of a group of ferritic ductile iron alloys. A set of equations are finally presented to predict room temperature mechanical properties of ferritic ductile irons by means of their chemical composition and pearlite content. (Author)

  19. Doxorubicin loaded PVA coated iron oxide nanoparticles for targeted drug delivery

    International Nuclear Information System (INIS)

    Kayal, S.; Ramanujan, R.V.

    2010-01-01

    Magnetic drug targeting is a drug delivery system that can be used in locoregional cancer treatment. Coated magnetic particles, called carriers, are very useful for delivering chemotherapeutic drugs. Magnetic carriers were synthesized by coprecipitation of iron oxide followed by coating with polyvinyl alcohol (PVA). Characterization was carried out using X-ray diffraction, TEM, TGA, FTIR and VSM techniques. The magnetic core of the carriers was magnetite (Fe 3 O 4 ), with average size of 10 nm. The room temperature VSM measurements showed that magnetic particles were superparamagnetic. The amount of PVA bound to the iron oxide nanoparticles were estimated by thermogravimetric analysis (TGA) and the attachment of PVA to the iron oxide nanoparticles was confirmed by FTIR analysis. Doxorubicin (DOX) drug loading and release profiles of PVA coated iron oxide nanoparticles showed that up to 45% of adsorbed drug was released in 80 h, the drug release followed the Fickian diffusion-controlled process. The binding of DOX to the PVA was confirmed by FTIR analysis. The present findings show that DOX loaded PVA coated iron oxide nanoparticles are promising for magnetically targeted drug delivery.

  20. The applicaton of neutron radioscopy to lithium-aluminum alloy target elements

    International Nuclear Information System (INIS)

    Antal, J.J.; Marotta, A.S.; Salaymeh, S.R.; Varallo, T.P.

    1989-01-01

    The authors show that neutron radioscopy is very useful in locating the position of a Li-A1 alloy core enriched in Lithium-6 in tubular aluminum target elements. The alloy core is displaced during a forming process and its location must be redetermined before processing can be completed. A low-flux mobile neutron radioscopy system was employed in these studies as a model system for possible on-line, in-plant use. A series of core end sections of target tubes containing from 0.1 to 4.6 grams of Lithium-6 per foot of length were examined radioscopically with thermal neutrons. The system was able to determine the extent of lithium alloy core from the highest concentrations down to about 0.2 grams of Lithium-6 per ft within one minute of data collection time

  1. Final report on in-reactor uniaxial tensile deformation of pure iron and Fe-Cr alloy

    International Nuclear Information System (INIS)

    Singh, B.N.; Xiaoxu Huang; Taehtinen, S.; Moilamen, P.; Jacquet, P.; Dekeyser, J.

    2007-11-01

    Traditionally, the effect of irradiation on mechanical properties of metals and alloys is determined using post-irradiation tests carried out on pre-irradiated specimens and in the absence of irradiation environment. The results of these tests may not be representative of deformation behaviour of materials used in the structural components of a fission or fusion reactor where the materials will be exposed concurrently to displacement damage and external and/or internal stresses. In an effort to evaluate and understand the dynamic response of materials under these conditions, we have recently performed a series of uniaxial tensile tests on Fe-Cr and pure iron specimens in the BR-2 reactor at Mol (Belgium). The present report first provides a brief description of the test facilities and the procedure used for performing the in-reactor tests. The results on the mechanical response of materials during these tests are presented in the form of stress-displacement dose and the conventional stress-strain curves. For comparison, the results of post-irradiation tests and tests carried out on unirradiated specimens are also presented. Results of microstructural investigations on the unirradiated and deformed, irradiated and undeformed, post-irradiation deformed and the in-reactor deformed specimens are also described. During the in-reactor tests the specimens of both Fe-Cr alloy and pure iron deform in a homogeneous manner and do not exhibit the phenomenon of yield drop. An increase in the pre-yield dose increases the yield stress but not the level of maximum flow stress during the in-reactor deformation of Fe-Cr alloy. Neither the in-reactor nor the post-irradiation deformed specimens of Fe-Cr alloy and pure iron showed any evidence of cleared channel formation. Both in Fe-Cr and pure iron, the in-reactor deformation leads to accumulation of dislocations in a homogeneous fashion and only to a modest density. No dislocation cells are formed during the in-reactor or post

  2. Theoretical study of the correlation between magnetism and the properties of defects in iron, chromium and their alloys

    International Nuclear Information System (INIS)

    Soulairol, R.

    2011-09-01

    This PhD thesis is devoted to the study of the correlation between the magnetism and the properties of defects in 3d metals, mainly iron- and chromium-based systems, which are used in many technological applications, such as the new-generation nuclear reactors. This work is based on two complementary approaches: the Density Functional Theory (DFT) and a Tight Binding model (TB). We begin this study by the properties of pure materials such as chromium and α-iron. For the first one, we observe that the presence of a spin density wave (SDW) induces an anisotropy in the formation of point defects as well as the migration of vacancies. For the second, the solution energy of various 3d impurities depends on two terms: a chemical contribution mainly linked to the difference between the number of d electrons of iron and solute, and a magnetic contribution that reveals to be predominant in Fe-Cr. In the following parts, we tackle the correlation between magnetism and extended defects. We show in particular that the existence of magnetic frustrations near Fe/Cr interfaces can lead to the creation of non collinear magnetic structures. It also influences the energetic stability of these interfaces. We have noticed, in agreement with experimental findings, the presence of SDW near Fe/Cr interfaces, which is able to decrease those magnetic frustrations at the interface. We have also studied the magnetic structure of iron or chromium clusters embedded in an Fe-Cr alloy. We have finally shown, in the last part of this work, how the TB approach was able to account for the energetic and magnetic properties of defects not only in pure iron or chromium, but also in Fe-Cr alloys. (author)

  3. Synthesis and characterization of iron-cobalt (FeCo) alloy nanoparticles supported on carbon

    DEFF Research Database (Denmark)

    Koutsopoulos, Sotiris; Barfod, Rasmus; Eriksen, Kim Michael

    2017-01-01

    of the alloy nanoparticles differed depending on the preparation method. When the wet impregnation technique of acetate precursor salts of Fe and Co were used for the synthesis, the size of FeCo alloy nanoparticles was approximately 13 nm. FeCo alloy nanoparticles were characterized by crystallography (XRD...

  4. The effect of thermal processing on microstructure and mechanical properties in a nickel-iron alloy

    Science.gov (United States)

    Yang, Ling

    The correlation between processing conditions, resulted microstructure and mechanical properties is of interest in the field of metallurgy for centuries. In this work, we investigated the effect of thermal processing parameters on microstructure, and key mechanical properties to turbine rotor design: tensile yield strength and crack growth resistance, for a nickel-iron based superalloy Inconel 706. The first step of the designing of experiments is to find parameter ranges for thermal processing. Physical metallurgy on superalloys was combined with finite element analysis to estimate variations in thermal histories for a large Alloy 706 forging, and the results were adopted for designing of experiments. Through the systematic study, correlation was found between the processing parameters and the microstructure. Five different types of grain boundaries were identified by optical metallography, fractography, and transmission electron microscopy, and they were found to be associated with eta precipitation at the grain boundaries. Proportions of types of boundaries, eta size, spacing and angle respect to the grain boundary were found to be dependent on processing parameters. Differences in grain interior precipitates were also identified, and correlated with processing conditions. Further, a strong correlation between microstructure and mechanical properties was identified. The grain boundary precipitates affect the time dependent crack propagation resistance, and different types of boundaries have different levels of resistance. Grain interior precipitates were correlated with tensile yield strength. It was also found that there is a strong environmental effect on time dependent crack propagation resistance, and the sensitivity to environmental damage is microstructure dependent. The microstructure with eta decorated on grain boundaries by controlled processing parameters is more resistant to environmental damage through oxygen embrittlement than material without eta

  5. Alloys of nickel-iron and nickel-silicon do not swell under fast neutron irradiation

    International Nuclear Information System (INIS)

    Silvestre, G.; Silvent, A.; Regnard, C.; Sainfort, G.

    1975-01-01

    This research is concerned with the effect of fast-neutron irradiation on the swelling of nickel and nickel alloys. Ni-Fe (0-60at%Fe) and Ni-Si (0-8at%Si) were studied, and the fluences were in the range 10 20 -4.3x10 22 n/cm 2 . In dilute alloys, the added elements are dissolved and reduce swelling, silicon being particularly effective. In more concentrated alloys, irradiation of Ni-Fe and Ni-Si alloys brings about the formation of plate-shaped precipitates of Ni 3 X and these alloys do not swell. (Auth.)

  6. Pure-iron/iron-based-alloy hybrid soft magnetic powder cores compacted at ultra-high pressure

    Science.gov (United States)

    Saito, Tatsuya; Tsuruta, Hijiri; Watanabe, Asako; Ishimine, Tomoyuki; Ueno, Tomoyuki

    2018-04-01

    We developed Fe/FeSiAl soft magnetic powder cores (SMCs) for realizing the miniaturization and high efficiency of an electromagnetic conversion coil in the high-frequency range (˜20 kHz). We found that Fe/FeSiAl SMCs can be formed with a higher density under higher compaction pressure than pure-iron SMCs. These SMCs delivered a saturation magnetic flux density of 1.7 T and iron loss (W1/20k) of 158 kW/m3. The proposed SMCs exhibited similar excellent characteristics even in block shapes, which are closer to the product shapes.

  7. Pure-iron/iron-based-alloy hybrid soft magnetic powder cores compacted at ultra-high pressure

    Directory of Open Access Journals (Sweden)

    Tatsuya Saito

    2018-04-01

    Full Text Available We developed Fe/FeSiAl soft magnetic powder cores (SMCs for realizing the miniaturization and high efficiency of an electromagnetic conversion coil in the high-frequency range (∼20 kHz. We found that Fe/FeSiAl SMCs can be formed with a higher density under higher compaction pressure than pure-iron SMCs. These SMCs delivered a saturation magnetic flux density of 1.7 T and iron loss (W1/20k of 158 kW/m3. The proposed SMCs exhibited similar excellent characteristics even in block shapes, which are closer to the product shapes.

  8. Study on wear resistance of vanadium alloying compacted/vermicular graphite cast iron

    International Nuclear Information System (INIS)

    Park, Yoon Woo

    1987-01-01

    Wear resistance of the Compacted/Vermicular graphite cast irons was studied by changing the vanadium content in the cast irons. The results obtained in this work are summarized as follows. 1. When the same amount of vanadium was added to the flake graphite cast iron, spheroidal graphitecast iron and Compacted/Vermicular graphite cast iron, spheroidal graphite cast iron and Compacted/Vermicular graphite cast iron wear resistance decreased in following sequence, that is, flake graphite cast iron> spheroidal graphite cast iron>Compacted/Vermicular graphite cast iron. 2. Addition of vanadium to the Compacted/Vermicular cast iron leaded to a remarkable increase in hardness because it made the amount of pearlite in matrix increase. 3. Addition of vanadium to the compacted/Vermicular graphite cast iron significantly enhanced wear resistance and the maximum resistance was achieved at about 0.36% vanadium. 4. The maximum amount of wear apppeared at sliding speed of about 1.4m/sec and wear mode was considered to be oxidation abrasion from the observation of wear tracks. (Author)

  9. Contribution to the Study of the Relation between Microstructure and Electrochemical Behavior of Iron-Based FeCoC Ternary Alloys

    Directory of Open Access Journals (Sweden)

    Farida Benhalla-Haddad

    2012-01-01

    Full Text Available This work deals with the relation between microstructure and electrochemical behavior of four iron-based FeCoC ternary alloys. First, the arc-melted studied alloys were characterized using differential thermal analyses and scanning electron microscopy. The established solidification sequences of these alloys show the presence of two primary crystallization phases (δ(Fe and graphite as well as two univariante lines : peritectic L+(Fe↔(Fe and eutectic L↔(Fe+Cgraphite. The ternary alloys were thereafter studied in nondeaerated solution of 10−3 M NaHCO3 + 10−3 M Na2SO4, at 25°C, by means of the potentiodynamic technique. The results indicate that the corrosion resistance of the FeCoC alloys depends on the carbon amount and the morphology of the phases present in the studied alloys.

  10. Lactoferrin modified graphene oxide iron oxide nanocomposite for glioma-targeted drug delivery.

    Science.gov (United States)

    Song, Meng-Meng; Xu, Huai-Liang; Liang, Jun-Xing; Xiang, Hui-Hui; Liu, Rui; Shen, Yu-Xian

    2017-08-01

    Targeting delivery of drugs in a specific manner represents a potential powerful technology in gliomas. Herein, we prepared a multifunctional targeted delivery system based on graphene oxide (GO) that contains a molecular bio-targeting ligand and superparamagnetic iron oxide nanoparticles on the surface of GO for magnetic targeting. Superparamagnetic Fe 3 O 4 nanoparticles was loaded on the surface of GO via chemical precipitation method to form GO@Fe 3 O 4 nanocomposites. Lactoferrin (Lf), an iron-transporting serum glycoprotein that binds to receptors overexpressed at the surface of glioma cells and vascular endothelial cell of the blood brain barrier, was chosen as the targeted ligand to construct the targeted delivery system Lf@GO@Fe 3 O 4 through EDC/NHS chemistry. With the confirmation of TEM, DLS and VSM, the resulting Lf@GO@Fe 3 O 4 had a size distribution of 200-1000nm and exhibited a superparamagnetic behavior. The nano delivery system had a high loading capacity and exhibited a pH-dependent release behavior. Compared with free DOX and DOX@GO@Fe 3 O 4 , Lf@GO@Fe 3 O 4 @DOX displayed greater intracellular delivery efficiency and stronger cytotoxicity against C6 glioma cells. The results demonstrated the potential utility of Lf conjugated GO@Fe 3 O 4 nanocomposites for therapeutic application in the treatment of gliomas. Copyright © 2017. Published by Elsevier B.V.

  11. On the rolling of hard-to-work iron-cobalt alloys with application of electric current of high density

    International Nuclear Information System (INIS)

    Klimov, K.M.; Mordukhovich, A.M.; Glezer, A.M.; Molotilov, B.V.

    1981-01-01

    Results on experimental fabrication of thin sheets of commercial iron-cobalt 49KF alloy (Se-Co-2%V) without preliminary quenching and intermediate annealings by rolling with application of high-density electric current are considered. It is shown that rolling with application of high-density electric current in the deformation zone permits to obtain thin sheets of difficult-to-form magnetically soft materials without preliminary thermal treatments. Electric current effect on metal in the deformation zone results in the increase of dislocation mobility and facilitates the cross glide [ru

  12. Investigation of electrochemical synthesis of ferrate, Part I: Electrochemical behavior of iron and its several alloys in concentrated alkaline solutions

    Directory of Open Access Journals (Sweden)

    Čekerevac Milan I.

    2009-01-01

    Full Text Available In recent years, considerable attention has been paid to various applications of Fe(VI due to its unique properties such as oxidizing power, selective reactivity, stability of the salt, and non-toxic decomposition by-products of ferric ion. In environmental remediation processes, Fe(VI has been proposed as green oxidant, coagulant, disinfectant, and antifoulant. Therefore, it is considered as a promising multi-purpose water treatment chemical. Fe(VI has also potential applications in electrochemical energy source, as 'green cathode'. The effectiveness of ferrate as a powerful oxidant in the entire pH range, and its use in environmental applications for the removal of wide range of contaminants has been well documented by several researchers. There is scientific evidence that ferrate can effectively remove arsenic, algae, viruses, pharmaceutical waste, and other toxic heavy metals. Although Fe(VI was first discovered in early eighteen century, detailed studies on physical and chemical properties of Fe(VI had to wait until efficient synthetic and analytical methods of Fe(VI were developed by Schreyer et al. in the 1950s. Actually, there have been developed three ways for the preparation of Fe(VI compounds : the wet oxidation of Fe(II and Fe(III compounds, the dry oxidation of the same, and the electrochemistry method, mainly based on the trans passive oxidation of iron. High purity ferrates Fe(VI can be generated when electrode of the pure iron metal or its alloys are anodized in concentrated alkaline solution. It is known that the efficiency of electrochemical process of Fe(VI production depends on many factors such as current density, composition of anode material, types of electrolyte etc. In this paper, the electrochemical synthesis of ferrate(VI solution by the anodic dissolution of iron and its alloys in concentrated water solution of NaOH and KOH is investigated. The process of transpassive dissolution of iron to ferrate(VI was studied by

  13. Iron

    DEFF Research Database (Denmark)

    Hansen, Jakob Bondo; Moen, I W; Mandrup-Poulsen, T

    2014-01-01

    and discuss recent evidence, suggesting that iron is a key pathogenic factor in both type 1 and type 2 diabetes with a focus on inflammatory pathways. Pro-inflammatory cytokine-induced β-cell death is not fully understood, but may include iron-induced ROS formation resulting in dedifferentiation by activation...... of transcription factors, activation of the mitochondrial apoptotic machinery or of other cell death mechanisms. The pro-inflammatory cytokine IL-1β facilitates divalent metal transporter 1 (DMT1)-induced β-cell iron uptake and consequently ROS formation and apoptosis, and we propose that this mechanism provides...

  14. Iron

    Science.gov (United States)

    ... Share: Search the ODS website Submit Search NIH Office of Dietary Supplements Consumer Datos en español Health ... eating a variety of foods, including the following: Lean meat, seafood, and poultry. Iron-fortified breakfast cereals ...

  15. Four-branched compounds coupled Si and iron-rich intermetallics in near eutectic Al-Si alloys

    International Nuclear Information System (INIS)

    Wu, Yuying; Liu, Xiangfa; Jiang, Binggang; Bian, Xiufang

    2007-01-01

    Many four-branched compounds coupled Si and iron-rich intermetallics were observed in near eutectic Al-Si alloy modified with Al-P master alloy. Such four-branched compounds have never been reported before, but in our case it seems to be commonly observed. In this work the growth characterization of the four-branched compounds are scrutinized with a JXA-8800 electron microprobe (EPMA). More deep study of the formation of four-branched compounds is performed by SEM and TEM analysis. The characterization of the four-branched compounds is that of a primary silicon in the center with four iron-rich intermetallics around. Experimental results also show that the precipitation of primary silicon is the key factor for the formation of four-branched compounds. And WHS-theory explains the growth mechanism of the four-branched compounds. In detail, subsequent twinning within the primary silicon provides four-fold coordination sites on the surface, and then the α-Al(Fe,Mn)-Si phase nucleates on the surface of the primary silicon

  16. Lactoferrin conjugated iron oxide nanoparticles for targeting brain glioma cells in magnetic particle imaging

    Science.gov (United States)

    Tomitaka, Asahi; Arami, Hamed; Gandhi, Sonu; Krishnan, Kannan M.

    2015-10-01

    Magnetic Particle Imaging (MPI) is a new real-time imaging modality, which promises high tracer mass sensitivity and spatial resolution directly generated from iron oxide nanoparticles. In this study, monodisperse iron oxide nanoparticles with median core diameters ranging from 14 to 26 nm were synthesized and their surface was conjugated with lactoferrin to convert them into brain glioma targeting agents. The conjugation was confirmed with the increase of the hydrodynamic diameters, change of zeta potential, and Bradford assay. Magnetic particle spectrometry (MPS), performed to evaluate the MPI performance of these nanoparticles, showed no change in signal after lactoferrin conjugation to nanoparticles for all core diameters, suggesting that the MPI signal is dominated by Néel relaxation and thus independent of hydrodynamic size difference or presence of coating molecules before and after conjugations. For this range of core sizes (14-26 nm), both MPS signal intensity and spatial resolution improved with increasing core diameter of nanoparticles. The lactoferrin conjugated iron oxide nanoparticles (Lf-IONPs) showed specific cellular internalization into C6 cells with a 5-fold increase in MPS signal compared to IONPs without lactoferrin, both after 24 h incubation. These results suggest that Lf-IONPs can be used as tracers for targeted brain glioma imaging using MPI.

  17. Cast irons

    CERN Document Server

    1996-01-01

    Cast iron offers the design engineer a low-cost, high-strength material that can be easily melted and poured into a wide variety of useful, and sometimes complex, shapes. This latest handbook from ASM covers the entire spectrum of one of the most widely used and versatile of all engineered materials. The reader will find the basic, but vital, information on metallurgy, solidification characteristics, and properties. Extensive reviews are presented on the low-alloy gray, ductile, compacted graphite, and malleable irons. New and expanded material has been added covering high-alloy white irons used for abrasion resistance and high-alloy graphitic irons for heat and corrosion resistance. Also discussed are melting furnaces and foundry practices such as melting, inoculation, alloying, pouring, gating and rising, and molding. Heat treating practices including stress relieving, annealing, normalizing, hardening and tempering, autempering (of ductile irons), and surface-hardening treatments are covered, too. ASM Spec...

  18. Biased Target Ion Beam Deposition and Nanoskiving for Fabricating NiTi Alloy Nanowires

    Science.gov (United States)

    Hou, Huilong; Horn, Mark W.; Hamilton, Reginald F.

    2016-12-01

    Nanoskiving is a novel nanofabrication technique to produce shape memory alloy nanowires. Our previous work was the first to successfully fabricate NiTi alloy nanowires using the top-down approach, which leverages thin film technology and ultramicrotomy for ultra-thin sectioning. For this work, we utilized biased target ion beam deposition technology to fabricate nanoscale (i.e., sub-micrometer) NiTi alloy thin films. In contrast to our previous work, rapid thermal annealing was employed for heat treatment, and the B2 austenite to R-phase martensitic transformation was confirmed using stress-temperature and diffraction measurements. The ultramicrotome was programmable and facilitated sectioning the films to produce nanowires with thickness-to-width ratios ranging from 4:1 to 16:1. Energy dispersive X-ray spectroscopy analysis confirmed the elemental Ni and Ti make-up of the wires. The findings exposed the nanowires exhibited a natural ribbon-like curvature, which depended on the thickness-to-width ratio. The results demonstrate nanoskiving is a potential nanofabrication technique for producing NiTi alloy nanowires that are continuous with an unprecedented length on the order of hundreds of micrometers.

  19. Corrosion resistance of cast irons and titanium alloys as reference engineered metal barriers for use in basalt geologic storage: a literature assessment

    International Nuclear Information System (INIS)

    Charlot, L.A.; Westerman, R.E.

    1981-07-01

    A survey and assessment of the literature on the corrosion resistance of cast irons and low-alloy titanium are presented. Selected engineering properties of cast iron and titanium are briefly described; however, the corrosion resistance of cast iron and titanium in aqueous solutions or in soils and their use in a basalt repository are emphasized. In evaluating the potential use of cast iron and titanium as structural barrier materials for long-lived nuclear waste packages, it is assumed that titanium has the general corrosion resistance to be used in relatively thin cross sections whereas the cost and availability of cast iron allows its use even in very thick cross sections. Based on this assumption, the survey showed that: The uniform corrosion of low-alloy titanium in a basalt environment is expected to be extremely low. A linear extrapolation of general corrosion rates with an added corrosion allowance suggests that a 3.2- to 6.4-mm-thick wall may have a life of 1000 yr. Pitting and crevice corrosion are not likely corrosion modes in basalt ground waters. It is also unlikely that stress corrosion cracking (SCC) will occur in the commercially pure (CP) titanium alloy or in palladiumor molybdenum-alloyed titanium materials. Low-alloy cast irons may be used as barrier metals if the environment surrounding the metal keeps the alloy in the passive range. The solubility of the corrosion product and the semipermeable nature of the oxide film allow significant uniform corrosion over long time periods. A linear extrapolation of high-temperature corrosion rates on carbon steels and corrosion rates of cast irons in soils gives an estimated metal penetration of 51 to 64 mm after 1000 yr. A corrosion allowance of 3 to 5 times that suggests that an acceptable cast iron wall may be from 178 to 305 mm thick. Although they cannot be fully assessed, pitting and crevice corrosion should not affect cast iron due to the ground-water chemistry of basalt

  20. Orthogonal Clickable Iron Oxide Nanoparticle Platform for Targeting, Imaging, and On-Demand Release.

    Science.gov (United States)

    Guldris, Noelia; Gallo, Juan; García-Hevia, Lorena; Rivas, José; Bañobre-López, Manuel; Salonen, Laura M

    2018-04-12

    A versatile iron oxide nanoparticle platform is reported that can be orthogonally functionalized to obtain highly derivatized nanomaterials required for a wide variety of applications, such as drug delivery, targeted therapy, or imaging. Facile functionalization of the nanoparticles with two ligands containing isocyanate moieties allows for high coverage of the surface with maleimide and alkyne groups. As a proof-of-principle, the nanoparticles were subsequently functionalized with a fluorophore as a drug model and with biotin as a targeting ligand towards tumor cells through Diels-Alder and azide-alkyne cycloaddition reactions, respectively. The thermoreversibility of the Diels-Alder product was exploited to induce the on-demand release of the loaded molecules by magnetic hyperthermia. Additionally, the nanoparticles were shown to target cancer cells through in vitro experiments, as analyzed by magnetic resonance imaging. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Iron alloy Fischer-tropsch catalysts--1. Oxidation-reduction studies of the Fe-Ni system

    Energy Technology Data Exchange (ETDEWEB)

    Unmuth, E.E.; Schwartz, L.H.; Butt, J.B.

    1980-01-01

    Catalysts containing 5% iron, nickel, or 4:1 iron-nickel on silica were hydrogen-reduced at 425/sup 0/C for 12 or 24 hr, reoxidized in air for 2 or 4 hr, reduced again in hydrogen for 12 hr, and studied at each treatment step by Moessbauer spectroscopy, X-ray diffraction, and temperature-programed desorption. The nickel was reduced directly to the metal, redispersed during the oxidation, and gave 20% smaller particles in the second reduction than in the first reduction. The ..cap alpha..-Fe/sub 2/O/sub 3/ reduced via an Fe/sub 3/O/sub 4/ intermediate and yielded approx. 70% metallic iron and the second reduction produced about the same particle size as the first reduction. The alloy catalyst reduced into a mixture of two phases, a face-centered cubic phase containing approx. 37.5% Ni, i.e., the bulk equilibrium value, and a body-centered cubic phase, and the particle sizes obtained in the first and second reductions were similar. The activation energies for the reduction were determined.

  2. Preparation and Cycling Performance of Iron or Iron Oxide Containing Amorphous Al-Li Alloys as Electrodes

    Directory of Open Access Journals (Sweden)

    Franziska Thoss

    2014-12-01

    Full Text Available Crystalline phase transitions cause volume changes, which entails a fast destroying of the electrode. Non-crystalline states may avoid this circumstance. Herein we present structural and electrochemical investigations of pre-lithiated, amorphous Al39Li43Fe13Si5-powders, to be used as electrode material for Li-ion batteries. Powders of master alloys with the compositions Al39Li43Fe13Si5 and Al39Li43Fe13Si5 + 5 mass-% FeO were prepared via ball milling and achieved amorphous/nanocrystalline states after 56 and 21.6 h, respectively. In contrast to their Li-free amorphous pendant Al78Fe13Si9, both powders showed specific capacities of about 400 and 700 Ah/kgAl, respectively, after the third cycle.

  3. Effect of deep cryogenic treatment and tempering on microstructure and mechanical behaviors of a wear-resistant austempered alloyed bainitic ductile iron

    Directory of Open Access Journals (Sweden)

    Chen Liqing

    2015-01-01

    Full Text Available In this paper, the effect of deep cryogenic treatment in combination with conven- tional heat treatment process was investigated on microstructure and mechanical behaviors of alloyed bainitic ductile iron. Three processing schedules were employed to treat this alloyed ductile iron including direct tempering treatment, tempering.+deep cryogenic treatment and deep cryogenic treatment.+tempering treatments. The microstructure and mechanical behavior, especially the wear resistance, have been evaluated after treated by these three schedules. The results show that martensite microstructure can be obviously refined and the precipitation of dispersed carbides is promoted by deep cryogenic treatment at .−196 ∘C for 3 h after tempered at 450 ∘C for 2 h. In this case, the alloyed bainitic ductile iron possesses rather high hardness and wear-resistance than those processed by other two schedules. The main wear mechanism of the austempered alloyed ductile iron with deep cryogenic treatment and tempering is micro-cutting wear in association with plastic deformation wear.

  4. Study of soft magnetic iron cobalt based alloys processed by powder injection molding

    International Nuclear Information System (INIS)

    Silva, Aline; Lozano, Jaime A.; Machado, Ricardo; Escobar, Jairo A.; Wendhausen, Paulo A.P.

    2008-01-01

    As a near net shape process, powder injection molding (PIM) opens new possibilities to process Fe-Co alloys for magnetic applications. Due to the fact that PIM does not involve plastic deformation of the material during processing, we envisioned the possibility of eliminating vanadium (V), which is generally added to Fe-Co alloys to improve the ductility in order to enable its further shaping by conventional processes such as forging and cold rolling. In our investigation we have found out two main futures related to the elimination of V, which lead to a cost-benefit gain in manufacturing small magnetic components where high-saturation induction is needed at low frequencies. Firstly, the elimination of V enables the achievement of much better magnetic properties when alloys are processed by PIM. Secondly, a lower sintering temperature can be used when the alloy is processed starting with elemental Fe and Co powders without the addition of V

  5. Templated synthesis of gold-iron alloy nanoparticles using pulsed laser deposition

    International Nuclear Information System (INIS)

    Chang, Won-Suk; Park, Jin-Won; Rawat, Vijay; Sands, Timothy; Lee, Gil U

    2006-01-01

    A means for synthesizing paramagnetic nanoparticles composed of an Au-Fe alloy is described using pulsed laser deposition (PLD) of the alloy into a mesoporous alumina membrane template. Nanoparticles 46 ± 13 nm in diameter and composed of a 17% Fe alloy have been created by depositing a 35% Fe alloy into a template with 65 nm diameter pores. These paramagnetic nanoparticles had a saturation magnetization of 11.5 emu g -1 at 2000 G, and their UV-visible extinction spectrum was dominated by strong absorption similar to that of Fe 3 O 4 nanoparticles. The surfaces of these nanoparticles were readily functionalized with a dense monolayer of DNA oligonucleotides that had a 5' thiol group. The Au-Fe nanoparticles appear to be well suited for biotechnological applications and single molecule measurements as they can be synthesized in a specific size range, are strongly paramagnetic, and may be easily functionalized with biological macromolecules

  6. Effect of cold working on the stress corrosion cracking resistance of nickel-chromium-iron alloys

    International Nuclear Information System (INIS)

    Yonezawa, T.; Onimura, K.

    1987-01-01

    In order to grasp the stress corrosion cracking resistance of cold worked nickel base alloys in PWR primary water, the effect of cold working on the stress corrosion cracking resistance of alloys 600, X-750 and 690, in high temperature water, have been studied. Stress corrosion cracking tests were conducted at 360 0 C (633K) in a simulated PWR primary water for about 12,000 hours (43.2Ms). From the test results, it is concluded that the stress corrosion cracking resistance in the cold worked Alloy 600 at the same applied stress level increases with an increase in cold working ratio, and the cold worked alloys of thermally treated 690 and X-750 have excellent stress corrosion cracking resistance. (Author)

  7. X-ray diffraction (XRD) characterization of microstrain in some iron and uranium alloys

    International Nuclear Information System (INIS)

    Kimmel, G.; Dayan, D.; Frank, G.A.; Landau, A.

    1996-01-01

    The high linear attenuation coefficient of steel, uranium and uranium based alloys is associated with the small penetration depth of X-rays with the usual wavelength used for diffraction. Nevertheless, by using the proper surface preparation technique, it is possible of obtaining surfaces with bulk properties (free of residual mechanical microstrain). Taking advantage of the feasibility to obtain well prepared surfaces, extensive work has been conducted in studying XRD line broadening effects from flat polycrystalline samples of steel, uranium and uranium alloys

  8. Microstructural and magnetic characterization of iron precipitation in Ni-Fe-Al alloys

    International Nuclear Information System (INIS)

    Duman, Nagehan; Mekhrabov, Amdulla O.; Akdeniz, M. Vedat

    2011-01-01

    The influence of annealing on the microstructural evolution and magnetic properties of Ni 50 Fe x Al 50-x alloys for x = 20, 25, and 30 has been investigated. Solidification microstructures of as-cast alloys reveal coarse grains of a single B2 type β-phase and typical off eutectic microstructure consisting of proeutectic B2 type β dendrites and interdendritic eutectic for x = 20 and x > 20 at.% Fe respectively. However, annealing at 1073 K results in the formation of FCC γ-phase particles along the grain boundaries as well as grain interior in x = 20 at.% Fe alloy. The volume fraction of interdentritic eutectic regions tend to decrease and their morphologies start to degenerate by forming FCC γ-phase for x > 20 at.% Fe alloys with increasing annealing temperatures. Increasing Fe content of alloys induce an enhancement in magnetization and a rise in the Curie transition temperature (T C ). Temperature scan magnetic measurements and transmission electron microscopy reveal that a transient rise in the magnetization at temperatures well above the T C of the alloys would be attributed to the precipitation of a nano-scale ferromagnetic BCC α-Fe phase. Retained magnetization above the Curie transition temperature of alloy matrix, together with enhanced room temperature saturation magnetization of alloys annealed at favorable temperatures support the presence of ferromagnetic precipitates. These nano-scale precipitates are shown to induce significant precipitation hardening of the β-phase in conjunction with enhanced room temperature saturation magnetization in particular when an annealing temperature of 673 K is used. - Research Highlights: → Evolution of microstructure and magnetic properties with varying Fe content. → Transient rise in magnetization via the formation of ferromagnetic phase. → Enhancements in saturation magnetization owing to precipitated ferromagnetic phase. → Nanoscale precipitation of ferromagnetic BCC α-Fe confirmed by TEM.

  9. Refinement of adsorptive coatings for fluorescent riboflavin-receptor-targeted iron oxide nanoparticles.

    Science.gov (United States)

    Tsvetkova, Yoanna; Beztsinna, Nataliia; Jayapaul, Jabadurai; Weiler, Marek; Arns, Susanne; Shi, Yang; Lammers, Twan; Kiessling, Fabian

    2016-01-01

    Flavin mononucleotide (FMN) is a riboflavin derivative that can be exploited to target the riboflavin transporters (RFTs) and the riboflavin carrier protein (RCP) in cells with high metabolic activity. In this study we present the synthesis of different FMN-coated ultrasmall superparamagnetic iron oxide nanoparticles (USPIOs) and their efficiency as targeting contrast agents. Since FMN alone cannot stabilize the nanoparticles, we used adenosine phosphates--AMP, ADP and ATP--as spacers to obtain colloidally stable nanoparticles. Nucleotides with di- and triphosphate groups were intended to increase the USPIO charge and thus improve zeta potential and stability. However, all nanoparticles formed negatively charged clusters with similar properties in terms of zeta potential (-28 ± 2 mV), relaxivity (228-259 mM(-1) s(-1) at 3 T) and hydrodynamic radius (53-85 nm). Molecules with a higher number of phosphate groups, such as ADP and ATP, have a higher adsorption affinity towards iron oxide, which, instead of providing more charge, led to partial desorption and replacement of FMN. Hence, we obtained USPIOs carrying different amounts of targeting agent, which significantly influenced the nanoparticles' uptake. The nanoparticles' uptake by different cancer cells and HUVECs was evaluated photometrically and with MR relaxometry, showing that the cellular uptake of the USPIOs increases with the FMN amount on their surface. Thus, for USPIOs targeted with riboflavin derivatives the use of spacers with increasing numbers of phosphate groups does not improve either zeta potential or the particles' stability, but rather detaches the targeting moieties from their surface, leading to lower cellular uptake. Copyright © 2015 John Wiley & Sons, Ltd.

  10. MicroRNAs and liver cancer associated with iron overload: Therapeutic targets unravelled

    Science.gov (United States)

    Greene, Catherine M; Varley, Robert B; Lawless, Matthew W

    2013-01-01

    Primary liver cancer is a global disease that is on the increase. Hepatocellular carcinoma (HCC) accounts for most primary liver cancers and has a notably low survival rate, largely attributable to late diagnosis, resistance to treatment, tumour recurrence and metastasis. MicroRNAs (miRNAs/miRs) are regulatory RNAs that modulate protein synthesis. miRNAs are involved in several biological and pathological processes including the development and progression of HCC. Given the poor outcomes with current HCC treatments, miRNAs represent an important new target for therapeutic intervention. Several studies have demonstrated their role in HCC development and progression. While many risk factors underlie the development of HCC, one process commonly altered is iron homeostasis. Iron overload occurs in several liver diseases associated with the development of HCC including Hepatitis C infection and the importance of miRNAs in iron homeostasis and hepatic iron overload is well characterised. Aberrant miRNA expression in hepatic fibrosis and injury response have been reported, as have dysregulated miRNA expression patterns affecting cell cycle progression, evasion of apoptosis, invasion and metastasis. In 2009, miR-26a delivery was shown to prevent HCC progression, highlighting its therapeutic potential. Several studies have since investigated the clinical potential of other miRNAs with one drug, Miravirsen, currently in phase II clinical trials. miRNAs also have potential as biomarkers for the diagnosis of HCC and to evaluate treatment efficacy. Ongoing studies and clinical trials suggest miRNA-based treatments and diagnostic methods will have novel clinical applications for HCC in the coming years, yielding improved HCC survival rates and patient outcomes. PMID:23983424

  11. Water based suspensions of iron oxide obtained by laser target evaporation for biomedical applications

    Energy Technology Data Exchange (ETDEWEB)

    Novoselova, I.P. [Ural Federal University, Department of Magnetism and Magnetic Nanomaterials, Lenin Ave. 51, 620083 Yekaterinburg (Russian Federation); Immanuel Kant Baltic Federal University, Science and Technology Park “Fabrica”, Gaidara St. 6, 236022 Kaliningrad (Russian Federation); Safronov, A.P. [Ural Federal University, Department of Magnetism and Magnetic Nanomaterials, Lenin Ave. 51, 620083 Yekaterinburg (Russian Federation); Institute of Electrophysics UD RAS, Amundsena St. 106, 620016 Yekaterinburg (Russian Federation); Samatov, O.M. [Institute of Electrophysics UD RAS, Amundsena St. 106, 620016 Yekaterinburg (Russian Federation); Beketov, I.V.; Medvedev, A.I. [Ural Federal University, Department of Magnetism and Magnetic Nanomaterials, Lenin Ave. 51, 620083 Yekaterinburg (Russian Federation); Institute of Electrophysics UD RAS, Amundsena St. 106, 620016 Yekaterinburg (Russian Federation); Kurlyandskaya, G.V. [Ural Federal University, Department of Magnetism and Magnetic Nanomaterials, Lenin Ave. 51, 620083 Yekaterinburg (Russian Federation); Universidad del País Vasco, UPV/EHU, Dpto. de Electricidad y Electrónica, P.O. Box 644, Bilbao 48080 (Spain)

    2016-10-01

    In this work spherical magnetic nanoparticles (MNPs) of iron oxide were obtained by laser target evaporation technique (LTE). Water based suspensions were prepared on the basis of obtained MNPs and their properties were also studied including inductive heat capacity. Their structure and properties were studied by a number of techniques including magnetometry and heat capacity measurements. Magnetic induction heating experiment show the specific loss power (SLP) value in the narrow range from 1.30 to 1.45 W/g for all samples under consideration when using alternating magnetic field of 1.7 kA/m and frequency of 210 kHz. These parameters insure that LTE MNPs are interesting materials promising for magnetic fluid hyperthermia. - Highlights: • Spheric oxide nanoparticles obtained by productive laser target evaporation method. • Experiment shows the specific loss power value in the narrow range for all samples. • Obtained results insure these objects as interesting material for hyperthermia.

  12. Water based suspensions of iron oxide obtained by laser target evaporation for biomedical applications

    International Nuclear Information System (INIS)

    Novoselova, I.P.; Safronov, A.P.; Samatov, O.M.; Beketov, I.V.; Medvedev, A.I.; Kurlyandskaya, G.V.

    2016-01-01

    In this work spherical magnetic nanoparticles (MNPs) of iron oxide were obtained by laser target evaporation technique (LTE). Water based suspensions were prepared on the basis of obtained MNPs and their properties were also studied including inductive heat capacity. Their structure and properties were studied by a number of techniques including magnetometry and heat capacity measurements. Magnetic induction heating experiment show the specific loss power (SLP) value in the narrow range from 1.30 to 1.45 W/g for all samples under consideration when using alternating magnetic field of 1.7 kA/m and frequency of 210 kHz. These parameters insure that LTE MNPs are interesting materials promising for magnetic fluid hyperthermia. - Highlights: • Spheric oxide nanoparticles obtained by productive laser target evaporation method. • Experiment shows the specific loss power value in the narrow range for all samples. • Obtained results insure these objects as interesting material for hyperthermia.

  13. APPLICATION OF SPHEROIDIZING «CHIPS»-MASTER ALLOY ON COPPER BASE CONTAINING NANOSCALE PARTICLES OF YTTRIUM OXIDE FOR HIGH-STRENGTH CAST IRON

    Directory of Open Access Journals (Sweden)

    A. S. Kalinichenko

    2016-01-01

    Full Text Available The peculiarity of the technology of obtaining high-strength cast iron is application in out-furnace treatment various inoculants containing magnesium. In practice of foundry production spheroidizing master alloys based on ferrosilicon (Fe-Si-Mg type and «heavy» alloying alloys on copper and nickel base are widespread. The urgent issue is to improve their efficiency by increasing the degree of magnesium assimilation, reduction of specific consumption of additives, and minimizing dust and gas emissions during the process of spheroidizing treatment of liquid iron. One method of solving this problem is the use of inoculants in a compact form in which the process of dissolution proceeds more efficiently. For example, rapidly quenched granules or «chip»-inoculants are interesting to apply.The aim of present work was to study the peculiarities of production and application of «Chips»-inoculants on copper and magnesium base with additions of yttrium oxide. The principle of mechatronics was used, including the briquetting inoculants’ components after their mixing with the subsequent high-speed mechanical impact and obtaining plates with a thickness of 1–2 mm.Spheroidizing treatment of molten metal has been produced by ladle method using «Chips»-inoculants in the amount of 0.8%. Secondary graphitization inoculation was not performed. Studies have shown that when the spheroidizing treatment of ductile iron was performed with inoculants developed, the process of interaction of magnesium with the liquid melt runs steadily without significant pyroeffect and emissions of metal outside of the ladle.This generates a structure of spheroidal graphite of regular shape (SGf5. The presence in the inoculant of yttrium oxide has a positive impact on the spheroidal graphite counts and the tendency of high-strength cast iron to form «white» cast iron structure. Mechanical properties of the obtained alloy correspond to high-strength cast iron HSCI60.

  14. Development of weldable, corrosion-resistant iron-aluminide (FeAl) alloys

    Energy Technology Data Exchange (ETDEWEB)

    Maziasz, P.J.; Goodwin, G.M.; Wang, X.L.; Alexander, D.J. [Oak Ridge National Lab., TN (United States)

    1997-04-01

    A boron-microalloyed FeAl alloy (Fe-36Al-0.2Mo-0.05Zr-0.13C, at.%, with 100-400 appm B) with improved weldability and mechanical properties was developed in FY 1994. A new scale-up and industry technology development phase for this work began in FY 1995, pursuing two parallel paths. One path was developing monolithic FeAl component and application technology, and the other was developing coating/cladding technology for alloy steels, stainless steels and other Fe-Cr-Ni alloys. In FY 1995, it was found that cast FeAl alloys had good strength at 700-750{degrees}C, and some (2.5%) ductility in air at room-temperature. Hot-extruded FeAl with refined grain size was found to have ductility and to also have good impact-toughness at room-temperature. Further, it was discovered that powder-metallurgy (P/M) FeAl, consolidated by direct hot-extrusion at 950-1000{degrees}C to have an ultra fine-grained microstructure, had the highest ductility, strength and impact-toughness ever seen in such intermetallic alloys.

  15. Performance of the electrical generator cell by the ferrous alloys of printed circuit board scrap and Iron Metal 1020

    Science.gov (United States)

    Sahan, Y.; Sudarsono, S.; Silviana, E.; Chairul; Wisrayetti

    2018-04-01

    Galvani cell is one of thealternative energy. This cell can be used as an electric resources. In this research, the generator cell was designed and builds to generate the electric. The generator cell consisted of the iron metal 1020 were used as anode, the ferrous alloys of printed circuit board scrapwas then used as chatode, and NaCl solution as an electrolyte. The aim of this research is to estimate the performance of this generator cell by using variation of NaCl concentration (i.e. 1%, 3%, 5%, 7%, and 9%) with the electrodes pair ( 1 and 8 pairs). The performance of the cell was measured with a multi tester equipment and a LED bulb (5-watt 3Volt). The Results shown that the generator cell can produce the electric power of 3.679 Volt maximally by using NaCl 9% and 8 electrode pairs applied for this condition.

  16. Study of the quenching and subsequent return to room temperature of uranium-chromium, uranium-iron, and uranium-molybdenum alloys containing only small amounts of the alloying element

    International Nuclear Information System (INIS)

    Delaplace, J.

    1960-09-01

    By means of an apparatus which makes possible thermal pre-treatments in vacuo, quenching carried out in a high purity argon atmosphere, and simultaneous recording of time temperature cooling and thermal contraction curves, the author has examined the transformations which occur in uranium-chromium, uranium-iron and uranium-molybdenum alloys during their quenching and subsequent return to room temperature. For uranium-chromium and uranium-iron alloys, the temperature at which the γ → β transformation starts varies very little with the rate of cooling. For uranium-molybdenum alloys containing 2,8 atom per cent of Mo, this temperature is lowered by 120 deg. C for a cooling rate of 500 deg. C/mn. The temperature at which the β → α transformation starts is lowered by 170 deg. C for a cooling rate of 500 deg. C/mn in the case of uranium-chromium alloy containing 0,37 atom per cent of Cr. The temperature is little affected in the case of uranium-iron alloys. The addition of chromium or iron makes it possible to conserve the form β at ordinary temperatures after quenching from the β and γ regions. The β phase is particularly unstable and changes into needles of the α form even at room temperatures according to an autocatalytic transformation law similar to the austenitic-martensitic transformation law in the case of iron. The β phase obtained by quenching from the β phase region is more stable than that obtained by quenching from the γ region. Chromium is a more effective stabiliser of the β phase than is iron. Unfortunately it causes serious surface cracking. The β → α transformation in uranium-chromium alloys has been followed at room temperature by means of micro-cinematography. The author has not observed the direct γ → α transformation in uranium-molybdenum alloys containing 2,8 per cent of molybdenum even for cooling rates of up to 2000 deg. C/s. He has however observed the formation of several martensitic structures. (author) [fr

  17. Development of a Novel Antimicrobial Screening System Targeting the Pyoverdine-Mediated Iron Acquisition System and Xenobiotic Efflux Pumps

    Directory of Open Access Journals (Sweden)

    Kazuki Sato

    2015-04-01

    Full Text Available The iron acquisition systems in Pseudomonas aeruginosa are inducible in response to low-iron conditions and important for growth of this organism under iron limitation. OprM is the essential outer membrane subunit of the MexAB-OprM xenobiotic efflux pump. We designed and constructed a new model antimicrobial screening system targeting both the iron-uptake system and xenobiotic efflux pumps. The oprM gene was placed immediately downstream of the ferri-pyoverdine receptor gene, fpvA, in the host lacking chromosomal oprM and the expression of oprM was monitored by an antibiotic susceptibility test under iron depleted and replete conditions. The recombinant cells showed wild-type susceptibility to pump substrate antibiotics, e.g., aztreonam, under iron limitation and became supersusceptible to them under iron repletion, suggesting that expression of oprM is under control of the iron acquisition system. Upon screening of a chemical library comprising 2952 compounds using this strain, a compound—ethyl 2-(1-acetylpiperidine-4-carboxamido-4,5,6,7-tetrahydrobenzo[b]thiophene-3-carboxylate—was found to enhance the efficacy of aztreonam under iron limitation, suggesting that the compound inhibits either the iron acquisition system or the MexAB-OprM efflux pump. This compound was subsequently found to inhibit the growth of wild-type cells in the presence of sublethal amounts of aztreonam, regardless of the presence or absence of dipyridyl, an iron-chelator. The compound was eventually identified to block the function of the MexAB-OprM efflux pump, showing the validity of this new method.

  18. Development of a novel antimicrobial screening system targeting the pyoverdine-mediated iron acquisition system and xenobiotic efflux pumps.

    Science.gov (United States)

    Sato, Kazuki; Ushioda, Kenichi; Akiba, Keiji; Matsumoto, Yoshimi; Maseda, Hideaki; Ando, Tasuke; Isogai, Emiko; Nakae, Taiji; Yoneyama, Hiroshi

    2015-04-29

    The iron acquisition systems in Pseudomonas aeruginosa are inducible in response to low-iron conditions and important for growth of this organism under iron limitation. OprM is the essential outer membrane subunit of the MexAB-OprM xenobiotic efflux pump. We designed and constructed a new model antimicrobial screening system targeting both the iron-uptake system and xenobiotic efflux pumps. The oprM gene was placed immediately downstream of the ferri-pyoverdine receptor gene, fpvA, in the host lacking chromosomal oprM and the expression of oprM was monitored by an antibiotic susceptibility test under iron depleted and replete conditions. The recombinant cells showed wild-type susceptibility to pump substrate antibiotics, e.g., aztreonam, under iron limitation and became supersusceptible to them under iron repletion, suggesting that expression of oprM is under control of the iron acquisition system. Upon screening of a chemical library comprising 2952 compounds using this strain, a compound-ethyl 2-(1-acetylpiperidine-4-carboxamido)-4,5,6,7-tetrahydrobenzo[b]thiophene-3-carboxylate-was found to enhance the efficacy of aztreonam under iron limitation, suggesting that the compound inhibits either the iron acquisition system or the MexAB-OprM efflux pump. This compound was subsequently found to inhibit the growth of wild-type cells in the presence of sublethal amounts of aztreonam, regardless of the presence or absence of dipyridyl, an iron-chelator. The compound was eventually identified to block the function of the MexAB-OprM efflux pump, showing the validity of this new method.

  19. The properties and transport phenomena in oxide films on iron, nickel, chromium and their alloys in aqueous environments

    Energy Technology Data Exchange (ETDEWEB)

    Laitinen, T.; Bojinov, M.; Betova, I.; Maekelae, K.; Saario, T. [VTT Manufacturing Technology, Espoo (Finland)

    1999-01-01

    The construction materials used in coolant systems in nuclear power plants become covered with oxide films as a result of exposure to the aqueous environment. The susceptibility of the materials to different forms of corrosion, as well as the extent of the incorporation of radioactive species on the surfaces of the primary circuit, are greatly influenced by the physical and chemical properties of these oxide films. The composition and characteristics of the oxide films in turn depend on the applied water chemistry. This work was undertaken in order to collect and evaluate the present views on the structure and behaviour of oxide films formed on iron- and nickel-based materials in aqueous environments. This survey should serve to recognise the areas in which more understanding and research effort is needed. The review begins with a discussion on the bulk oxides of iron, nickel and chromium, as well as their mixed oxides. In addition to bulk oxides, the structure and properties of oxide films forming on pure iron, nickel and chromium and on iron- and nickel-based engineering alloys are considered. General approaches to model the structure and growth of oxide films on metals are discussed in detail. The specific features of the oxide structures, properties and growth at high temperatures are presented with special focus on the relevance of existing models. Finally, the role of oxide films in localised corrosion, oxide breakdown pitting. Stress corrosion cracking and related phenomena is considered. The films formed on the surfaces of iron- and nickel-based alloys in high-temperature aqueous environments generally comprise two layers, i.e. the so-called duplex structure. The inner part is normally enriched in chromium and has a more compact structure, while the outer part is enriched in iron and has a cracked or porous structure. The information collected clearly indicates the effect of the chemical environment on the properties of oxide films growing on metal surfaces

  20. The properties and transport phenomena in oxide films on iron, nickel, chromium and their alloys in aqueous environments

    International Nuclear Information System (INIS)

    Laitinen, T.; Bojinov, M.; Betova, I.; Maekelae, K.; Saario, T.

    1999-01-01

    The construction materials used in coolant systems in nuclear power plants become covered with oxide films as a result of exposure to the aqueous environment. The susceptibility of the materials to different forms of corrosion, as well as the extent of the incorporation of radioactive species on the surfaces of the primary circuit, are greatly influenced by the physical and chemical properties of these oxide films. The composition and characteristics of the oxide films in turn depend on the applied water chemistry. This work was undertaken in order to collect and evaluate the present views on the structure and behaviour of oxide films formed on iron- and nickel-based materials in aqueous environments. This survey should serve to recognise the areas in which more understanding and research effort is needed. The review begins with a discussion on the bulk oxides of iron, nickel and chromium, as well as their mixed oxides. In addition to bulk oxides, the structure and properties of oxide films forming on pure iron, nickel and chromium and on iron- and nickel-based engineering alloys are considered. General approaches to model the structure and growth of oxide films on metals are discussed in detail. The specific features of the oxide structures, properties and growth at high temperatures are presented with special focus on the relevance of existing models. Finally, the role of oxide films in localised corrosion, oxide breakdown pitting. Stress corrosion cracking and related phenomena is considered. The films formed on the surfaces of iron- and nickel-based alloys in high-temperature aqueous environments generally comprise two layers, i.e. the so-called duplex structure. The inner part is normally enriched in chromium and has a more compact structure, while the outer part is enriched in iron and has a cracked or porous structure. The information collected clearly indicates the effect of the chemical environment on the properties of oxide films growing on metal surfaces

  1. The Properties Of And Transport Phenomena In Oxide Films On Iron, Nickel, Chromium And Their Alloys In Aqueous Environments

    International Nuclear Information System (INIS)

    Saario, T.; Laitinen, T.; Maekelae, K.; Bojinov, M.; Betova, I.

    1998-07-01

    The construction materials used in coolant systems in nuclear power plants become covered with oxide films as a result of exposure to the aqueous environment. The susceptibility of the materials to different forms of corrosion, as well as the extent of the incorporation of radioactive species on the surfaces of the primary circuit, are greatly influenced by the physical and chemical properties of these oxide films. The composition and characteristics of the oxide films in turn depend on the applied water chemistry. This work was undertaken in order to collect and evaluate the present views on the structure and behaviour of oxide films formed on iron- and nickel-based materials in aqueous environments. This survey should serve to recognise the areas in which more understanding and research effort is needed. The review begins with a discussion on the bulk oxides of iron, nickel and chromium, as well as their mixed oxides. In addition to bulk oxides, the structure and properties of oxide films forming on pure iron, nickel and chromium and on iron- and nickel-based engineering alloys are considered. General approaches to model the structure and growth of oxide films on metals are discussed in detail. The specific features of the oxide structures, properties and growth at high temperatures are presented with special focus on the relevance of existing models. Finally, the role of oxide films in localised corrosion, oxide breakdown, pitting, stress corrosion cracking and related phenomena is considered. The films formed on the surfaces of iron- and nickel-based alloys in high-temperature aqueous environments generally comprise two layers, i.e. the so-called duplex structure. The inner part is normally enriched in chromium and has a more dense structure, while the outer part is enriched in iron and has a cracked or porous structure. The information collected clearly indicates the effect of the chemical environment on the properties of oxide films growing on metal surfaces

  2. Control of nitrogen concentration in liquid lithium by iron-titanium alloy

    International Nuclear Information System (INIS)

    Hirakane, Shinji; Yoneoka, Toshiaki; Tanaka, Satoru

    2006-01-01

    Reducing the nitrogen concentration in liquid lithium is one of the most important steps in creating a liquid lithium blanket system. In this study, in order to verify the nitrogen gettering performance of Fe-Ti alloy, the variation in the nitrogen concentration in liquid lithium, into which Fe-10 at.% Ti or Fe-5 at.% Ti getter was immersed, was examined. The results confirmed a gettering performance of Fe-Ti alloy comparable to that of V-Ti alloy, although the effects were not durable in either the Fe-Ti or the V-Ti alloy. After the immersion test, the existing states of nitrogen absorbed in the gettering material were analyzed by means of XRD, XMA and XPS. TiN and some nitrogen dissolved in α-Fe without forming TiN were observed. It was indicated that nitrogen gettering is prevented not only by the surface nitrides, but also by the internal diffusion barriers originating from the absorbed nitrogen

  3. PROTECTORS FOR PROOFING OF IRON-CARBON-ALLOYS FROM CORROSIVE EFFECT

    Directory of Open Access Journals (Sweden)

    A. A. Pivovarchyk

    2017-01-01

    Full Text Available The article presents the results of practical testing of the developed compositions of protectors for proofing of low-carbon alloys used in the automotive industry and made from melting stocks of secondary aluminum raw materials. The results of the study of the effectiveness of the proofing of the developed protectors are presented.

  4. Polyethylene Glycol Modified, Cross-Linked Starch Coated Iron Oxide Nanoparticles for Enhanced Magnetic Tumor Targeting

    Science.gov (United States)

    Cole, Adam J.; David, Allan E.; Wang, Jianxin; Galbán, Craig J.; Hill, Hannah L.; Yang, Victor C.

    2010-01-01

    While successful magnetic tumor targeting of iron oxide nanoparticles has been achieved in a number of models, the rapid blood clearance of magnetically suitable particles by the reticuloendothelial system (RES) limits their availability for targeting. This work aimed to develop a long-circulating magnetic iron oxide nanoparticle (MNP) platform capable of sustained tumor exposure via the circulation and, thus, enhanced magnetic tumor targeting. Aminated, cross-linked starch (DN) and aminosilane (A) coated MNPs were successfully modified with 5 kDa (A5, D5) or 20 kDa (A20, D20) polyethylene glycol (PEG) chains using simple N-Hydroxysuccinimide (NHS) chemistry and characterized. Identical PEG-weight analogues between platforms (A5 & D5, A20 & D20) were similar in size (140–190 nm) and relative PEG labeling (1.5% of surface amines – A5/D5, 0.4% – A20/D20), with all PEG-MNPs possessing magnetization properties suitable for magnetic targeting. Candidate PEG-MNPs were studied in RES simulations in vitro to predict long-circulating character. D5 and D20 performed best showing sustained size stability in cell culture medium at 37°C and 7 (D20) to 10 (D5) fold less uptake in RAW264.7 macrophages when compared to previously targeted, unmodified starch MNPs (D). Observations in vitro were validated in vivo, with D5 (7.29 hr) and D20 (11.75 hr) showing much longer half-lives than D (0.12 hr). Improved plasma stability enhanced tumor MNP exposure 100 (D5) to 150 (D20) fold as measured by plasma AUC0-∞ Sustained tumor exposure over 24 hours was visually confirmed in a 9L-glioma rat model (12 mg Fe/kg) using magnetic resonance imaging (MRI). Findings indicate that both D5 and D20 are promising MNP platforms for enhanced magnetic tumor targeting, warranting further study in tumor models. PMID:21176955

  5. Study of the laser-matter interaction in the case of a short duration pulse: application to the structural transformation of an iron-nickel alloy

    International Nuclear Information System (INIS)

    Grevey, Dominique

    1988-01-01

    Pulsed laser can be used to study the effect of a shock (in this case a shock wave) on a material, thus solving problems raised by the use of explosives. After an in-depth bibliographical study on lasers, on conditions of plasma formation, and on the role of plasma in the evolutions of microstructure, this research thesis reports an analysis of events occurring above an irradiated target by using various techniques (fast cinematography, ballistics, micrography, and so on), and the development of a simple and realistic model able to describe laser-matter interaction. The author also reports the analysis of mechanical and metallurgical phenomena (strain hardening, martensitic transformation, creation of micro-twinning and twinning at the vicinity of impacts leading to the emergence of surface and in-depth traction residual stresses) induced by the shock wave on various materials such as aluminium, low carbon steel, and more particularly an iron-nickel alloy. Various characterisation techniques have been used: hardness measurement, optical microscopy, transmission and scanning electron microscopy X ray diffractometry (for phase identification, residual stress measurements, and texture determination), destructive methods to determine residual stresses. By using the obtained results, it has been possible to develop interpretations for a better but partial understanding of hardening mechanisms, and of mechanisms of generation of residual stresses and of conventional martensitic micro-structural transformation [fr

  6. Influence of 'third' elements and structure on the results of spectral analysis of high alloyed steels and cast iron with glow discharge

    International Nuclear Information System (INIS)

    Buravlev, Yu.M.; Zamarajev, V.P.; Chernyavskaya, N.V.

    1989-01-01

    The experimental technique consists in estimation of mutual arrangement of the calibration curves obtained using standard reference materials of low-alloyed and high-alloyed (high-chrome, stainless, high-speed) steels as well as of the curves for carbon steels and cast iron differing in their structure. ARL-31000 and Polyvac E-1000 quantometers with U=1300 V, I=0.12 A and argon pressure ∼1 kPa are used. The influence of third elements is shown in shift and slope changes of the curves for abovementioned high-alloyed steels in comparison to ones for low-alloyed steels accepted as basic. The influence magnitude runs up to 10-30 relative percents and more in the case of analysis of carbon, phosphorus, sulfur, silicon and other elements and depends on the type of the element and on the alloy composition. It is shown that the contribution of structure factor caused by different alloy thermal treatment makes up 10 to 20 relative percents. The experiments showed that the increase of influence of these factors caused by their imposing as well as the weakening of this influence caused by their counteraction is possible. When analyzed alloys differ in their composition and manufacturing technology it is necessary to take into consideration the influence of these effects. (author)

  7. Magnetic Mineralogy of Troilite-Inclusions and their Fe-Ni Host Alloys in IAB Iron Meteorites

    Science.gov (United States)

    Kontny, A. M.; Kramar, U.; Luecke, W.

    2011-12-01

    Iron-nickel meteorites often contain isolated, mostly rounded troilite nodules enclosed in a bulk of Fe-Ni alloy. As sulfur has a low solubility in metal, it is excluded from the crystallization of metal during cooling. Therefore troilite nodules are interpreted to be trapped droplets of residual sulfur-enriched melts. Microscopic examinations of the interface (mm-range) between troilite inclusions and Fe-Ni alloy yield clear mineralogical differences compared to the troilite inclusion. Such rims around troilite nodules seem to occur exclusively in Fe-Ni meteorites with slow cooling rates, and therefore might provide interesting clues on segregation, fractional crystallization and reequilibration processes between the Fe-Ni alloy and the sulfide phases. These interfaces however are also highly sensitive to terrestrial weathering. We present microscopic observations in combination with temperature-dependent magnetic susceptibility (k-T curves) in order to identify the magnetic mineralogy of the Morasko (Poland) and Coahuila (Mexico) meteorites, which both geochemically belong to the non-magmatic IAB or IIICD group. In the k-T curves both, rim and troilite nodule are characterized by Curie temperatures (TC) that can be related to magnetite, daubreelite (FeCr2O4), Fe-hydroxide and sometimes cohenite. Therefore the interface seems to be geochemically more similar to the troilite nodule than the Fe-Ni alloy. Optical microscopy in combination with the ferrofluid method revealed complex microstructures of intergrown magnetic (TC = 780-785 °C) and non-magnetic phases in the Fe-Ni alloy, which differ in their Ni-concentration. Towards the rim of the troilite nodule the concentration of magnetic cohenite ((Fe,Ni)3C) and especially schreibersite ((Fe,Ni)3P), which are both intergrown with the metal, increases. Cohenite is easily identified microscopically by a very characteristic stripe-like magnetic domain structure and it shows a TC at about 200 °C. The carbon-rich, dark

  8. Enhanced magnetoelectric effects in composite of piezoelectric ceramics, rare-earth iron alloys, and shape-optimized nanocrystalline alloys.

    Science.gov (United States)

    Zhang, Jitao; Li, Ping; Wen, Yumei; He, Wei; Yang, Aichao; Lu, Caijiang

    2014-03-01

    An enhancement for magnetoelectric (ME) effects is studied in a three-phase ME architecture consisting of two magnetostrictive Terfenol-D (Tb(0.3)Dy(0.7)Fe(1.92)) plates, a piezoelectric PZT (Pb(Zr,Ti)O3) plate, and a pair of shape-optimized FeCuNbSiB nanocrystalline alloys. By modifying the conventional shape of the magnetic flux concentrator, the shape-optimized flux concentrator has an improved effective permeability (μ(eff)) due to the shape-induced demagnetizing effect at its end surface. The flux concentrator concentrates and amplifies the external magnetic flux into Terfenol-D plate by means of changing its internal flux concentrating manner. Consequently, more flux lines can be uniformly concentrated into Terfenol-D plates. The effective piezomagnetic coefficients (d(33m)) of Terfenol-D plate and the ME voltage coefficients (α(ME)) can be further improved under a lower magnetic bias field. The dynamic magneto-elastic properties and the effective magnetic induction of Terfenol-D are taken into account to derive the enhanced effective ME voltage coefficients (α(ME,eff)), the consistency of experimental results and theoretical analyses verifies this enhancement. The experimental results demonstrate that the maximum d(33m) in our proposed architecture achieves 22.48 nm/A under a bias of 114 Oe. The maximum α(ME) in the bias magnetic range 0-900 Oe reaches 84.73 mV/Oe under the low frequency of 1 kHz, and 2.996 V/Oe under the resonance frequency of 102.3 kHz, respectively. It exhibits a 1.43 times larger piezomagnetic coefficient and a 1.87 times higher ME voltage coefficient under a smaller magnetic bias of 82 Oe than those of a conventional Terfenol-D/PZT/Terfenol-D composite. These shape-induced magnetoelectric behaviors provide the possibility of using this ME architecture in ultra-sensitive magnetic sensors.

  9. Thermal Coefficient of Linear Expansion Modified by Dendritic Segregation in Nickel-Iron Alloys

    Science.gov (United States)

    Ogorodnikova, O. M.; Maksimova, E. V.

    2018-05-01

    The paper presents investigations of thermal properties of Fe-Ni and Fe-Ni-Co casting alloys affected by the heterogeneous distribution of their chemical elements. It is shown that nickel dendritic segregation has a negative effect on properties of studied invars. A mathematical model is proposed to explore the influence of nickel dendritic segregation on the thermal coefficient of linear expansion (TCLE) of the alloy. A computer simulation of TCLE of Fe-Ni-Co superinvars is performed with regard to a heterogeneous distribution of their chemical elements over the whole volume. The ProLigSol computer software application is developed for processing the data array and results of computer simulation.

  10. A Program for Iron Economy during Deficiency Targets Specific Fe Proteins.

    Science.gov (United States)

    Hantzis, Laura J; Kroh, Gretchen E; Jahn, Courtney E; Cantrell, Michael; Peers, Graham; Pilon, Marinus; Ravet, Karl

    2018-01-01

    Iron (Fe) is an essential element for plants, utilized in nearly every cellular process. Because the adjustment of uptake under Fe limitation cannot satisfy all demands, plants need to acclimate their physiology and biochemistry, especially in their chloroplasts, which have a high demand for Fe. To investigate if a program exists for the utilization of Fe under deficiency, we analyzed how hydroponically grown Arabidopsis ( Arabidopsis thaliana ) adjusts its physiology and Fe protein composition in vegetative photosynthetic tissue during Fe deficiency. Fe deficiency first affected photosynthetic electron transport with concomitant reductions in carbon assimilation and biomass production when effects on respiration were not yet significant. Photosynthetic electron transport function and protein levels of Fe-dependent enzymes were fully recovered upon Fe resupply, indicating that the Fe depletion stress did not cause irreversible secondary damage. At the protein level, ferredoxin, the cytochrome- b 6 f complex, and Fe-containing enzymes of the plastid sulfur assimilation pathway were major targets of Fe deficiency, whereas other Fe-dependent functions were relatively less affected. In coordination, SufA and SufB, two proteins of the plastid Fe-sulfur cofactor assembly pathway, were also diminished early by Fe depletion. Iron depletion reduced mRNA levels for the majority of the affected proteins, indicating that loss of enzyme was not just due to lack of Fe cofactors. SufB and ferredoxin were early targets of transcript down-regulation. The data reveal a hierarchy for Fe utilization in photosynthetic tissue and indicate that a program is in place to acclimate to impending Fe deficiency. © 2018 American Society of Plant Biologists. All Rights Reserved.

  11. Short-range clustering and decomposition in copper-nickel and copper-nickel-iron alloys

    International Nuclear Information System (INIS)

    Aalders, T.J.A.

    1982-07-01

    The thermodynamic equilibrium state of short-range clustering and the kinetics of short-range clustering and decomposition has been studied for a number of CuNi(Fe)-alloys by means of neutron scattering. The validity of the theories, which are usually applied to describe spinodal decomposition, nucleation and growth, coarsening etc., was investigated. It was shown that for the investigated substances the conventional theory of spinodal decomposition is valid for the relaxation of short-range clustering only for the case that the initial and final states do not differ too much. The dynamical scaling procedure described by Lebowitz et al. did not lead to a time-independent scaled function F(x) for the relaxation of short-range clustering, for the early stages of decomposition and for the case that an alloy, which was already decomposed at the quench temperature T 1 , was annealed at a temperature T 2 (T 1 ). For the later stages of decomposition, however, the scaling procedure was indeed successful. The coarsening of the alloys could, except for the later stages, be described by the Lifshitz-Slyozov theory. (Auth.)

  12. Generation and Characterization of Anisotropic Microstructures in Rare Earth-Iron-Boron Alloys

    Energy Technology Data Exchange (ETDEWEB)

    Oster, Nathaniel [Iowa State Univ., Ames, IA (United States)

    2012-01-01

    The goal of this work is to investigate methods in which anisotropy could be induced in fine-grained alloys. We have identified two general processing routes to creating a fine, textured microstructure: form an amorphous precursor and devitrify in a manner that induces texture or form the fine, textured microstructure upon cooling directly from the liquid state. Since it is possible to form significant amounts of amorphous material in RE-Fe-B alloys, texture could be induced through biasing the orientationof the crystallites upon crystallization of the amorphous material. One method of creating this bias is to form glassy material and apply uniaxial pressure during crystallization. Experiments on this are presented. All of the work presented here utilizes melt-spinning, either to create precursor material, or to achieve a desired final microstructure. To obtain greater control of the system to process these materials, a study was done on the effects of heating the wheel and modifying the wheel’s surface finish on glass formation and phase selection. The second general approach—creating the desired microstructure directly from the liquid—can be done through directional rapid solidification. In particular, alloys melt-spun at low tangential wheel speeds often display directional columnar growth through a portion of the ribbon. By refining and stabilizing the columnar growth, a highly textured fine microstructure is achieved. The effects of adding a segregating element (Ag) on the columnar growth are characterized and presented.

  13. Semiconductor properties and protective role of passive films of iron base alloys

    International Nuclear Information System (INIS)

    Fujimoto, Shinji; Tsuchiya, Hiroaki

    2007-01-01

    Semiconductor properties of passive films formed on the Fe-18Cr alloy in a borate buffer solution (pH = 8.4) and 0.1 M H 2 SO 4 solution were examined using a photoelectrochemical spectroscopy and an electrochemical impedance spectroscopy. Photo current reveals two photo action spectra that derived from outer hydroxide and inner oxide layers. A typical n-type semiconductor behaviour is observed by both photo current and impedance for the passive films formed in the borate buffer solution. On the other hand, a negative photo current generated, the absolute value of which decreased as applied potential increased in the sulfuric acid solution. This indicates that the passive film behaves as a p-type semiconductor. However, Mott-Schottky plot revealed the typical n-type semiconductor property. It is concluded that the passive film on the Fe-18Cr alloy formed in the borate buffer solution is composed of both n-type outer hydroxide and inner oxide layers. On the other hand, the passive film of the Fe-18Cr alloy in the sulphuric acid consists of p-type oxide and n-type hydroxide layers. The behaviour of passive film growth and corrosion was discussed in terms of the electronic structure in the passive film

  14. A study on the behavior of boron in iron-base alloys by neutron induced autoradiography

    Energy Technology Data Exchange (ETDEWEB)

    Jang, Jin Sung; Rhee, Chang Kyu; Cho, Hae Dong; Han, Chang Hee; Lee, Chang Hee; Jung, Jung Hwan; Kim, Yi Kyung; Lee, Yong Bok

    2001-02-01

    Boron is widely utilized in steel or alloy making to improve certain properties. However, due to its lightness boron is difficult to detect or characterize its behavior even through TEM/EDS or EELS techniques. Although many companies recognize the beneficial effects of boron, the role or mechanism of the boron is not yet clearly understood. Therefore it is required to develop the autoradiography technique to elucidate the boron behavior in alloys. As the only institute operating research reactor in the country, it would be the responsibility of the institute to develop the technique and provide it to the industries. Quantitative analyses of boron in type 316 L stainless steel by neutron induced autoradiography was attempted in this study. Nine experimental reference alloys with different amount of boron were prepared and reliable chemical composition data were obtained. Autoradiographs of reference materials with three different neutron fluences ( 1.9 10{sup 13}, 1.9 10{sup 14} and 1.9 10{sup 15}/cm{sup 2} ) were obtained and a trial calibration curve of boron content vs. track density was acquired.

  15. Evolution of the gas atmosphere during filing the sand moulds with iron alloys

    Directory of Open Access Journals (Sweden)

    J. Mocek

    2009-10-01

    Full Text Available Evolution of atmosphere of the mould cavity when pouring the cast iron has been analyzed. It was find that in dry sand mold the cavity is filled by air throughout the casting time. In green sand the air is removed by the water vapor the hydrogen or carbon oxides formed in contact with the liquid metal. The theoretical results have been confirmed experimentally.

  16. Atomic-scale simulation study of some bulk and interfacial properties of iron aluminium ordered alloys

    International Nuclear Information System (INIS)

    Besson, Remy

    1997-01-01

    A semi-empirical potential was designed for B 2 and DO 3 iron aluminides and used to study point defects and grain boundaries in these compounds. At low temperature, departure from B 2 stoichiometry is accommodated with antisite defects; when T increases, iron vacancies appear and defects have a trend to form clusters, the structure of which is very sensitive to this departure. Our calculations, relying on T = 0 K formation energies, predict the nature of major defects, but lead to underestimated quantitative results, which may point out the essential role of atomic vibrations. In the stoichiometric B 2 compound, the diffusion of both species is induced by four-jump cycles involving iron vacancies. Although the agreement between our calculated activation energies and other experiments is good, the calculated diffusion coefficients are below the experimental ones. Here again, this discrepancy may be put down to the overlooking of phonon contributions. The second application concerns the atomic structures of the [001] (310) symmetric tilt grain boundary in the B 2 and DO 3 compounds. At low temperature, in the stoichiometric B 2 compound, we obtain an iron-rich single stable structure (pseudo-symmetric), whose structure is strongly influenced by the bulk composition (with intergranular segregation of the major element). In the stoichiometric DO 3 compound, many energetically equivalent structures exist, all being systematically aluminium-rich. The study of the B 2 grain boundary structure at high temperature shows a phase transition favouring a symmetric structure. Its high excess energy at low temperature emphasizes the influence of atomic vibrations in the interfacial properties of B 2 Fe-Al compounds. (author) [fr

  17. Effect of impact angles on ejecta and crater shape of aluminum alloy 6061-T6 targets in hypervelocity impacts

    Directory of Open Access Journals (Sweden)

    Hayashi K.

    2012-08-01

    Full Text Available The effect of the impact angle of projectiles on the crater shape and ejecta in thick aluminum alloy targets was investigated in hypervelocity impacts. When polycarbonate projectiles and aluminum alloy 6061-T6 target were used, the impact angle of the projectiles clearly affected the crater shape, as expected. The impact angle also affected the ejecta mass, ejecta size and scatter angle. However, the effect at 15∘ and 22.5∘ was not great. When the impact angles were 30∘ and 45∘, the effect was clearly confirmed. The impact angle clearly affected the axial ratio of ejecta fragments, c/a.

  18. Hyaluronic acid-modified hydrothermally synthesized iron oxide nanoparticles for targeted tumor MR imaging.

    Science.gov (United States)

    Li, Jingchao; He, Yao; Sun, Wenjie; Luo, Yu; Cai, Hongdong; Pan, Yunqi; Shen, Mingwu; Xia, Jindong; Shi, Xiangyang

    2014-04-01

    We report a polyethyleneimine (PEI)-mediated approach to synthesizing hyaluronic acid (HA)-targeted magnetic iron oxide nanoparticles (Fe3O4 NPs) for in vivo targeted tumor magnetic resonance (MR) imaging applications. In this work, Fe3O4 NPs stabilized by PEI were first synthesized via a one-pot hydrothermal method. The formed PEI-stabilized Fe3O4 NPs were then modified with fluorescein isothiocyanate (FI) and HA with two different molecular weights to obtain two different Fe3O4 NPs (Fe3O4-PEI-FI-HA6K and Fe3O4-PEI-FI-HA31K NPs) with a size of 15-16 nm. The formed HA-modified multifunctional Fe3O4 NPs were characterized via different techniques. We show that the multifunctional Fe3O4 NPs are water-dispersible and colloidal stable in different aqueous media. In vitro cell viability and hemolysis studies reveal that the particles are quite cytocompatible and hemocompatible in the given concentration range. Furthermore, confocal microscopy and flow cytometry data demonstrate that HA-targeted Fe3O4 NPs are able to be uptaken specifically by cancer cells overexpressing CD44 receptors, and be used as efficient probes for targeted MR imaging of cancer cells in vitro and xenografted tumor models in vivo. With the tunable amine-based conjugation chemistry, the PEI-stabilized Fe3O4 NPs may be functionalized with other biological ligands or drugs for diagnosis and therapy of different biological systems. Copyright © 2014 Elsevier Ltd. All rights reserved.

  19. Backfill barriers: the use of engineered barriers based on geologic materials to assure isolation of radioactive wastes in a repository. [Nickel-iron alloys

    Energy Technology Data Exchange (ETDEWEB)

    Apps, J.A.; Cook, N.G.W.

    1981-06-01

    A preliminary assessment is made to show that canisters fabricated of nickel-iron alloys, and surrounded by a suitable backfill, may produce an engineered barrier where the canister material is thermodynamically stable with respect to its environment. As similar conditions exist in nature, the performance of such systems as barriers to isolate radionuclides can be predicted over very long periods, of the order of 10/sup 6/ years.

  20. Fe-based bulk amorphous alloys with iron contents as high as 82 at%

    Energy Technology Data Exchange (ETDEWEB)

    Li, Jin-Feng; Liu, Xue; Zhao, Shao-Fan; Ding, Hong-Yu [School of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); Yao, Ke-Fu, E-mail: kfyao@tsinghua.edu.cn [School of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China)

    2015-07-15

    Fe-based bulk amorphous alloys (BAAs) with high Fe contents are advantageous due to their high saturation magnetization and low cost. However, preparing Fe-based BAAs with Fe contents higher than 80 at% is difficult due to their poor glass forming abilities (GFA). In this study, an Fe{sub 81}P{sub 8.5}C{sub 5.5}B{sub 2}Si{sub 3} BAA with a diameter of 1 mm and a saturation magnetization of 1.56 T was successfully prepared using the fluxing and copper mold casting methods. In addition, by introducing a small amount of elemental Mo to the alloy, an Fe{sub 82}Mo{sub 1}P{sub 6.5}C{sub 5.5}B{sub 2}Si{sub 3} BAA rod with a diameter of 1 mm, a high saturation magnetization of 1.59 T, a high yield stress of 3265 MPa, and a clear plasticity of 1.3% was prepared in the same way. The cost effectiveness and good magnetic properties of these newly-developed Fe-based BAAs with Fe contents as high as 82 at% would be advantageous and promising for industrial applications. - Highlights: • Novel Fe-based BAA with no other metallic element except 81 at% Fe was prepared. • Fe-based bulk amorphous alloy (BAA) with the highest Fe content (82%) was prepared. • Very high saturation magnetization of 1.59 T has been achieved. • A new thought for designing Fe-based BAA with high Fe content was provided.

  1. Transient liquid phase bonding of titanium-, iron- and nickel-based alloys

    Science.gov (United States)

    Rahman, A. H. M. Esfakur

    The operating temperature of land-based gas turbines and jet engines are ever-increasing to increase the efficiency, decrease the emissions and minimize the cost. Within the engines, complex-shaped parts experience extreme temperature, fatigue and corrosion conditions. Ti-based, Ni-based and Fe-based alloys are commonly used in gas turbines and jet engines depending on the temperatures of different sections. Although those alloys have superior mechanical, high temperature and corrosion properties, severe operating conditions cause fast degradation and failure of the components. Repair of these components could reduce lifecycle costs. Unfortunately, conventional fusion welding is not very attractive, because Ti reacts very easily with oxygen and nitrogen at high temperatures, Ni-based superalloys show heat affected zone (HAZ) cracking, and stainless steels show intergranular corrosion and knife-line attack. On the other hand, transient liquid phase (TLP) bonding method has been considered as preferred joining method for those types of alloys. During the initial phase of the current work commercially pure Ti, Fe and Ni were diffusion bonded using commercially available interlayer materials. Commercially pure Ti (Ti-grade 2) has been diffusion bonded using silver and copper interlayers and without any interlayer. With a silver (Ag) interlayer, different intermetallics (AgTi, AgTi2) appeared in the joint centerline microstructure. While with a Cu interlayer eutectic mixtures and Ti-Cu solid solutions appeared in the joint centerline. The maximum tensile strengths achieved were 160 MPa, 502 MPa, and 382 MPa when Ag, Cu and no interlayers were used, respectively. Commercially pure Fe (cp-Fe) was diffusion bonded using Cu (25 m) and Au-12Ge eutectic interlayer (100 microm). Cu diffused predominantly along austenite grain boundaries in all bonding conditions. Residual interlayers appeared at lower bonding temperature and time, however, voids were observed in the joint

  2. Targeted Delivery of Amoxicillin to C. trachomatis by the Transferrin Iron Acquisition Pathway.

    Directory of Open Access Journals (Sweden)

    Jun Hai

    Full Text Available Weak intracellular penetration of antibiotics makes some infections difficult to treat. The Trojan horse strategy for targeted drug delivery is among the interesting routes being explored to overcome this therapeutic difficulty. Chlamydia trachomatis, as an obligate intracellular human pathogen, is responsible for both trachoma and sexually transmitted diseases. Chlamydia develops in a vacuole and is therefore protected by four membranes (plasma membrane, bacterial inclusion membrane, and bacterial membranes. In this work, the iron-transport protein, human serum-transferrin, was used as a Trojan horse for antibiotic delivery into the bacterial vacuole. Amoxicillin was grafted onto transferrin. The transferrin-amoxicillin construct was characterized by mass spectrometry and absorption spectroscopy. Its affinity for transferrin receptor 1, determined by fluorescence emission titration [KaffTf-amox = (1.3 ± 1.0 x 108], is very close to that of transferrin [4.3 x 108]. Transmission electron and confocal microscopies showed a co-localization of transferrin with the bacteria in the vacuole and were also used to evaluate the antibiotic capability of the construct. It is significantly more effective than amoxicillin alone. These promising results demonstrate targeted delivery of amoxicillin to suppress Chlamydia and are of interest for Chlamydiaceae and maybe other intracellular bacteria therapies.

  3. Comparison of high temperature, high frequency core loss and dynamic B-H loops of two 50 Ni-Fe crystalline alloys and an iron-based amorphous alloy

    International Nuclear Information System (INIS)

    Wieserman, W.R.; Schwarze, G.E.; Niedra, J.M.

    1994-01-01

    The availability of experimental data that characterizes the performance of soft magnetic materials for the combined conditions of high temperature and high frequency is almost non-existent. An experimental investigation was conducted over the temperature range of 23 to 300 C and frequency range of 1 to 50 kHz to determine the effects of temperature and frequency on the core loss and dynamic B-H loops of three different soft magnetic materials; an oriented-grain 50Ni-50Fe alloy, a nonoriented-grain 50Ni-50Fe alloy, and an iron-based amorphous material (Metglas 2605SC). A comparison of these materials show that the nonoriented-grain 50Ni-50Fe alloy tends to have either the lowest or next lowest core loss for all temperatures and frequencies investigated

  4. MRI contrast demonstration of antigen-specific targeting with an iron-based ferritin construct

    Energy Technology Data Exchange (ETDEWEB)

    Walsh, Edward G., E-mail: edward_walsh@brown.edu [Brown University, Department of Neuroscience (United States); Mills, David R. [Rhode Island Hospital/Warren Alpert Medical School of Brown University, Division of Hematology and Oncology, Department of Medicine (United States); Lim, Sierin; Sana, Barindra [Nanyang Technological University, Division of Bioengineering (Singapore); Brilliant, Kate E. [Rhode Island Hospital/Warren Alpert Medical School of Brown University, Division of Hematology and Oncology, Department of Medicine (United States); Park, William K. C. [Rhode Island Hospital, Department of Diagnostic Imaging (United States)

    2013-01-15

    A genetically modified ferritin has been examined for its properties as a tumor-selective magnetic resonance imaging (MRI) contrast agent. The engineered ferritin described herein was derived from Archaeoglobus fulgidus (AfFtn-AA), which stores a significantly greater quantity of iron than wild-type ferritins. Relaxivity measurements were taken at 3 Tesla of ferritin particles uniformly distributed in an agarose gel to assess relaxivities r{sub 1} and r{sub 2}. The r{sub 1} and r{sub 2} values of the uniformly distributed modified ferritin were significantly higher (r{sub 1} = 1,290 mM{sup -1} s{sup -1} and r{sub 2} = 5,740 mM{sup -1} s{sup -1}) than values observed for wild-type ferritin (e.g., horse spleen, r{sub 1} = 0.674 mM{sup -1} s{sup -1}, r{sub 2} = 95.54 mM{sup -1} s{sup -1}). The modified iron-enriched ferritin (14.5 nm diameter) was conjugated with a monoclonal antibody (10 nm length) against rat Necl-5, a cell surface glycoprotein overexpressed by many epithelial cancers. In vitro studies showed strong reactivity of the assembled nanoconjugate to transformed Necl-5 positive rat prostate epithelial cells. Furthermore, MRI demonstrated a significant T{sub 2} contrast with negligible T{sub 1} effect when bound to cells. These findings highlight the utility of the modified ferritin construct as a novel MRI contrast agent that can be manipulated to target antigen-specific tissues.

  5. Iron and iron oxide nanoparticles are highly toxic to Culex quinquefasciatus with little non-target effects on larvivorous fishes.

    Science.gov (United States)

    Murugan, Kadarkarai; Dinesh, Devakumar; Nataraj, Devaraj; Subramaniam, Jayapal; Amuthavalli, Pandiyan; Madhavan, Jagannathan; Rajasekar, Aruliah; Rajan, Mariappan; Thiruppathi, Kulandhaivel Palani; Kumar, Suresh; Higuchi, Akon; Nicoletti, Marcello; Benelli, Giovanni

    2018-04-01

    The control of filariasis vectors has been enhanced in several areas, but there are main challenges, including increasing resistance to insecticides and lack of cheap and eco-friendly products. The toxicity of iron (Fe 0 ) and iron oxide (Fe 2 O 3 ) nanoparticles has been scarcely investigated yet. We studied the larvicidal and pupicidal activity of Fe 0 and Fe 2 O 3 nanoparticles against Culex quinquefasciatus. Fe 0 and Fe 2 O 3 nanoparticles produced by green (using a Ficus natalensis aqueous extract) and chemical nanosynthesis, respectively, were analyzed by UV-Vis spectrophotometry, FT-IR spectroscopy, XRD analysis, SEM, and EDX assays. In larvicidal and pupicidal experiments on Cx. quinquefasciatus, LC 50 of Fe 0 nanoparticles ranged from 20.9 (I instar larvae) to 43.7 ppm (pupae) and from 4.5 (I) to 22.1 ppm (pupae) for Fe 2 O 3 nanoparticles synthesized chemically. Furthermore, the predation efficiency of the guppy fish, Poecilia reticulata, after a single treatment with sub-lethal doses of Fe 0 and Fe 2 O 3 nanoparticles was magnified. Overall, this work provides new insights about the toxicity of Fe 0 and Fe 2 O 3 nanoparticles against mosquito vectors; we suggested that green and chemical fabricated nano-iron may be considered to develop novel and effective pesticides.

  6. Optimizing Wear Resistance and Impact Toughness in High Chromium Iron Mo-Ni Alloy

    Science.gov (United States)

    Singh, K. K.; Verma, R. S.; Murty, G. M. D.

    2009-06-01

    An alloy with carbon and chromium in the range of 2.0 to 2.5% and 20 to 25%, respectively, with the addition of Mo and Ni in the range of 1.0 to 1.5% each when heat-treated at a quenching temperature of 1010 °C and tempering temperature of 550 °C produces a hardness in the range of 54 to 56 HRC and a microstructure that consists of discontinuous bands of high volume (35-40%) of wear resistant primary (eutectic) carbides in a tempered martensitic matrix with uniformly dispersed secondary precipitates. This alloy has been found to possess adequate impact toughness (5-6 J/cm2) with a wear resistance of the order of 3-4 times superior to Mn steel and 1.25 times superior to martensitic stainless steel with a reduction in cost-to-life ratio by a factor of 1.25 in both the cases.

  7. Strain hardening of aluminium alloy 3004 in the deep drawing and ironing processes

    International Nuclear Information System (INIS)

    Courbon, J.; Duval, J.L.

    1993-01-01

    The evolution of material hardening resulting from the canmaking operations on aluminium beverage cans has been investigated. Tensile tests in cup walls revealed that deep drawing induced softening in the hoop direction and hardening in the meridian direction. This anisotropy is retained in the ironing operation. Changes in strain path on a heavily cold-rolled material probably cause such a complex behaviour. To determine hardening laws for deep drawing, simple shear tests were thus performed because of the strain path similarity. They allowed to determine hardening laws over larger strains than tension could reach and revealed a saturation of stress. Altogether they proved adapted to the understanding of deep drawing. (orig.)

  8. Mass-selected iron-cobalt alloy clusters. Correlation of magnetic and structural properties; Massenselektierte Eisen-Kobalt-Legierungscluster. Korrelation magnetischer und struktureller Eigenschaften

    Energy Technology Data Exchange (ETDEWEB)

    Bulut, Furkan

    2008-10-13

    In this work, I present results concerning structural and magnetic properties of massselected iron-cobalt alloy clusters with diameters between 5 and 15 nm. I have studied the structure of FeCo alloy clusters with high resolution transmission electron microscopy (HRTEM) and scanning tunneling microscopy (STM). I have also investigated the crystalline structure of pure iron and pure cobalt clusters with HRTEM to ensure a reliable determination of the lattice parameter for the alloy clusters. The FeCo nanoparticles have a truncated dodecahedral shape with a CsCl-structure. The clusters were produced with a continuously working arc cluster ion source and subsequently mass-selected with an electrostatic quadrupole deflector. The composition of the alloy clusters was checked with energy dispersive x-ray spectroscopy (EDX). The lateral size distribution was investigated by TEM and the height of the deposited FeCo clusters on the (110) surface of tungsten was determined by STM. Comparing the results I have observed that the supported clusters were flattened due to the high surface energy of W(110). The decrease in height of the mass-selected supported clusters amounts to about 1 nm. Furthermore, element specific magnetic studies performed by means of X-ray magnetic circular dichroism (XMCD) have shown that magnetic moments of Fe{sub 50}Co{sub 50} alloy clusters are in good agreement with the theoretically expected values in the bulk. I have also examined the behavior of the alloy clusters at elevated temperatures. The clusters exhibit an anisotropic melting on the W(110) surface. (orig.)

  9. Characterization and cytotoxic assessment of ballistic aerosol particulates for tungsten alloy penetrators into steel target plates.

    Science.gov (United States)

    Machado, Brenda I; Murr, Lawrence E; Suro, Raquel M; Gaytan, Sara M; Ramirez, Diana A; Garza, Kristine M; Schuster, Brian E

    2010-09-01

    The nature and constituents of ballistic aerosol created by kinetic energy penetrator rods of tungsten heavy alloys (W-Fe-Ni and W-Fe-Co) perforating steel target plates was characterized by scanning and transmission electron microscopy. These aerosol regimes, which can occur in closed, armored military vehicle penetration, are of concern for potential health effects, especially as a consequence of being inhaled. In a controlled volume containing 10 equispaced steel target plates, particulates were systematically collected onto special filters. Filter collections were examined by scanning and transmission electron microscopy (SEM and TEM) which included energy-dispersive (X-ray) spectrometry (EDS). Dark-field TEM identified a significant nanoparticle concentration while EDS in the SEM identified the propensity of mass fraction particulates to consist of Fe and FeO, representing target erosion and formation of an accumulating debris field. Direct exposure of human epithelial cells (A549), a model for lung tissue, to particulates (especially nanoparticulates) collected on individual filters demonstrated induction of rapid and global cell death to the extent that production of inflammatory cytokines was entirely inhibited. These observations along with comparisons of a wide range of other nanoparticulate species exhibiting cell death in A549 culture may suggest severe human toxicity potential for inhaled ballistic aerosol, but the complexity of the aerosol (particulate) mix has not yet allowed any particular chemical composition to be identified.

  10. Characterization and Cytotoxic Assessment of Ballistic Aerosol Particulates for Tungsten Alloy Penetrators into Steel Target Plates

    Directory of Open Access Journals (Sweden)

    Brian E. Schuster

    2010-08-01

    Full Text Available The nature and constituents of ballistic aerosol created by kinetic energy penetrator rods of tungsten heavy alloys (W-Fe-Ni and W-Fe-Co perforating steel target plates was characterized by scanning and transmission electron microscopy. These aerosol regimes, which can occur in closed, armored military vehicle penetration, are of concern for potential health effects, especially as a consequence of being inhaled. In a controlled volume containing 10 equispaced steel target plates, particulates were systematically collected onto special filters. Filter collections were examined by scanning and transmission electron microscopy (SEM and TEM which included energy-dispersive (X-ray spectrometry (EDS. Dark-field TEM identified a significant nanoparticle concentration while EDS in the SEM identified the propensity of mass fraction particulates to consist of Fe and FeO, representing target erosion and formation of an accumulating debris field. Direct exposure of human epithelial cells (A549, a model for lung tissue, to particulates (especially nanoparticulates collected on individual filters demonstrated induction of rapid and global cell death to the extent that production of inflammatory cytokines was entirely inhibited. These observations along with comparisons of a wide range of other nanoparticulate species exhibiting cell death in A549 culture may suggest severe human toxicity potential for inhaled ballistic aerosol, but the complexity of the aerosol (particulate mix has not yet allowed any particular chemical composition to be identified.

  11. Contribution to the study of the electrodeposition of iron-nickel alloys; Contribution a l'etude du depot electrolytique des alliages fer-nickel

    Energy Technology Data Exchange (ETDEWEB)

    Valignat, J [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

    1967-12-01

    Using a coulometric technique based upon the anodic intentiostatic dissolution, we studied the potentiostatic, deposition of nickel, iron and nickel iron alloys. We have shown that the minimum of the curve I = f (t) (deposition current versus time) is probably due to the transitory blocking of the surface by hydrogen and that the syn-crystallisation of nickel and iron is responsible for the anomalous co-deposition of these two elements. (author) [French] En employant une methode coulometrique par dissolution anodique intensipstatique, nous avons etudie le depot potentiostatique du nickel, du fer et des alliages fer-nickel. Nous avons pu montrer que le minimum de la courbe I = f (t) enregistree au cours du depot est du probablement au blocage momentane de la surface par l'hydrogene et que la syncristallisation du fer et du nickel est responsable de l'anomalie du depot simultane de ces deux elements. (auteur)

  12. Aluminium alloyed iron-silicide/silicon solar cells: A simple approach for low cost environmental-friendly photovoltaic technology.

    Science.gov (United States)

    Kumar Dalapati, Goutam; Masudy-Panah, Saeid; Kumar, Avishek; Cheh Tan, Cheng; Ru Tan, Hui; Chi, Dongzhi

    2015-12-03

    This work demonstrates the fabrication of silicide/silicon based solar cell towards the development of low cost and environmental friendly photovoltaic technology. A heterostructure solar cells using metallic alpha phase (α-phase) aluminum alloyed iron silicide (FeSi(Al)) on n-type silicon is fabricated with an efficiency of 0.8%. The fabricated device has an open circuit voltage and fill-factor of 240 mV and 60%, respectively. Performance of the device was improved by about 7 fold to 5.1% through the interface engineering. The α-phase FeSi(Al)/silicon solar cell devices have promising photovoltaic characteristic with an open circuit voltage, short-circuit current and a fill factor (FF) of 425 mV, 18.5 mA/cm(2), and 64%, respectively. The significant improvement of α-phase FeSi(Al)/n-Si solar cells is due to the formation p(+-)n homojunction through the formation of re-grown crystalline silicon layer (~5-10 nm) at the silicide/silicon interface. Thickness of the regrown silicon layer is crucial for the silicide/silicon based photovoltaic devices. Performance of the α-FeSi(Al)/n-Si solar cells significantly depends on the thickness of α-FeSi(Al) layer and process temperature during the device fabrication. This study will open up new opportunities for the Si based photovoltaic technology using a simple, sustainable, and los cost method.

  13. Effect of vanadium neighbors on the hyperfine properties of iron-vanadium alloys

    Energy Technology Data Exchange (ETDEWEB)

    Elzain, M., E-mail: elzain@squ.edu.om; Yousif, A.; Gismelseed, A.; Al Rawas, A.; Widatallah, H.; Bouziane, K.; Al-Omari, I. [College of Science, Sultan Qaboos University, Physics Department (Oman)

    2008-06-15

    The electronic and magnetic structures of Fe-V alloys are calculated using the discrete-variational and full-potential linearized-augmented-plane wave methods. The derived hyperfine properties at Fe sites are studied against the number of Fe atoms in the neighbouring shells. As expected the magnetic hyperfine field depends strongly on the number of Fe atoms in the first and second shells of neighbours while its dependence on the variation of atoms in the third shell is weak. The calculated distribution of the magnetic hyperfine fields at the Fe sites, are compared to the experimental data of Krause et al. (Phys Rev B 61:6196-6204, 2000). The contact charge densities and the magnetic moments are also calculated. It was found that the contact charge density increases with increasing V contents and this leads to negative isomer shift on addition of V.

  14. Effect of carbon and silicon on nitrogen solubility in liquid chromium and iron-chromium alloys

    International Nuclear Information System (INIS)

    Khyakkinen, V.I.; Bezobrazov, S.V.

    1986-01-01

    The study is aimed at specifying the role of carbon and silicon in high-chromium melts nitridation processes. It is shown that in high-chromium melts of the Cr-Fe-C system the nitrogen solubility is reduced with the growth of carbon content and in the chromium concentration range of 70-100% at 1873 K and P N 2 =0.1 MPa it is described by the lg[%N] Cr-Fe-C =lg[%N] cr-fe -0.098[%C] equation. While decreasing the temperature the nitrogen solubility in alloys is increased. Silicon essentially decreases the nitrogen solubility in liquid chromium. For the 0-10% silicon concentration range the relation between the equilibrium content of nitrogen and silicon at 1873 K and P N 2 =0.1 MPa is described by the straight line equation [%N] Cr-Si =6.1-0.338 [%Si

  15. Heat Treatment of Iron-Carbon Alloys in a Magnetic Field (Phase 2)

    Energy Technology Data Exchange (ETDEWEB)

    Ludtka, Gerard Michael [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2017-11-01

    Thermomagnetic processing was shown to shift the phase transformation temperatures and therefore microstructural evolution in the high performance engine valve spring 9254 steel alloy by applying a high magnetic field during cooling. These effects would be anticipated to improve performance such as high cycle fatigue as demonstrated in prior projects. Thermomagnetic processing of gears and crank shafts was constrained by the size of the prototype equipment currently available at ORNL. However, the commercial procurement viability of production scale 9-Tesla, 16-inch diameter bore thermomagnetic processing equipment for truck idler gears up to ~11-inch diameter and potential crank shaft applications was shown, as multiple superconducting magnet manufacturing companies (in conjunction with an induction heat treating company, AjaxTOCCO Magnethermic) offered cryogen-free or cryocooler equipment designs to Cummins.

  16. Measurements of Neutron Spectra Produced from a Thick Iron Target Bombarded with 1.5-GeV Protons

    International Nuclear Information System (INIS)

    Meigo, Shin-ichiro; Shigyo, Nobuhiro; Iga, Kiminori; Iwamoto, Yosuke; Kitsuki, Hirohiko; Ishibashi, Kenji; Maehata, Keisuke; Arima, Hidehiko; Nakamoto, Tatsushi; Numajiri, Masaharu

    2005-01-01

    For validation of calculation codes that are employed in the design of accelerator facilities, spectra of neutrons produced from a thick iron target bombarded with 1.5-GeV protons were measured. The calculated results with NMTC/JAM were compared with the present experimental results. It is found that the NMTC/JAM generally shows good agreement with experiment. Furthermore, the calculation gives good agreement with the experiment for the energy region 20 to 80 MeV for iron, whereas the NMTC/JAM gives 50% of the experimental data for the heavy-nuclides such as lead and tungsten

  17. Magneto x-ray study of a gadolinium-iron amorphous alloy

    International Nuclear Information System (INIS)

    Keller, E.N.

    1985-01-01

    This work reports the measurement of the magnetic x-ray absorption of an amorphous Gd-Fe ferrimagnetic thin film. The Gd to Fe concentration in the sample was 1:4. The magnetic x-ray effect is the x-ray analog of magneto-optic absorption effects. Magneto x-ray effects arise when a solid has different indices of refraction for right and left circularly polarized x-rays. The difference in absorption of left and right circularly polarized x-rays is called the magneto x-ray absorption. This absorption is proportional to the net spin of the final state density of states. At the L3 edge, the main x-ray transition is from initial Gd(2p) core states to final Gd(5d) unoccupied states. Since the 5d states have a net spin polarization in ferromagnetic Gd, this experiment hoped to directly observe how that polarization changes for Gd in the alloy. The magneto x-ray absorption at the Gd L3 edge will be proportional to the sign and amount of the net spin polarization of the 5d electrons. The magnetic x-ray absorption coefficient was found to be at least 0.0005 smaller than the linear absorption coefficient at the Gd white line energy. This was measured for the amorphous alloy at room temperature. Lock-in techniques were used to obtain the small limit to the absorption. A simple model for the size of the magnetic x-ray absorption coefficient in Gd suggests that the Gd(5d) net spin polarization is less than 0.01 Bohr magnetons per atom

  18. Phase transformation and magnetic anisotropy of an iron-palladium ferromagnetic shape-memory alloy

    International Nuclear Information System (INIS)

    Cui, J.; Shield, T.W.; James, R.D.

    2004-01-01

    Martensitic phase transformations in an Fe 7 Pd 3 alloy were studied using various experimental techniques: visual observation, differential scanning calorimeter (DSC) measurements and X-ray diffraction. Magnetic measurements on this alloy were made using a vibrating sample magnetometer (VSM) and a Susceptibility Kappa bridge. The VSM measurements were made with the sample in a compression fixture to bias the martensite phase to a single variant. Both X-ray and DSC measurements show that the FCC-FCT transformation is a weak first-order thermoelastic transition. The average lattice parameters are a=3.822±0.001 A and c=3.630±0.001 A for the FCT martensite, and a 0 =3.756±0.001 A for the FCC austenite. The latent heat of the FCC-FCT transformation is 10.79±0.01 J/cm 3 . A Susceptibility Kappa bridge measurement determined the Curie temperature to be 450 deg. C. The saturation magnetization from VSM data is m s =1220±10 emu/cm 3 at -20 deg. C for the martensite and m s =1080±10 emu/cm 3 at 60 deg. C for the austenite. The easy axes of a single variant of FCT martensite are the [1 0 0] and [0 1 0] directions (the a-axes of the FCT lattice) and the [0 0 1] direction (FCT c-axis) is the hard direction. The cubic magnetic anisotropy constant K 1 is -5±2x10 3 erg/cm 3 for the austenite at 60 deg. C, and the tetragonal anisotropy constant K 1 +K 2 is 3.41 ± 0.02 x 10 5 erg/cm 3 for the martensite at a temperature of -20 deg. C and under 8 MPa of compressive stress in the [0 0 1] direction

  19. Josephinite. A terrestrial alloy with radiogenic xenon-129 and the noble gas imprint of iron meteorites

    Energy Technology Data Exchange (ETDEWEB)

    Downing, R G; Hennecke, E W; Manuel, O K [Missouri Univ., Rolla (USA). Dept. of Chemistry

    1977-12-01

    Analyses of noble gases released by stepwise heating of Josephinite reveal two radiogenic components, radiogenic /sup 129/Xe asymptotically equals 1 x 10/sup -12/ ccSTP/g and radiogenic /sup 40/Ar asymptotically equals 1 x 10/sup -6/ cc STP/g, and the following components of trapped noble gases: He with /sup 3/He//sup 4/He asymptotically equals 4 x 10/sup -5/, Ne with /sup 20/Ne//sup 22/Ne=10.5, Ar with /sup 40/Ar//sup 36/Ar=3 x 10/sup 2/, and Kr and Xe with isotopic compositions similar to those observed in iron meteorites. The excess of /sup 40/Ar and literature values of K in bulk Josephinite yield and apparent K-Ar age of asymptotically equals 4.6 x 10/sup 9/ years.

  20. A study of point defects created by electron irradiation of dilute iron-carbon alloys

    International Nuclear Information System (INIS)

    Leveque, J.L.

    1969-10-01

    Resistivity and magnetic after effect (m.a.e.) measurements are used to study the influence of carbon atoms on the annealing process of point defects created by electron irradiation (3 MeV) at low temperature (20 deg. K). The presence of the carbon atoms has a strong influence on the recovery sub-stage I E and stage III. For the former, the carbon impurity traps the freely migrating iron interstitial. For the latter the effect is interpreted as being due to formation during annealing, of a carbon vacancy pair. A pronounced m.a.e. band is attributed to the reorientation of this carbon vacancy complex. All these results are coherent with the interpretation of a low temperature migrating free interstitial. (author) [fr

  1. Formation of coatings from a liquid phase on the surface of iron-base alloys

    Directory of Open Access Journals (Sweden)

    A. Tatarek

    2008-12-01

    Full Text Available The study discloses the present state of the art regarding the technology and investigations of the phenomena that take place during the formation and growth of aluminum and zinc coatings hot-dip formed on iron products. In its cognitive aspect, the study offers an in-depth analysis of the partial processes that proceed in metal bath at the solid body – liquid metal interface. It is expected that the present study will help in a more detailed description of the respective phenomena and in full explanation of the mechanism of the coating growth, taking as an example the growth of aluminum coatings. The obtained results can serve as a background for some general conclusions regarding the thickness evolution process in other hot-dip coatings.

  2. Polymer encapsulated upconversion nanoparticle/iron oxide nanocomposites for multimodal imaging and magnetic targeted drug delivery.

    Science.gov (United States)

    Xu, Huan; Cheng, Liang; Wang, Chao; Ma, Xinxing; Li, Yonggang; Liu, Zhuang

    2011-12-01

    Multimodal imaging and imaging-guided therapies have become a new trend in the current development of cancer theranostics. In this work, we encapsulate hydrophobic upconversion nanoparticles (UCNPs) together with iron oxide nanoparticles (IONPs) by using an amphiphilic block copolymer, poly (styrene-block-allyl alcohol) (PS(16)-b-PAA(10)), via a microemulsion method, obtaining an UC-IO@Polymer multi-functional nanocomposite system. Fluorescent dye and anti-cancer drug molecules can be further loaded inside the UC-IO@Polymer nanocomposite for additional functionalities. Utilizing the Squaraine (SQ) dye loaded nanocomposite (UC-IO@Polymer-SQ), triple-modal upconversion luminescence (UCL)/down-conversion fluorescence (FL)/magnetic resonance (MR) imaging is demonstrated in vitro and in vivo, and also applied for in vivo cancer cell tracking in mice. On the other hand, a chemotherapy drug, doxorubicin, is also loaded into the nanocomposite, forming an UC-IO@Polymer-DOX complex, which enables novel imaging-guided and magnetic targeted drug delivery. Our work provides a method to fabricate a nanocomposite system with highly integrated functionalities for multimodal biomedical imaging and cancer therapy. Copyright © 2011 Elsevier Ltd. All rights reserved.

  3. Dual drug loaded superparamagnetic iron oxide nanoparticles for targeted cancer therapy.

    Science.gov (United States)

    Dilnawaz, Fahima; Singh, Abhalaxmi; Mohanty, Chandana; Sahoo, Sanjeeb K

    2010-05-01

    The primary inadequacy of chemotherapeutic drugs is their relative non-specificity and potential side effects to the healthy tissues. To overcome this, drug loaded multifunctional magnetic nanoparticles are conceptualized. We report here an aqueous based formulation of glycerol monooleate coated magnetic nanoparticles (GMO-MNPs) devoid of any surfactant capable of carrying high payload hydrophobic anticancer drugs. The biocompatibility was confirmed by tumor necrosis factor alpha assay, confocal microscopy. High entrapment efficiency approximately 95% and sustained release of encapsulated drugs for more than two weeks under in vitro conditions was achieved for different anticancer drugs (paclitaxel, rapamycin, alone or combination). Drug loaded GMO-MNPs did not affect the magnetization properties of the iron oxide core as confirmed by magnetization study. Additionally the MNPs were functionalized with carboxylic groups by coating with DMSA (Dimercaptosuccinic acid) for the supplementary conjugation of amines. For targeted therapy, HER2 antibody was conjugated to GMO-MNPs and showed enhanced uptake in human breast carcinoma cell line (MCF-7). The IC(50) doses revealed potential antiproliferative effect in MCF-7. Therefore, antibody conjugated GMO-MNPs could be used as potential drug carrier for the active therapeutic aspects in cancer therapy. Copyright 2010 Elsevier Ltd. All rights reserved.

  4. Rice and Bean Targets for Biofortification Combined with High Carotenoid Content Crops Regulate Transcriptional Mechanisms Increasing Iron Bioavailability

    Science.gov (United States)

    Dias, Desirrê Morais; de Castro Moreira, Maria Eliza; Gomes, Mariana Juste Contin; Lopes Toledo, Renata Celi; Nutti, Marilia Regini; Pinheiro Sant’Ana, Helena Maria; Martino, Hércia Stampini Duarte

    2015-01-01

    Iron deficiency affects thousands of people worldwide. Biofortification of staple food crops aims to support the reduction of this deficiency. This study evaluates the effect of combinations of common beans and rice, targets for biofortification, with high carotenoid content crops on the iron bioavailability, protein gene expression, and antioxidant effect. Iron bioavailability was measured by the depletion/repletion method. Seven groups were tested (n = 7): Pontal bean (PB); rice + Pontal bean (R + BP); Pontal bean + sweet potato (PB + SP); Pontal bean + pumpkin (PB + P); Pontal bean + rice + sweet potato (PB + R + P); Pontal bean + rice + sweet potato (PB + R + SP); positive control (Ferrous Sulfate). The evaluations included: hemoglobin gain, hemoglobin regeneration efficiency (HRE), gene expression of divalente metal transporter 1 (DMT-1), duodenal citocromo B (DcytB), ferroportin, hephaestin, transferrin and ferritin and total plasma antioxidant capacity (TAC). The test groups, except the PB, showed higher HRE (p bioavailability and antioxidant capacity. PMID:26610564

  5. Corrosion study of iron-cobalt alloys for MRI-based propulsion embedded in untethered microdevices operating in the vascular network.

    Science.gov (United States)

    Pouponneau, Pierre; Savadogo, Oumarou; Napporn, Teko; Yahia, L'hocine; Martel, Sylvain

    2010-04-01

    Our group have shown in an experiment performed in the carotid artery of a living swine that magnetic gradients generated by a clinical magnetic resonance imaging (MRI) system could propel and navigate untethered medical microdevices and micro-nanorobots in the human vasculature. The main problem with these devices is that the metal necessary for magnetic propulsion may corrode and induce cytotoxic effects. The challenge, then, is to find an alloy with low corrosion yet providing an adequate magnetization level for propulsion in often stringent physiological conditions. Because of their high magnetization, we studied the corrosion behavior of two iron-cobalt alloys, Permendur (49% Fe, 49% Co, 2% V) and Vacoflux 17 (81% Fe, 17% Co, 2% Cr), in physiological solution by potentiodynamic polarization assay, surface analysis, and corrosion electrolyte analysis. Both alloys exhibited low corrosion parameters such as a corrosion potential (E(corr)) of -0.57 V/SCE and E(corr) of -0.42 V/SCE for Vacoflux 17. The surface of Permendur samples was homogenously degraded. Vacoflux 17 surface was impaired by cracks and crevices. Both alloys had a stoichiometric dissolution in the electrolyte, and they released enough cobalt to induce cytotoxic effects. This study concluded that Fe-Co alloys could be used preferably in medical microdevices if they were coated so as not to come in contact with physiological solutions.

  6. Rational Design of Iron Oxide Nanoparticles as Targeted Nanomedicines for Cancer Therapy

    Science.gov (United States)

    Kievit, Forrest M.

    2011-07-01

    Nanotechnology provides a flexible platform for the development of effective therapeutic nanomaterials that can interact specifically with a target in a biological system and provoke a desired biological response. Of the nanomaterials studied, superparamagnetic iron oxide nanoparticles (SPIONs) have emerged as one of top candidates for cancer therapy due to their intrinsic superparamagnetism that enables non-invasive magnetic resonance imaging (MRI) and biodegradability favorable for in vivo application. This dissertation is aimed at development of SPION-based nanomedicines to overcome the current limitations in cancer therapy. These limitations include non-specificity of therapy which can harm healthy tissue, the difficulty in delivering nucleic acids for gene therapy, the formation of drug resistance, and the inability to detect and treat micrometastases. First, a SPION-based non-viral gene delivery vehicle was developed through functionalization of the SPION core with a co-polymer designed to provide stable binding of DNA and low toxicity which showed excellent gene delivery in vitro and in vivo. This SPION-based non-viral gene delivery vehicle was then activated with a targeting agent to improve gene delivery throughout a xenograft tumor of brain cancer. It was found that targeting did not promote the accumulation of SPIONs at the tumor site, but rather improved the distribution of SPIONs throughout the tumor so a higher proportion of cells received treatment. Next, the high surface area of SPIONs was utilized for loading large amounts of drug which was shown to overcome the multidrug resistance acquired by many cancer cells. Drug bound to SPIONs showed significantly higher multidrug resistant cell uptake as compared to free drug which translated into improved cell kill. Also, an antibody activated SPION was developed and was shown to be able to target micrometastases in a transgenic animal model of metastatic breast cancer. These SPION-based nanomedicines

  7. Measurements of neutron spectra produced from a thick iron target bombarded with 1.5 GeV protons

    International Nuclear Information System (INIS)

    Meigo, Shin-ichiro; Takada, Hiroshi

    2001-01-01

    For validation of calculation codes which are employed in the design of accelerator facilities, spectra of neutrons produced from a thick iron target bombarded with 1.5-GeV protons were measured. The calculated results with NMTC/JAM were compared with the present experimental results. It is found the NMTC/JAM generally shows in good agreement with experiment. Furthermore, the calculation gives good agreement with the experiment for the energy region 20-80 MeV, whereas the NMTC/JAM gives 50% of the experimental data for the heavy nuclide target such as lead and tungsten target. (author)

  8. Uranium exploration target selection for proterozoic iron oxide/breccia complex type deposits in India

    International Nuclear Information System (INIS)

    Dwivedy, K.K.; Sinha, K.K.

    1997-01-01

    Multimetal iron oxide/breccia complex (IOBC) type deposits exemplified by Olympic Dam in Australia, fall under low grade, large tonnage deposits. A multidisciplinary integrated exploration programme consisting of airborne surveys, ground geological surveys, geophysical and geochemical investigations and exploratory drilling, supported adequately by the state of the art analytical facilities, data processing using various software and digital image processing has shown moderate success in the identification of target areas for this type of deposits in the Proterozoic terrains of India. Intracratonic, anorogenic, continental rift to continental margin environment have been identified in a very wide spectrum of rock associations. The genesis and evolution of such associations during the Middle Proterozoic period have been reviewed and applied for target selection in the (i) Son-Narmada rift valley zone; (ii) areas covered by Dongargarh Supergroup of rocks in Madhya Pradesh; (iii) areas exposing ferruginous breccia in the western part of the Singhbhum Shear Zone (SSZ) around Lotapahar; (iv) Siang Group of rocks in Arunachal Pradesh; (v) Crystalline rocks of Garo Hills around Anek; and (vi) Chhotanagpur Gneissic complex in the Bahia-Ulatutoli tract of Ranchi Plateau. Of theses six areas, the Son-Narmada rift area appears to be the most promising area for IOBC type deposits. Considering occurrences of the uranium anomalies near Meraraich, Kundabhati, Naktu and Kudar and positive favourability criteria observed in a wide variety of rocks spatially related to the rifts and shears, certain sectors in Son-Narmada rift zone have been identified as promising for intense subsurface exploration. 20 refs, 4 figs, 1 tab

  9. Effects of iron-reducing bacteria and nitrate-reducing bacteria on the transformations of iron corrosion products, magnetite and siderite, formed at the surface of non-alloy steel

    International Nuclear Information System (INIS)

    Etique, Marjorie

    2014-01-01

    Radioactive waste is one of the major problems facing the nuclear industry. To circumvent this issue France plans to store vitrified high-level nuclear waste in a stainless steel container, placed into a non-alloy steel overpack, at a depth of 500 m in an argillaceous formation. The main iron corrosion products formed at the surface of the non-alloy steel are siderite (Fe II CO 3 ) and magnetite (Fe II Fe III 2 O 4 ). These compounds are formed in the anoxic conditions present in the nuclear waste repository and play a protective role against corrosion as a passive layer. This work aims to investigate the activity of nitrate-reducing bacteria (NRB, Klebsiella mobilis) and iron-reducing bacteria (IRB, Shewanella putrefaciens) during the transformation of siderite and magnetite, especially those involved in anoxic iron biogeochemical cycle. Klebsiella mobilis and Shewanella putrefaciens were first incubated with siderite or magnetite suspensions (high surface specific area) in order to exacerbate the microbial iron transformation, subsequently incubated with a magnetite/siderite film synthesized by anodic polarization at applied current density. The transformation of siderite and magnetite by direct or indirect microbial processes led to the formation of carbonated green rust (Fe II 4 Fe III 2 (OH) 12 CO 3 ). As a transient phase shared by several bacterial reactions involving Fe II and Fe III , this compound is the cornerstone of the anoxic iron biogeochemical cycle. The novelty of this thesis is the consideration of bacterial metabolisms of NRB and IRB often overlooked in bio-corrosion processes. (author) [fr

  10. Effect of replacement of vanadium by iron on the electrochemical behaviour of titanium alloys in simulated physiological media

    Directory of Open Access Journals (Sweden)

    Mareci, D.

    2009-02-01

    Full Text Available The electrochemical behaviour of Ti6Al4V, Ti6Al3.5Fe and Ti5Al2.5Fe alloys has been evaluated in Ringer’s solution at 25 °C. The effect of the substitution of vanadium in Ti6Al4V alloy has been specifically addressed. The evaluation of the corrosion resistance was carried out through the analysis of the open circuit potential variation with time, potentiodynamic polarization curves, and electrochemical impedance spectroscopy (EIS tests. Very low current densities were obtained (order of nA/cm2 from the polarization curves and EIS, indicating a typical passive behaviour for all investigated alloys. The EIS results exhibited relative capacitive behaviour (large corrosion resistance with phase angle close to –80° and relative high impedance values (order of 105 Ω•cm2 at low and medium frequencies, which are indicative of the formation of a highly stable film on these alloys in Ringer’s solution. In conclusion, the electrochemical behaviour of Ti6Al4V is not affected by the substitution of vanadium with iron.

    El comportamiento electroquímico de las aleaciones Ti6Al4V, Ti6Al3.5Fe y Ti5Al2.5Fe fue evaluado en una disolución Ringer a 25 °C. Se ha estudiado especialmente el efecto de la sustitución del vanadio en la aleación Ti6Al4V. La evaluación de la resistencia a la corrosión se ha llevado a cabo a través del análisis de la variación del potencial de un circuito abierto con el tiempo, las curvas de polarización potenciodinámicas y los ensayos de espectroscopía de impedancia electroquímica (EIS. Se han obtenido densidades de corriente muy bajas (del orden de nA/cm2 en las curvas de polarización y EIS, indicando un comportamiento pasivo típico para todas las aleaciones investigadas. Los resultados de la EIS mostraron un comportamiento capacitivo relativo (gran resistencia a la corrosión con ángulos de fase próximos a –80° y valores de impedancia relativamente altos (del orden de

  11. Preparation of hard magnetic materials based on nitrogenated rare-earth iron alloys; Preparacao de materiais magneticamente duros a base de ligas de terra rara - ferro nitrogenadas

    Energy Technology Data Exchange (ETDEWEB)

    Guilherme, Eneida da Graca

    1999-07-01

    Nd Fe{sub 11}Ti, Nd Fe{sub 10.5} Mo{sub 1.5} and Nd Fe{sub 10.75} Mo{sub 1.25} alloys were synthesized by reduction-diffusion calciothermic process (RDC) from neodymium chloride (NdCl{sub 3}), iron, titanium, molybdenum and reduction agent (metallic calcium). The effect of process variables, like temperature, time, excess amount of NdCl{sub 3}, heating rate, and composition variation of the Nd Fe{sub 12-x}Mo{sub x} (1 {>=} x {>=} 2). Mother alloys in which 1:12 phase is major were nitrogenated by gas-solid reaction with N{sub 2} and by chemical reaction with sodium zide (Na N{sub 3}). In addition, the influence of reducing particle size of the powdered mother alloys in the nitrogenation step with Na N{sub 3} were studied. As prepared and interstitially modified Nd Fe{sub 11} Ti, Nd Fe{sub 10.5} Mo{sub 1.5} and Nd Fe{sub 10.75} Mo{sub 1.25} alloys with nitrogen , were characterized by X-ray diffraction, Moessbauer spectroscopy, thermomagnetic, SEM and EDS. Nitrogenation by gas-solid reaction with N{sub 2} is found to be not promising, since resulted Curie temperatures (Tc) were lower than literature values. However, nitrogenation by chemical reaction with Na N{sub 3} was efficient with higher or same Tc than previous reported results. The average increases on Tc and volumetric expansion were 200 deg C and 4%, respectively. Milling of the mother alloys before nitrogenation at 330 deg C is preferred because reaction kinetics is enhanced. Nevertheless, at 450 deg C, a competition between the interstitially modified compound formation (alloy + N) and alloy dissociation has occurred, resulting in a Fe-{alpha} phase increase. (author)

  12. Manufacturing of Dysprosium-Iron Alloys by Electrolysis in Fluoride-Based Electrolytes: Oxide Solubility Determinations

    Science.gov (United States)

    Martinez, Ana Maria; Støre, Anne; Osen, Karen Sende

    2018-04-01

    Electrolytic production of light rare earth elements and alloys takes place in a fluoride-based electrolyte using rare earth oxides as raw material. The optimization of this method, mainly in terms of the energy efficiency and environmental impact control, is rather challenging. Anode effects, evolution of fluorine-containing compounds, and side cathode reactions could largely be minimized by a good control of the amount of rare earth oxide species dissolved in the fluoride-based electrolyte and their dissolution rate. The oxide content of the fluoride melts REF3-LiF (RE = Nd, Dy) at different compositions and temperatures were experimentally determined by carbothermal analysis of melt samples. The highest solubility values of oxide species, added as Dy2O3 and Dy2(CO3)3, were obtained to be of ca. 3 wt pct (expressed as Dy2O3) in the case of the equimolar DyF3-LiF melt at 1323 K (1050 °C). The oxide saturation values increased with the amount of REF3 present in the molten bath and the working temperature.

  13. The Influence of Hot-Rolled Temperature on Plasma Nitriding Behavior of Iron-Based Alloys

    Science.gov (United States)

    El-Hossary, F. M.; Khalil, S. M.; Lotfy, Kh.; Kassem, M. A.

    2009-07-01

    Experiments were performed with an aim of studying the effect of hot-rolled temperature (600 and 900°C) on radio frequency (rf) plasma nitriding of Fe93Ni4Zr3 alloy. Nitriding was carried out for 10 min in a nitrogen atmosphere at a base pressure of 10-2 mbarr. Different continuous plasma processing powers of 300-550 W in steps 50 W or less were applied. Nitrided hot-rolled specimens were characterized by optical microscopy (OM), X-ray diffraction (XRD) and microhardness measurements. The results reveal that the surface of hot-rolled rf plasma nitrided specimens at 600°C is characterized with a fine microstructure as a result of the high nitrogen solubility and diffusivity. Moreover, the hot-rolled treated samples at 600°C exhibit higher microhardness value than the associated values of hot-rolled treated samples at 900°C. The enhancement of microhardness is due to precipitation and predominance of new phases ( γ and ɛ phases). Mainly, this conclusion has been attributed to the high defect densities and small grain sizes of the samples hot-rolled at 600°C. Generally, the refinement of grain size plays a dramatic role in improvement of mechanical properties of tested samples.

  14. Standard Practice for Characterizing Neutron Exposures in Iron and Low Alloy Steels in Terms of Displacements Per Atom (DPA), E 706(ID)

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2001-01-01

    1.1 This practice describes a standard procedure for characterizing neutron irradiations of iron (and low alloy steels) in terms of the exposure index displacements per atom (dpa) for iron. 1.2 Although the general procedures of this practice apply to any material for which a displacement cross section d(E) is known (see Practice E 521), this practice is written specifically for iron. 1.3 It is assumed that the displacement cross section for iron is an adequate approximation for calculating displacements in steels that are mostly iron (95 to 100 %) in radiation fields for which secondary damage processes are not important. 1.4 Procedures analogous to this one can be formulated for calculating dpa in charged particle irradiations. (See Practice E 521.) 1.5 The application of this practice requires knowledge of the total neutron fluence and flux spectrum. Refer to Practice E 521 for determining these quantities. 1.6 The correlation of radiation effects data is beyond the scope of this practice. This stand...

  15. Effects of silicon, copper and iron on static and dynamic properties of alloy 206 (aluminum-copper) in semi-solids produced by the SEED process

    Science.gov (United States)

    Lemieux, Alain

    The advantages of producing metal parts by rheocasting are generally recognised for common foundry alloys of Al-Si. However, other more performing alloys in terms of mechanical properties could have a great interest in specialized applications in the automotive industry, while remaining competitive in the forming. Indeed, the growing demand for more competitive products requires the development of new alloys better suited to semi-solid processes. Among others, Al-Cu alloys of the 2XX series are known for their superior mechanical strength. However, in the past, 2XX alloys were never candidates for pressure die casting. The main reason is their propensity to hot tearing. Semi-solid processes provide better conditions for molding with the rheological behavior of dough and molding temperatures lower reducing this type of defect. In the initial phase, this research has studied factors that reduce hot tearing susceptibility of castings produced by semi-solid SEED of alloy 206. Subsequently, a comparative study on the tensile properties and fatigue was performed on four variants of the alloy 206. The results of tensile strength and fatigue were compared with the specifications for applications in the automotive industry and also to other competing processes and alloys. During this study, several metallurgical aspects were analyzed. The following main points have been validated: i) the main effects of compositional variations of silicon, iron and copper alloy Al-Cu (206) on the mechanical properties, and ii) certain relationships between the mechanism of hot cracking and the solidification rate in semi-solid. Parts produced from the semi-solid paste coming from the SEED process combined with modified 206 alloys have been successfully molded and achieved superior mechanical properties than the requirements of the automotive industry. The fatigue properties of the two best modified 206 alloys were higher than those of A357 alloy castings and are close to those of the

  16. Superparamagnetic iron oxide nanoparticles (SPIONs)-loaded Trojan microparticles for targeted aerosol delivery to the lung.

    Science.gov (United States)

    Tewes, Frederic; Ehrhardt, Carsten; Healy, Anne Marie

    2014-01-01

    Targeted aerosol delivery to specific regions of the lung may improve therapeutic efficiency and minimise unwanted side effects. Targeted delivery could potentially be achieved with porous microparticles loaded with superparamagnetic iron oxide nanoparticles (SPIONs)-in combination with a target-directed magnetic gradient field. The aim of this study was to formulate and evaluate the aerodynamic properties of SPIONs-loaded Trojan microparticles after delivery from a dry powder inhaler. Microparticles made of SPIONs, PEG and hydroxypropyl-β-cyclodextrin (HPβCD) were formulated by spray drying and characterised by various physicochemical methods. Aerodynamic properties were evaluated using a next generation cascade impactor (NGI), with or without a magnet positioned at stage 2. Mixing appropriate proportions of SPIONs, PEG and HPβCD allowed Trojan microparticle to be formulated. These particles had a median geometric diameter of 2.8±0.3μm and were shown to be sensitive to the magnetic field induced by a magnet having a maximum energy product of 413.8kJ/m(3). However, these particles, characterised by a mass median aerodynamic diameter (MMAD) of 10.2±2.0μm, were considered to be not inhalable. The poor aerodynamic properties resulted from aggregation of the particles. The addition of (NH4)2CO3 and magnesium stearate (MgST) to the formulation improved the aerodynamic properties of the Trojan particles and resulted in a MMAD of 2.2±0.8μm. In the presence of a magnetic field on stage 2 of the NGI, the amount of particles deposited at this stage increased 4-fold from 4.8±0.7% to 19.5±3.3%. These Trojan particles appeared highly sensitive to the magnetic field and their deposition on most of the stages of the NGI was changed in the presence compared to the absence of the magnet. If loaded with a pharmaceutical active ingredient, these particles may be useful for treating localised lung disease such as cancer nodules or bacterial infectious foci. Copyright

  17. Determination of low alloying element concentrations in cast iron by laser induced breakdown spectroscopy based on TEA CO2 laser system

    Directory of Open Access Journals (Sweden)

    Savović Jelena J.

    2017-01-01

    Full Text Available The analytical capability of laser-produced plasma for the analysis of low alloying elements in cast iron samples has been investigated. The plasma was induced by irradiation of a sample in air at atmospheric pressure using an infrared CO2 laser. Emission spectra were recorded by time-integrated spatially- resolved measurement technique. A set of ten cast iron samples in a powder or particulate form were provided by BAM (Bundesanstalt für Material Forschung und Prüfung, Deutschland, seven of which were used for calibration, and three were treated as unknowns. Linear calibration curves were obtained for copper, chromium, and nickel, with correlation coefficients above 0.99. Precision and accuracy of the LIBS method was evaluated and compared to those obtained by the inductively coupled plasma (ICP analysis of the same samples. Detection limits for Cu, Cr and Ni were close to those reported in the literature for other comparable iron-based alloys obtained using different LIBS systems. Analytical figures of merit of the studied LIBS system may be considered as satisfying, especially in the light of other advantages of the method, like cost effective and fast analysis with no sample preparation, and with a possibility for real-time on-site analysis. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. 172019

  18. Magnetic Resonance Imaging of Atherosclerosis Using CD81-Targeted Microparticles of Iron Oxide in Mice

    Directory of Open Access Journals (Sweden)

    Fei Yan

    2015-01-01

    Full Text Available The goal of this study is to investigate the feasibility of using CD81- (Cluster of Differentiation 81 protein- targeted microparticles of iron oxide (CD81-MPIO for magnetic resonance imaging (MRI of the murine atherosclerosis. CD81-MPIO and IgG- (Immunoglobulin G- MPIO were prepared by covalently conjugating, respectively, with anti-CD81 monoclonal and IgG antibodies to the surface of the tosyl activated MPIO. The relevant binding capability of the MPIO was examined by incubating them with murine bEnd.3 cells stimulated with phenazine methosulfate (PMS and its effect in shortening T2 relaxation time was also examined. MRI in apolipoprotein E-deficient mice was studied in vivo. Our results show that CD81-MPIO, but not IgG-MPIO, can bind to the PMS-stimulated bEnd.3 cells. The T2 relaxation time was significantly shortened for stimulated bEnd.3 cells when compared with IgG-MPIO. In vivo MRI in apolipoprotein E-deficient mice showed highly conspicuous areas of low signal after CD81-MPIO injection. Quantitative analysis of the area of CD81-MPIO contrast effects showed 8.96- and 6.98-fold increase in comparison with IgG-MPIO or plain MPIO, respectively (P<0.01. Histological assay confirmed the expression of CD81 and CD81-MPIO binding onto atherosclerotic lesions. In conclusion, CD81-MPIO allows molecular assessment of murine atherosclerotic lesions by magnetic resonance imaging.

  19. Indium oxide-based transparent conductive films deposited by reactive sputtering using alloy targets

    Science.gov (United States)

    Miyazaki, Yusuke; Maruyama, Eri; Jia, Junjun; Machinaga, Hironobu; Shigesato, Yuzo

    2017-04-01

    High-quality transparent conductive oxide (TCO) films, Sn-doped In2O3 (ITO) and In2O3-ZnO (IZO), were successfully deposited on either synthetic silica or polyethylene terephthalate (PET) substrates in the “transition region” by reactive dc magnetron sputtering using In-Zn and In-Sn alloy targets, respectively, with a specially designed plasma emission feedback system. The composition, crystallinity, surface morphology, and electrical and optical properties of the films were analyzed. All of the IZO films were amorphous, whereas the ITO films were polycrystalline over a wide range of deposition conditions. The minimum resistivities of the IZO and ITO films deposited on the heated PET substrates at 150 °C were 3.3 × 10-4 and 5.4 × 10-4 Ω·cm, respectively. By applying rf bias to unheated PET substrates, ITO films with a resistivity of 4.4 × 10-4 Ω·cm were deposited at a dc self-bias voltage of -60 V.

  20. Use of indexed sensitivity factors in the analysis of nickel and iron based alloys: study of the decalibration of sheathed Chromel/Alumel thermocouples

    International Nuclear Information System (INIS)

    Christie, W.H.

    1978-01-01

    Sheathed Chromel versus Alumel thermocouples decalibrate when exposed to temperatures in excess of 1100 0 C. Thermocouples sheathed in Inconel-600 and type 304 stainless steel were studied in this work. Quantified SIMS data showed that the observed decalibrations were due to significant alterations that took place in the Chromel and Alumel thermoelements. The amount of alteration was different for each thermocouple and was influenced by the particular sheath material used in the thermocouple construction. Relative sensitivity factors, indexed by a matrix ion species ratio, were used to quantify SIMS data for three nickel-based alloys, Chromel, Alumel, and Inconel-600, and an iron-based alloy, type 304 stainless steel. Oxygen pressure >2 x 10 -6 torr in the sputtering region gave enhanced sensitivity and superior quantitative results as compared to data obtained at instrumental residual pressure

  1. Influence of Chemical Composition on Rupture Properties at 1200 Degrees F. of Forged Chromium-Cobalt-Nickel-Iron Base Alloys in Solution-Treated and Aged Condition

    Science.gov (United States)

    Reynolds, E E; Freeman, J W; White, A E

    1951-01-01

    The influence of systematic variations of chemical composition on rupture properties at 1200 degrees F. was determined for 62 modifications of a basic alloy containing 20 percent chromium, 20 percent nickel, 20 percent cobalt, 3 percent molybdenum, 2 percent tungsten, 1 percent columbium, 0.15 percent carbon, 1.7 percent manganese, 0.5 percent silicon, 0.12 percent nitrogen and the balance iron. These modifications included individual variations of each of 10 elements present and simultaneous variations of molybdenum, tungsten, and columbium. Laboratory induction furnace heats were hot-forged to round bar stock, solution-treated at 2200 degrees F., and aged at 1400 degrees F. The melting and fabrication conditions were carefully controlled in order to minimize all variable effects on properties except chemical composition. Information is presented which indicates that melting and hot-working conditions play an important role in high-temperature properties of alloys of the type investigated.

  2. Corrosion resisting properties of 90/10 copper-nickel-iron alloy with particular reference to offshore oil and gas applications

    Energy Technology Data Exchange (ETDEWEB)

    Gilbert, P T

    1979-01-01

    The use of a copper-nickel-iron alloy for seawater pipeline systems and various other applications on offshore oil and gas platforms is now proving attractive, according to the UK's Yorkshire Imperial Metals Ltd. The alloy has already proved a useful and reliable material in many applications: It has given good results in seawater-cooled condensers and heat exchangers and seawater piping systems, in power stations, ships, desalination plant, and refrigeration service. Its antifouling and corrosion-resistant properties are valuable in these applications. The main limitations that have to be observed in its use are (1) the design, construction, and operation of systems within prescribed velocity and turbulence limits, to avoid the occurrence of impingement attack, and (2) problems that may arise because of badly polluted seawater.

  3. Investigations on chloride-induced high temperature corrosion of iron-, nickel-, cobalt-base alloys by scanning electron microscopy and energy dispersive X-ray microspot analysis

    International Nuclear Information System (INIS)

    Ross, W.; Umland, F.

    1984-01-01

    The direct oxidation at 900 0 C in air and the corrosion of alloys in air after short exposure to chloride have been compared under identical conditions. Chloride destroys the original oxide layers by recristallisation and modifies the following scale growing in such a manner that no firmly sticking layers can be rebuilt. After a chloride induction therefore all other following corrosions will be enhanced. Experiments in a closed system, a so called transport furnace, showed that the chloride also acts as a gas phase carrier transporting firstly the oxide layer, under reducing conditions metals, too, as volatile chloro metal gas complexes in this case from hot to cold region of the furnace. Cobalt base alloys are less attacked than iron or nickel base alloys. As chloride is not found implicitly on the treated surface the identification of the chloride induced corrosion is difficult. However the scanning electron microscopy combined with quantitative energy dispersive X-ray analysis has been proved as an appropriate method for early detection. As the phenomena depend on the type of alloy, respectively, an illustration and interpretation catalogue is necessary. (orig.) [de

  4. Development of the white cast iron with niobium alloy, heat treating, to wear of the abrasive resistance; Desenvolvimento de uma liga de ferro fundido branco alto cromo com niobio, tratada termicamente, para resistencia ao desgaste abrasivo

    Energy Technology Data Exchange (ETDEWEB)

    Farah, Alessandro Fraga

    1997-07-01

    This work presents the heat treatment and abrasion tests results of a white cast iron with niobium alloy. The hardening heat treatment were made 950, 1000, 1050 e 110 deg C temperatures cooled by forced air. The tempering treatment were made at 450, 500 e 550 deg C temperatures. The heat treating alloy were compared, in the abrasive tests, with commercial alloys used as hardfacing by welding process in wear pieces. The abrasion tests was realized in pin on disk test. Additional tests were carried out for microstructural characterization to identify the different phases presents in the alloys. In a general way, the alloy studies showed the best wear rate for the heat treatments that results in higher hardness. It performance was superior than that of the commercial alloys. (author)

  5. Effect of temperature during ion sputtering on the surface segregation rate of antimony in an iron-antimony alloy at higher temperatures

    International Nuclear Information System (INIS)

    Oku, M.; Hirokawa, K.; Kimura, H.; Suzuki, S.

    1986-01-01

    The surface segregation of antimony in an iron-0.23 at% antimony alloy was studied by XPS. The segregation rate in the temperature range between 800 and 900 K depends on the temperature during sputtering with argon ion of kinetic energy of 1 keV. The sputtering at room temperature or 473 K gives higher values of the segregation rate than those at 673 K. Both cases give the activation energy of 170 kJmol -1 for the surface segregation rate. The segregation of antimony is not observed after the sample is heated at 1000 K. (author)

  6. Rice and Bean Targets for Biofortification Combined with High Carotenoid Content Crops Regulate Transcriptional Mechanisms Increasing Iron Bioavailability

    Directory of Open Access Journals (Sweden)

    Desirrê Morais Dias

    2015-11-01

    Full Text Available Iron deficiency affects thousands of people worldwide. Biofortification of staple food crops aims to support the reduction of this deficiency. This study evaluates the effect of combinations of common beans and rice, targets for biofortification, with high carotenoid content crops on the iron bioavailability, protein gene expression, and antioxidant effect. Iron bioavailability was measured by the depletion/repletion method. Seven groups were tested (n = 7: Pontal bean (PB; rice + Pontal bean (R + BP; Pontal bean + sweet potato (PB + SP; Pontal bean + pumpkin (PB + P; Pontal bean + rice + sweet potato (PB + R + P; Pontal bean + rice + sweet potato (PB + R + SP; positive control (Ferrous Sulfate. The evaluations included: hemoglobin gain, hemoglobin regeneration efficiency (HRE, gene expression of divalente metal transporter 1 (DMT-1, duodenal citocromo B (DcytB, ferroportin, hephaestin, transferrin and ferritin and total plasma antioxidant capacity (TAC. The test groups, except the PB, showed higher HRE (p < 0.05 than the control. Gene expression of DMT-1, DcytB and ferroportin increased (p < 0.05 in the groups fed with high content carotenoid crops (sweet potato or pumpkin. The PB group presented lower (p < 0.05 TAC than the other groups. The combination of rice and common beans, and those with high carotenoid content crops increased protein gene expression, increasing the iron bioavailability and antioxidant capacity.

  7. Theranostic MUC-1 aptamer targeted gold coated superparamagnetic iron oxide nanoparticles for magnetic resonance imaging and photothermal therapy of colon cancer

    DEFF Research Database (Denmark)

    Azhdarzadeh, Morteza; Atyabi, Fatemeh; Saei, Amir Ata

    2016-01-01

    Favorable physiochemical properties and the capability to accommodate targeting moieties make superparamegnetic iron oxide nanoparticles (SPIONs) popular theranostic agents. In this study, we engineered SPIONs for magnetic resonance imaging (MRI) and photothermal therapy of colon cancer cells...

  8. On the use of lead/tin alloys as target material for the production of spallation neutrons

    International Nuclear Information System (INIS)

    Atchison, F.; Baumann, P.; Brys, T.; Daum, M.; Egorov, A.; Fierlinger, P.; Fuchs, P.; Henneck, R.; Joray, St.; Keil, R.; Kirch, K.; Krutova, R.; Kuehne, G.; Lebedev, V.T.; Obermeier, H.; Orlova, D.N.; Perret, Ch.; Pichlmaier, A.; Richard, Ph.; Serebrov, A.; Thies, S.

    2005-01-01

    We have examined the suitability of lead (Pb)/tin (Sn) alloys with atomic ratios between 4:1 and 12:1 for use as a spallation target material for the PSI spallation ultracold neutron source. The measured corrosion rate with distilled water, R c -5 cm/year, is more than a factor of 80, less than for normal Pb; this corrosion rate is satisfactory. Microscopic investigations of the surface after the exposure to water revealed no visual changes. Small angle neutron scattering showed that the alloy is mechanically stable under thermal cycling. An experimental simulation of a water-cooled spallation neutron target made of Pb/Sn pebbles with a filling factor of 60% was investigated; the pulsed proton beam was simulated using hot and cold water in the target 'cooling' circuit. With realistic operational parameters for the cooling circuit, serious deformation of the PbSn pebbles occurred which finally blocked the cooling circuit. The Pb/Sn alloys solve the corrosion problem but its mechanical properties are inadequate leading to too short a lifetime to be practical in the PSI spallation source

  9. Damage induced by swift heavy ions in a pure metallic target: iron. Experimental results and numerical simulation

    International Nuclear Information System (INIS)

    Legrand, P.

    1993-01-01

    The damage induced when a high energy deposition occurs in the electronic system of a pure metal (Ag, Co, Fe, Ni, Pd, Pt, Ti, W, Zr) has been investigated using two methods: low temperature swift heavy ion (O, Ar, Kr, Xe, Pb, u) irradiations and computer simulations by molecular dynamics. Irradiations reveal that up to now, it is only in iron, titanium, cobalt and zirconium targets that high levels of energy deposition in electronic excitations lead to a new mechanism of defect creation in addition to the effects of elastic collisions. This mechanism might be the Coulomb explosion: the incident ion creates in its wake a cylinder of highly ionized matter; Coulomb repulsions of short duration in metallic targets could then set a great number of neighbouring atoms into motion and lead to permanent atomic displacements. Using molecular dynamics, we confirm that atomic displacements can indeed occur when neighbouring perturbated atoms receive even a very small amount of kinetic energy (≤ 1 eV). This happens only if the repulsive movements are collective and coherent. Defect creation and annealing of preexisting defects which occur in iron at different energy deposition levels are successfully simulated. An original empirical N-body potential, allowing a realistic description of the bulk properties of the body centered cubic iron, is used. (author). refs., figs., tabs

  10. Relation between feeding mechanisms and solidification mode in 380 aluminium alloy with different iron contents; Relacion entre los mecanismos de alimentacion y el modo de solidificacion en una aleacion de aluminio 380 con distintos contenidos de hierro

    Energy Technology Data Exchange (ETDEWEB)

    Tovio, D. O.; Gonzalez, A.C.; Mugica, G. W.; Cuyas, J. C.

    2003-07-01

    In the present work the effect of iron (0.15, 0.42 and 0.86%) content in feeding mechanisms for 380 aluminium alloy has been studied. The feeding capacity has been evaluated by a device that produces a barrier removable to allowing the movement of the inter dendritic liquid. The results show the flow of different quantity of liquid, it depends of the temperature of operating the device and of the iron content. For minimum and maximum iron content, the inter dendritic and bursts feeding mechanisms are fundamentally involved, for 0.42% of iron the feeding mechanisms was the inter dendritic. The authors establish this behavior by the solidification mode of alloy, which promotes the presence of particles of Si or plates of b-Al{sub 3}FeDi phase, in the inter dendritic channels and produce the different feeding mechanisms. (Author) 15 refs.

  11. Auger electron spectroscopy study of surface segregation in the binary alloys copper-1 atomic percent indium, copper-2 atomic percent tin, and iron-6.55 atomic percent silicon

    Science.gov (United States)

    Ferrante, J.

    1973-01-01

    Auger electron spectroscopy was used to examine surface segregation in the binary alloys copper-1 at. % indium, copper-2 at. % tin and iron-6.55 at. % silicon. The copper-tin and copper-indium alloys were single crystals oriented with the /111/ direction normal to the surface. An iron-6.5 at. % silicon alloy was studied (a single crystal oriented in the /100/ direction for study of a (100) surface). It was found that surface segregation occurred following sputtering in all cases. Only the iron-silicon single crystal alloy exhibited equilibrium segregation (i.e., reversibility of surface concentration with temperature) for which at present we have no explanation. McLean's analysis for equilibrium segregation at grain boundaries did not apply to the present results, despite the successful application to dilute copper-aluminum alloys. The relation of solute atomic size and solubility to surface segregation is discussed. Estimates of the depth of segregation in the copper-tin alloy indicate that it is of the order of a monolayer surface film.

  12. Influence of the thermal history of a particle during atomization on the morphology of carbides in a hypereutectic iron based alloy

    International Nuclear Information System (INIS)

    Kusý, M.; Behúlová, M.; Grgač, P.

    2012-01-01

    Highlights: ► Identification of solidification microstructures in RS powder from iron based alloy. ► Microstructures affected and nonaffected during the post-recalescence period. ► Thermokinetic newtonian model of rapid solidification of a droplet in gas atomization. ► Droplet thermal history and conditions for the microstructure development. ► Parameters influencing development of different solidification microstructures. - Abstract: Basic principles and consequences of the rapid solidification processing of melts have been successfully exploited in several progressive technologies of material production. In the paper, the solidification microstructures developed in the hypereutectic iron based alloy with the chemical composition of 3% C–3% Cr–12% V (wt.%) prepared by nitrogen gas atomization are presented and analysed. Several main types of solidification microstructures were identified in the rapidly solidified powder particles. According to the morphological features of carbide phases and computed thermal history of rapidly solidified particles, the microstructures were divided into two groups – microstructures morphologically non-affected during the post-recalescence period of solidification, and microstructures with morphological transitions occurring during the quasi-isothermal period of structure development. Based on the thermokinetic newtonian model of rapid solidification of a spherical droplet in the process of atomization, the thermal history of droplets with diameter from 20 μm to 400 μm rapidly solidified from different nucleation temperatures was studied. The thermo-physical conditions necessary for the development of variable microstructures in single rapidly solidified powder particles are predicted and discussed. The nucleation temperature, recalescence temperature and duration of quasi-isothermal plateau are supposed to be the most important parameters influencing the microstructure development in the rapidly solidified

  13. Magnetic nanoparticles for precision oncology: theranostic magnetic iron oxide nanoparticles for image-guided and targeted cancer therapy.

    Science.gov (United States)

    Zhu, Lei; Zhou, Zhiyang; Mao, Hui; Yang, Lily

    2017-01-01

    Recent advances in the development of magnetic nanoparticles (MNPs) have shown promise in the development of new personalized therapeutic approaches for clinical management of cancer patients. The unique physicochemical properties of MNPs endow them with novel multifunctional capabilities for imaging, drug delivery and therapy, which are referred to as theranostics. To facilitate the translation of those theranostic MNPs into clinical applications, extensive efforts have been made on designing and improving biocompatibility, stability, safety, drug-loading ability, targeted delivery, imaging signal and thermal- or photodynamic response. In this review, we provide an overview of the physicochemical properties, toxicity and theranostic applications of MNPs with a focus on magnetic iron oxide nanoparticles.

  14. Ultrasmall cationic superparamagnetic iron oxide nanoparticles as nontoxic and efficient MRI contrast agent and magnetic-targeting tool

    Science.gov (United States)

    Uchiyama, Mayara Klimuk; Toma, Sergio Hiroshi; Rodrigues, Stephen Fernandes; Shimada, Ana Lucia Borges; Loiola, Rodrigo Azevedo; Cervantes Rodríguez, Hernán Joel; Oliveira, Pedro Vitoriano; Luz, Maciel Santos; Rabbani, Said Rahnamaye; Toma, Henrique Eisi; Poliselli Farsky, Sandra Helena; Araki, Koiti

    2015-01-01

    Fully dispersible, cationic ultrasmall (7 nm diameter) superparamagnetic iron oxide nanoparticles, exhibiting high relaxivity (178 mM−1s−1 in 0.47 T) and no acute or subchronic toxicity in Wistar rats, were studied and their suitability as contrast agents for magnetic resonance imaging and material for development of new diagnostic and treatment tools demonstrated. After intravenous injection (10 mg/kg body weight), they circulated throughout the vascular system causing no microhemorrhage or thrombus, neither inflammatory processes at the mesentery vascular bed and hepatic sinusoids (leukocyte rolling, adhesion, or migration as evaluated by intravital microscopy), but having been spontaneously concentrated in the liver, spleen, and kidneys, they caused strong negative contrast. The nanoparticles are cleared from kidneys and bladder in few days, whereas the complete elimination from liver and spleen occurred only after 4 weeks. Ex vivo studies demonstrated that cationic ultrasmall superparamagnetic iron oxide nanoparticles caused no effects on hepatic and renal enzymes dosage as well as on leukocyte count. In addition, they were readily concentrated in rat thigh by a magnet showing its potential as magnetically targeted carriers of therapeutic and diagnostic agents. Summarizing, cationic ultrasmall superparamagnetic iron oxide nanoparticles are nontoxic and efficient magnetic resonance imaging contrast agents useful as platform for the development of new materials for application in theranostics. PMID:26251595

  15. X-ray tube targets

    International Nuclear Information System (INIS)

    Hirsch, H.H.

    1980-01-01

    In rotary targets for X-ray tubes warping is a problem which causes X-ray deficiency. A rotary target is described in which warping is reduced by using alloys of molybdenum with 0.05 to 10% iron, silicon, cobalt, tantalum, niobium, hafnium, stable metal oxide or mixture thereof. Suitable mixtures are 0.5 to 10% of tantalum, niobium or hafnium with from 0.5 to 5% yttrium oxide, or 0.05 to 0.3% of cobalt or silicon. Optionally 0.1 to 5% by weight of additional material may be alloyed with the molybdenum, such as tantalum or hafnium carbides. (author)

  16. Tick iron and heme metabolism – New target for an anti-tick intervention

    Czech Academy of Sciences Publication Activity Database

    Hajdušek, Ondřej; Šíma, Radek; Perner, Jan; Loosová, Gabriela; Harcubová, Adéla; Kopáček, Petr

    2016-01-01

    Roč. 7, č. 4 (2016), s. 565-572 ISSN 1877-959X R&D Projects: GA ČR GA13-11043S; GA ČR GP13-27630P; GA ČR GP13-12816P EU Projects: European Commission(XE) 316304 - MODBIOLIN Institutional support: RVO:60077344 Keywords : tick * iron * heme * RNAi * vaccine Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.230, year: 2016

  17. Targeting higher ferritin concentrations with intravenous iron dextran lowers erythropoietin requirement in hemodialysis patients.

    Science.gov (United States)

    DeVita, M V; Frumkin, D; Mittal, S; Kamran, A; Fishbane, S; Michelis, M F

    2003-11-01

    Although clinical use of recombinant human erythropoietin (rHuEPO) since 1989 has improved anemia in most end-stage renal disease patients, there are still many hemodialysis patients unable to maintain an adequate hematocrit (HCT) without large doses of rHuEPO. This suggests that anemia is not solely a consequence of rHuEPO deficiency, but may be due to other factors including functional iron deficiency. Since the optimal prescription for iron replacement is not yet known, we evaluated the effect of intravenous iron dextran (IVFe) infusion on serum ferritin (SFer) concentration and rHuEPO dose. Our objective was to raise and maintain serum ferritin concentrations to 2 different levels above the National Kidney Foundation Dialysis Outcome Quality Initiative standard of 100 ng/ml to determine whether, and by what degree rHuEPO dose could be lowered. HD patients on i.v. rHuEPO with a SFer concentration > or = 70 ng/ml and an HCT of requirements.

  18. Effect of microstructure and strain on the degradation behavior of novel bioresorbable iron-manganese alloy implants.

    Science.gov (United States)

    Heiden, Michael; Kustas, Andrew; Chaput, Kevin; Nauman, Eric; Johnson, David; Stanciu, Lia

    2015-02-01

    Advancing the understanding of microstructural effects and deformation on the degradability of Fe-Mn bioresorbable alloys (specifically, Fe-33%Mn) will help address the current problems associated with designing degradable fracture fixation implants for hard tissues. Potentiostatic polarization tests were conducted on a wide variety of metal samples to examine how different deformation processes affect the instantaneous rate of degradation of Fe-Mn alloys. Large-strain machining (LSM), a novel severe plastic deformation (SPD) technique was utilized during these experiments to modify the degradation properties of the proposed Fe-Mn alloy. It was discovered that Fe-33%Mn after LSM with a rake angle of 0° (effective strain = 2.85) showed the most promising increase in degradation rate compared to as-cast, annealed, and additional deformation conditions (rolled and other LSM parameters) for the same alloy. The mechanisms for enhancement of the corrosion rate are discussed. © 2014 Wiley Periodicals, Inc.

  19. High molecular weight chitosan derivative polymeric micelles encapsulating superparamagnetic iron oxide for tumor-targeted magnetic resonance imaging

    Directory of Open Access Journals (Sweden)

    Xiao Y

    2015-02-01

    Full Text Available Yunbin Xiao,1,* Zuan Tao Lin,2,* Yanmei Chen,1 He Wang,1 Ya Li Deng,2 D Elizabeth Le,3 Jianguo Bin,1 Meiyu Li,1 Yulin Liao,1 Yili Liu,1 Gangbiao Jiang,2 Jianping Bin1 1State Key Laboratory of Organ Failure Research, Division of Cardiology, Nanfang Hospital, Southern Medical University, Guangzhou, People’s Republic of China; 2Department of Pharmaceutical Engineering, South China Agricultural University, Guangzhou, People’s Republic of China; 3Cardiovascular Division, Oregon Health and Science University, Portland, OR, USA *These authors contributed equally to this work Abstract: Magnetic resonance imaging (MRI contrast agents based on chitosan derivatives have great potential for diagnosing diseases. However, stable tumor-targeted MRI contrast agents using micelles prepared from high molecular weight chitosan derivatives are seldom reported. In this study, we developed a novel tumor-targeted MRI vehicle via superparamagnetic iron oxide nanoparticles (SPIONs encapsulated in self-aggregating polymeric folate-conjugated N-palmitoyl chitosan (FAPLCS micelles. The tumor-targeting ability of FAPLCS/SPIONs was demonstrated in vitro and in vivo. The results of dynamic light scattering experiments showed that the micelles had a relatively narrow size distribution (136.60±3.90 nm and excellent stability. FAPLCS/SPIONs showed low cytotoxicity and excellent biocompatibility in cellular toxicity tests. Both in vitro and in vivo studies demonstrated that FAPLCS/SPIONs bound specifically to folate receptor-positive HeLa cells, and that FAPLCS/SPIONs accumulated predominantly in established HeLa-derived tumors in mice. The signal intensities of T2-weighted images in established HeLa-derived tumors were reduced dramatically after intravenous micelle administration. Our study indicates that FAPLCS/SPION micelles can potentially serve as safe and effective MRI contrast agents for detecting tumors that overexpress folate receptors. Keywords: superparamagnetic

  20. Fabrication and Characterization of Targets for Shock Propagation and Radiation Burnthrough Measurements on Be-0.9 AT. % Cu Alloy

    International Nuclear Information System (INIS)

    Nobile, A.; Dropinski, S.C.; Edwards, J.M.; Rivera, G.; Margevicius, R.W.; Sebring, R.J.; Olson, R. E.; Tanner, D.L.

    2004-01-01

    Beryllium-copper alloy (Be0.9%Cu) ICF capsules are being developed for the pursuit of thermonuclear ignition at the National Ignition Facility (NIF). Success of this capsule material requires that its shock propagation and radiation burnthrough characteristics be accurately understood. To this end, experiments are being conducted to measure the shock propagation and radiation burnthrough properties of Be0.9%Cu alloy. These experiments involve measurements on small Be0.9%Cu wedge, step and flat samples. Samples are mounted on 1.6-mm-diameter x 1.2-mm-length hohlraums that are illuminated by the OMEGA laser at the University of Rochester. X-rays produced by the hohlraum drive the sample. A streaked optical pyrometer detects breakout of the shock produced by the X-ray pulse. In this paper we describe synthesis of the alloy material, fabrication and characterization of samples, and assembly of the targets. Samples were produced from Be0.9%Cu alloy that was synthesized by hot isostatic pressing of Be powder and copper flake. Samples were 850 μm diameter disks with varying thickness in the case of wedge and step samples, and uniform thickness in the case of flat samples. Sample thickness varied in the range 10-90 μm. Samples were prepared by precision lathe machining and electric discharge machining. The samples were characterized by a Veeco white light interferometer and an optical thickness measurement device that simultaneously measured the upper and lower surface contours of samples using two confocal laser probes. Several campaigns with these samples have been conducted over the past two years

  1. Magnetic tumor targeting of β-glucosidase immobilized iron oxide nanoparticles

    Science.gov (United States)

    Zhou, Jie; Zhang, Jian; David, Allan E.; Yang, Victor C.

    2013-09-01

    Directed enzyme/prodrug therapy (DEPT) has promising application for cancer therapy. However, most current DEPT strategies face shortcomings such as the loss of enzyme activity during preparation, low delivery and transduction efficiency in vivo and difficultly of monitoring. In this study, a novel magnetic directed enzyme/prodrug therapy (MDEPT) was set up by conjugating β-glucosidase (β-Glu) to aminated, starch-coated, iron oxide magnetic iron oxide nanoparticles (MNPs), abbreviated as β-Glu-MNP, using glutaraldehyde as the crosslinker. This β-Glu-MNP was then characterized in detail by size distribution, zeta potential, FTIR spectra, TEM, SQUID and magnetophoretic mobility analysis. Compared to free enzyme, the conjugated β-Glu on MNPs retained 85.54% ± 6.9% relative activity and showed much better temperature stability. The animal study results showed that β-Glu-MNP displays preferable pharmacokinetics characteristics in relation to MNPs. With an adscititious magnetic field on the surface of a tumor, a significant quantity of β-Glu-MNP was selectively delivered into a subcutaneous tumor of a glioma-bearing mouse. Remarkably, the enzyme activity of the delivered β-Glu in tumor lesions showed as high as 20.123±5.022 mU g-1 tissue with 2.14 of tumor/non-tumor β-Glu activity.

  2. Magnetic targeting of iron-oxide-labeled fluorescent hepatoma cells to the liver

    Energy Technology Data Exchange (ETDEWEB)

    Luciani, Alain [Universite Rene Descartes, Hopital Europeen Georges Pompidou, Laboratoire de Recherche en Imagerie, EA 4062, Paris (France); Imagerie Medicale, Faculte de Medecine Paris XII, CHU Henri Mondor, Creteil cedex (France); Wilhelm, Claire; Gazeau, Florence [Universite Paris Diderot, Batiment Condorcet, Laboratoire Matiere et Systemes Complexes, CNRS-UMR 7057, Paris Cedex (France); Bruneval, Patrick [Anatomopathologie, Hopital Europeen Georges Pompidou, Paris (France); Cunin, Patrick [Unite de Recherche Clinique, Faculte de Medecine Paris XII, CHU Henri Mondor, Creteil cedex (France); Autret, Gwennhael; Clement, Olivier [Universite Rene Descartes, Hopital Europeen Georges Pompidou, Laboratoire de Recherche en Imagerie, EA 4062, Paris (France); Rahmouni, Alain [Imagerie Medicale, Faculte de Medecine Paris XII, CHU Henri Mondor, Creteil cedex (France)

    2009-05-15

    The purpose of this study was to determine whether an external magnet field can induce preferential trafficking of magnetically labeled Huh7 hepatoma cells to the liver following liver cell transplantation. Huh7 hepatoma cells were labeled with anionic magnetic nanoparticles (AMNP) and tagged with a fluorescent membrane marker (PKH67). Iron-uptake was measured by magnetophoresis. Twenty C57Bl6 mice received an intrasplenic injection of 2 x 10{sup 6} labeled cells. An external magnet (0.29 T; 25 T/m) was placed over the liver of 13 randomly selected animals (magnet group), while the remaining 7 animals served as controls. MRI (1.5 T) and confocal fluorescence microscopy (CFM) were performed 10 days post-transplantation. The presence and location of labeled cells within the livers were compared in the magnet group and controls, and confronted with histological analysis representing the standard of reference. Mean iron content per cell was 6 pg. Based on histology, labeled cells were more frequently present within recipient livers in the magnet group (p < 0.01) where their distribution was preferentially peri-vascular (p<0.05). MRI and CFM gave similar results for the overall detection of transplanted cells (kappa=0.828) and for the identification of peri-vascular cells (kappa=0.78). Application of an external magnet can modify the trafficking of transplanted cells, especially by promoting the formation of perivascular aggregates. (orig.)

  3. Magnetic targeting of iron-oxide-labeled fluorescent hepatoma cells to the liver

    International Nuclear Information System (INIS)

    Luciani, Alain; Wilhelm, Claire; Gazeau, Florence; Bruneval, Patrick; Cunin, Patrick; Autret, Gwennhael; Clement, Olivier; Rahmouni, Alain

    2009-01-01

    The purpose of this study was to determine whether an external magnet field can induce preferential trafficking of magnetically labeled Huh7 hepatoma cells to the liver following liver cell transplantation. Huh7 hepatoma cells were labeled with anionic magnetic nanoparticles (AMNP) and tagged with a fluorescent membrane marker (PKH67). Iron-uptake was measured by magnetophoresis. Twenty C57Bl6 mice received an intrasplenic injection of 2 x 10 6 labeled cells. An external magnet (0.29 T; 25 T/m) was placed over the liver of 13 randomly selected animals (magnet group), while the remaining 7 animals served as controls. MRI (1.5 T) and confocal fluorescence microscopy (CFM) were performed 10 days post-transplantation. The presence and location of labeled cells within the livers were compared in the magnet group and controls, and confronted with histological analysis representing the standard of reference. Mean iron content per cell was 6 pg. Based on histology, labeled cells were more frequently present within recipient livers in the magnet group (p < 0.01) where their distribution was preferentially peri-vascular (p<0.05). MRI and CFM gave similar results for the overall detection of transplanted cells (kappa=0.828) and for the identification of peri-vascular cells (kappa=0.78). Application of an external magnet can modify the trafficking of transplanted cells, especially by promoting the formation of perivascular aggregates. (orig.)

  4. Investigation of structural and magnetic properties of rapidly-solidified iron-silicon alloys at ambient and elevated temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Jayaraman, T. V.; Meka, V. M.; Jiang, X.; Overman, N. R.; Doyle, J.; Shield, J. E.; Mathaudhu, S. N.

    2018-04-01

    In this work, we investigated the ambient temperature structural properties (~300 K) and the ambient and high temperature (up to 900 K) direct current (DC) magnetic properties of melt-spun Fe-x wt.% Si (x = 3, 5, & 8) alloys. The wheel surface speeds selected for the study were 30 m/s and 40 m/s. The thickness, width, lattice parameter, saturation magnetization (MS), and intrinsic coercivity (HCI) of the melt spun ribbons are presented and compared with data in the literature. The ribbons produced at the lower wheel surface speed (30 m/s) were continuous having relatively uniform edges compared to the ribbons produced at the higher wheel surface speed. The thickness and the width of the melt-spun ribbons ranged between ~15-60 μm and 500-800 μm, respectively. The x-ray diffraction spectra of the melt-spun ribbons indicated the presence of disordered α-phase, irrespective of the composition, and the wheel-surface speed. The lattice parameter decreased gradually as a function of increasing silicon content from ~0.2862 nm (Fe-3 wt.% Si) to ~0.2847 nm (Fe-8 wt.% Si). Wheel surface speed was not shown to have a significant effect on the magnetization, but primarily impacted the ribbon structure. A decreasing trend in the saturation magnetization was observed as a function of increased silicon content. The intrinsic coercivity of the melt-spun alloys ranged between ~50 to 200 A/m. Elevated temperature evaluation of the magnetization in the case of Fe-3 & 5 wt.% Si alloy ribbons was distinctly different from the Fe-8 wt.% Si alloy ribbons. The curves of the as-prepared Fe-3 wt.% Si and Fe-5 wt.% Si alloy ribbons were irreversible while that of Fe-8 wt.% Si was reversible. The MS for any of the combinations of wheel surface speed and composition decreased monotonically with the increase in temperature (from 300 – 900 K). The percentage decrease in MS from 300 K to 900 K for the Fe-3 wt.% Si and Fe-5 wt.% Si alloys was ~19-22 %, while the percentage decrease in the same

  5. Aluminium-nickel-iron alloys resistant to corrosion by water at high temperature. Their basic properties - their improvement

    International Nuclear Information System (INIS)

    Coriou, H.; Fournier, R.; Grall, L.; Hure, J.

    1959-01-01

    The development of the investigations carried out on these alloys is reviewed, showing the establishment of their fundamental, particularly structural, properties. This is followed by studies on: 1 - The penetration process in corrosion. The results of micrographic studies of the metal oxide interface are given for a series of alloys treated in water and steam between 350 and 395 deg. C. The hypothesis of attack by pockets of gas pressure is corroborated, and a second process of deep penetration by islands of intergranular-type corrosion is shown to take place. These patches, distinct from the surface corrosion layer and sometimes forming at a considerable depth inside the metal, would be due to heterogeneities in composition of the solid solution making up the matrix of these alloys. 2 - The role of titanium and zirconium additions on rolled metal. Systematic studies are carried out on a series of alloys with titanium and zirconium contents between 0.05 and 0.15 per cent. The favourable effect of titanium in particular has been demonstrated. Zirconium acts in the same way, but less efficiently. The improvement due to these additions can be compared to their action on the distribution of the second phases, which tend to become more pronounced and more homogeneously distributed. The influence of solder on these alloys has been studied, showing up the part played by the structure gradients introduced by fission. (author) [fr

  6. Study of nitrogen solubility in multicomponent iron alloys at its pressure in gaseous phase up to 1000kPa

    International Nuclear Information System (INIS)

    Pomarin, Yu.M.; Grigorenko, G.M.; Latash, Yu.V.; Kanibolotskij, S.A.

    1983-01-01

    A facility in which metal is melted in a weighed state and nitrogen partical pressure during relting may be charge from 0 to 1000 kPa is developed to investigate nitrogen solubility is liquim metals and alloys. Investigation of nitrogen solubility was performed using samples of 03Kh25N5AM3 steel and Kh20N5, Kh20N10, Kh40N10, Kh40N20 alloys. Positive deflection of [N]=f(√Psub(Nsub(2))) dependence from the Henry law is shown to be observed in the Kh40N10 alloy in the 100-1000 kPa pressure range. In this case the vatue of positive deflection decreases with temperature growth and at T=2273 K nitrogen solubility in the alloy submits to the law of square root. An equation permitting to calculate nitrogen solubility in alloys of Fe-Cr-Ni and Fe-Cr-Mn systems in the 0 to 1000 kPa range of nitrogen partial pressures is obtained

  7. Evaluation and economics aspects of the lying of rare earth and iron-alloys in the Seis Lagos Carbonatite Complex-Amazonas-Brazil

    International Nuclear Information System (INIS)

    Wetterle Bonow, C. de; Issler, R.S.

    1980-01-01

    New data on rare earth mineralization and iron-alloys as well as other rare elements in the Seis Lagos Carbonatite Complex are described. Drilling and field work data have permited to define in surface, subsidence zones (subsurface collapses), in the interval of 14.65 to 73.10 meters depth a carbonaceous clay sequence, sapropelic, neogenic, highly enriched in Re, Nb, Th, V, Zn and Be as well as Sc, Y, Ga, Co and Sn as by-products were detected. Sedimentogenic aspects of the enrichment of detect elements, the scintillometric survey, the reserve calculation, the detected elements, the by-products and the complementary study for the deposit are discussed and finaly a value of US$ 6.7 x 10 9 is estimated for the detect deposit. (Author) [pt

  8. Effect of iron addition on the work-hardening characteristics of Al-16 wt%Ag alloy

    International Nuclear Information System (INIS)

    Abd El-Salam, F.; Mahmoud, M.A.; Abd El-Khalek, A.M.; Nada, R.H.

    2002-01-01

    The effect of pre-aging time (up to 120 min) and temperatures (428-498 K) on the stress-strain characteristics of Al-16 wt%Ag and Al-16 wt%Ag-0.28 wt%Fe alloys was investigated at different deformation temperatures in the range 353-413 K. The tensile parameters measured for both alloys showed general increase with increasing pre-aging time at 428 and 458 K, while the samples pre-aged at 498 K showed initial softening up to pre-aging time of 60 min followed by increased hardening for longer pre-aging times. The Fe-free samples were generally harder than the ternary samples. The activation energy of the fracture mechanism in both alloys was around 28 kJ/mol

  9. Stress corrosion cracking of iron-nickel-chromium alloys in primary circuit environment of PWR-type reactors

    International Nuclear Information System (INIS)

    Boursier, Jean-Marie

    1993-01-01

    Stress corrosion cracking of Alloy 600 steam generator tubing is a great concern for pressurized water reactors. The mechanism that controls intergranular stress corrosion cracking of Alloy 600 in primary water (lithiated-borated water) has yet to be clearly identified. A study of stress corrosion cracking behaviour, which can identify the main parameters that control the cracking phenomenon, was so necessary to understand the stress corrosion cracking process. Constant extension rate tests, and constant load tests have evidenced that Alloy 600 stress corrosion cracking involves firstly an initiation period, then a slow propagation stage with crack less than 50 to 80 micrometers, and finally a rapid propagation stage leading to failure. The influence of mechanical parameters have shown the next points: - superficial strain hardening and cold work have a strong effect of stress corrosion cracking resistance (decrease of initiation time and increase of crack growth rate), - strain rate was the most suitable parameter for describing the different stage of propagation. The creep behaviour of alloy 600 has shown an increase of creep rate in primary water compared to air, which implies a local interaction plasticity/corrosion. An assessment of the durations of the initiation and the propagation stages was attempted for the whole uniaxial tensile tests, using the macroscopic strain rate: - the initiation time is less than 100 hours and seems to be an electrochemical process, - the durations of the propagation stage are strongly dependent on the strain rate. The behaviour in high primary water temperature of Alloys 690 and 800, which replace Alloy 600, was studied to appraise their margin, and validate their choice. Then the last chapter has to objective to evaluate the crack tip strain rate, in order to better describe the evolution of the different stages of cracking. (author) [fr

  10. Segregation across the metal/oxide interface occurring during oxidation at high temperatures of diluted iron based alloys

    International Nuclear Information System (INIS)

    Geneve, D.; Rouxel, D.; Weber, B.; Confente, M.

    2006-01-01

    Industrial steels being elaborated in air at high temperature oxidize and cover with a complex oxide layer. The oxidation reaction drastically alters the surface composition. Such modifications have been investigated, in this work, by Auger Electron Spectroscopy (AES) using an original method to characterize the composition of the metal/oxide interfaces. Analysis of the concentration gradients across the interfaces allows to better understand how the alloy elements contribute to the oxidation process. The development of new alloy phases, the interdependencies between elements and the diffusion of different species are discussed considering thermodynamic properties of each element

  11. Cell wall targeted in planta iron accumulation enhances biomass conversion and seed iron concentration in Arabidopsis and rice

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Haibing [Center for Direct Catalytic Conversion Of Biomass to Biofuels (C3Bio), Purdue University, West Lafayette IN USA; Department of Horticulture, Purdue University, West Lafayette IN USA; Department of Biological Sciences, Purdue University, West Lafayette IN USA; Wei, Hui [Biosciences Center, National Renewable Energy Laboratory, Golden CO USA; Ma, Guojie [Center for Direct Catalytic Conversion Of Biomass to Biofuels (C3Bio), Purdue University, West Lafayette IN USA; Department of Horticulture, Purdue University, West Lafayette IN USA; Antunes, Mauricio S. [Center for Direct Catalytic Conversion Of Biomass to Biofuels (C3Bio), Purdue University, West Lafayette IN USA; Department of Biological Sciences, Purdue University, West Lafayette IN USA; Vogt, Stefan [X-ray Science Division, Advanced Photon Source, Argonne National Laboratory, Argonne IL USA; Cox, Joseph [Center for Direct Catalytic Conversion Of Biomass to Biofuels (C3Bio), Purdue University, West Lafayette IN USA; Department of Horticulture, Purdue University, West Lafayette IN USA; Zhang, Xiao [Department of Horticulture, Purdue University, West Lafayette IN USA; Liu, Xiping [Center for Direct Catalytic Conversion Of Biomass to Biofuels (C3Bio), Purdue University, West Lafayette IN USA; Department of Horticulture, Purdue University, West Lafayette IN USA; Bu, Lintao [National Bioenergy Center, National Renewable Energy Laboratory, Golden CO USA; Gleber, S. Charlotte [X-ray Science Division, Advanced Photon Source, Argonne National Laboratory, Argonne IL USA; Carpita, Nicholas C. [Department of Biological Sciences, Purdue University, West Lafayette IN USA; Department of Botany and Plant Pathology, Purdue University, West Lafayette IN USA; Makowski, Lee [Department of Bioengineering, Northeastern University, Boston MA USA; Department of Chemistry and Chemical Biology, Northeastern University, Boston MA USA; Himmel, Michael E. [Biosciences Center, National Renewable Energy Laboratory, Golden CO USA; Tucker, Melvin P. [X-ray Science Division, Advanced Photon Source, Argonne National Laboratory, Argonne IL USA; McCann, Maureen C. [Center for Direct Catalytic Conversion Of Biomass to Biofuels (C3Bio), Purdue University, West Lafayette IN USA; Department of Biological Sciences, Purdue University, West Lafayette IN USA; Murphy, Angus S. [Center for Direct Catalytic Conversion Of Biomass to Biofuels (C3Bio), Purdue University, West Lafayette IN USA; Department of Horticulture, Purdue University, West Lafayette IN USA; Department of Plant Science and Landscape Architecture, University of Maryland, College Park MD USA; Peer, Wendy A. [Center for Direct Catalytic Conversion Of Biomass to Biofuels (C3Bio), Purdue University, West Lafayette IN USA; Department of Horticulture, Purdue University, West Lafayette IN USA; Department of Plant Science and Landscape Architecture, University of Maryland, College Park MD USA; Department of Environmental Science and Technology, University of Maryland, College Park MD USA

    2016-04-07

    Conversion of nongrain biomass into liquid fuel is a sustainable approach to energy demands as global population increases. Previously, we showed that iron can act as a catalyst to enhance the degradation of lignocellulosic biomass for biofuel production. However, direct addition of iron catalysts to biomass pretreatment is diffusion-limited, would increase the cost and complexity of biorefinery unit operations and may have deleterious environmental impacts. Here, we show a new strategy for in planta accumulation of iron throughout the volume of the cell wall where iron acts as a catalyst in the deconstruction of lignocellulosic biomass. We engineered CBM-IBP fusion polypeptides composed of a carbohydrate-binding module family 11 (CBM11) and an iron-binding peptide (IBP) for secretion into Arabidopsis and rice cell walls. CBM-IBP transformed Arabidopsis and rice plants show significant increases in iron accumulation and biomass conversion compared to respective controls. Further, CBM-IBP rice shows a 35% increase in seed iron concentration and a 40% increase in seed yield in greenhouse experiments. CBM-IBP rice potentially could be used to address iron deficiency, the most common and widespread nutritional disorder according to the World Health Organization.

  12. Core–shell composite particles composed of biodegradable polymer particles and magnetic iron oxide nanoparticles for targeted drug delivery

    Energy Technology Data Exchange (ETDEWEB)

    Oka, Chiemi; Ushimaru, Kazunori [Department of Innovative and Engineered Materials, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama 226-8502 (Japan); Horiishi, Nanao [Bengala Techno Laboratory, 9-5-1006, 1-1 Kodai, Miyamae-ku, Kawasaki 216-0007 (Japan); Tsuge, Takeharu [Department of Innovative and Engineered Materials, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama 226-8502 (Japan); Kitamoto, Yoshitaka, E-mail: kitamoto.y.aa@m.titech.ac.jp [Department of Innovative and Engineered Materials, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama 226-8502 (Japan)

    2015-05-01

    Core–shell composite particles with biodegradability and superparamagnetic behavior were prepared using a Pickering emulsion for targeted drug delivery based on magnetic guidance. The composite particles were composed of a core of biodegradable polymer and a shell of assembled magnetic iron oxide nanoparticles. It was found that the dispersibility of the nanoparticles is crucial for controlling the core–shell structure. The addition of a small amount of dispersant into the nanoparticle's suspension could improve the dispersibility and led to the formation of composite particles with a thin magnetic shell covering a polymeric core. The composite particles were also fabricated with a model drug loaded into the core, which was released via hydrolysis of the core under strong alkaline conditions. Because the core can also be biodegraded by lipase, this result suggests that the slow release of the drug from the composite particles should occur inside the body. - Highlights: • Core−shell composites with biodegradability and magnetism are prepared. • O/W emulsion stabilized by iron oxide nanoparticles is utilized for the preparation. • The nanoparticle's dispersibility is crucial for controlling the composite structure. • Composites loading a model drug are also prepared. • The model drug is released with decomposition of the composites.

  13. Electroplating Gold-Silver Alloys for Spherical Capsules for NIF Double-Shell Targets

    Energy Technology Data Exchange (ETDEWEB)

    Bhandarkar, N. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Horwood, C. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Bunn, T. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Stadermann, M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2017-08-17

    For Inertial Confinement Fusion (ICF) implosions, a design based on gradients of high and mid Z materials could potentially be more robust than single element capsule systems. To that end, gold and silver alloys were electroplated on 2.0 mm diameter surrogate brass spheres using a new flow–based pulsed plating method specifically designed to minimize surface roughness without reducing plating rates. The coatings were analyzed by scanning electron microscope (SEM) and white light interferometry for surface topography, and by energy dispersive x-ray spectroscopy (EDX) to determine near-surface gold and silver compositions. The alloy range attainable was 15 to 85 weight percent gold using 1:1 and 1:3 silver to gold ratio plating baths at applied potentials of -0.7 volts to -1.8 volts. This range was bounded by the open circuit potential of the system and hydrogen evolution, and in theory could be extended by using ionic liquids or aprotic solutions. Preliminary gradient trials proved constant composition alloy data could be translated to smooth gradient plating, albeit at higher gold compositions.

  14. An Assessment of the General Applicability of the Relationship Between Nucleation of CO Bubbles and Mass Transfer of Phosphorus in Liquid Iron Alloys

    Science.gov (United States)

    Gu, Kezhuan; Dogan, Neslihan; Coley, Kenneth S.

    2018-06-01

    The current paper seeks to demonstrate the general applicability of the authors' recently developed treatment of surface renewal during decarburization of Fe-C-S alloys and its effect on the mass transport of phosphorus in the metal phase. The proposed model employs a quantitative model of CO bubble nucleation in the metal to predict the rate of surface renewal, which can then in turn be used to predict the mass-transfer coefficient for phosphorus. A model of mixed transport control in the slag and metal phases was employed to investigate the dephosphorization kinetics between a liquid iron alloy and oxidizing slag. Based on previous studies of the mass-transfer coefficient of FeO in the slag, it was possible to separate the mass transfer coefficient of phosphorus in metal phase, km , from the overall mass-transfer coefficient k_{{o}} . Using this approach, km was investigated under a wide range of conditions and shown to be represented reasonably by the mechanism proposed. The mass-transfer model was tested against results from the literature over a wide range of conditions. The analysis showed that the FeO content in the slag, silicon in the metal and the experimental temperature have strong impact on, km , almost entirely because of their effect on decarburization behavior.

  15. High-temperature oxidation of iron, Fe-0.5 wt. % Al and Fe-1 wt% Al alloys in CO2 at atmospheric pressure

    International Nuclear Information System (INIS)

    Hoogewys, Marcel; Paideassi, Jean.

    1978-12-01

    The oxidation of several grades of iron (on being a zone-melting grade) in the poly- and monocrystalline forms between 570 and 1150 0 C proceeds along a linear, then a transitory and a parabolic law in correspondence with the growth of wustite possibly covered with magnetite, whereas in the 400-570 0 C range where the parabolic law is rapidly establishing, the scale is entirely formed of magnetite. The oxidation of the two Fe-A1 alloys follows similarly a quasi linear law after a very short linear period. Their weight gains differ only at 10% at most while remaining close to that of iron (except above 570 0 C where they are much lower). The activation energies correspponding to the parabolic process -and in some cases to the linear one- have been determined for each material. They are in the range 11 to 43 Kcal.mole -1 , such values being rather low. The characteristics of the oxide layers: mode and facies of nucleation and crystal growth -particularly of the ridges at grain boundaries- the evolution of interfaces, precipitation of magnetite within wustite, etc... have been thoroughly investigated. Finally mechanisms concerning the linear, transitory and parabolic oxidation processes have been proposed after a careful discussion of the results [fr

  16. Doxorubicin loaded PEG-b-poly(4-vinylbenzylphosphonate) coated magnetic iron oxide nanoparticles for targeted drug delivery

    Energy Technology Data Exchange (ETDEWEB)

    Hałupka-Bryl, Magdalena, E-mail: magdalenahalupka@op.pl [The NanoBioMedical Centre, Adam Mickiewicz University, Poznań (Poland); Division of Medical Physics, Faculty of Physics, Adam Mickiewicz University, Poznań (Poland); Department of Materials Sciences, Graduate School of Pure and Applied Sciences, University of Tsukuba (Japan); Bednarowicz, Magdalena [The NanoBioMedical Centre, Adam Mickiewicz University, Poznań (Poland); Division of Medical Physics, Faculty of Physics, Adam Mickiewicz University, Poznań (Poland); Department of Materials Sciences, Graduate School of Pure and Applied Sciences, University of Tsukuba (Japan); Dobosz, Bernadeta; Krzyminiewski, Ryszard [The NanoBioMedical Centre, Adam Mickiewicz University, Poznań (Poland); Division of Medical Physics, Faculty of Physics, Adam Mickiewicz University, Poznań (Poland); Zalewski, Tomasz [The NanoBioMedical Centre, Adam Mickiewicz University, Poznań (Poland); Wereszczyńska, Beata [Department of Macromolecular Physics, Adam Mickiewicz University, Poznań (Poland); Nowaczyk, Grzegorz; Jarek, Marcin [The NanoBioMedical Centre, Adam Mickiewicz University, Poznań (Poland); Nagasaki, Yukio [Department of Materials Sciences, Graduate School of Pure and Applied Sciences, University of Tsukuba (Japan); Master’s School of Medicinal Sciences, Graduate School of Comprehensive Human Sciences, University of Tsukuba (Japan); International Centre for Materials Nanoarchitectonics Satellite (WPI-MANA), National Institute For Materials Sciences (NIMS) and University of Tsukuba (Japan)

    2015-06-15

    Due to their unique physical properties, superparamagnetic iron oxide nanoparticles are increasingly used in medical applications. They are very useful carriers for delivering antitumor drugs in targeted cancer treatment. Magnetic nanoparticles with chemiotherapeutic were synthesized by coprecipitation method followed by coating with biocompatible polymer. The aim of this work is to characterize physical and magnetic properties of synthesized nanoparicles. Characterization was carried out using EPR, HRTEM, X-ray diffraction, SQUID and NMR methods. The present findings show that synthesized nanosystem is promising tool for potential magnetic drug delivery. - Highlights: • Synthesized PEG-PIONs/DOX have excellent physical properties. • PEG-PIONs/DOX have a potential to in vivo application. • PEG-PIONs/DOX could be used as drug delivery system as well as contrast agents.

  17. Nanocrystallinity and magnetic property enhancement in melt-spun iron-rare earth-base hard magnetic alloys

    International Nuclear Information System (INIS)

    Davies, H.A.; Manaf, A.; Zhang, P.Z.

    1993-01-01

    Refinement of the grain size below ∼35 nm mean diameter in melt-spun FeNdB-base alloys leads to enhancement of remanent polarization, J r , above the level predicted by the Stoner-Wohlfarth theory for an aggregate of independent, randomly oriented, and uniaxial magnetic particles. This article summarizes the results of the recent systematic research on this phenomenon, including the influence of alloy composition and processing conditions on the crystallite size, degree of enhancement of J r , and maximum energy product (BH) max . It has been shown that the effect can also occur in ternary FeNdB alloys, without the addition of silicon or aluminum, which was originally thought necessary, providing the nanocrystallites are not magnetically decoupled by a paramagnetic second phase. Values of (BH) max above 160 kJ. m -3 have been achieved. The relationship between grain size, J r , intrinsic coercivity, J H c , and (BH) max are discussed in terms of magnetic exchange coupling, anisotropy, and other parameters. Recent extension of this work to the enhancement of properties in Fe-Mischmental-Boron-base alloys and to bonded magnets with a nanocrystalline structure is also described

  18. Design of multifunctional magnetic iron oxide nanoparticles/mitoxantrone-loaded liposomes for both magnetic resonance imaging and targeted cancer therapy.

    Science.gov (United States)

    He, Yingna; Zhang, Linhua; Zhu, Dunwan; Song, Cunxian

    2014-01-01

    Tumor-targeting multifunctional liposomes simultaneously loaded with magnetic iron oxide nanoparticles (MIONs) as a magnetic resonance imaging (MRI) contrast agent and anticancer drug, mitoxantrone (Mit), were developed for targeted cancer therapy and ultrasensitive MRI. The gonadorelin-functionalized MION/Mit-loaded liposome (Mit-GML) showed significantly increased uptake in luteinizing hormone-releasing hormone (LHRH) receptor overexpressing MCF-7 (Michigan Cancer Foundation-7) breast cancer cells over a gonadorelin-free MION/Mit-loaded liposome (Mit-ML) control, as well as in an LHRH receptor low-expressing Sloan-Kettering HER2 3+ Ovarian Cancer (SK-OV-3) cell control, thereby leading to high cytotoxicity against the MCF-7 human breast tumor cell line. The Mit-GML formulation was more effective and less toxic than equimolar doses of free Mit or Mit-ML in the treatment of LHRH receptors overexpressing MCF-7 breast cancer xenografts in mice. Furthermore, the Mit-GML demonstrated much higher T2 enhancement than did Mit-ML controls in vivo. Collectively, the study indicates that the integrated diagnostic and therapeutic design of Mit-GML nanomedicine potentially allows for the image-guided, target-specific treatment of cancer.

  19. Integrin-targeting thermally cross-linked superparamagnetic iron oxide nanoparticles for combined cancer imaging and drug delivery

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Mi Kyung; Park, Jinho; Jon, Sangyong [School of Life Sciences, Gwangju Institute of Science and Technology, 261 Chemdangwagi-ro, Gwangju 500-712 (Korea, Republic of); Jeong, Yong Yeon [Department of Diagnostic Radiology, Jeonnam National University Hwasun Hospital, 160 Ilsim-ri, Hwasun-eup, Jeonnam 519-809 (Korea, Republic of); Moon, Woo Kyung, E-mail: syjon@gist.ac.kr [Diagnostic Radiology, Seoul National University Hospital and the Institute of Radiation Medicine, Medical Research Center Seoul National University, Seoul 110-744 (Korea, Republic of)

    2010-10-15

    We report multifunctional nanoparticles that are capable of cancer targeting and simultaneous cancer imaging and therapy. The nanoparticles are composed of cyclic arginine-glycine-aspartic acid (cRGD) peptide ligand bioconjugated thermally cross-linked superparamagnetic iron oxide nanoparticles (TCL-SPION) that enable loading of the anticancer drug doxorubicin (Dox). The cyclic RGD-conjugated TCL-SPION (cRGD{sub T}CL-SPION) had a mean hydrodynamic size of 34 {+-} 8 nm with approximately 0.39 wt% of cyclic RGD attached to the surface of the nanoparticles. The cRGD{sub T}CL-SPION exhibited preferential binding towards target cancer cells (U87MG, integrin {alpha}{sub v{beta}3} +) when analyzed by T{sub 2}-weighted magnetic resonance (MR) imaging. When Dox was loaded onto the polymeric coating layers of cRGD{sub T}CL-SPION via ionic interaction, the resulting Dox-loaded cRGD{sub T}CL-SPION (Dox-cRGD{sub T}CL-SPION) showed much higher cytotoxicity in U87MG cells than Dox-TCL-SPION lacking cRGD (IC{sub 50} value of 0.02 {mu}M versus 0.12 {mu}M). These results suggest that Dox-cRGD{sub T}CL-SPION has potential for use as an integrin-targeted, combined imaging and therapeutic agent.

  20. Corrosion of iron and low alloyed steel within a water saturated brick of clay under anaerobic deep geological disposal conditions: An integrated experiment

    International Nuclear Information System (INIS)

    Martin, F.A.; Bataillon, C.; Schlegel, M.L.

    2008-01-01

    The aim of this study was to determine the corrosion behaviour of iron and low alloyed steels under simulated geological disposal conditions, related to long-term disposal of nuclear wastes in the site of Bure (Meuse-Haute Marne, Champagne, France). The dedicated experiment was a fully integrated set-up: three different bars of material (iron, steel or nickel) have been introduced inside a solid block of clay, which has been saturated with synthetic Bure water and maintained at 90 deg. C during 8 months. Two types of clay have been tested: first, a compacted MX80 (Wyoming, USA) and second, argilite directly taken from the Bure site (Callovo-Oxfordian). In situ electrochemistry has been performed: impedance spectra, chronopotentiometry... The samples have been analysed using a combination of techniques, such as SEM, XRD, EDS, μXAS, μRaman, gravimetry after desquamation. In both cases, the steel or the iron seemed to passivate in contact with the clay. Post-processing of the EIS determined the corrosion rates and the changes in the kinetics have been noticed. The post mortem analysis of the corrosion products showed in both cases the presence of an internal layer made of magnetite (Raman, EDX). The external layer was made of partially Ca-substituted siderite (Fe 1-x Ca x CO 3 ), which could play an extra role in the passivation. Moreover, the samples embedded in the Bure argilite presented an intermediate unique layer containing Fe, O, Na and Si. This study suggests the corrosion products started to react with the silica issued from the dissolution of the Bure clay minerals, resulting in clay minerals neo-formation and in corrosion kinetic changes

  1. Long term corrosion of iron and non alloy or low alloy steels in clay soils. Physico-chemical characterisation and electrochemical study of archaeological analogues

    International Nuclear Information System (INIS)

    Pons, Emmanuelle

    2002-01-01

    Archaeological objects of Gallo-Roman and Merovingian time, and from a battlefield of World War 1, were studied to better understand long term corrosion phenomena of iron in clay soils. This study is part of the French national program about nuclear waste deep repository, conducted by the ANDRA (French national Agency for Radioactive Waste Management). Iron archaeological analogues make a valuable contribution to the specifying of containers for long lived and high level wastes (HLWs), because they provide access to the considered time scale. The experimental issue is divided into two major parts: - a physico-chemical characterisation of corrosion products, by Raman spectroscopy; - an electrochemical study of the behaviour of the different corrosion layers. Although the metallic material is different between ancient artefacts (ferrite) and 1914-1918 remains (hypo-eutectoid steels), the same stable phases are identified in their corrosion products: mainly iron oxides and oxi-hydroxides. From a macroscopic point of view, these products are staggered into two layers: an internal one, and an external one, which contains soil markers. Under the microscope, a complex composite structure appears. Goethite a-FeOOH, which was identified on each object, is frequently in contact with the metal core. The average corrosion rate in the burial environment, deduced from the layers thickness, highlights a significant slowdown of corrosion after the first burial time, about one century. The electrochemical study showed the predominant role of transport phenomena in the pores of corrosion layers. The behaviour of the metal - internal layer system is well explained by a model of porous electrode (De Levie theory). Despite its porosity, the internal layer is protective, as it leads to a significant decrease of the corrosion rate (about ten time). (author) [fr

  2. Ultrasmall cationic superparamagnetic iron oxide nanoparticles as nontoxic and efficient MRI contrast agent and magnetic-targeting tool

    Directory of Open Access Journals (Sweden)

    Uchiyama MK

    2015-07-01

    thigh by a magnet showing its potential as magnetically targeted carriers of therapeutic and diagnostic agents. Summarizing, cationic ultrasmall superparamagnetic iron oxide nanoparticles are nontoxic and efficient magnetic resonance imaging contrast agents useful as platform for the development of new materials for application in theranostics.Keywords: cationic USPIOs, MRI, contrast agent, magnetic targeting, in vivo toxicity, intravital microscopy

  3. Investigation on powder metallurgy Cr-Si-Ta-Al alloy target for high-resistance thin film resistors with low temperature coefficient of resistance

    International Nuclear Information System (INIS)

    Wang, X.Y.; Zhang, Z.S.; Bai, T.

    2010-01-01

    The sputtering target for high-resistance thin film resistors plays a decisive role in temperature coefficient of resistance (TCR). Silicon-rich chromium (Cr)-silicon (Si) target was designed and smelted for high-resistance thin film resistors with low TCR. Valve metal tantalum (Ta) and aluminum (Al) were introduced to the Cr-Si target to improve the performance of the target prepared. The measures for grain refining in smelting Cr-Si-Ta-Al target were taken to improve the performance of the prepared target. The mechanism and role of grain refinement were discussed in the paper. The phase structure of the prepared target was detected by X-ray diffraction (XRD). Rate of temperature drop was studied to reduce the internal stress of alloy target and conquer the easy cracking disadvantage of silicon-rich target. The electrical properties of sputtered thin film resistors were tested to evaluate the performance of the prepared target indirectly.

  4. Design risk analysis comparison between low-activation composite and aluminum alloy target chamber for the National Ignition Facility

    International Nuclear Information System (INIS)

    Streckert, H.H.; Schleicher, R.W.

    1997-01-01

    The baseline design for the target chamber for the National Ignition Facility (NIF) consists of an aluminum alloy spherical shell. A low-activation composite chamber (e.g., carbon fiber/epoxy) has important advantages such as enhanced environmental and safety characteristics, improved chamber accessibility due to reduced neutron-induced radioactivity, and elimination of the concrete shield. However, it is critical to determine the design and manufacturing risk for the first application. The replacement of such a critical component requires a detailed development risk assessment. A semiquantitative approach to risk assessment has been applied to this problem based on failure modes, effects, and criticality analysis. This analysis consists of a systematic method for organizing the collective judgment of the designers to identify failure modes, estimate probabilities, judge the severity of the consequence, and illustrate risk in a matrix representation. The results of the analyses indicate that the composite chamber has a reasonably high probability of success in the NIF application. The aluminum alloy chamber, however, represents a lower risk, partially based on a more mature technology. 8 refs., 4 figs., 5 tabs

  5. Gold-Coated Iron Composite Nanospheres Targeted the Detection of Escherichia coli

    Directory of Open Access Journals (Sweden)

    İlker Dinçer

    2013-03-01

    Full Text Available We report the preparation and characterization of spherical core-shell structured Fe3O4–Au magnetic nanoparticles, modified with two component self-assembled monolayers (SAMs consisting of 3–mercaptophenylboronic acid (3–MBA and 1–decanethiol (1–DT. The rapid and room temperature synthesis of magnetic nanoparticles was achieved using the hydroxylamine reduction of HAuCl4 on the surface of ethylenediaminetetraacetic acid (EDTA-immobilized iron (magnetite Fe3O4 nanoparticles in the presence of an aqueous solution of hexadecyltrimetylammonium bromide (CTAB as a dispersant. The reduction of gold on the surface of Fe3O4 nanoparticles exhibits a uniform, highly stable, and narrow particle size distribution of Fe3O4–Au nanoparticles with an average diameter of 9 ± 2 nm. The saturation magnetization value for the resulting nanoparticles was found to be 15 emu/g at 298 K. Subsequent surface modification with SAMs against glucoside moieties on the surface of bacteria provided effective magnetic separation. Comparison of the bacteria capturing efficiency, by means of different molecular recognition agents 3–MBA, 1–DT and the mixed monolayer of 3–MBA and 1–DT was presented. The best capturing efficiency of E. coli was achieved with the mixed monolayer of 3–MBA and 1–DT-modified nanoparticles. Molecular specificity and selectivity were also demonstrated by comparing the surface-enhanced Raman scattering (SERS spectrum of E. coli-nanoparticle conjugates with bacterial growth media.

  6. Multifunctional pH-sensitive superparamagnetic iron-oxide nanocomposites for targeted drug delivery and MR imaging.

    Science.gov (United States)

    Zhu, Lijuan; Wang, Dali; Wei, Xuan; Zhu, Xinyuan; Li, Jianqi; Tu, Chunlai; Su, Yue; Wu, Jieli; Zhu, Bangshang; Yan, Deyue

    2013-08-10

    A multifunctional pH-sensitive superparamagnetic iron-oxide (SPIO) nanocomposite system was developed for simultaneous tumor magnetic resonance imaging (MRI) and therapy. Small-size SPIO nanoparticles were chemically bonded with antitumor drug doxorubicin (DOX) and biocompatible poly(ethylene glycol) (PEG) through pH-sensitive acylhydrazone linkages, resulting in the formation of SPIO nanocomposites with magnetic targeting and pH-sensitive properties. These DOX-conjugated SPIO nanocomposites exhibited not only good stability in aqueous solution but also high saturation magnetizations. Under an acidic environment, the DOX was quickly released from the SPIO nanocomposites due to the cleavage of pH-sensitive acylhydrazone linkages. With the help of magnetic field, the DOX-conjugated SPIO nanocomposites showed high cellular uptake, indicating their magnetic targeting property. Comparing to free DOX, the DOX-conjugated SPIO nanocomposites showed better antitumor effect under magnetic field. At the same time, the relaxivity value of these SPIO nanocomposites was higher than 146s(-1)mM(-1) Fe, leading to ~4 times enhancement compared to that of free SPIO nanoparticles. As a negative contrast agent, these SPIO nanocomposites illustrated high resolution in MRI diagnosis of tumor-bearing mice. All of these results confirm that these pH-sensitive SPIO nanocomposites are promising hybrid materials for synergistic MRI diagnosis and tumor therapy. Copyright © 2013 Elsevier B.V. All rights reserved.

  7. Targeted Mesoporous Iron Oxide Nanoparticles-Encapsulated Perfluorohexane and a Hydrophobic Drug for Deep Tumor Penetration and Therapy.

    Science.gov (United States)

    Su, Yu-Lin; Fang, Jen-Hung; Liao, Chia-Ying; Lin, Chein-Ting; Li, Yun-Ting; Hu, Shang-Hsiu

    2015-01-01

    A magneto-responsive energy/drug carrier that enhances deep tumor penetration with a porous nano-composite is constructed by using a tumor-targeted lactoferrin (Lf) bio-gate as a cap on mesoporous iron oxide nanoparticles (MIONs). With a large payload of a gas-generated molecule, perfluorohexane (PFH), and a hydrophobic anti-cancer drug, paclitaxel (PTX), Lf-MIONs can simultaneously perform bursting gas generation and on-demand drug release upon high-frequency magnetic field (MF) exposure. Biocompatible PFH was chosen and encapsulated in MIONs due to its favorable phase transition temperature (56 °C) and its hydrophobicity. After a short-duration MF treatment induces heat generation, the local pressure increase via the gasifying of the PFH embedded in MION can substantially rupture the three-dimensional tumor spheroids in vitro as well as enhance drug and carrier penetration. As the MF treatment duration increases, Lf-MIONs entering the tumor spheroids provide an intense heat and burst-like drug release, leading to superior drug delivery and deep tumor thermo-chemo-therapy. With their high efficiency for targeting tumors, Lf-MIONs/PTX-PFH suppressed subcutaneous tumors in 16 days after a single MF exposure. This work presents the first study of using MF-induced PFH gasification as a deep tumor-penetrating agent for drug delivery.

  8. Studies of iron carbon alloys; Contribution a l'etude des alliages dilues de carbone dans le fer {alpha}

    Energy Technology Data Exchange (ETDEWEB)

    Anagnostopoulos, T [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

    1971-07-01

    Precipitation of carbon in {alpha} iron during a thermal treatment was followed using the magnetic after effect. A study was made of the influence of different parameters such as quenching speed, annealing rate, carbon concentration with or without impurity, irradiation effects. A transient sur-saturation occurs during dissolution of carbon in iron at 500 C. (author) [French] La precipitation du carbone dans le fer au cours d'un traitement thermique a ete suivie au moyen du trainage magnetique. L'etude de differents parametres tels que: vitesse de trempe, mode de recuit, concentration en carbone, presence d'impuretes, effet d'une irradiation, ont ete menes a bien. Un phenomene de sursaturation transitoire au cours de la remise en solution a 500 C a ete mis en evidence. (auteur)

  9. Final report on in-reactor uniaxial tensile deformation of pure iron and Fe-Cr alloy

    DEFF Research Database (Denmark)

    Singh, Bachu Narain; Huang, X.; Tähtinen, S.

    , the in-reactor deformation leads to accumulation of dislocations in a homogeneous fashion and only to a modest density. No dislocation cells are formed during the in-reactor or post-irradiation deformation of Fe-Cr and pure iron. Furthermore, in both cases, the slip systems even in the planes with Schmid...... factor value of almost zero get activated during the in-reactor as well as post-irradiation deformation. The main implications of these results are briefly discussed....

  10. Fe3O4 thin films sputter deposited from iron oxide targets

    International Nuclear Information System (INIS)

    Peng, Yingguo; Park, Chandro; Laughlin, David E.

    2003-01-01

    Fe 3 O 4 thin films have been directly sputter deposited from a target consisting of a mixture of Fe 3 O 4 and Fe 2 O 3 onto Si and glass substrates. The magnetic properties and microstructures of the films have been characterized and correlated. The columnar growth of the Fe 3 O 4 grains was found to be initialized from the substrate surface without any critical thickness. Substrate bias was found to be a very effective means of improving the crystal quality and magnetic properties of the thin films. The crystallographic defects revealed by high resolution transmission electron microscopy seem to be a characteristic of the films prepared by this method

  11. Goat red blood cells as precursor for iron oxide nanocrystal synthesis to develop nuclear targeted lung cancer therapy

    Energy Technology Data Exchange (ETDEWEB)

    Sreevani, Vellingiri; Shanthi, Krishnamurthy; Kannan, Soundarapandian, E-mail: sk_protein@buc.edu.in

    2013-09-01

    Graphical abstract: - Highlights: • Molecular approach of synthesis of Fe{sub 2}O{sub 3}-NC using goat blood as a bio-precursor. • The method is simple, efficient and environment friendly. • Synthesized nanocrystals were characterized by UV–vis spectroscopy, XRD, SEM, TEM, DLS and EDS. • Nanocrystals exhibited potent cytotoxicity against A549 cancer cell. • Nuclear targeting with expression of caspase-3, caspase-7 and Bcl-2 in A549 cancer cells. - Abstract: In this study, we synthesised iron oxide nanocrystals (Fe{sub 2}O{sub 3}-NC) from goat blood (bio-precursor) using red blood cells (RBC) lysis method (a molecular level approach) for the first time. The formation of Fe{sub 2}O{sub 3}-NC was achieved through a single-phase chemical reduction method. The size distribution of Fe{sub 2}O{sub 3}-NC falls between 20–30 nm for pellet and 100–200 nm for lysate and were found to be crystalline. Fe{sub 2}O{sub 3}-NC demonstrated significant cytotoxicity on A549. We report the direct visualization of interactions between Fe{sub 2}O{sub 3}-NC and the cancer cell nucleus. The active transport of Fe{sub 2}O{sub 3}-NC to the nucleus induces major changes to nuclear phenotype via nuclear envelope invaginations. We further examined the root cause for the involvement of Fe{sub 2}O{sub 3}-NC on the expression of caspase-3, caspase-7 and Bcl-2 in A549 cancer cells. This functional proteomic analysis clearly implies that the lung cancer cell proliferation is perfectly targeted by the biosynthesised Fe{sub 2}O{sub 3}-NC which could provide new insight for nuclear-targeted cancer therapy.

  12. Design of multifunctional magnetic iron oxide nanoparticles/mitoxantrone-loaded liposomes for both magnetic resonance imaging and targeted cancer therapy

    Directory of Open Access Journals (Sweden)

    He Y

    2014-08-01

    Full Text Available Yingna He,1 Linhua Zhang,2 Dunwan Zhu,2 Cunxian Song2 1Laboratory of Chinese Medicine Pharmacology, College of Pharmacy, Hebei University of Chinese Medicine, Shijiazhuang, Hebei, People’s Republic of China; 2Key Laboratory of Biomedical Material of Tianjin, Institute of Biomedical Engineering, Peking Union Medical College and Chinese Academy of Medical Sciences, Tianjin, People’s Republic of China Abstract: Tumor-targeting multifunctional liposomes simultaneously loaded with magnetic iron oxide nanoparticles (MIONs as a magnetic resonance imaging (MRI contrast agent and anticancer drug, mitoxantrone (Mit, were developed for targeted cancer therapy and ultrasensitive MRI. The gonadorelin-functionalized MION/Mit-loaded liposome (Mit-GML showed significantly increased uptake in luteinizing hormone–releasing hormone (LHRH receptor overexpressing MCF-7 (Michigan Cancer Foundation-7 breast cancer cells over a gonadorelin-free MION/Mit-loaded liposome (Mit-ML control, as well as in an LHRH receptor low-expressing Sloan-Kettering HER2 3+ Ovarian Cancer (SK-OV-3 cell control, thereby leading to high cytotoxicity against the MCF-7 human breast tumor cell line. The Mit-GML formulation was more effective and less toxic than equimolar doses of free Mit or Mit-ML in the treatment of LHRH receptors overexpressing MCF-7 breast cancer xenografts in mice. Furthermore, the Mit-GML demonstrated much higher T2 enhancement than did Mit-ML controls in vivo. Collectively, the study indicates that the integrated diagnostic and therapeutic design of Mit-GML nanomedicine potentially allows for the image-guided, target-specific treatment of cancer. Keywords: multifunctional liposome, magnetic resonance imaging, theranostic nanomedicine, mitoxantrone, gonadorelin

  13. An iron-57 Moessbauer spectroscopic study of titania-supported iron- and iron-iridium catalysts

    International Nuclear Information System (INIS)

    Berry, F.J.; Jobson, S.

    1992-01-01

    57 Fe Moessbauer spectroscopy shows that titania-supported iron is reduced by treatment in hydrogen at significantly lower temperatures than corresponding silica- and alumina-supported catalysts. The metallic iron formed under hydrogen at 600deg C is partially converted to carbide by treatment in carbon monoxide and hydrogen. In contrast to its alumina- and silica-supported counterparts, the remainder of the titania-supported iron is unchanged by this gaseous mixture. The 57 Fe Moessbauer spectra of EXAFS show that iron and iridium in the titania-supported iron-iridium catalysts are reduced in hydrogen at even lower temperatures and, after treatment at 600deg C, are predominantly present as the iron-iridium alloy. The treatment of these reduced catalysts in carbon monoxide and hydrogen is shown by Moessbauer spectroscopy and EXAFS to induce the segregation of iron from the iron-iridium alloy and its conversion to iron oxide. (orig.)

  14. Contribution to the influence of selected alloy elements on the strain cycling and creep behaviour of cast iron with spheroidal graphite at temperatures above 450 C; Beitrag zum Einfluss ausgewaehlter Legierungselemente auf das Dehnwechsel- und Zeitstandverhalten von Gusseisen mit Kugelgraphit bei Temperaturen oberhalb 450 C

    Energy Technology Data Exchange (ETDEWEB)

    Michel, Susanne

    2012-02-15

    In this report for the first time an all-embracing databases was raised about the correlation of microstructure and high temperature mechanical properties concerning spheroidal cast iron at temperatures above 450 C. Its basic concept is a systematic variation of alloying elements and benchmarking fatigue and creep behavior of all created heats as a function of microstructure and alloys.

  15. Targeting experimental orthotopic glioblastoma with chitosan-based superparamagnetic iron oxide nanoparticles (CS-DX-SPIONs).

    Science.gov (United States)

    Shevtsov, Maxim; Nikolaev, Boris; Marchenko, Yaroslav; Yakovleva, Ludmila; Skvortsov, Nikita; Mazur, Anton; Tolstoy, Peter; Ryzhov, Vyacheslav; Multhoff, Gabriele

    2018-01-01

    Glioblastoma is the most devastating primary brain tumor of the central nervous system in adults. Magnetic nanocarriers may help not only for a targeted delivery of chemotherapeutic agents into the tumor site but also provide contrast enhancing properties for diagnostics using magnetic resonance imaging (MRI). Synthesized hybrid chitosan-dextran superparamagnetic nanoparticles (CS-DX-SPIONs) were characterized using transmission electron microscopy (TEM) and relaxometry studies. Nonlinear magnetic response measurements were employed for confirming the superparamagnetic state of particles. Following in vitro analysis of nanoparticles cellular uptake tumor targeting was assessed in the model of the orthotopic glioma in rodents. CS-DX-SPIONs nanoparticles showed a uniform diameter of 55 nm under TEM and superparamagentic characteristics as determined by T 1 (spin-lattice relaxation time) and T 2 (spin-spin relaxation time) proton relaxation times. Application of the chitosan increased the charge from +8.9 to +19.3 mV of the dextran-based SPIONs. The nonlinear magnetic response at second harmonic of CS-DX-SPIONs following the slow change of stationary magnetic fields with very low hysteresis evidenced superparamagnetic state of particles at ambient temperatures. Confocal microscopy and flow cytometry studies showed an enhanced internalization of the chitosan-based nanoparticles in U87, C6 glioma and HeLa cells as compared to dextran-coated particles. Cytotoxicity assay demonstrated acceptable toxicity profile of the synthesized nanoparticles up to a concentration of 10 μg/ml. Intravenously administered CS-DX-SPIONs in orthotopic C6 gliomas in rats accumulated in the tumor site as shown by high-resolution MRI (11.0 T). Retention of nanoparticles resulted in a significant contrast enhancement of the tumor image that was accompanied with a dramatic drop in T 2 values ( P chitosan-dextran magnetic particles demonstrated high MR contrast enhancing properties for the

  16. Low cycle fatigue of austempered ductile cast iron alloyed with nickel at room and at depressed temperature

    Czech Academy of Sciences Publication Activity Database

    Petrenec, Martin; Beran, Přemysl; Šmíd, Miroslav; Roupcová, Pavla; Tesařová, H.

    2009-01-01

    Roč. 16, 3a (2009), s. 1-6 ISSN 1335-0803. [Degradácia konštrukčných materiálov 2009. Tatranská Lomnica, 02.09.2009-04.09.2009] R&D Projects: GA AV ČR 1QS200410502 Institutional research plan: CEZ:AV0Z20410507; CEZ:AV0Z10480505 Keywords : Low cycle fatigue * ADI with nickel alloying * Neutron diffraction * Fatigue crack initiation * Depressed temperature Subject RIV: JL - Materials Fatigue , Friction Mechanics

  17. THE INFLUENCE OF PRE-HEAT TREATMENT ON WHITE CAST IRONS PLASTICITY

    Directory of Open Access Journals (Sweden)

    T. M. Myronova

    2013-11-01

    Full Text Available Purpose. The development of heat treatment modes of white cast irons for structure changes in their eutectic constituent, namely in disturbing the monolithic structure of ledeburite colonies cementite structure and eutectic net continuity. Also the mentioned heat treatment modes are targeted to the eutectic net shift for the most suitable position from the point of plastic deforming. Methodology. The hypoeutectic white cast irons with 2.92…3.35 % carbon content and additionally alloyed by 3.18 % vanadium have been used as the research materials. The mentioned alloys have been pre-heat treated and hot twist tested. Findings. The research results showed that the carbide net breaking by plastic deforming leads to cast irons mechanical properties increasing but has difficulties in implementation due to the white cast irons low plasticity. The influence of different pre-heat treatment modes on structure and plasticity of white hypoeutectic cast irons have been investigated. They include the isotherm soaking under the different temperatures as well as multiply soakings and thermo-cycling. The influence of eutectic level, as well as pre heat treatment modes on different composition white cast irons hot plasticity have been investigated. Originality. It was determined that the heat treatment, which leads to double α→γ recrystallization under 860 – 950 °С and reperlitization under 720-680 °С results in significant increase of plasticity, as well as in un-alloyed and alloyed by vanadium white cast irons. It takes place due to carbide matrix phase separation in ledeburite colonies by new phase boundaries forming especially due to carbide transformations under vanadium alloying. Practical value. The implementation of pre-heat treatment with phase recrystallization resulted in hypoeutectic white cast irons plasticity increasing. The obtained level of cast iron plasticity corresponds to the one of carbide class steels, which ensures the successful

  18. INFLUENCE OF IRON CONTENT AND PLASTIC DEFORMATION ...

    African Journals Online (AJOL)

    eobe

    MECHANICAL PROPERTIES OF 8011-TYPE Al-Fe-Si ALLOY. O. H. Yakubu1, I. ... properties such as formability, corrosion, light weight and also ... In aluminium alloy, a large number of iron-containing intermetallic ... conditions and alloy composition. Although ... and tensile behaviour of 7075 aluminium alloy [8] observed ...

  19. Development of iron aluminides

    International Nuclear Information System (INIS)

    McKamey, C.G.; Viswanathan, S.; Goodwin, G.M.; Sikka, V.K.

    1994-01-01

    Recent studies demonstrating that improved engineering ductility (to 10-15% in Fe 3 Al) can be achieved in wrought Fe 3 Al-based iron aluminide alloys through control of composition and microstructure are discussed. Accompanying this improvement has been an increased understanding of the causes for ambient temperature embrittlement in this system. Because of these advances, iron aluminide alloys are being considered for many structural uses, especially for applications where their excellent corrosion resistance is needed. The understanding and control of cast structures are important steps in making iron-aluminide alloys viable engineering materials. This includes understanding the various components of cast structure, their evolution, their properties, their behavior during further processing, and, finally, their effect on mechanical properties. The first phase of the study of cast Fe 3 Al-based alloys characterized the various components of the cast structure in the FA-129 alloy, while the current phase of the research involves characterizing the as-cast mechanical properties of Fe 3 Al-based alloys. The investigation of the room temperature mechanical properties of as-cast Fe 3 Al, including tensile tests in air, oxygen, and water vapor environments is described. Studies have begun to refine the grain size of the cast structure. An investigation of the effect of environmental hydrogen embrittlement on the weldability of wrought alloys was also initiated during this period with the aim of understanding the role of environment in the cold-cracking of iron aluminides

  20. Manufacturing of Dysprosium-Iron Alloys by Electrolysis in Fluoride-Based Electrolytes. Electrolysis in a Laboratory-Scale Cell

    Science.gov (United States)

    Martinez, Ana Maria; Osen, Karen Sende; Støre, Anne; Gudbrandsen, Henrik; Kjos, Ole Sigmund; Solheim, Asbjørn; Wang, Zhaohui; Oury, Alexandre; Namy, Patrick

    2018-04-01

    Electrolytic production of light rare earth elements and rare earth alloys with transition elements takes place in a fluoride-based electrolyte using rare earth oxides as raw material. The optimization of this method, mainly in terms of the energy efficiency and environmental impact control, is rather challenging. Anode effects, evolution of fluorine-containing compounds and side cathode reactions could largely be minimized by good control of the amount of rare earth oxide species dissolved in the fluoride-based electrolyte and their dissolution rate. The Dy2O3 feed rate needed for stable cell operation was studied by following up the anode voltage and gas analysis. On-line analysis of the cell off-gases by FTIR showed that the electrochemical reaction for the formation of Dy-Fe alloy gives mainly CO gas and that CF4 is starting to evolve gradually at anode voltages of ca. 3.25 V. The limiting current density for the discharge of the oxide ions at the graphite anode was in the range of 0.1 to 0.18 A cm-2 at dissolved Dy2O3 contents of ca. 1 wt pct. Modeling of the laboratory cell reactor was also carried out by implementing two models, i.e., an electrical model simulating the current density distribution at the electrodes and a laminal bubbly flow model that explains the electrolyte velocity induced by gas bubble production at the anode.

  1. Effect of zinc additions on oxide rupture strain and repassivation kinetics of iron-based alloys in 288 C water

    International Nuclear Information System (INIS)

    Angeliu, T.M.; Andresen, P.L.

    1996-01-01

    The effect of Zn water chemistry additions on the mechanism of intergranular stress corrosion cracking (IGSCC) of Fe-based alloys in water at 288 C was evaluated in terms of the slip-dissolution model. In this model, an increase in the oxide film rupture strain or surface film repassivation kinetics improved resistance to IGSCC. The oxide rupture strain of type 304L (UNS S30403) stainless steel (SS) increased up to a factor of two in deaerated and 200 ppb oxygenated, high-purity water ( 300 h of exposure. Repassivation kinetics experiments showed Zn additions of ∼ 100 ppb increased the repassivation rate of an Fe-12% Cr alloys up to a factor of two in various deaerated water environments at 288 C. Life prediction modeling revealed that the combination of a more ductile oxide film and faster repassivation kinetics resulted in a reduction in the overall crack growth rate (CGR) by at least a factor of four. This factor of improvement was consistent with data from compact tension experiments in similar environments where CGR decreased as the Zn addition increased, with a greater decrease in CGR realized at lower pre-Zn CGR

  2. High strength alloys

    Science.gov (United States)

    Maziasz, Phillip James [Oak Ridge, TN; Shingledecker, John Paul [Knoxville, TN; Santella, Michael Leonard [Knoxville, TN; Schneibel, Joachim Hugo [Knoxville, TN; Sikka, Vinod Kumar [Oak Ridge, TN; Vinegar, Harold J [Bellaire, TX; John, Randy Carl [Houston, TX; Kim, Dong Sub [Sugar Land, TX

    2010-08-31

    High strength metal alloys are described herein. At least one composition of a metal alloy includes chromium, nickel, copper, manganese, silicon, niobium, tungsten and iron. System, methods, and heaters that include the high strength metal alloys are described herein. At least one heater system may include a canister at least partially made from material containing at least one of the metal alloys. At least one system for heating a subterranean formation may include a tubular that is at least partially made from a material containing at least one of the metal alloys.

  3. Nonspecific targeting of iron oxide nanoparticles to the liver, kidney and spleen: A novel approach to achieving specificity

    Science.gov (United States)

    Palihawadana Arachchige, Maheshika; Flack, Amanda; Chen, Xuequn; Li, Jing; Oupicky, David; Cheng, Y.-C. Norman; Shen, Yimin; Jena, Bhanu; Lawes, Gavin

    2013-03-01

    Recently, there has been significant interest in developing Fe3O4 nanoparticles for biomedical applications including targeted drug delivery and magnetic resonance imaging. One of the major problems in these applications is the undesirable filtration of these materials by the mononuclear phagocyte system. Preliminary magnetic resonance imaging and magnetization studies on hyaluronic acid coated nanoparticles injected intravenously into mice confirm that the nanoparticles accumulate in the liver, spleen, and kidneys. To identify whether certain specific proteins are responsible for nanoparticle accumulation in these organs, we exposed hyaluronic acid coated nanoparticles to proteins extracted from the liver, spleen, and kidneys, together with blood plasma proteins, then subsequently used gel electrophoresis and mass spectroscopy to identify the proteins binding to the nanoparticles. We find that the unwanted accumulation of nanoparticles in these organs can potentially be attributed to specific binding by a small number of proteins. By appropriately functionalizing the iron oxide nanoparticles, we expect that the nanoparticles uptake in the liver, spleen, and kidneys will be reduced.

  4. Targeting EGFR-overexpressing tumor cells using Cetuximab-immunomicelles loaded with doxorubicin and superparamagnetic iron oxide

    International Nuclear Information System (INIS)

    Liao Chengde; Sun Qiquan; Liang, Biling; Shen Jun; Shuai Xintao

    2011-01-01

    Epidermal growth factor receptor (EGFR), a cellular transmembrane receptor, plays a key role in cell proliferation and is linked to a poor prognosis in various human cancers. In this study, we constructed Cetuximab-immunomicelles in which the anti-EGFR monoclonal antibody was linked to poly(ethylene glycol)-block-poly(ε-caprolactone) (PEG–PCL) nanomicelles that were loaded with doxorubicin (DOX) and superparamagnetic iron oxide (SPIO). The specific interactions between EGFR-overexpressing tumor cells (A431) and immunomicelles were observed using confocal laser scanning microscopy (CLSM) and flow cytometry. Furthermore, the capacity of transporting SPIO into tumor cells using these immunomicelles was evaluated with a 1.5 T clinical magnetic resonance imaging (MRI) scanner. It was found that the acquired MRI T2 signal intensity of A431 cells that were treated with the SPIO-loaded and antibody-functionalized micelles decreased significantly. Using the thiazolyl blue tetrazolium bromide (MTT) assay, we also demonstrated that the immunomicelles inhibited cell proliferation more effectively than their nontargeting counterparts. Our results suggest that Cetuximab-immunomicelles are a useful delivery vehicle for DOX and SPIO to EGFR-overexpressing tumor cells in vitro and that Cetuximab-immunomicelles can serve as a MRI-visible and targeted drug delivery agent for better tumor imaging and therapy.

  5. Microstructure and Sliding Wear Behaviour of In-Situ TiC-Reinforced Composite Surface Layers Fabricated on Ductile Cast Iron by Laser Alloying.

    Science.gov (United States)

    Janicki, Damian

    2018-01-05

    TiC-reinforced composite surface layers (TRLs) on a ductile cast iron EN-GJS-700-2 grade (DCI) substrate were synthesized using a diode laser surface alloying with a direct injection of titanium powder into the molten pool. The experimental results were compared with thermodynamic calculations. The TRLs having a uniform distribution of the TiC particles and their fraction up to 15.4 vol % were achieved. With increasing titanium concentration in the molten pool, fractions of TiC and retained austenite increase and the shape of TiC particles changes from cubic to dendritic form. At the same time, the cementite fraction decreases, lowering the overall hardness of the TRL. A good agreement between experimental and calculated results was achieved. Comparative dry sliding wear tests between the as-received DCI, the TRLs and also laser surface melted layers (SMLs) have been performed following the ASTM G 99 standard test method under contact pressures of 2.12 and 4.25 MPa. For both the as-received DCI and the SMLs, the wear rates increased with increasing contact pressure. The TRLs exhibited a significantly higher wear resistance than the others, which was found to be load independent.

  6. Morphological variants of carbides of solidification origin in the rapidly solidified powder particles of hypereutectic iron alloy

    International Nuclear Information System (INIS)

    Kusy, M.; Grgac, P.; Behulova, M.; Vyrostkova, A.; Miglierini, M.

    2004-01-01

    The paper deals with the analysis of the morphological variants of solidification microstructures and vanadium rich M 4 C 3 carbide phases in the rapidly solidified (RS) powder particles from hypereutectic Fe-C-Cr-V alloy prepared by the nitrogen gas atomisation. Five main types of solidification microstructures were identified in RS particles: microstructure with globular carbides, microstructure with globular and star-like carbides, microstructure with primary carbides in the centres of eutectic colonies, microstructure with eutectic colonies without primary carbides and microstructure with eutectic spherulites. Based on the morphological features of carbide phases and the thermal history of RS particles, the microstructures were divided into two groups - microstructures morphologically affected and non-affected during the post-recalescence period of solidification. Thermophysical reasons for the morphologically different M 4 C 3 carbide phases development in the RS powder particles are discussed

  7. Multicomponent, peptide-targeted glycol chitosan nanoparticles containing ferrimagnetic iron oxide nanocubes for bladder cancer multimodal imaging

    Directory of Open Access Journals (Sweden)

    Key J

    2016-08-01

    , by using cyanine 5.5 fluorescence molecules. We changed the physicochemical properties of glycol chitosan nanoparticles by conjugating bladder cancer-targeting peptides and loading many ferrimagnetic iron oxide NCs per glycol chitosan nanoparticle to improve MRI contrast. The 22 nm ferrimagnetic NCs were stabilized in physiological conditions by encapsulating them within modified chitosan nanoparticles. The multimodal nanoparticles were compared with in vivo MRI and near infrared fluorescent systems. We demonstrated significant and important changes in the biodistribution and tumor accumulation of nanoparticles with different physicochemical properties. Finally, we demonstrated that multimodal nanoparticles specifically visualize small tumors and show minimal accumulation in other organs. This work reveals the importance of finely modulating physicochemical properties in designing multimodal nanoparticles for bladder cancer imaging.Keywords: MRI, NIRF, multimodal imaging, chitosan, iron oxide, bladder cancer

  8. Experimental investigation and thermodynamic modeling of molybdenum and vanadium-containing carbide hardened iron-based alloys

    International Nuclear Information System (INIS)

    Cabrol, E.; Bellot, C.; Lamesle, P.; Delagnes, D.; Povoden-Karadeniz, E.

    2013-01-01

    Highlights: ► Improvement of a carbide selective extraction method. ► Determination of experimental data on the Fe–C–Cr–Mo–V system for carbides above 900 °C: crystallographic structures and compositions of precipitates, matrix composition. ► High molybdenum solubility in FCC carbides. ► Improvement of thermodynamic databases from experimental results. ► Validation of the optimized database with different compositions steels. -- Abstract: A technique for the microstructural study of steels, based on the use of matrix dissolution to collect the very low number density precipitates formed in martensitic steels, has been considerably improved. This technique was applied to two different grades of alloy, characterized by high nickel and cobalt contents and varying chromium, molybdenum and vanadium contents. The technique was implemented at temperatures ranging between 900 °C and 1000 °C, in order to accurately determine experimental data including the crystallographic structure and chemical composition of the carbides, the carbide solvus temperatures, and variations in the chemical composition of the matrix. These experimental investigations reveal that the solubility of molybdenum in FCC carbides can be very high. These results have been compared with the behavior predicted by computational thermodynamics, and used to evaluate and improve the thermodynamic Matcalc steel database. This upgraded database has been validated on three other steels with different chemical compositions, characterized by the same Fe–Cr–Mo–V–C system

  9. Constructing superhydrophobic WO3@TiO2 nanoflake surface beyond amorphous alloy against electrochemical corrosion on iron steel

    Science.gov (United States)

    Yu, S. Q.; Ling, Y. H.; Wang, R. G.; Zhang, J.; Qin, F.; Zhang, Z. J.

    2018-04-01

    To eliminate harmful localized corrosion, a new approach by constructing superhydrophobic WO3@TiO2 hierarchical nanoflake surface beyond FeW amorphous alloy formed on stainless steel was proposed. Facile dealloying and liquid deposition was employed at low temperature to form a nanostructured layer composing inner WO3 nanoflakes coated with TiO2 nanoparticles (NPs) layer. After further deposition of PFDS on nanoflakes, the contact angle reached 162° while the corrosion potential showed a negative shift of 230 mV under illumination, resulting in high corrosion resistance in 3.5 wt% NaCl solution. The tradeoff between superhydrophobic surface and photo-electro response was investigated. It was found that this surface feature makes 316 SS be immune to localized corrosion and a pronounced photo-induced process of electron storage/release as well as the stability of the functional layer were detected with or without illumination, and the mechanism behind this may be related to the increase of surface potential due to water repellence and the delayed cathodic protection of semiconducting coating derived mainly from the valence state changes of WO3. This study demonstrates a simple and low-cost electrochemical approach for protection of steel and novel means to produce superhydrophobic surface and cathodic protection with controllable electron storage/release on engineering scale.

  10. Experimental investigation and thermodynamic modeling of molybdenum and vanadium-containing carbide hardened iron-based alloys

    Energy Technology Data Exchange (ETDEWEB)

    Cabrol, E., E-mail: ecabrol@mines-albi.fr [Institut Clément Ader, Mines Albi, Campus Jarlard, F-81013 Albi Cedex 09 (France); Aubert and Duval, BP1 F-63770 Les Ancizes (France); Bellot, C. [Institut Clément Ader, Mines Albi, Campus Jarlard, F-81013 Albi Cedex 09 (France); Aubert and Duval, BP1 F-63770 Les Ancizes (France); Lamesle, P.; Delagnes, D. [Institut Clément Ader, Mines Albi, Campus Jarlard, F-81013 Albi Cedex 09 (France); Povoden-Karadeniz, E. [Christian Doppler Laboratory for Early Stages of Precipitation, Vienna University of Technology, Favoritenstrasse 9-11, A-1040 Vienna (Austria)

    2013-04-15

    Highlights: ► Improvement of a carbide selective extraction method. ► Determination of experimental data on the Fe–C–Cr–Mo–V system for carbides above 900 °C: crystallographic structures and compositions of precipitates, matrix composition. ► High molybdenum solubility in FCC carbides. ► Improvement of thermodynamic databases from experimental results. ► Validation of the optimized database with different compositions steels. -- Abstract: A technique for the microstructural study of steels, based on the use of matrix dissolution to collect the very low number density precipitates formed in martensitic steels, has been considerably improved. This technique was applied to two different grades of alloy, characterized by high nickel and cobalt contents and varying chromium, molybdenum and vanadium contents. The technique was implemented at temperatures ranging between 900 °C and 1000 °C, in order to accurately determine experimental data including the crystallographic structure and chemical composition of the carbides, the carbide solvus temperatures, and variations in the chemical composition of the matrix. These experimental investigations reveal that the solubility of molybdenum in FCC carbides can be very high. These results have been compared with the behavior predicted by computational thermodynamics, and used to evaluate and improve the thermodynamic Matcalc steel database. This upgraded database has been validated on three other steels with different chemical compositions, characterized by the same Fe–Cr–Mo–V–C system.

  11. Development and characterization of magnetic iron oxide nanoparticles with a cisplatin-bearing polymer coating for targeted drug delivery

    Directory of Open Access Journals (Sweden)

    Unterweger H

    2014-08-01

    potential of –45 mV. No signs of particle precipitation were observed over a period of at least 8 weeks. Analysis of drug-release kinetics using the dialysis tube method revealed that these were driven by inverse ligand substitution and diffusion through the polymer shell as well as enzymatic degradation of hyaluronic acid. The biological activity of the particles was investigated in a nonadherent Jurkat cell line using flow cytometry. Further, cell viability and proliferation was examined in an adherent PC-3 cell line using xCELLigence analysis. Both tests demonstrated that particles without cisplatin were biocompatible with these cells, whereas particles with the drug induced apoptosis in a dose-dependent manner, with secondary necrosis after prolonged incubation. In conclusion, combination of dextran-coated SPIONs with hyaluronic acid and cisplatin represents a promising approach for magnetic drug targeting in the treatment of cancer. Keywords: magnetic drug targeting, superparamagnetic iron oxide nanoparticles, dextran, hyaluronic acid

  12. Evaluation of iron and zinc bioavailability of beans targeted for biofortification using in vitro and in vivo models and their effect on the nutritional status of preschool children.

    Science.gov (United States)

    Vaz-Tostes, Maria das Graças; Verediano, Thaisa Agrizzi; de Mejia, Elvira Gonzalez; Brunoro Costa, Neuza Maria

    2016-03-15

    Biofortified beans have been produced with higher nutrient concentrations. The objective was to evaluate the in vitro and in vivo iron and zinc bioavailability of common beans Pontal (PO), targeted for biofortification, compared with conventional Perola (PE) and their effects on the iron and zinc nutritional status of preschool children. In Caco-2 cells, PO and PE beans did not show differences in ferritin (PO, 13.1 ± 1.4; PE, 13.6 ± 1.4 ng mg(-1) protein) or zinc uptake (PO, 15.9 ± 1.5; PE, 15.5 ± 3.5 µmol mg(-1) protein). In the rat, PO and PE beans presented high iron bioavailability (PO, 109.6 ± 29.5; PE, 110.7 ± 13.9%). In preschool children, no changes were observed in iron and zinc nutritional status comparing before and after PO consumption (ferritin, 41.2 ± 23.2 and 28.9 ± 40.4 µg L(-1) ; hemoglobin, 13.7 ± 2.2 and 13.1 ± 3.2 g dL(-1) ; plasma zinc, 119.2 ± 24.5 and 133.9 ± 57.7 µg dL(-1) ; erythrocyte zinc, 53.5 ± 13.8 and 59.4 ± 17.1 µg g(-1) hemoglobin). Iron and zinc bioavailability in PO and PE beans was not statistically different using either cell culture, animal or human models. Efforts should focus on increasing mineral bioavailability of beans targeted for biofortification. © 2015 Society of Chemical Industry.

  13. Control of chilling tendency in grey cast iron reuse

    Directory of Open Access Journals (Sweden)

    Saliu Ojo Seidu

    2013-02-01

    Full Text Available In grey cast iron remelt and recycling, white iron can result in the cast product if careful control of the chilling tendency is not ensured. Many jobbing foundries are constrained in furnace types and available foundry additives that the operation always results in white irons. This study is towards ensuring grey iron is reproduced from cast iron scrap auto engine blocks, when using a diesel fired rotary furnace and a FeSi alloy for structural modification (inoculation. With varying addition rate of the FeSi alloy to the tapped molten metal, chill wedge tests were performed on two different wedge samples of type W (according to ASTM A367- wedge test with cooling modulus of 0.45 cm (W3½ and 0.54 cm (W4. The carbon equivalents for the test casts were within hypoeutectic range (3.85 wt. (% to 4.11 wt. (%. In the W4 wedge sample, at 2.0 wt. (% addition rate of the FeSi alloy, the relative clear chill was totally reduced to zero from 19.76%, while the relative mottled chill was brought down to 9.59% from 33.71%. The microstructure from the cast at this level of addition was free of carbidic phases; it shows randomly oriented graphite flakes evenly distributed in the iron matrix. Hardness assessment shows that increasing rate of FeSi addition results in decreasing hardness, with maximum effect at 2.0 wt. (% addition. With equivalent aspect ratio (cooling modulus in a target cast product, this addition rate for this FeSi alloy under this furnace condition will attain graphitized microstructure in the cast product.

  14. Control of chilling tendency in grey cast iron reuse

    Directory of Open Access Journals (Sweden)

    Saliu Ojo Seidu

    2012-01-01

    Full Text Available In grey cast iron remelt and recycling, white iron can result in the cast product if careful control of the chilling tendency is not ensured. Many jobbing foundries are constrained in furnace types and available foundry additives that the operation always results in white irons. This study is towards ensuring grey iron is reproduced from cast iron scrap auto engine blocks, when using a diesel fired rotary furnace and a FeSi alloy for structural modification (inoculation. With varying addition rate of the FeSi alloy to the tapped molten metal, chill wedge tests were performed on two different wedge samples of type W (according to ASTM A367- wedge test with cooling modulus of 0.45 cm (W3½ and 0.54 cm (W4. The carbon equivalents for the test casts were within hypoeutectic range (3.85 wt. (% to 4.11 wt. (%. In the W4 wedge sample, at 2.0 wt. (% addition rate of the FeSi alloy, the relative clear chill was totally reduced to zero from 19.76%, while the relative mottled chill was brought down to 9.59% from 33.71%. The microstructure from the cast at this level of addition was free of carbidic phases; it shows randomly oriented graphite flakes evenly distributed in the iron matrix. Hardness assessment shows that increasing rate of FeSi addition results in decreasing hardness, with maximum effect at 2.0 wt. (% addition. With equivalent aspect ratio (cooling modulus in a target cast product, this addition rate for this FeSi alloy under this furnace condition will attain graphitized microstructure in the cast product.

  15. Systemic combinatorial peptide selection yields a non-canonical iron-mimicry mechanism for targeting tumors in a mouse model of human glioblastoma

    Science.gov (United States)

    Staquicini, Fernanda I.; Ozawa, Michael G.; Moya, Catherine A.; Driessen, Wouter H.P.; Barbu, E. Magda; Nishimori, Hiroyuki; Soghomonyan, Suren; Flores, Leo G.; Liang, Xiaowen; Paolillo, Vincenzo; Alauddin, Mian M.; Basilion, James P.; Furnari, Frank B.; Bogler, Oliver; Lang, Frederick F.; Aldape, Kenneth D.; Fuller, Gregory N.; Höök, Magnus; Gelovani, Juri G.; Sidman, Richard L.; Cavenee, Webster K.; Pasqualini, Renata; Arap, Wadih

    2010-01-01

    The management of CNS tumors is limited by the blood-brain barrier (BBB), a vascular interface that restricts the passage of most molecules from the blood into the brain. Here we show that phage particles targeted with certain ligand motifs selected in vivo from a combinatorial peptide library can cross the BBB under normal and pathological conditions. Specifically, we demonstrated that phage clones displaying an iron-mimic peptide were able to target a protein complex of transferrin and transferrin receptor (TfR) through a non-canonical allosteric binding mechanism and that this functional protein complex mediated transport of the corresponding viral particles into the normal mouse brain. We also showed that, in an orthotopic mouse model of human glioblastoma, a combination of TfR overexpression plus extended vascular permeability and ligand retention resulted in remarkable brain tumor targeting of chimeric adeno-associated virus/phage particles displaying the iron-mimic peptide and carrying a gene of interest. As a proof of concept, we delivered the HSV thymidine kinase gene for molecular-genetic imaging and targeted therapy of intracranial xenografted tumors. Finally, we established that these experimental findings might be clinically relevant by determining through human tissue microarrays that many primary astrocytic tumors strongly express TfR. Together, our combinatorial selection system and results may provide a translational avenue for the targeted detection and treatment of brain tumors. PMID:21183793

  16. Development of Advanced High Strength Cast Alloys for Heavy Duty Engines

    Energy Technology Data Exchange (ETDEWEB)

    Barlow, James [Caterpillar Inc., Mossville, IL (United States)

    2017-06-13

    Gray iron has been the primary alloy for heavy duty diesel engine core castings for decades. During recent decades the limitations of gray iron have been reached in some applications, leading to the use of compacted graphite iron in engine blocks and heads. Caterpillar has had compacted graphite designs in continuous production since the late 1980’s. Due to the drive for higher power density, decreased emissions and increased fuel economy, cylinder pressures and temperatures continue to increase. Currently no viable replacement for today’s compacted graphite irons exist at an acceptable cost level. This project explored methods to develop the next generation of heavy duty diesel engine materials as well as demonstrated some results on new alloy designs although cost targets will likely not be met.

  17. MicroRNA-210 regulates mitochondrial free radical response to hypoxia and krebs cycle in cancer cells by targeting iron sulfur cluster protein ISCU.

    Directory of Open Access Journals (Sweden)

    Elena Favaro

    2010-04-01

    Full Text Available Hypoxia in cancers results in the upregulation of hypoxia inducible factor 1 (HIF-1 and a microRNA, hsa-miR-210 (miR-210 which is associated with a poor prognosis.In human cancer cell lines and tumours, we found that miR-210 targets the mitochondrial iron sulfur scaffold protein ISCU, required for assembly of iron-sulfur clusters, cofactors for key enzymes involved in the Krebs cycle, electron transport, and iron metabolism. Down regulation of ISCU was the major cause of induction of reactive oxygen species (ROS in hypoxia. ISCU suppression reduced mitochondrial complex 1 activity and aconitase activity, caused a shift to glycolysis in normoxia and enhanced cell survival. Cancers with low ISCU had a worse prognosis.Induction of these major hallmarks of cancer show that a single microRNA, miR-210, mediates a new mechanism of adaptation to hypoxia, by regulating mitochondrial function via iron-sulfur cluster metabolism and free radical generation.

  18. Recombinant epidermal growth factor-like domain-1 from coagulation factor VII functionalized iron oxide nanoparticles for targeted glioma magnetic resonance imaging.

    Science.gov (United States)

    Liu, Heng; Chen, Xiao; Xue, Wei; Chu, Chengchao; Liu, Yu; Tong, Haipeng; Du, Xuesong; Xie, Tian; Liu, Gang; Zhang, Weiguo

    The highly infiltrative and invasive nature of glioma cells often leads to blurred tumor margins, resulting in incomplete tumor resection and tumor recurrence. Accurate detection and precise delineation of glioma help in preoperative delineation, surgical planning and survival prediction. In this study, recombinant epidermal growth factor-like domain-1, derived from human coagulation factor VII, was conjugated to iron oxide nanoparticles (IONPs) for targeted glioma magnetic resonance (MR) imaging. The synthesized EGF1-EGFP-IONPs exhibited excellent targeting ability toward tissue factor (TF)-positive U87MG cells and human umbilical vein endothelial cells in vitro, and demonstrated persistent and efficient MR contrast enhancement up to 12 h for preclinical glioma models with high targeting specificity in vivo. They hold great potential for clinical translation and developing targeted theranostics against brain glioma.

  19. Anodic oxidation of Ta/Fe alloys

    International Nuclear Information System (INIS)

    Mato, S.; Alcala, G.; Thompson, G.E.; Skeldon, P.; Shimizu, K.; Habazaki, H.; Quance, T.; Graham, M.J.; Masheder, D.

    2003-01-01

    The behaviour of iron during anodizing of sputter-deposited Ta/Fe alloys in ammonium pentaborate electrolyte has been examined by transmission electron microscopy, Rutherford backscattering spectroscopy, glow discharge optical emission spectroscopy and X-ray photoelectron spectroscopy. Anodic films on Ta/1.5 at.% Fe, Ta/3 at.% Fe and Ta/7 at.% Fe alloys are amorphous and featureless and develop at high current efficiency with respective formation ratios of 1.67, 1.60 and 1.55 nm V -1 . Anodic oxidation of the alloys proceeds without significant enrichment of iron in the alloy in the vicinity of the alloy/film interface and without oxygen generation during film growth, unlike the behaviour of Al/Fe alloys containing similar concentrations of iron. The higher migration rate of iron species relative to that of tantalum ions leads to the formation of an outer iron-rich layer at the film surface

  20. Aluminum fin-stock alloys

    International Nuclear Information System (INIS)

    Gul, R.M.; Mutasher, F.

    2007-01-01

    Aluminum alloys have long been used in the production of heat exchanger fins. The comparative properties of the different alloys used for this purpose has not been an issue in the past, because of the significant thickness of the finstock material. However, in order to make fins lighter in weight, there is a growing demand for thinner finstock materials, which has emphasized the need for improved mechanical properties, thermal conductivity and corrosion resistance. The objective of this project is to determine the effect of iron, silicon and manganese percentage increment on the required mechanical properties for this application by analyzing four different aluminum alloys. The four selected aluminum alloys are 1100, 8011, 8079 and 8150, which are wrought non-heat treatable alloys with different amount of the above elements. Aluminum alloy 1100 serve as a control specimen, as it is commercially pure aluminum. The study also reports the effect of different annealing cycles on the mechanical properties of the selected alloys. Metallographic examination was also preformed to study the effect of annealing on the precipitate phases and the distribution of these phases for each alloy. The microstructure analysis of the aluminum alloys studied indicates that the precipitated phase in the case of aluminum alloys 1100 and 8079 is beta-FeAI3, while in 8011 it is a-alfa AIFeSi, and the aluminum alloy 8150 contains AI6(Mn,Fe) phase. The comparison of aluminum alloys 8011 and 8079 with aluminum alloy 1100 show that the addition of iron and silicon improves the percent elongation and reduces strength. The manganese addition increases the stability of mechanical properties along the annealing range as shown by the comparison of aluminum alloy 8150 with aluminum alloy 1100. Alloy 8150 show superior properties over the other alloys due to the reaction of iron and manganese, resulting in a preferable response to thermal treatment and improved mechanical properties. (author)

  1. Measurements of attenuation lengths through concrete and iron for neutrons produced by 800-MeV proton on tantalum target at ISIS

    CERN Document Server

    Nunomiya, T; Wright, P; Nakamura, T; Kim, E; Kurosawa, T; Taniguchi, S; Sasaki, M; Iwase, H; Uwamino, Y; Shibata, T; Ito, S; Perry, D R

    2002-01-01

    A deep penetration experiment through a thick bulk shield was performed at an intense spallation neutron source facility, ISIS, of the Rutherford Appleton Laboratory (RAL), United Kingdom. ISIS is a 800 MeV-200 mu A proton accelerator facility. Neutrons are produced from a tantalum target, and are shielded with approximately 3-m thick steel and 1-m thick ordinary concrete. On top of the shield, we measured the neutron flux attenuation through concrete and iron shields, which were additionally placed up to 120-cm and 60-cm thickness, respectively, using activation detectors of graphite and bismuth. The attenuation lengths of concrete and iron for high-energy neutrons above 20 MeV were obtained from the sup 1 sup 2 C(n, 2n) sup 1 sup 1 C reaction of graphite.

  2. Efficient laser-induced 6-8 keV x-ray production from iron oxide aerogel and foil-lined cavity targets

    Energy Technology Data Exchange (ETDEWEB)

    Pérez, F.; Kay, J. J.; Patterson, J. R.; Kane, J.; Villette, B.; Girard, F.; Reverdin, C.; May, M.; Emig, J.; Sorce, C.; Colvin, J.; Gammon, S.; Jaquez, J.; Satcher, J. H.; Fournier, K. B.

    2012-08-01

    The performance of new iron-based laser-driven x-ray sources has been tested at the OMEGA laser facility for production of x rays in the 6.5–8.5 keV range. Two types of targets were experimentally investigated: low-density iron oxide aerogels (density 6-16 mg/cm36-16 mg/cm3) and stainless steel foil-lined cavity targets (steel thickness 1-5 μm1-5 μm). The targets were irradiated by 40 beams of the OMEGA laser (500 J/beam, 1 ns pulse, wavelength 351 nm). All targets showed good coupling with the laser, with <5%<5% of the incident laser light backscattered by the resulting plasma in all cases (typically <2.5%<2.5%). The aerogel targets produced Te=2Te=2 to 3 keV, ne=0.12-0.2ne=0.12-0.2 critical density plasmas yielding a 40%–60% laser-to-x-ray total conversion efficiency (CE) (1.2%–3% in the Fe K-shell range). The foil cavity targets produced Te~2 keV, Te~2 keV, ne~0.15ne~0.15 critical density plasmas yielding a 60%–75% conversion efficiency (1.6%–2.2% in the Fe K-shell range). Time-resolved images illustrate that the volumetric heating of low-density aerogels allow them to emit a higher K-shell x-ray yield even though they contain fewer Fe atoms. However, their challenging fabrication process leads to a larger shot-to-shot variation than cavity targets.

  3. Structural thermodynamics of alloys

    CERN Document Server

    Manenc, Jack

    1973-01-01

    Technical progress has for a very long time been directly dependent on progress in metallurgy, which is itself connected with improvements in the technology of alloys. Metals are most frequently used in the form of alloys for several reasons: the quantity of pure metal in its native state in the earth's crust is very limited; pure metals must be extracted from ores which are themselves impure. Finally, the methods of treatment used lead more easily to alloys than to pure metals. The most typical case is that of iron, where a pure ore may be found, but which is the starting point for cast iron or steel, alloys of iron and carbon. In addition, the properties of alloys are in general superior to those of pure metals and modem metallurgy consists of controlling these properties so as to make them conform to the requirements of the design office. Whilst the engineer was formerly compelled to adapt his designs and constructions to the materials available, such as wood, stone, bronze, iron, cast iron and ordinary st...

  4. Addition of iron for the removal of the {beta}-AlFeSi intermetallic by refining of {alpha}-AlFeSi phase in an Al-7.5Si-3.6Cu alloy

    Energy Technology Data Exchange (ETDEWEB)

    Belmares-Perales, S. [Facultad de Ingenieria Mecanica y Electrica, Universidad Autonoma de Nuevo Leon (Mexico); Zaldivar-Cadena, A.A., E-mail: azaldiva70@hotmail.com [Facultad de Ingenieria Civil, Departamento de Ecomateriales y Energia, Instituto de Ingenieria Civil, Av. Fidel Velasquez and Av. Universidad S/N, Cd. Universitaria, San Nicolas de los Garza, N.L. 66450 (Mexico)

    2010-10-25

    Addition of iron into the molten metal for the removal of the {beta}-AlFeSi intermetallic by refining of {alpha}-AlFeSi phase has been studied. Solidification conditions and composition determine the final microstructure and mechanical properties of a casting piece. It is known that increasing the iron content will produce an increasing of the {alpha}-AlFeSi and {beta}-AlFeSi phases. This phenomenon was confirmed with calculations made by Thermo-Calc{sup TM} software and validated with experimental results, however, the technique of iron addition in this study plays an important role on the solidification kinetics of these iron phases because the refining of {alpha}-AlFeSi and removal of {beta}-AlFeSi phases can be improved. Final results showed an improvement in mechanical properties by removal and refining of {beta}-AlFeSi and {alpha}-AlFeSi phases, respectively. This study shows a new method of removal of {beta}-AlFeSi that could be adopted in the aluminum smelting industry in aluminum alloys with a low cooling rate with a secondary dendritic spacing of about 37 {mu}m.

  5. Addition of iron for the removal of the β-AlFeSi intermetallic by refining of α-AlFeSi phase in an Al-7.5Si-3.6Cu alloy

    International Nuclear Information System (INIS)

    Belmares-Perales, S.; Zaldivar-Cadena, A.A.

    2010-01-01

    Addition of iron into the molten metal for the removal of the β-AlFeSi intermetallic by refining of α-AlFeSi phase has been studied. Solidification conditions and composition determine the final microstructure and mechanical properties of a casting piece. It is known that increasing the iron content will produce an increasing of the α-AlFeSi and β-AlFeSi phases. This phenomenon was confirmed with calculations made by Thermo-Calc TM software and validated with experimental results, however, the technique of iron addition in this study plays an important role on the solidification kinetics of these iron phases because the refining of α-AlFeSi and removal of β-AlFeSi phases can be improved. Final results showed an improvement in mechanical properties by removal and refining of β-AlFeSi and α-AlFeSi phases, respectively. This study shows a new method of removal of β-AlFeSi that could be adopted in the aluminum smelting industry in aluminum alloys with a low cooling rate with a secondary dendritic spacing of about 37 μm.

  6. Effect of positively charged particles on sputtering damage of organic electro-luminescent diodes with Mg:Ag alloy electrodes fabricated by facing target sputtering

    Directory of Open Access Journals (Sweden)

    Kouji Suemori

    2017-04-01

    Full Text Available We investigated the influence of the positively charged particles generated during sputtering on the performances of organic light-emitting diodes (OLEDs with Mg:Ag alloy electrodes fabricated by sputtering. The number of positively charged particles increased by several orders of magnitude when the target current was increased from 0.1 A to 2.5 A. When a high target current was used, many positively charged particles with energies higher than the bond energy of single C–C bonds, which are typically found in organic molecules, were generated. In this situation, we observed serious OLED performance degradation. On the other hand, when a low target current was used, OLED performance degradation was not observed when the number of positively charged particles colliding with the organic underlayer increased. We concluded that sputtering damage caused by positively charged particles can be avoided by using a low target current.

  7. Seal welded cast iron nuclear waste container

    International Nuclear Information System (INIS)

    Filippi, A.M.; Sprecace, R.P.

    1987-01-01

    An article of manufacture is described comprising a cast iron container having an opening at one end and a cast iron plug; a first nickel-carbon alloy fusion weldable insert surrounding the opening and metallurgically bonded to the cast iron container at the one end of the container; a second nickel-carbon alloy insert metallurgically bonded to the cast iron plug located within the opening and surrounded by the first insert the inserts being jointed by a fusion bond in the opening without heating the cast iron container to an austenite formation temperature thereby sealing the interior of the container from the exterior ambient outside the opening; the nickel-carbon alloy containing about 2 to 5 w% carbon; and both the nickel-carbon alloy insert and the cast iron container have a microstructure containing a graphite phase

  8. Improvement of corrosion protection property of Mg-alloy by DLC and Si-DLC coatings with PBII technique and multi-target DC-RF magnetron sputtering

    International Nuclear Information System (INIS)

    Masami, Ikeyama; Setsuo, Nakao; Tsutomu, Sonoda; Junho, Choi

    2009-01-01

    Magnesium alloys have been considered as one of the most promising light weight materials with potential applications for automobile and aircraft components. Their poor corrosion resistance, however, has to date prevented wider usage. Diamond-like carbon (DLC) and silicon-incorporated DLC (Si-DLC) coatings are known to provide a high degree of corrosion protection, and hold accordingly promise for enhancing the corrosion resistance of the magnesium alloys. In this work we have studied the effect of coating conditions of DLC coatings as well as Si incorporation into coating on corrosion resistance, deposited onto AZ91 magnesium alloy substrates by plasma based ion implantation (PBII). The influences of a Ti interlayer beneath the DLC, Si-DLC and Ti incorporated DLC (Ti-DLC) coatings fabricated by multi-target direct-current radio-frequency (DC-RF) magnetron sputtering were also examined on both the adhesion strength and corrosion resistance of the materials. We have also examined the effect of the Si content in the Si-DLC coatings made by magnetron sputtering on the alloys' corrosion resistance. The results of potentiodynamic polarization measurements demonstrate that Si-DLC coating deposited by PBII exhibits the highest corrosion resistance in an aqueous 0.05 M NaCl solution. Although Ti layer is helpful in increasing adhesion between DLC coating and AZ91 substrate, it also influences adversely corrosion protection. The ozone treatment of the magnesium alloy's surface before the formation of coatings has been found to improve both adhesion strength and corrosion resistance.

  9. Improvement of corrosion protection property of Mg-alloy by DLC and Si-DLC coatings with PBII technique and multi-target DC-RF magnetron sputtering

    Science.gov (United States)

    Masami, Ikeyama; Setsuo, Nakao; Tsutomu, Sonoda; Junho, Choi

    2009-05-01

    Magnesium alloys have been considered as one of the most promising light weight materials with potential applications for automobile and aircraft components. Their poor corrosion resistance, however, has to date prevented wider usage. Diamond-like carbon (DLC) and silicon-incorporated DLC (Si-DLC) coatings are known to provide a high degree of corrosion protection, and hold accordingly promise for enhancing the corrosion resistance of the magnesium alloys. In this work we have studied the effect of coating conditions of DLC coatings as well as Si incorporation into coating on corrosion resistance, deposited onto AZ91 magnesium alloy substrates by plasma based ion implantation (PBII). The influences of a Ti interlayer beneath the DLC, Si-DLC and Ti incorporated DLC (Ti-DLC) coatings fabricated by multi-target direct-current radio-frequency (DC-RF) magnetron sputtering were also examined on both the adhesion strength and corrosion resistance of the materials. We have also examined the effect of the Si content in the Si-DLC coatings made by magnetron sputtering on the alloys' corrosion resistance. The results of potentiodynamic polarization measurements demonstrate that Si-DLC coating deposited by PBII exhibits the highest corrosion resistance in an aqueous 0.05 M NaCl solution. Although Ti layer is helpful in increasing adhesion between DLC coating and AZ91 substrate, it also influences adversely corrosion protection. The ozone treatment of the magnesium alloy's surface before the formation of coatings has been found to improve both adhesion strength and corrosion resistance.

  10. Targeted therapy for human hepatic carcinoma cells using folate-functionalized polymeric micelles loaded with superparamagnetic iron oxide and sorafenib in vitro

    Directory of Open Access Journals (Sweden)

    Zhang L

    2013-04-01

    Full Text Available Lei Zhang,1 Faming Gong,2 Fang Zhang,3 Jing Ma,1 Peidong Zhang,1 Jun Shen3 1Department of Hepatobiliary and Pancreatic Surgery, 2PCFM Laboratory of Ministry of Education, School of Chemistry and Chemical Engineering, 3Department of Radiology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, People's Republic of China Background: The purpose of this study was to evaluate the inhibitory effect of targeted folate-functionalized micelles containing superparamagnetic iron oxide nanoparticles (SPIONs and sorafenib on human hepatic carcinoma (HepG2 cells in vitro, and to observe the feasibility of surveillance of this targeting therapeutic effect by magnetic resonance imaging. Methods: Sorafenib and SPIONs were loaded into polymeric micelles. The targeted nanocarrier was synthesized by functionalizing the micelles with folate. Folate-free micelles loaded with sorafenib and SPIONs were used as control (nontargeted micelles. Uptake of the nanocarrier by cells was assessed using Prussian blue staining after 1 hour of incubation with the polymeric micelles. The inhibitory effect of the targeted micelles on HepG2 cell proliferation at various concentrations of sorafenib was assessed in vitro using the methyl thiazolyl tetrazolium (MTT assay and apoptotic analysis using flow cytometry. Magnetic resonance imaging using a clinical 1.5 T scanner was performed to detect changes in the signal intensity of cells after incubation with the targeted micelles. Results: Prussian blue staining showed significantly more intracellular SPIONs in cells incubated with the targeted micelles than those incubated with nontargeted micelles. The MTT assay showed that the average inhibitory ratio in the targeted group was significantly higher than that in the nontargeted group (38.13% versus 22.54%, P = 0.028. The mean apoptotic rate in the targeted cells, nontargeted cells, and untreated cells was 17.01%, 11.04%, and 7.89%, respectively. The apoptotic rate in the

  11. Synthesis and characterization of Bombesin-superparamagnetic iron oxide nanoparticles as a targeted contrast agent for imaging of breast cancer using MRI

    International Nuclear Information System (INIS)

    Jafari, Atefeh; Shayesteh, Saber Farjami; Salouti, Mojtaba; Heidari, Zahra; Rajabi, Ahmad Bitarafan; Boustani, Komail; Nahardani, Ali

    2015-01-01

    The targeted delivery of superparamagnetic iron oxide nanoparticles (SPIONs) as a contrast agent may facilitate their accumulation in cancer cells and enhance the sensitivity of MR imaging. In this study, SPIONs coated with dextran (DSPIONs) were conjugated with bombesin (BBN) to produce a targeting contrast agent for detection of breast cancer using MRI. X-ray diffraction, transmission electron microscopy, and vibrating sample magnetometer analyses indicated the formation of dextran-coated superparamagnetic iron oxide nanoparticles with an average size of 6.0 ± 0.5 nm. Fourier transform infrared spectroscopy confirmed the conjugation of the BBN with the DSPIONs. A stability study proved the high optical stability of DSPION–BBN in human blood serum. DSPION–BBN biocompatibility was confirmed by cytotoxicity evaluation. A binding study showed the targeting ability of DSPION–BBN to bind to T47D breast cancer cells overexpressing gastrin-releasing peptide (GRP) receptors. T 2 -weighted and T 2 *-weighted color map MR images were acquired. The MRI study indicated that the DSPION–BBN possessed good diagnostic ability as a GRP-specific contrast agent, with appropriate signal reduction in T 2 *-weighted color map MR images in mice with breast tumors. (paper)

  12. Innovative cast iron pipes. Part 1. Corrosion protection of buried cast iron pipes on the basis of a zinc-aluminium alloy 85-15; Gussrohr-Innovation. T. 1. Korrosionsschutz von erdueberdeckten Rohrleitungen aus duktilem Gusseisen auf Basis einer Zink-Aluminium-Legierung 85-15

    Energy Technology Data Exchange (ETDEWEB)

    Mischo, Michael [SAINT-GOBAIN PAM DEUTSCHLAND GmbH und Co. KG, Saarbruecken (Germany)

    2009-07-15

    On the basis of more than 50 years of experience with zinc-coated pipes and more than 25 years of experience with the alloy ZnAl 85-15, an innovative coating system was developed for pipes made of ductile cast iron. While the conventional system consists of a Zn coating of 200 g/m{sup 2} and a bitumen coating, the ZnAl 85-15 coating is twice as thick, i.e. 400 g/m{sup 2}, and has a blue epoxy resin cover coating which identifies the pipes as water pipes. (orig.)

  13. Solubility of iron in liquid lead

    International Nuclear Information System (INIS)

    Ali-Khan, I.

    1981-01-01

    The use of liquid lead in high temperature chemical and metallurgical processes is well known. The structural materials applied for the containment of these processes are either iron base alloys or possess iron as an alloying element. Besides that, lead itself is alloyed in some steels to achieve some very useful properties. For understanding the effect of liquid lead in such structural materials, it is important to determine the solubility of iron in liquid lead which would also be indicative of the stability of these alloys. At the institute of reactor materials of KFA Juelich, investigations have been conducted to determine the solubility of iron in liquid lead up to a temperature of about 1000 0 C. In this presentation the data concerning the solubility of iron in liquid lead are brought up to date and discussed including the results of our previous investigations. (orig.)

  14. Solidification, processing and properties of ductile cast iron

    DEFF Research Database (Denmark)

    Tiedje, Niels Skat

    2010-01-01

    Ductile cast iron has been an important engineering material in the past 50 years. In that time, it has evolved from a complicated material that required the foundry metallurgist's highest skill and strict process control to being a commonly used material that can easily be produced with modern...... of the latest years of research indicate that ductile cast iron in the future will become a highly engineered material in which strict control of a range of alloy elements combined with intelligent design and highly advanced processing allows us to target properties to specific applications to a much higher...... degree than we have seen previously. It is the aim of the present paper to present ductile iron as a modern engineering material and present the many different possibilities that the material hides. Focus will be on the latest research in solidification and melt treatment. But for completeness...

  15. A precise determination of the nucleon structure functions in charged-current interactions on an iron target

    International Nuclear Information System (INIS)

    Vallage, B.

    1987-01-01

    570 000 neutrino-iron and 370 000 antineutrino-iron charged-current events were obtained from the Wide Band Beam exposure of the CDHS detector at CERN in 1983, at energies ranging from 20 to 400 GeV. These large statistics allowed a precise measurement of the charged-current differential cross-sections and a detailed study of systematic effects. The nucleon structure functions have been determined in the framework of the quark-parton model, in the kinematic range: 0.015 2 2 /c 2 . The longitudinal structure function F L (x) is in good agreement with the QCD predicted shape. Deviations from scale invariance are clearly seen from the functions F 2 and xF 3 . The Q 2 evolution of the valence quark distribution has been compared with the QCD prediction in order to measure the scale parameter Λ. A good agreement is obtained only if the low Q 2 points are removed from the comparison. Our experiment favours a value of Λ between 50 and 250 MeV [fr

  16. Study of the effect of low-power pulse laser on arc plasma and magnesium alloy target in hybrid welding by spectral diagnosis technique

    Science.gov (United States)

    Liu, Liming; Hao, Xinfeng

    2008-10-01

    In order to study the effect of laser pulses on arc plasma and target metal in the hybrid welding process, the spectra of the plasmas in the welding process of magnesium alloys are analysed in this paper. The acquisition system of plasma spectra is set up and the spectral lines of welding plasma are acquired. Compared with tungsten-inert gas (TIG) welding, the intensities of the spectral lines of magnesium increase sharply while those of Ar decrease for strong evaporation and ionization of magnesium alloys in low-power laser/arc hybrid welding. The electron temperature and density are estimated by the Boltzmann plot method and the Stark broadening effect. The result shows that the electron temperature of arc plasma in the hybrid welding process is much lower than that in TIG welding, especially in the laser beam-affected zone. In contrast, the electron density of the plasma is enhanced. The influences of laser parameters on electron temperature are also studied. The changes in electron temperature and density indicate that the effect of laser pulse on the target metal is the dominant factor influencing the electron temperature and density in low-power laser/arc hybrid welding.

  17. HIGH TEMPERATURE BRAZING ALLOY FOR JOINT Fe-Cr-Al MATERIALS AND AUSTENITIC AND FERRITIC STAINLESS STEELS

    Science.gov (United States)

    Cost, R.C.

    1958-07-15

    A new high temperature brazing alloy is described that is particularly suitable for brazing iron-chromiumaluminum alloys. It consists of approximately 20% Cr, 6% Al, 10% Si, and from 1.5 to 5% phosphorus, the balance being iron.

  18. A Functional Iron Oxide Nanoparticles Modified with PLA-PEG-DG as Tumor-Targeted MRI Contrast Agent.

    Science.gov (United States)

    Xiong, Fei; Hu, Ke; Yu, Haoli; Zhou, Lijun; Song, Lina; Zhang, Yu; Shan, Xiuhong; Liu, Jianping; Gu, Ning

    2017-08-01

    Tumor targeting could greatly promote the performance of magnetic nanomaterials as MRI (Magnetic Resonance Imaging) agent for tumor diagnosis. Herein, we reported a novel magnetic nanoparticle modified with PLA (poly lactic acid)-PEG (polyethylene glycol)-DG (D-glucosamine) as Tumor-targeted MRI Contrast Agent. In this work, we took use of the D-glucose passive targeting on tumor cells, combining it on PLA-PEG through amide reaction, and then wrapped the PLA-PEG-DG up to the Fe 3 O 4 @OA NPs. The stability and anti phagocytosis of Fe 3 O 4 @OA@PLA-PEG-DG was tested in vitro; the MRI efficiency and toxicity was also detected in vivo. These functional magnetic nanoparticles demonstrated good biocompatibility and stability both in vitro and in vivo. Cell experiments showed that Fe 3 O 4 @OA@PLA-PEG-DG nanoparticles exist good anti phagocytosis and high targetability. In vivo MRI images showed that the contrast effect of Fe 3 O 4 @OA@PLA-PEG-DG nanoparticles prevailed over the commercial non tumor-targeting magnetic nanomaterials MRI agent at a relatively low dose. The DG can validly enhance the tumor-targetting effect of Fe 3 O 4 @OA@PLA-PEG nanoparticle. Maybe MRI agents with DG can hold promise as tumor-targetting development in the future.

  19. Molecular magnetic resonance imaging of activated hepatic stellate cells with ultrasmall superparamagnetic iron oxide targeting integrin αvβ3 for staging liver fibrosis in rat model

    Directory of Open Access Journals (Sweden)

    Zhang C

    2016-03-01

    Full Text Available Caiyuan Zhang,1,* Huanhuan Liu,1,* Yanfen Cui,1,* Xiaoming Li,1 Zhongyang Zhang,1 Yong Zhang,2 Dengbin Wang1 1Department of Radiology, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, 2MR Advanced Application and Research Center, GE Healthcare China, Shanghai, People’s Republic of China *These authors contributed equally to this work Purpose: To evaluate the expression level of integrin αvβ3 on activated hepatic stellate cells (HSCs at different stages of liver fibrosis induced by carbon tetrachloride (CCl4 in rat model and the feasibility to stage liver fibrosis by using molecular magnetic resonance imaging (MRI with arginine-glycine-aspartic acid (RGD peptide modified ultrasmall superparamagnetic iron oxide nanoparticle (USPIO specifically targeting integrin αvβ3.Materials and methods: All experiments received approval from our Institutional Animal Care and Use Committee. Thirty-six rats were randomly divided into three groups of 12 subjects each, and intraperitoneally injected with CCl4 for either 3, 6, or 9 weeks. Controls (n=10 received pure olive oil. The change in T2* relaxation rate (ΔR2* pre- and postintravenous administration of RGD-USPIO or naked USPIO was measured by 3.0T clinical MRI and compared by one-way analysis of variance or the Student’s t-test. The relationship between expression level of integrin αvβ3 and liver fibrotic degree was evaluated by Spearman’s ranked correlation.Results: Activated HSCs were confirmed to be the main cell types expressing integrin αvβ3 during liver fibrogenesis. The protein level of integrin αv and β3 subunit expressed on activated HSCs was upregulated and correlated well with the progression of liver fibrosis (r=0.954, P<0.001; r=0.931, P<0.001, respectively. After injection of RGD-USPIO, there is significant difference in ΔR2* among rats treated with 0, 3, 6, and 9 weeks of CCl4 (P<0.001. The accumulation of iron particles in fibrotic liver specimen is

  20. CD163-Macrophages Are Involved in Rhabdomyolysis-Induced Kidney Injury and May Be Detected by MRI with Targeted Gold-Coated Iron Oxide Nanoparticles.

    Science.gov (United States)

    Rubio-Navarro, Alfonso; Carril, Mónica; Padro, Daniel; Guerrero-Hue, Melanie; Tarín, Carlos; Samaniego, Rafael; Cannata, Pablo; Cano, Ainhoa; Villalobos, Juan Manuel Amaro; Sevillano, Ángel Manuel; Yuste, Claudia; Gutiérrez, Eduardo; Praga, Manuel; Egido, Jesús; Moreno, Juan Antonio

    2016-01-01

    Macrophages play an important role in rhabdomyolysis-acute kidney injury (AKI), although the molecular mechanisms involved in macrophage differentiation are poorly understood. We analyzed the expression and regulation of CD163, a membrane receptor mainly expressed by anti-inflammatory M2 macrophages, in rhabdomyolysis-AKI and developed targeted probes for its specific detection in vivo by MRI. Intramuscular injection of glycerol in mice promoted an early inflammatory response, with elevated proportion of M1 macrophages, and partial differentiation towards a M2 phenotype in later stages, where increased CD163 expression was observed. Immunohistological studies confirmed the presence of CD163-macrophages in human rhabdomyolysis-AKI. In cultured macrophages, myoglobin upregulated CD163 expression via HO-1/IL-10 axis. Moreover, we developed gold-coated iron oxide nanoparticles vectorized with an anti-CD163 antibody that specifically targeted CD163 in kidneys from glycerol-injected mice, as determined by MRI studies, and confirmed by electron microscopy and immunological analysis. Our findings are the first to demonstrate that CD163 is present in both human and experimental rhabdomyolysis-induced AKI, suggesting an important role of this molecule in this pathological condition. Therefore, the use of probes targeting CD163-macrophages by MRI may provide important information about the cellular composition of renal lesion in rhabdomyolysis.

  1. The influence of Fe2+ concentration and deposition time on the corrosion resistance of the electrodeposited zinc–nickel–iron alloys

    Directory of Open Access Journals (Sweden)

    M.M. Abou-Krisha

    2016-11-01

    Full Text Available Electrodeposition operating conditions for Zn–Ni–Fe alloys from sulfate baths and the corrosion resistance of the electrodeposited alloys were studied. The comparison between Zn–Ni and Zn–Ni–Fe alloys co-deposition revealed that the remarkable inhibition of Ni and Fe deposition takes place due to the presence of Zn2+ in the plating bath. The electrodeposition was performed on the steel substrate, under galvanostatic conditions, for varying Fe2+ bath concentrations and at different times. X-ray diffraction studies of the deposit showed the presence of Fe3Ni2 phase and γ-phase with a composition of Ni2Zn11. The obtained data also exposed that the corrosion resistance increases as a result of increasing Fe2+ concentration and deposition time. Investigation was carried out using cyclic voltammetry and galvastatic techniques for electrodeposition, while linear polarization resistance and anodic linear sweeping voltammetry techniques were used for corrosion study.

  2. Effect of electrical discharge machining on uranium-0.75 titanium and tungsten-3.5 nickel-1.5 iron alloys

    International Nuclear Information System (INIS)

    Anderson, R.C.

    1976-06-01

    It was found that U--0.75 Ti alloy cracked if the EDM parameters were out of control, and precipitation of carbides adjacent to the EDM surface took place during subsequent solution quenching. Cracks form in the ''recast'' layer when solution-quenched U--0.75 Ti alloy undergoes EDM, and the cracks propagated during subsequent nickel plating. If the recast layer was removed prior to nickel plating, only a slight loss in strength resulted, compared to conventional machining. W--3.5 Ni--1.5 Fe alloy also sustained some surface damage during EDM and also experienced a small loss in strength compared to conventionally machined material. 12 figures, 4 tables

  3. High-rate deposition of high-quality Sn-doped In2O3 films by reactive magnetron sputtering using alloy targets

    International Nuclear Information System (INIS)

    Oka, Nobuto; Kawase, Yukari; Shigesato, Yuzo

    2012-01-01

    Sn-doped In 2 O 3 (ITO) films were deposited on heated (200 °C) fused silica glass substrates by reactive DC sputtering with mid-frequency pulsing (50 kHz) and a plasma control unit combined with a feedback system of the optical emission intensity for the atomic O* line at 777 nm. A planar In–Sn alloy target was connected to the switching unit, which was operated in the unipolar pulse mode. The power density on the target was maintained at 4.4 W cm −2 during deposition. The feedback system precisely controlled the oxidation of the target surface in “the transition region.” The ITO film with lowest resistivity (3.1 × 10 −4 Ω cm) was obtained with a deposition rate of 310 nm min −1 and transmittance in the visible region of approximately 80%. The deposition rate was about 6 times higher than that of ITO films deposited by conventional sputtering using an oxide target.

  4. Rieske iron-sulfur protein of the cytochrome bc(1) complex: a potential target for fungicide discovery.

    Science.gov (United States)

    Yang, Wen-Chao; Li, Hui; Wang, Fu; Zhu, Xiao-Lei; Yang, Guang-Fu

    2012-07-23

    The cytochrome bc(1) complex (complex III, cyt bc(1)) is an essential component of cellular respiration. Cyt bc(1) has three core subunits that are required for its catalytic activity: cytochrome b, cytochrome c(1), and the Rieske iron-sulfur protein (ISP). Although most fungicides inhibit this enzyme by binding to the cytochrome b subunit, resistance to these fungicides has developed rapidly due to their widespread application. Resistance is mainly associated with mutations in cytochrome b, the only subunit encoded by mitochondrial DNA. Recently, the flexibility and motion of the ISP and its essential role in electron transfer have received intense attention; this leads us to propose a new classification of cyt bc(1) inhibitors (three types of Q(o) inhibitors) that mobilize, restrict, or fix the rotation of the ISP. Importantly, the strengths of the ISP-inhibitor interactions correlate with inhibitor activity and the development of resistance to Q(o) inhibitors, thereby offering clues for designing novel cyt bc(1) inhibitors with high potency and a low risk of resistance. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Experimental tests of LiSn alloys as potential liquid metal for the divertor target in a fusion reactor

    Directory of Open Access Journals (Sweden)

    F.L. Tabarés

    2017-08-01

    Full Text Available The first experiments of exposure of a LiSn alloy (Li/Sn atomic ratio= 20/80 to a hydrogen plasma in TJ-II are here presented. Solid and liquid samples have been inserted at the edge and evidence of sample melting of a solid sample during plasma exposure has been observed. A negligible perturbation of the plasma has been recorded, even when stellarator plasmas are particularly sensitive to high Z elements due to the tendency to central impurity accumulation. Melting of the sample by the plasma thermal load did not lead to any deleterious effect on the plasma performance. Strong lithium emission was detected at the LiSn sample but no sign of Sn contamination and low values of Zeff and radiated power were deduced. Hydrogen recycling was studied at two different temperatures and no change was detected in the range of 300–750K. The retention of H2 by the alloy was addressed in separate experiments at the laboratory. Values in the order of 0.01% H/(Sn+Li were deduced in agreement with in situ TDS analysis of the plasma exposed samples and previous reports.

  6. Synthesis and Properties of Metallic Technetium and Technetium-Zirconium Alloys as Transmutation Target and Radioactive waste storage form in the UREX+1 Process

    Energy Technology Data Exchange (ETDEWEB)

    Hartmann, Thomas [Idaho State University/Idaho National Laboratory, 1776 Science Center Drive, Idaho Falls, ID 83402 (United States)]|[Harry Reid Center, University Nevada - Las Vegas, 4505 Maryland Parkway, Las Vegas, NV (United States); Poineau, Frederic; Czerwinski, Kenneth R. [Harry Reid Center, University Nevada - Las Vegas, 4505 Maryland Parkway, Las Vegas, NV (United States)

    2008-07-01

    In the application of UREX+1 process, technetium will be separated together with uranium and iodine within the first process step. After the separation of uranium, technetium and iodine must be immobilized by their incorporation in a suitable waste storage-form. Based on recent activities within the AFCI community, a potential candidate as waste storage form to immobilize technetium is to alloy the metal with excess zirconium. Alloys in the binary Tc-Zr system may act as potential transmutation targets in order to transmute Tc-99 into Ru-100. We are presenting first results in the synthesis of metallic technetium, and the synthesis of equilibrium phases in the binary Tc-Zr system at 1400 deg. C after arc-melting and isothermal annealing under inert conditions. Samples were analyzed using X-ray powder diffraction, Rietveld analysis, scanning electron microscopy, and electron probe micro-analysis, which allows us to construct the binary Tc-Zr phase diagram for the isothermal section at 1400 deg. C. (authors)

  7. Targeting, Monitoring and Effect of Oral Iron Therapy on Haemoglobin Levels in Older Patients Discharged to Primary Care from Inpatient Rehabilitation: A Cohort Study Using Routinely Collected Data.

    Science.gov (United States)

    Thomson, Zach; Hands, Katherine J; Witham, Miles D

    2016-08-01

    Oral iron is commonly prescribed to older patients with suspected or confirmed iron-deficiency anaemia; however, few studies have examined the effectiveness of oral iron therapy in the real world in this population. We therefore determined the prevalence of iron deficiency in older people prescribed oral iron, examined the response mounted to therapy and ascertained predictors of response to oral iron. We analysed a routinely collected, linked dataset from older patients who had undergone inpatient rehabilitation between 1999 and 2011. An initial analysis examined patients within this cohort who were prescribed iron after rehabilitation and derived three groups based upon their ferritin and transferrin indices: probably, possibly and not iron deficient. A second analysis compared pre- and post-treatment haemoglobin to determine the degree of response to iron therapy across each category of deficiency. Finally, patient demographics, linked biochemistry data and comorbid disease based on International Classification of Disease (ICD-10) codes from previous hospital admissions were used in regression modelling to evaluate factors affecting response to therapy. A total of 490 patients were prescribed oral iron within 90 days of rehabilitation discharge. Of these, 413 (84 %) had iron indices performed; 94 (23 %) were possibly deficient, 224 (54 %) were probably deficient, and 95 (23 %) were not deficient. Of the 490 patients, 360 had both pre- and post-treatment haemoglobin data and iron indices; probably deficient patients mounted a slightly greater response to oral iron (17 vs. 12 g/L for not deficient; p < 0.05). Only pre-treatment haemoglobin, mean cell volume and lower gastrointestinal pathology were significant predictors of a response to oral iron therapy. Notably, acid-suppressant use was not a predictor of response. We conclude that many older patients are exposed to oral iron without good evidence of either iron deficiency or a significant response to

  8. The effect of adding aluminum and iron to Tb–Dy–Ho–Co multicomponent alloys on their structure and magnetic and magnetocaloric properties

    Czech Academy of Sciences Publication Activity Database

    Politova, G.A.; Burkhanov, G.S.; Tereshina, I. S.; Kaminskaya, T.; Chzhan, V.B.; Tereshina, Evgeniya

    2017-01-01

    Roč. 62, č. 4 (2017), s. 577-582 ISSN 1063-7842 Institutional support: RVO:68378271 Keywords : multicomponent alloys * Laves phase compounds * magnetocaloric effect Subject RIV: BM - Solid Matter Physics ; Magnetism OBOR OECD: Condensed matter physics (including formerly solid state physics, supercond.) Impact factor: 0.632, year: 2016

  9. Anti-HER2 antibody and ScFvEGFR-conjugated antifouling magnetic iron oxide nanoparticles for targeting and magnetic resonance imaging of breast cancer

    Directory of Open Access Journals (Sweden)

    Chen H

    2013-10-01

    Full Text Available Hongwei Chen,1,* Liya Wang,1,2,* Qiqi Yu,1,2 Weiping Qian,3 Diana Tiwari,1 Hong Yi,4 Andrew Y Wang,5 Jing Huang,1,2 Lily Yang,3 Hui Mao1,2 1Department of Radiology and Imaging Sciences, 2Center for Systems Imaging, 3Department of Surgery, Emory University School of Medicine, 4Robert Apkarian Electron Microscopy Core, Emory University, Atlanta, GA, 5Ocean NanoTech LLC, Springdale, AK, USA *These authors contributed equally to this work Abstract: Antifouling magnetic iron oxide nanoparticles (IONPs coated with block copolymer poly(ethylene oxide-block-poly(γ-methacryloxypropyltrimethoxysilane (PEO-b-PγMPS were investigated for improving cell targeting by reducing nonspecific uptake. Conjugation of a HER2 antibody, Herceptin®, or a single chain fragment (ScFv of antibody against epidermal growth factor receptor (ScFvEGFR to PEO-b-PγMPS-coated IONPs resulted in HER2-targeted or EGFR-targeted IONPs (anti-HER2-IONPs or ScFvEGFR-IONPs. The anti-HER2-IONPs bound specifically to SK-BR-3, a HER2-overexpressing breast cancer cell line, but not to MDA-MB-231, a HER2-underexpressing cell line. On the other hand, the ScFvEGFR-IONPs showed strong reactivity with MDA-MB-231, an EGFR-positive human breast cancer cell line, but not with MDA-MB-453, an EGFR-negative human breast cancer cell line. Transmission electron microscopy revealed internalization of the receptor-targeted nanoparticles by the targeted cancer cells. In addition, both antibody-conjugated and non-antibody-conjugated IONPs showed reduced nonspecific uptake by RAW264.7 mouse macrophages in vitro. The developed IONPs showed a long blood circulation time (serum half-life 11.6 hours in mice and low accumulation in both the liver and spleen. At 24 hours after systemic administration of ScFvEGFR-IONPs into mice bearing EGFR-positive breast cancer 4T1 mouse mammary tumors, magnetic resonance imaging revealed signal reduction in the tumor as a result of the accumulation of the targeted IONPs

  10. Polyethyleneimine-modified iron oxide nanoparticles for brain tumor drug delivery using magnetic targeting and intra-carotid administration

    OpenAIRE

    Chertok, Beata; David, Allan E.; Yang, Victor C.

    2010-01-01

    This study aimed to examine the applicability of polyethyleneimine (PEI)-modified magnetic nanoparticles (GPEI) as a potential vascular drug/gene carrier to brain tumors. In vitro, GPEI exhibited high cell association and low cell toxicity – properties which are highly desirable for intracellular drug/gene delivery. In addition, a high saturation magnetization of 93 emu/g Fe was expected to facilitate magnetic targeting of GPEI to brain tumor lesions. However, following intravenous administra...

  11. Intestinal Iron Homeostasis and Colon Tumorigenesis

    Directory of Open Access Journals (Sweden)

    Yatrik M. Shah

    2013-06-01

    Full Text Available Colorectal cancer (CRC is the third most common cause of cancer-related deaths in industrialized countries. Understanding the mechanisms of growth and progression of CRC is essential to improve treatment. Iron is an essential nutrient for cell growth. Iron overload caused by hereditary mutations or excess dietary iron uptake has been identified as a risk factor for CRC. Intestinal iron is tightly controlled by iron transporters that are responsible for iron uptake, distribution, and export. Dysregulation of intestinal iron transporters are observed in CRC and lead to iron accumulation in tumors. Intratumoral iron results in oxidative stress, lipid peroxidation, protein modification and DNA damage with consequent promotion of oncogene activation. In addition, excess iron in intestinal tumors may lead to increase in tumor-elicited inflammation and tumor growth. Limiting intratumoral iron through specifically chelating excess intestinal iron or modulating activities of iron transporter may be an attractive therapeutic target for CRC.

  12. Experimental study of the features of the running part liquid metal target on lead-bismuth alloy

    International Nuclear Information System (INIS)

    Beznosov, A.V.; Meluzov, A.G.; Novozhilova, O.O.; Efanov, A.D.

    2007-01-01

    The results of experimental investigations of the through part of a full-scale liquid metal target of an accelerator-control system, where the working cavity of the target communicates directly with the particle accelerator cavity, are presented. Two design variants were investigated - with vertical and horizontal orientation of the target axis in space and spinning of the flow in front of the nozzle adapter located in front of the entrance of the eutectic into the working cavity of the target. The profiles obtained for the free coolant surface with liquid metal flowing through vertically and horizontally positioned targets are presented. It is confirmed that when the pressure of the free surface of the liquid metal corresponds to the pressure in the accelerator cavity it is possible that liquid metal will not flow into the cavity simulating the connecting piece for inflow of accelerated particles with the piece oriented vertically or horizontally [ru

  13. Poly (dopamine) coated superparamagnetic iron oxide nanocluster for noninvasive labeling, tracking, and targeted delivery of adipose tissue-derived stem cells

    Science.gov (United States)

    Liao, Naishun; Wu, Ming; Pan, Fan; Lin, Jiumao; Li, Zuanfang; Zhang, Da; Wang, Yingchao; Zheng, Youshi; Peng, Jun; Liu, Xiaolong; Liu, Jingfeng

    2016-01-01

    Tracking and monitoring of cells in vivo after transplantation can provide crucial information for stem cell therapy. Magnetic resonance imaging (MRI) combined with contrast agents is believed to be an effective and non-invasive technique for cell tracking in living bodies. However, commercial superparamagnetic iron oxide nanoparticles (SPIONs) applied to label cells suffer from shortages such as potential toxicity, low labeling efficiency, and low contrast enhancing. Herein, the adipose tissue-derived stem cells (ADSCs) were efficiently labeled with SPIONs coated with poly (dopamine) (SPIONs cluster@PDA), without affecting their viability, proliferation, apoptosis, surface marker expression, as well as their self-renew ability and multi-differentiation potential. The labeled cells transplanted into the mice through tail intravenous injection exhibited a negative enhancement of the MRI signal in the damaged liver-induced by carbon tetrachloride, and subsequently these homed ADSCs with SPIONs cluster@PDA labeling exhibited excellent repair effects to the damaged liver. Moreover, the enhanced target-homing to tissue of interest and repair effects of SPIONs cluster@PDA-labeled ADSCs could be achieved by use of external magnetic field in the excisional skin wound mice model. Therefore, we provide a facile, safe, noninvasive and sensitive method for external magnetic field targeted delivery and MRI based tracking of transplanted cells in vivo.

  14. Poly (dopamine) coated superparamagnetic iron oxide nanocluster for noninvasive labeling, tracking, and targeted delivery of adipose tissue-derived stem cells.

    Science.gov (United States)

    Liao, Naishun; Wu, Ming; Pan, Fan; Lin, Jiumao; Li, Zuanfang; Zhang, Da; Wang, Yingchao; Zheng, Youshi; Peng, Jun; Liu, Xiaolong; Liu, Jingfeng

    2016-01-05

    Tracking and monitoring of cells in vivo after transplantation can provide crucial information for stem cell therapy. Magnetic resonance imaging (MRI) combined with contrast agents is believed to be an effective and non-invasive technique for cell tracking in living bodies. However, commercial superparamagnetic iron oxide nanoparticles (SPIONs) applied to label cells suffer from shortages such as potential toxicity, low labeling efficiency, and low contrast enhancing. Herein, the adipose tissue-derived stem cells (ADSCs) were efficiently labeled with SPIONs coated with poly (dopamine) (SPIONs cluster@PDA), without affecting their viability, proliferation, apoptosis, surface marker expression, as well as their self-renew ability and multi-differentiation potential. The labeled cells transplanted into the mice through tail intravenous injection exhibited a negative enhancement of the MRI signal in the damaged liver-induced by carbon tetrachloride, and subsequently these homed ADSCs with SPIONs cluster@PDA labeling exhibited excellent repair effects to the damaged liver. Moreover, the enhanced target-homing to tissue of interest and repair effects of SPIONs cluster@PDA-labeled ADSCs could be achieved by use of external magnetic field in the excisional skin wound mice model. Therefore, we provide a facile, safe, noninvasive and sensitive method for external magnetic field targeted delivery and MRI based tracking of transplanted cells in vivo.

  15. Iron deficiency anemia referral to the hematologist. Real-world data from Mexico: the need for targeted teaching in primary care.

    Science.gov (United States)

    López-García, Yadith Karina; Colunga-Pedraza, Perla Rocío; Tarín-Arzaga, Luz; López Garza, Mariana Itzel; Jaime-Pérez, José Carlos; Gómez-Almaguer, David

    2018-04-11

    To determine the referral patterns and etiology of iron deficiency anemia (IDA) at an academic hematology center in northeast Mexico. We included all consecutive outpatients older than 16 years, non-pregnant, with IDA diagnosed in the Hematology Service of the Dr. José E. González University Hospital between January 2012 and May 2017. Appropriate data were collected retrospectively from the electronic medical record. Data regarding first medical contact (primary care physician or hematologist) were compared. One hundred fifty-three patients were included in this study. The median age was 43 years (interquartile range, 35-51) and 85.6% were female; 128 (83.7%) patients were seen by a primary care physician before our evaluation. Abnormal uterine bleeding (AUB) was the cause of IDA in 76 patients (49.6%), gastrointestinal bleeding (GIB) in 31 (20.2%), H. pylori infection in 12 (7.8%), urinary tract bleeding in three (1.9%) and malabsorption-syndrome in two (1.3%). The etiology remained unknown in 29 (18.9%). The p value was <0.05 between groups according to the first medical contact, including frequency of at least one sign or symptom of IDA, previous use of iron supplementation and blood transfusion, comorbidities, complete blood count at diagnosis, and resolution rates of anemia. The majority of our IDA patients were referred by another physician. Nearly half of the patients with IDA had AUB. IDA remains a diagnostic challenge for first contact physicians requiring a targeted educational intervention to improve IDA awareness and diagnostic skills.

  16. Study of the quenching and subsequent return to room temperature of uranium-chromium, uranium-iron, and uranium-molybdenum alloys containing only small amounts of the alloying element; Etude de la trempe et du revenu a la temperature ordinaire d'alliages uranium-chrome, uranium-fer et uranium-molybdene, a faible teneur en element d'alliage

    Energy Technology Data Exchange (ETDEWEB)

    Delaplace, J [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1960-09-15

    By means of an apparatus which makes possible thermal pre-treatments in vacuo, quenching carried out in a high purity argon atmosphere, and simultaneous recording of time temperature cooling and thermal contraction curves, the author has examined the transformations which occur in uranium-chromium, uranium-iron and uranium-molybdenum alloys during their quenching and subsequent return to room temperature. For uranium-chromium and uranium-iron alloys, the temperature at which the {gamma} {yields} {beta} transformation starts varies very little with the rate of cooling. For uranium-molybdenum alloys containing 2,8 atom per cent of Mo, this temperature is lowered by 120 deg. C for a cooling rate of 500 deg. C/mn. The temperature at which the {beta} {yields} {alpha} transformation starts is lowered by 170 deg. C for a cooling rate of 500 deg. C/mn in the case of uranium-chromium alloy containing 0,37 atom per cent of Cr. The temperature is little affected in the case of uranium-iron alloys. The addition of chromium or iron makes it possible to conserve the form {beta} at ordinary temperatures after quenching from the {beta} and {gamma} regions. The {beta} phase is particularly unstable and changes into needles of the {alpha} form even at room temperatures according to an autocatalytic transformation law similar to the austenitic-martensitic transformation law in the case of iron. The {beta} phase obtained by quenching from the {beta} phase region is more stable than that obtained by quenching from the {gamma} region. Chromium is a more effective stabiliser of the {beta} phase than is iron. Unfortunately it causes serious surface cracking. The {beta} {yields} {alpha} transformation in uranium-chromium alloys has been followed at room temperature by means of micro-cinematography. The author has not observed the direct {gamma} {yields} {alpha} transformation in uranium-molybdenum alloys containing 2,8 per cent of molybdenum even for cooling rates of up to 2000 deg. C

  17. Study of the quenching and subsequent return to room temperature of uranium-chromium, uranium-iron, and uranium-molybdenum alloys containing only small amounts of the alloying element; Etude de la trempe et du revenu a la temperature ordinaire d'alliages uranium-chrome, uranium-fer et uranium-molybdene, a faible teneur en element d'alliage

    Energy Technology Data Exchange (ETDEWEB)

    Delaplace, J. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1960-09-15

    By means of an apparatus which makes possible thermal pre-treatments in vacuo, quenching carried out in a high purity argon atmosphere, and simultaneous recording of time temperature cooling and thermal contraction curves, the author has examined the transformations which occur in uranium-chromium, uranium-iron and uranium-molybdenum alloys during their quenching and subsequent return to room temperature. For uranium-chromium and uranium-iron alloys, the temperature at which the {gamma} {yields} {beta} transformation starts varies very little with the rate of cooling. For uranium-molybdenum alloys containing 2,8 atom per cent of Mo, this temperature is lowered by 120 deg. C for a cooling rate of 500 deg. C/mn. The temperature at which the {beta} {yields} {alpha} transformation starts is lowered by 170 deg. C for a cooling rate of 500 deg. C/mn in the case of uranium-chromium alloy containing 0,37 atom per cent of Cr. The temperature is little affected in the case of uranium-iron alloys. The addition of chromium or iron makes it possible to conserve the form {beta} at ordinary temperatures after quenching from the {beta} and {gamma} regions. The {beta} phase is particularly unstable and changes into needles of the {alpha} form even at room temperatures according to an autocatalytic transformation law similar to the austenitic-martensitic transformation law in the case of iron. The {beta} phase obtained by quenching from the {beta} phase region is more stable than that obtained by quenching from the {gamma} region. Chromium is a more effective stabiliser of the {beta} phase than is iron. Unfortunately it causes serious surface cracking. The {beta} {yields} {alpha} transformation in uranium-chromium alloys has been followed at room temperature by means of micro-cinematography. The author has not observed the direct {gamma} {yields} {alpha} transformation in uranium-molybdenum alloys containing 2,8 per cent of molybdenum even for cooling rates of up to 2000 deg. C

  18. Chemical degradation of drinking water disinfection byproducts by millimeter-sized particles of iron-silicon and magnesium-aluminum alloys.

    Science.gov (United States)

    Li, Tianyu; Chen, Yongmei; Wan, Pingyu; Fan, Maohong; Yang, X Jin

    2010-03-03

    The candidature of Fe-Si and Mg-Al alloys at millimeter-scale particle sizes for chemical degradation of disinfection byproducts (DBPs) in drinking water systems was substantiated by their enhanced corrosion resistance and catalytic effect on the degradation. The Mg-Al particles supplied electrons for reductive degradation, and the Fe-Si particles acted as a catalyst and provided the sites for the reaction. The alloy particles are obtained by mechanical milling and stable under ambient conditions. The proposed method for chemical degradation of DBPs possesses the advantages of relatively constant degradation performance, long-term durability, no secondary contamination, and ease of handling, storage and maintenance in comparison with nanoparticle systems.

  19. Optimization of the composition and structure of heat-resistant casting aluminium alloys with additions of cerium, iron, nickel and zirconium

    International Nuclear Information System (INIS)

    Belov, N.A.; Lavrishchev, Yu.V.

    2000-01-01

    A study is made of the effect of composition and structure on mechanical properties of cast alloys of the Al-Ce-Ni-Fe-Zr system in which binary and ternary eutectics with participation of low alloyed aluminium solid solution and Al 4 Ce, Al 3 Ni and Al 9 FeNi phases are crystallized. It is found that microhardness of eutectics is heavily dependent on the volume fraction of aluminides and their dispersivity. It was shown that essential hardening of aluminium matrix can be achieved at the cost of zirconium additive in quantity of 0.6 % when using two-stage manufacturing operation. Experimental compositions of Al-10 % Ce-5% Ni-0.6 % Zr and Al-1.5 % Fe-1.5 % Ni-0.6 % Zr on the basis of ternary and binary eutectics respectively as billets essentially exceed industrial heat-resistant cast aluminium alloys AK12MMgN and AM5 as to a set of room and high-temperature mechanical properties and hot brittleness index [ru

  20. Polyethyleneimine-modified iron oxide nanoparticles for brain tumor drug delivery using magnetic targeting and intra-carotid administration.

    Science.gov (United States)

    Chertok, Beata; David, Allan E; Yang, Victor C

    2010-08-01

    This study aimed to examine the applicability of polyethyleneimine (PEI)-modified magnetic nanoparticles (GPEI) as a potential vascular drug/gene carrier to brain tumors. In vitro, GPEI exhibited high cell association and low cell toxicity--properties which are highly desirable for intracellular drug/gene delivery. In addition, a high saturation magnetization of 93 emu/g Fe was expected to facilitate magnetic targeting of GPEI to brain tumor lesions. However, following intravenous administration, GPEI could not be magnetically accumulated in tumors of rats harboring orthotopic 9L-gliosarcomas due to its poor pharmacokinetic properties, reflected by a negligibly low plasma AUC of 12 +/- 3 microg Fe/ml min. To improve "passive" GPEI presentation to brain tumor vasculature for subsequent "active" magnetic capture, we examined the intra-carotid route as an alternative for nanoparticle administration. Intra-carotid administration in conjunction with magnetic targeting resulted in 30-fold (p=0.002) increase in tumor entrapment of GPEI compared to that seen with intravenous administration. In addition, magnetic accumulation of cationic GPEI (zeta-potential = + 37.2 mV) in tumor lesions was 5.2-fold higher (p=0.004) than that achieved with slightly anionic G100 (zeta-potential= -12 mV) following intra-carotid administration, while no significant accumulation difference was detected between the two types of nanoparticles in the contra-lateral brain (p=0.187). These promising results warrant further investigation of GPEI as a potential cell-permeable, magnetically-responsive platform for brain tumor delivery of drugs and genes. 2010 Elsevier Ltd. All rights reserved.

  1. Hydrogen and deuterium trapping in iron

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, H H; Lin, R W

    1981-02-01

    The research described is directed at present almost exclusively to hydrogen transport, including both chemical and physical trapping, in iron and iron-base alloys. Some attention is directed to isotope effects. Efforts are made to clarify and understand hydrogen-related phenomena which are believed to be of direct importance to practical performance.

  2. Phosphorus in antique iron music wire.

    Science.gov (United States)

    Goodway, M

    1987-05-22

    Harpsichords and other wire-strung musical instruments were made with longer strings about the beginning of the 17th century. This change required stronger music wire. Although these changes coincided with the introduction of the first mass-produced steel (iron alloyed with carbon), carbon was not found in samples of antique iron harpsichord wire. The wire contained an amount of phosphorus sufficient to have impeded its conversion to steel, and may have been drawn from iron rejected for this purpose. The method used to select pig iron for wire drawing ensured the highest possible phosphorus content at a time when its presence in iron was unsuspected. Phosphorus as an alloying element has had the reputation for making steel brittle when worked cold. Nevertheless, in replicating the antique wire, it was found that lowcarbon iron that contained 0.16 percent phosphorus was easily drawn to appropriate gauges and strengths for restringing antique harpsichords.

  3. In vivo tumor targeting and imaging with anti-vascular endothelial growth factor antibody-conjugated dextran-coated iron oxide nanoparticles

    Directory of Open Access Journals (Sweden)

    Hsieh WJ

    2012-06-01

    Full Text Available Wan-Ju Hsieh,1 Chan-Jung Liang,1 Jen-Jie Chieh,4 Shu-Huei Wang,1 I-Rue Lai,1 Jyh-Horng Chen,2 Fu-Hsiung Chang,3 Wei-Kung Tseng,4–6 Shieh-Yueh Yang,4 Chau-Chung Wu,7 Yuh-Lien Chen11Institute of Anatomy and Cell Biology, College of Medicine, 2Department of Electrical Engineering, 3Institute of Biochemistry and Molecular Biology, National Taiwan University, Taipei, Taiwan; 4Institute of Electro-Optical Science and Technology, National Taiwan Normal University, Taipei, Taiwan; 5Division of Cardiology, Department of Internal Medicine, E-Da Hospital, Taipei, Taiwan; 6Department of Medical Imaging and Radiological Sciences, I-Shou University, Taipei, Taiwan; 7Department of Internal Medicine and Primary Care Medicine, National Taiwan University Hospital, Taipei, TaiwanBackground: Active targeting by specific antibodies combined with nanoparticles is a promising technology for cancer imaging and detection by magnetic resonance imaging (MRI. The aim of the present study is to investigate whether the systemic delivery of antivascular endothelial growth factor antibodies conjugating to the surface of functionalized supermagnetic iron oxide nanoparticles (anti-VEGF-NPs led to target-specific accumulation in the tumor.Methods: The VEGF expression in human colon cancer and in Balb/c mice bearing colon cancers was examined by immunohistochemistry. The distribution of these anti-VEGF-NPs particles or NPs particles were evaluated by MRI at days 1, 2, or 9 after the injection into the jugular vein of Balb/c mice bearing colon cancers. Tumor and normal tissues (liver, spleen, lung, and kidney were collected and were examined by Prussian blue staining to determine the presence and distribution of NPs in the tissue sections.Results: VEGF is highly expressed in human and mouse colon cancer tissues. MRI showed significant changes in the T*2 signal and T2 relaxation in the anti-VEGF-NP- injected-mice, but not in mice injected with NP alone. Examination of paraffin

  4. Measurements of activation reaction rates in transverse shielding concrete exposed to the secondary particle field produced by intermediate energy heavy ions on an iron target

    International Nuclear Information System (INIS)

    Ogawa, T.; Morev, M.N.; Iimoto, T.; Kosako, T.

    2012-01-01

    Reaction rate distributions were measured inside a 60-cm thick concrete pile placed at the lateral position of a thick (stopping length) iron target that was bombarded with heavy ions, 400 MeV/u C and 800 MeV/u Si. Foils of aluminum and gold, as well as gold, tungsten and manganese covered with cadmium were inserted at various locations in the concrete pile to serve as activation detectors. Features of reaction rate distribution, such as the shape of the reaction rate profile, contribution of the neutrons from intra-nuclear cascade and that from evaporation to the activation reactions are determined by the analysis of measured reaction rates. The measured reaction rates were compared with those calculated with radiation transport simulation codes, FLUKA and PHITS, to verify their capability to predict induced activity. The simulated reaction rates agree with the experimental results within a factor of three in general. However, systematic discrepancies between simulated reaction rates and measured reaction rates attributed to the neutron source terms are observed.

  5. Saturation and negative temperature coefficient of electrical resistivity in liquid iron-sulfur alloys at high densities from first-principles calculations

    Science.gov (United States)

    Wagle, Fabian; Steinle-Neumann, Gerd; de Koker, Nico

    2018-03-01

    We report results on electronic transport properties of liquid Fe-S alloys at conditions of planetary cores, computed using first-principle techniques in the Kubo-Greenwood formalism. We describe a combined effect of resistivity saturation due to temperature, compression, and chemistry by comparing the electron mean free path from the Drude response of optical conductivity to the mean interatomic distance. At high compression and high sulfur concentration the Ioffe-Regel condition is satisfied, and the temperature coefficient of resistivity changes sign from positive to negative. We show that this happens due to a decrease in the d density of states at the Fermi level in response to thermal broadening.

  6. Irradiation hardening of Fe–9Cr-based alloys and ODS Eurofer: Effect of helium implantation and iron-ion irradiation at 300 °C including sequence effects

    Energy Technology Data Exchange (ETDEWEB)

    Heintze, C. [Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstraße 400, 01328 Dresden (Germany); Bergner, F., E-mail: f.bergner@hzdr.de [Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstraße 400, 01328 Dresden (Germany); Hernández-Mayoral, M. [CIEMAT, Avenida Complutense 22, 28040 Madrid (Spain); Kögler, R.; Müller, G.; Ulbricht, A. [Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstraße 400, 01328 Dresden (Germany)

    2016-03-15

    Single-beam, dual-beam and sequential iron- and/or helium-ion irradiations are widely accepted to emulate more application-relevant but hardly accessible irradiation conditions of generation-IV fission and fusion candidate materials for certain purposes such as material pre-selection, identification of basic mechanisms or model calibration. However, systematic investigations of sequence effects capable to critically question individual approaches are largely missing. In the present study, sequence effects of iron-ion irradiations at 300 °C up to 5 dpa and helium implantations up to 100 appm He are investigated by means of post-irradiation nanoindentation of an Fe9%Cr model alloy, ferritic/martensitic 9%Cr steels T91 and Eurofer97 and oxide dispersion strengthened (ODS) Eurofer. Different types of sequence effects, both synergistic and antagonistic, are identified and tentative interpretations are suggested. It is found that different accelerated irradiation approaches have a great impact on the mechanical hardening. This stresses the importance of experimental design in attempts to emulate in-reactor conditions. - Highlights: • The single-beam He-ion implantations do not give rise to significant hardening. • The single-beam Fe-ion irradiations give rise to significant hardening, ΔH{sub Fe}. • Hardening due to sequential He-/Fe-ion irradiation is smaller than ΔH{sub Fe}. • Hardening due to simultaneous He-/Fe-ion irradiation is larger than ΔH{sub Fe}. • The He–Fe synergism for ODS-Eurofer is less pronounced than for Eurofer97.

  7. Volatilization from PCA steel alloy

    Energy Technology Data Exchange (ETDEWEB)

    Hagrman, D.L.; Smolik, G.R.; McCarthy, K.A.; Petti, D.A.

    1996-08-01

    The mobilizations of key components from Primary Candidate Alloy (PCA) steel alloy have been measured with laboratory-scale experiments. The experiments indicate most of the mobilization from PCA steel is due to oxide formation and spalling but that the spalled particles are large enough to settle rapidly. Based on the experiments, models for the volatization of iron, manganese, and cobalt from PCA steel in steam and molybdenum from PCA steel in air have been derived.

  8. The investigation of the microstructure and mechanical properties of ordered alominide-iron (boron) nanostructures produced by mechanical alloying and sintering

    Science.gov (United States)

    Izadi, S.; Akbari, Gh.; Janghorban, K.; Ghaffari, M.

    In this study, mechanical alloying (MA) of Fe-50Al, Fe-49.5Al-1B, and Fe-47.5Al-5B (at.%) alloy powders and mechanical properties of sintered products of the as-milled powders were investigated. X-ray diffraction (XRD) results showed the addition of B caused more crystallite refinement compared to the B-free powders. To consider the sintering and ordering behaviors of the parts produced from cold compaction of the powders milled for 80 h, sintering was conducted at various temperatures. It was found that the sintering temperature has no meaningful effect on the long-range order parameter. The transformation of the disordered solid solution developed by MA to ordered Fe-Al- (B) intermetallics was a consequence of sintering. Also, the nano-scale structure of the samples was retained even after sintering. The microhardness of pore-free zones of the nanostructured specimens decreased by increasing the sintering temperature. Moreover, the sintering temperature has no effect on the compressive yield stress. However, the fracture strain increased by increasing the sintering temperature. The samples containing 1 at.% B showed more strain to fracture compared with the B-free and 5 at.% B samples.

  9. Junta de soldadura disímil de la aleación hk – 40 y del hierro fundido 24//Dissimilar welding joints of the alloy hk - 40 and of the cast iron 24

    Directory of Open Access Journals (Sweden)

    Tomás Fernández‐Columbié

    2014-05-01

    Full Text Available El objetivo del trabajo es establecer el comportamiento microestructural de una unión soldada disímil en una aleación HK 40 y el hierro fundido 24, la cual se realiza en equipo que prestan servicios en la industria del níquel y que por las características de la unión, surgen en el mismo problema de agrietamiento. Se realizó una caracterización química de ambas aleaciones, luego por el proceso demecanizado se prepararon un total de nueve muestras, las que fueron soldada por proceso manual por arco eléctrico, los electrodos revestidos empleados fueron el E 312–16, el UTP 65 y el Castell Xiron 244, demostrándose en el análisis microestructural y en el diagrama de Schaeffler, que la disposición de la unión con el electrodo E 312–16 provoca la aparición de estructura interdendritica con origen a la fundición blanca, siendo más favorable la unión con el electrodo UTP 65. Se le realizó el análisis de microdureza en cada unión.Palabras claves: disímil, aleación, agrietamiento, soldadura, electrodos._____________________________________________________________________________AbstractIt is paper have the objective to establish the behaviour microstructure of an union welded dissimilar in an alloy HK 40 and the cast iron 24, which is carried out in team that you lend services in the industry of the nickel and that for the characteristics of the union, they arise in the same cracking problem. He was carried out a chemical characterization of both alloys, then for the process ofautomated got ready a total of nine samples, those that were welding for process shield for electric arch (SMAW, the electrodes lined employees were the E 312 - 16, the UTP 65 and the Castell Xiron 244, being demonstrated in the analysis microstructure and in the diagram of Schaeffler that the disposition of the union with the electrode E 312 - 16 cause the appearance of structure inter dendritewith origin to the white foundry, being more available the union

  10. Low temperature nickel titanium iron shape memory alloys: Actuator engineering and investigation of deformation mechanisms using in situ neutron diffraction at Los Alamos National Laboratory

    Science.gov (United States)

    Krishnan, Vinu B.

    Shape memory alloys are incorporated as actuator elements due to their inherent ability to sense a change in temperature and actuate against external loads by undergoing a shape change as a result of a temperature-induced phase transformation. The cubic so-called austenite to the trigonal so-called R-phase transformation in NiTiFe shape memory alloys offers a practical temperature range for actuator operation at low temperatures, as it exhibits a narrow temperature-hysteresis with a desirable fatigue response. Overall, this work is an investigation of selected science and engineering aspects of low temperature NiTiFe shape memory alloys. The scientific study was performed using in situ neutron diffraction measurements at the newly developed low temperature loading capability on the Spectrometer for Materials Research at Temperature and Stress (SMARTS) at Los Alamos National Laboratory and encompasses three aspects of the behavior of Ni46.8Ti50Fe3.2 at 92 K (the lowest steady state temperature attainable with the capability). First, in order to study deformation mechanisms in the R-phase in NiTiFe, measurements were performed at a constant temperature of 92 K under external loading. Second, with the objective of examining NiTiFe in one-time, high-stroke, actuator applications (such as in safety valves), a NiTiFe sample was strained to approximately 5% (the R-phase was transformed to B19' phase in the process) at 92 K and subsequently heated to full strain recovery under a load. Third, with the objective of examining NiTiFe in cyclic, low-stroke, actuator applications (such as in cryogenic thermal switches), a NiTiFe sample was strained to 1% at 92 K and subsequently heated to full strain recovery under load. Neutron diffraction spectra were recorded at selected time and stress intervals during these experiments. The spectra were subsequently used to obtain quantitative information related to the phase-specific strain, texture and phase fraction evolution using the

  11. Electroplating technologies of alloys

    International Nuclear Information System (INIS)

    Kim, Joung Soo; Kim, Seung Ho; Jeong, Hyun Kyu; Hwnag, Sung Sik; Seo, Yong Chil; Kim, Dong Jin; Seo, Moo Hong

    2001-12-01

    In localization of electrosleeving technique, there are some problems like the following articles. Firstly, Patents published by OHT have claimed Ni-P, Ni-B alloy plating and Mo, Mn Cr, W, Co as a pinning agent. Secondly, alloy platings have many restrictions. There are some method to get alloy plating in spite of the various restrictions. If current density increase above limiting current density in one of the metals, both of the metals discharge at the same time. The addition of surface active agent(sufactant) in the plating solution is one of the methods to get alloy plating. Alloy plating using pulse current easily controls chemical composition and structure of deposit. Ni-Fe alloy plating is known to exhibit anomalous type of plating behavior in which deposition of the less noble metal is favoured. Presence of hypophohphite ion can control the iron codeposition by changing the deposition mechanism. Hypophohphite suppresses the deposition of Fe and also promotes Ni. Composite plating will be considered to improve the strength at the high temperature. Addition of particle size of 10δ400μm makes residual stress compressive in plate layer and suppress the grain growth rate at the high temperature. Addition of particle makes suface roughness high and fracture stress low at high temperature. But, selection of the kinds of particle and control of additives amount overcome the problems above

  12. The effect of the cooling rate during quenching, electron bombardment and plastic deformation on the kinetics of a solid solution disintegration in iron-copper alloys

    International Nuclear Information System (INIS)

    Fedorov, G.B.; Zhukov, V.P.; Braun, A.G.; Smirnov, E.A.

    1974-01-01

    From the electroresistivity variation at 77 0 K, the influence of nonequilibrium point defect density and of complexes and dislocations on the decay process of the iron-copper solid solution is determined. Owing to high quenching rate of thin foils, isochrones of their electroconductivity curves appear shifted by about 200 0 C to lower temperatures. For quenched and irradiated specimens at 200-250 0 C a sharp retardation of electroconductivity decline is observed due to a zone stage. The plastic deformation (15%) leads to a partial suppression of that stage. Both irradiation and deformation initiate the process of copper separation from the solid solution, the latter being the stronger, the more copper is in the solid solution

  13. Flame-photometric determination of boron in alloys with chromatographic separation

    International Nuclear Information System (INIS)

    Telegin, G.F.; Popandopulo, Yu.I.; Grazhuiene, S.S.

    1983-01-01

    A study was made on the possibility of using flame-photometric method for boron determination in iron base alloys. The method of extraction chromatography was used for boron separation from iron. It is possible to reliably determine boron in Fesub(x)Bsub(100-x) alloys only at a concentration ratio of iron to boron <=0.2. The technique for determination of boron in Fesub(x)Bsub(100-x) alloys was developed on the base of the conducted investigation

  14. Flame-photometric determination of boron in alloys with chromatographic separation

    Energy Technology Data Exchange (ETDEWEB)

    Telegin, G.F.; Popandopulo, Yu.I.; Grazhuiene, S.S. (AN SSSR, Chernogolovka. Inst. Fiziki Tverdogo Tela)

    1983-01-01

    A study was made on the possibility of using flame-photometric method for boron determination in iron base alloys. The method of extraction chromatography was used for boron separation from iron. It is possible to reliably determine boron in Fesub(x)Bsub(100-x) alloys only at a concentration ratio of iron to boron <=0.2. The technique for determination of boron in Fesub(x)Bsub(100-x) alloys was developed on the base of the conducted investigation.

  15. A Study of Protection of Copper Alloys

    International Nuclear Information System (INIS)

    Kim, E. A.; Kim, S. H.; Kim, C. R.

    1974-01-01

    Volatile treatment of high capacity boiler water with hydrazine and ammonia is studied. Ammonia comes from the decomposition of excess hydrazine injected to treat dissolved oxygen. Ammonia is also injected for the control of pH. To find an effect of such ammonia on the copper alloy, the relations between pH and iron, and ammonia and copper are studied. Since the dependence of corrosion of iron on pH differs from that of copper, a range of pH was selected experimentally to minimize the corrosion rates of both copper and iron. Corrosion rates of various copper alloys are also compared

  16. Elastic and plastic properties of iron-aluminium alloys. Special problems raised by the brittleness of alloys of high aluminium content; Proprietes elastiques et plastiques des alliages fer-aluminium. Problemes particuliers poses par la fragilite des alliages a forte teneur en aluminium

    Energy Technology Data Exchange (ETDEWEB)

    Mouturat, P. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1966-06-01

    The present study embodies the results obtained with iron-aluminium alloys whose composition runs from 0 to nearly 50 atoms per cent aluminium. Conditions of elaboration and transformation have been studied successively, as well as the Young's modulus and the flow stress; the last chapter embodies, a study of the Portevin-le-Chatelier effect in alloys of 40 atoms per cent of aluminium. I) The principal difficulty to clear up consisted in the intergranular brittleness of ordered alloys; this brittleness has been considerably reduced with appropriate conditions of elaboration and transformation. II) The studies upon the Young's modulus are in connection with iron-aluminium alloys; transformation temperatures are well shown up. The formation of covalent bonds on and after 25 atoms per cent show the highest values of the modulus. III) The analysis of variations of the flow stress according to the temperature show some connection with ordered structures, the existence of antiphase domains and the existence of sur-structure dislocations. IV) In the ordered Fe Al domain the kinetics of the Portevin-le-Chatelier effect could be explained by a mechanism of diffusion of vacancies. The role they play has been specified by the influence they exert upon the dislocations; this has led us to the inhomogeneous Rudman order; this inhomogeneous order could explain the shape of the traction curves. (author) [French] Cette etude comporte les resultats obtenus avec des alliages fer-aluminium dont la composition s'etend de 0 a pres de 50 atomes pour cent d'aluminium. Nous avons etudie successivement les conditions d'elaboration et de transformation, le module elastique et la limite elastique; un dernier chapitre est consacre a l'etude du phenomene Portevin-le-Chatelier dans les alliages a 40 atomes pour cent d'aluminium. I) La principale difficulte a resoudre residait dans la fragilite intergranulaire des alliages ordonnes; celle-ci a ete

  17. Elastic and plastic properties of iron-aluminium alloys. Special problems raised by the brittleness of alloys of high aluminium content; Proprietes elastiques et plastiques des alliages fer-aluminium. Problemes particuliers poses par la fragilite des alliages a forte teneur en aluminium

    Energy Technology Data Exchange (ETDEWEB)

    Mouturat, P [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1966-06-01

    The present study embodies the results obtained with iron-aluminium alloys whose composition runs from 0 to nearly 50 atoms per cent aluminium. Conditions of elaboration and transformation have been studied successively, as well as the Young's modulus and the flow stress; the last chapter embodies, a study of the Portevin-le-Chatelier effect in alloys of 40 atoms per cent of aluminium. I) The principal difficulty to clear up consisted in the intergranular brittleness of ordered alloys; this brittleness has been considerably reduced with appropriate conditions of elaboration and transformation. II) The studies upon the Young's modulus are in connection with iron-aluminium alloys; transformation temperatures are well shown up. The formation of covalent bonds on and after 25 atoms per cent show the highest values of the modulus. III) The analysis of variations of the flow stress according to the temperature show some connection with ordered structures, the existence of antiphase domains and the existence of sur-structure dislocations. IV) In the ordered Fe Al domain the kinetics of the Portevin-le-Chatelier effect could be explained by a mechanism of diffusion of vacancies. The role they play has been specified by the influence they exert upon the dislocations; this has led us to the inhomogeneous Rudman order; this inhomogeneous order could explain the shape of the traction curves. (author) [French] Cette etude comporte les resultats obtenus avec des alliages fer-aluminium dont la composition s'etend de 0 a pres de 50 atomes pour cent d'aluminium. Nous avons etudie successivement les conditions d'elaboration et de transformation, le module elastique et la limite elastique; un dernier chapitre est consacre a l'etude du phenomene Portevin-le-Chatelier dans les alliages a 40 atomes pour cent d'aluminium. I) La principale difficulte a resoudre residait dans la fragilite intergranulaire des alliages ordonnes; celle-ci a ete considerablement reduite par des conditions

  18. Solidification of cast iron - A study on the effect of microalloy elements on cast iron

    DEFF Research Database (Denmark)

    Moumeni, Elham

    The present thesis deals with the heat transfer and solidification of ductile and microalloyed grey cast iron. Heterogeneous nucleation of nodular graphite at inclusions in ductile iron during eutectic solidification has been investigated. A series of ductile iron samples with two different...... of the austenite, in the last region to solidify. The superfine graphite which forms in this type of irons is short (10-20µm) and stubby. The microstructure of this kind of graphite flakes in titanium alloyed cast iron is studied using electron microscopy techniques. The methods to prepare samples of cast iron...... for comprehensive transmission electron microscopy of graphite and the surrounding iron matrix have been developed and explained. Dual beam microscopes are used for sample preparation. A TEM study has been carried out on graphite flakes in grey cast iron using selected area electron diffraction (SAED). Based...

  19. Microstructure of oxide dispersion strengthened Eurofer and iron-chromium alloys investigated by means of small-angle neutron scattering and transmission electron microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Heintze, C. [Forschungszentrum Dresden-Rossendorf, P.O. Box 510119, 01314 Dresden (Germany); Bergner, F., E-mail: f.bergner@fzd.de [Forschungszentrum Dresden-Rossendorf, P.O. Box 510119, 01314 Dresden (Germany); Ulbricht, A. [Forschungszentrum Dresden-Rossendorf, P.O. Box 510119, 01314 Dresden (Germany); Hernandez-Mayoral, M. [CIEMAT, Avenida Complutense 22, 28040 Madrid (Spain); Keiderling, U. [Helmholtz-Zentrum Berlin, Hahn-Meitner Platz 1, 14109 Berlin (Germany); Lindau, R. [Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany); Weissgaerber, T. [Fraunhofer Institute IFAM-Dresden, Winterbergstr. 28, 01277 Dresden (Germany)

    2011-09-01

    Oxide dispersion strengthening of ferritic/martensitic chromium steels is a promising route for the extension of the range of operation temperatures for nuclear applications. The investigation of dedicated model alloys is an important means in order to separate individual effects contributing to the mechanical behaviour under irradiation and to improve mechanistic understanding. A powder metallurgy route based on spark plasma sintering was applied to fabricate oxide dispersion strengthened (ODS) Fe9Cr model materials. These materials along with Eurofer97 and ODS-Eurofer were investigated by means of small-angle neutron scattering (SANS) and TEM. For Fe9Cr-0.6 wt.%Y{sub 2}O{sub 3}, TEM results indicate a peak radius of the size distribution of Y{sub 2}O{sub 3} particles of 4.2 nm with radii ranging up to 15 nm, and a volume fraction of 0.7%, whereas SANS indicates a peak radius of 3.8 nm and a volume fraction of 0.6%. It was found that the non-ODS Fe9Cr and Eurofer97 are suitable reference materials for ODS-Fe9Cr and ODS-Eurofer, respectively, and that the ODS-Fe9Cr variants are suitable model materials for the separated investigation of irradiation-Y{sub 2}O{sub 3} particle interaction effects.

  20. Standard practice for determining the susceptibility of stainless steels and related Nickel-Chromium-Iron Alloys to stress-corrosion cracking in polythionic acids

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2010-01-01

    1.1 This practice covers procedures for preparing and conducting the polythionic acid test at room temperature, 22 to 25°C (72 to 77°F), to determine the relative susceptibility of stainless steels or other related materials (nickel-chromiumiron alloys) to intergranular stress corrosion cracking. 1.2 This practice can be used to evaluate stainless steels or other materials in the “as received” condition or after being subjected to high-temperature service, 482 to 815°C (900 to 1500°F), for prolonged periods of time. 1.3 This practice can be applied to wrought products, castings, and weld metal of stainless steels or other related materials to be used in environments containing sulfur or sulfides. Other materials capable of being sensitized can also be tested in accordance with this test. 1.4 This practice may be used with a variety of stress corrosion test specimens, surface finishes, and methods of applying stress. 1.5 This standard does not purport to address all of the safety concerns, if any, ...

  1. Alloy materials

    Energy Technology Data Exchange (ETDEWEB)

    Hans Thieme, Cornelis Leo (Westborough, MA); Thompson, Elliott D. (Coventry, RI); Fritzemeier, Leslie G. (Acton, MA); Cameron, Robert D. (Franklin, MA); Siegal, Edward J. (Malden, MA)

    2002-01-01

    An alloy that contains at least two metals and can be used as a substrate for a superconductor is disclosed. The alloy can contain an oxide former. The alloy can have a biaxial or cube texture. The substrate can be used in a multilayer superconductor, which can further include one or more buffer layers disposed between the substrate and the superconductor material. The alloys can be made a by process that involves first rolling the alloy then annealing the alloy. A relatively large volume percentage of the alloy can be formed of grains having a biaxial or cube texture.

  2. Cast iron - a predictable material

    Directory of Open Access Journals (Sweden)

    Jorg C. Sturm

    2011-02-01

    Full Text Available High strength compacted graphite iron (CGI or alloyed cast iron components are substituting previously used non-ferrous castings in automotive power train applications. The mechanical engineering industry has recognized the value in substituting forged or welded structures with stiff and light-weight cast iron castings. New products such as wind turbines have opened new markets for an entire suite of highly reliable ductile iron cast components. During the last 20 years, casting process simulation has developed from predicting hot spots and solidification to an integral assessment tool for foundries for the entire manufacturing route of castings. The support of the feeding related layout of the casting is still one of the most important duties for casting process simulation. Depending on the alloy poured, different feeding behaviors and self-feeding capabilities need to be considered to provide a defect free casting. Therefore, it is not enough to base the prediction of shrinkage defects solely on hot spots derived from temperature fields. To be able to quantitatively predict these defects, solidification simulation had to be combined with density and mass transport calculations, in order to evaluate the impact of the solidification morphology on the feeding behavior as well as to consider alloy dependent feeding ranges. For cast iron foundries, the use of casting process simulation has become an important instrument to predict the robustness and reliability of their processes, especially since the influence of alloying elements, melting practice and metallurgy need to be considered to quantify the special shrinkage and solidification behavior of cast iron. This allows the prediction of local structures, phases and ultimately the local mechanical properties of cast irons, to asses casting quality in the foundry but also to make use of this quantitative information during design of the casting. Casting quality issues related to thermally driven

  3. Microstructure and Aging of Powder-Metallurgy Al Alloys

    Science.gov (United States)

    Blackburn, L. B.

    1987-01-01

    Report describes experimental study of thermal responses and aging behaviors of three new aluminum alloys. Alloys produced from rapidly solidified powders and contain 3.20 to 5.15 percent copper, 0.24 to 1.73 percent magnesium, 0.08 to 0.92 percent iron, and smaller amounts of manganese, nickel, titanium, silicon, and zinc. Peak hardness achieved at lower aging temperatures than with standard ingot-metallurgy alloys. Alloys of interest for automobile, aircraft, and aerospace applications.

  4. Local atomic order in nanocrystalline Fe-based alloys obtained by mechanical alloying

    International Nuclear Information System (INIS)

    Jartych, E.

    2003-01-01

    Using the 57 Fe Moessbauer spectroscopy, a local atomic order in nanocrystalline alloys of iron with Al, Ni, W and Mo has been determined. Alloys were prepared by mechanical alloying method. Analysis of Moessbauer spectra was performed on the basis of the local environment model in terms of Warren-Cowley parameters. It was shown that impurity atoms are not randomly distributed in the volume of the first and the second co-ordination spheres of 57 Fe nuclei and they form clusters

  5. Zirconium alloy barrier having improved corrosion resistance

    International Nuclear Information System (INIS)

    Adamson, R.B.; Rosenbaum, H.S.

    1983-01-01

    A nuclear fuel element for use in the core of a nuclear reactor has a composite cladding container having a substrate and a dilute zirconium alloy liner bonded to the inside surface of the substrate. The dilute zirconium alloy liner forms about 1 to about 20 percent of the thickness of the cladding and is comprised of zirconium and a metal selected from the group consisting of iron, chromium, iron plus chromium, and copper. The dilute zirconium alloy liner shields the substrate from impurities or fission products from the nuclear fuel material and protects the substrate from stress corrosion and stress cracking. The dilute zirconium alloy liner displays greater corrosion resistance, especially to oxidation by hot water or steam than unalloyed zirconium. The substrate material is selected from conventional cladding materials, and preferably is a zirconium alloy. (author)

  6. Ti-Pt Alloys form mechanical milling

    CSIR Research Space (South Africa)

    Nxumalo, S

    2009-12-01

    Full Text Available C maximum in these alloys. A few researchers have studied the martensitic transformation in TiPt alloys using arc melted cast samples. In this work high temperature shape memory alloys are targeted using powder metallurgy as a processing route....

  7. Superparamagnetic iron oxides for MRI

    International Nuclear Information System (INIS)

    Weissleder, R.; Reimer, P.

    1993-01-01

    Pharmaceutical iron oxide preparations have been used as MRI contrast agents for a variety of purposes. These agents predominantly decrease T2 relaxation times and therefore cause a decrease in signal intensity of tissues that contain the agent. After intravenous administration, dextran-coated iron oxides typically accumulate in phagocytic cells in liver and spleen. Clinical trials have shown that iron oxide increases lesion/liver and lesion/spleen contrast, that more lesions can be depicted than on plain MRI or CT, and that the size threshold for lesion detection decreases. Decreased uptake of iron oxides in liver has been observed in hepatitis and cirrhosis, potentially allowing the assessment of organ function. More recently a variety of novel, target-specific monocrystalline iron oxides compounds have been used for receptor and immunospecific images. Future development of targeted MRI contrast agents is critical for organ- or tissue-specific quantitative and functional MRI. (orig.)

  8. Superparamagnetic iron oxides for MRI

    Energy Technology Data Exchange (ETDEWEB)

    Weissleder, R [MGH-NMR Center, Dept. of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA (United States); Reimer, P [MGH-NMR Center, Dept. of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA (United States); [Inst. fuer Klinische Radiologie, Zentrale Roentgendiagnostik, Westfaelische-Wilhelms-Univ., Muenster (Germany)

    1993-06-01

    Pharmaceutical iron oxide preparations have been used as MRI contrast agents for a variety of purposes. These agents predominantly decrease T2 relaxation times and therefore cause a decrease in signal intensity of tissues that contain the agent. After intravenous administration, dextran-coated iron oxides typically accumulate in phagocytic cells in liver and spleen. Clinical trials have shown that iron oxide increases lesion/liver and lesion/spleen contrast, that more lesions can be depicted than on plain MRI or CT, and that the size threshold for lesion detection decreases. Decreased uptake of iron oxides in liver has been observed in hepatitis and cirrhosis, potentially allowing the assessment of organ function. More recently a variety of novel, target-specific monocrystalline iron oxides compounds have been used for receptor and immunospecific images. Future development of targeted MRI contrast agents is critical for organ- or tissue-specific quantitative and functional MRI. (orig.)

  9. Colour Metallography of Cast Iron - Chapter 2: Grey Iron (Ⅱ

    Directory of Open Access Journals (Sweden)

    Zhou Jiyang

    2009-08-01

    Full Text Available Cast iron, as a traditional metal material, has advantages of low total cost, good castability and machinability, good wear resistance and low notch sensitivity, and is still facing tough challenge in quality, property and variety of types etc. Experts and engineers studying and producing iron castings all around world extremely concern this serious challenge. Over more than 30 years, a great of research work has been carried out on how to further improve its property, expand its application and combine cast iron technology with some hi-techs (for example, computer technology. Nevertheless, cast iron is a multi-element and multi-phase alloy and has complex and variety of structures and still has great development potential in structure and property. For further studying and developing cast iron, theoretical research work is important promise, and the study on solidification process and control mechanism of graphite morphology is fundamental for improving property of cast iron and developing new type of cast iron. Metallography of cast iron normally includes two sections: liquid phase transformation and solid phase transformation. The book, Colour Metallography of Cast Iron, uses colour metallography technique to study solidification structures of cast irons: graphite, carbides, austenite and eutectics; and focuses on solidification processes. With progress of modern solidification theory, the control of material solidification process becomes important measure for improving traditional materials and developing new materials. Solidification structure not only influences mechanical and physical properties of cast iron, but also affects its internal quality. The book uses a large amount of colour photos to describe the formation of solidification structures and their relations. Crystallization phenomena, which cannot be displayed with traditional metallography, are presented and more phase transformation information is obtained from these colour

  10. Rare earth-iron-boron premanent magnets

    International Nuclear Information System (INIS)

    Ghendehari, M.H.

    1988-01-01

    This patent describes a method for producing rare earth-iron-boron permanent magnets containing added rare earth oxide, comprising the steps of: (a) mixing a particulate alloy containing at least one rare earth metal, iron, and boron with at least one particulate rare earth oxide; (b) aligning magnetic domains of the mixture in a magnetic field; (c) compacting the aligned mixture to form a shape; and (d) sintering the compacted shape

  11. Influence of Nickel Addition on Properties of Secondary AlSi7Mg0.3 Alloy

    Directory of Open Access Journals (Sweden)

    Richtárech L.

    2015-06-01

    Full Text Available This paper deals with influence on segregation of iron based phases on the secondary alloy AlSi7Mg0.3 microstructure by nickel. Iron is the most common and harmful impurity in aluminum casting alloys and has long been associated with an increase of casting defects. In generally, iron is associated with the formation of Fe-rich intermetallic phases. It is impossible to remove iron from melt by standard operations. Some elements eliminates iron by changing iron intermetallic phase morphology, decreasing its extent and by improving alloy properties. Realization of experiments and results of analysis show new view on solubility of iron based phases during melt preparation with higher iron content and influence of nickel as iron corrector of iron based phases.

  12. Colour Metallography of Cast Iron

    Directory of Open Access Journals (Sweden)

    Zhou Jiyang

    2009-05-01

    Full Text Available Cast iron, as a traditional metal material, has advantages of low total cost, good castability and machinability, good wear resistance and low notch sensitivity, and is still facing tough challenge in quality, property and variety of types etc. Experts and engineers studying and producing iron castings all around world extremely concern this serious challenge. Over more than 30 years, a great of research work has been carried out on how to further improve its property, expand its application and combine cast iron technology with some hi-techs (for example, computer technology. Nevertheless, cast iron is a multi-element and multi-phase alloy and has complex and variety of structures and still has great development potential in structure and property. For further studying and developing cast iron, theoretical research work is important promise, and the study on solidification process and control mechanism of graphite morphology is fundamental for improving property of cast iron and developing new type of cast iron.Metallography of cast iron normally includes two sections: liquid phase transformation and solid phase transformation. The book, Colour Metallography of Cast Iron , uses colour metallography technique to study solidification structures of cast irons: graphite, carbides, austenite and eutectics; and focuses on solidification processes. With progress of modern solidification theory, the control of material solidification process becomes important measure for improving traditionalmaterials and developing new materials. Solidification structure not only influences mechanical and physical properties of cast iron, but also affects its internal quality. The book uses a large amount of colour photos to describe the formation of solidification structures and their relations. Crystallization phenomena, which cannot be displayed with traditional metallography, are presented and more phase transformation information is obtained from these colour

  13. Thermodynamic Properties of Alloys of Iron and Silicon; Proprietes Thermodynamiques des Alliages Fer-Silicium; Termodinamicheskie svojstva splavov zheleza s kremniem; Propiedades Termodinamicas de las Aleaciones de Hierro y Silicio

    Energy Technology Data Exchange (ETDEWEB)

    Vecher, R. A.; Gejderih, V. A.; Gerasimov, Ja. I. [Moskovskij Gosudarstvennyj Universitet Im.M.V. Lomonosova, Moskva, SSSR (Russian Federation)

    1966-01-15

    The Fe-Si phase diagram is complex. At 1000 Degree-Sign K there are FeSi{sub 2}({beta}) and FeSi phases and solid solutions of silicon in {alpha} and {alpha}' iron. EMF measurements were made on the electrochemical cells: Fe|Fe{sup 2+} , KI + Nal|Fe-Si at 600-800 Degree-Sign C molten The alloys were prepared from particularly pure components by powder metallurgy and protracted annealing. Studies were made of ten alloys with silicon content between 85 and 4% in all the phase fields in the diagram section at 1000 Degree-Sign K. We calculated the integral thermodynamic quantities {Delta}G, {Delta}H and {Delta}S for the formation of the silicides FeSi{sub 2}({beta}), FeSi and Fe{sub 3}Si at the mean temperature for the experimental range (1000 Degree-Sign K), and also (using the thermal capacity of the silicides, the iron and the silicon) at 298, 1188 and 1798 Degree-Sign K. The heats of formation of the silicides mentioned at 298 Degree-Sign K (kcal/mole) are -19.4, -17.6 and -22.4 respectively. The data existing in the literature enable us to calculate the heat of formation of FeSi{sub 2.33} ({alpha}-leboite) at 298 Degree-Sign K and this is found to be -14.4 kcal/mole. The heats calculated by us are 1.5-3 kcal higher than the experimental values of Corber and Olsen. The heats of mixing calculated by us for liquid alloys agree well with data in the literature. The data obtained can be regarded as due to the change in the character of the bond in silicides from metallic to covalent when the silicon content is increased. From the data for alloy solutions of silicon in a-iron, the iron activities were calculated. It was found that the {alpha} Rightwards-Harpoon-Over-Leftwards-Harpoon {alpha}' transformation observed is a real phase transformation. The two-phase range is wider than shown in the phase diagram (from data in the literature). Conversion of the iron activities in solid solution to liquid solution gives good agreement with the data of Chipman. (author) [French

  14. Corrosion of aluminum alloys as a function of alloy composition

    International Nuclear Information System (INIS)

    Johnson, A.B. Jr.

    1969-10-01

    A study was initiated which included nineteen aluminum alloys. Tests were conducted in high purity water at 360 0 C and flow tests (approx. 20 ft/sec) in reactor process water at 130 0 C (TF-18 loop tests). High-silicon alloys and AlSi failed completely in the 360 0 C tests. However, coupling of AlSi to 8001 aluminum suppressed the failure. The alloy compositions containing iron and nickel survived tht 360 0 C autoclave exposures. Corrosion rates varied widely as a function of alloy composition, but in directions which were predictable from previous high-temperature autoclave experience. In the TF-18 loop flow tests, corrosion penetrations were similar on all of the alloys and on high-purity aluminum after 105 days. However, certain alloys established relatively low linear corrosion rates: Al-0.9 Ni-0.5 Fe-0.1 Zr, Al-1.0 Ni-0.15 Fe-11.5 Si-0.8 Mg, Al-1.2 Ni-1.8 Fe, and Al-7.0 Ni-4.8 Fe. Electrical polarity measurements between AlSi and 8001 alloys in reactor process water at temperatures up to 150 0 C indicated that AlSi was anodic to 8001 in the static autoclave system above approx. 50 0 C

  15. Effect of iron content on the structure and mechanical properties of Al25Ti25Ni25Cu25 and (AlTi)60-xNi20Cu20Fex (x=15, 20) high-entropy alloys

    International Nuclear Information System (INIS)

    Fazakas, É.; Zadorozhnyy, V.; Louzguine-Luzgin, D.V.

    2015-01-01

    Highlights: • Three new refractory alloys namely: Al 25 Ti 25 Ni 25 Cu 25 , Al 22.5 Ti 22.5 Ni 20 Cu 20 Fe 15 and Al 20 Ti 20 Ni 20 Cu 20 Fe 20 , were produced by induction-melting and casting. • This kind of alloys exhibits high resistance to annealing softening. • Most the alloys in the annealed state possess even higher Vickers microhardness than the as-cast alloys. • The Al 22.5 Ti 22.5 Ni 20 Cu 20 Fe 15 and Al 20 Ti 20 Ni 20 Cu 20 Fe 20 alloys annealed at 973 K show the highest compressive stress and ductility values. - Abstract: In this work, we investigated the microstructure and mechanical properties of Al 25 Ti 25 Ni 25 C u25 Al 22.5 Ti 22.5 Ni 20 Cu 20 Fe 15 and Al 20 Ti 20 Ni 20 Cu 20 Fe 20 high entropy alloys, produced by arc melting and casting in an inert atmosphere. The structure of these alloys was studied by X-ray diffractometry and scanning electron microscopy. The as-cast alloys were heat treated at 773, 973 and 1173 K for 1800 s to investigate the effects of aging on the plasticity, hardness and elastic properties. Compared to the conventional high-entropy alloys the Al 25 Ti 25 Ni 25 Cu 25 , Al 22.5 Ti 22.5 Ni 20 Cu 20 Fe 15 and Al 20 Ti 20 Ni 20 Cu 20 Fe 20 alloys are relatively hard and ductile. Being heat treated at 973 K the Al 22.5 Ti 22.5 Ni 20 Cu 20 Fe 15 alloy shows considerably high strength and relatively homogeneous deformation under compression. The plasticity, hardness and elastic properties of the studied alloys depend on the fraction and intrinsic properties of the constituent phases. Significant hardening effect by the annealing is found.

  16. Nickel aluminide alloy suitable for structural applications

    Science.gov (United States)

    Liu, C.T.

    1998-03-10

    Alloys are disclosed for use in structural applications based upon NiAl to which are added selected elements to enhance room temperature ductility and high temperature strength. Specifically, small additions of molybdenum produce a beneficial alloy, while further additions of boron, carbon, iron, niobium, tantalum, zirconium and hafnium further improve performance of alloys at both room temperature and high temperatures. A preferred alloy system composition is Ni--(49.1{+-}0.8%)Al--(1.0{+-}0.8%)Mo--(0.7 + 0.5%)Nb/Ta/Zr/Hf--(nearly zero to 0.03%)B/C, where the % is at. % in each of the concentrations. All alloys demonstrated good oxidation resistance at the elevated temperatures. The alloys can be fabricated into components using conventional techniques. 4 figs.

  17. Effect of titanium on the near eutectic grey iron

    DEFF Research Database (Denmark)

    Moumeni, Elham; Tiedje, Niels Skat; Hattel, Jesper Henri

    The effect of Titanium on the microstructure of grey iron was investigated experimentally in this work. Tensile test bars of grey cast iron of near eutectic alloys containing 0.01, 0.1, 0.26 and 0.35% Ti, respectively were made in green sand moulds. Chemical analysis, metallographic investigation...

  18. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... risk for iron-deficiency anemia, including: Vegetarian or vegan eating patterns. Not eating enough iron-rich foods, ... iron-fortified foods that have iron added. Vegetarian diets can provide enough iron if you choose nonmeat ...

  19. Control of cast iron and casts manufacturing by Inmold method

    Directory of Open Access Journals (Sweden)

    S. Pietrowski

    2009-07-01

    Full Text Available In this paper the usability of cast iron spheroidizing process in mould control by ATD method as well as by ultrasonic method were presented. Structure of instrumentation needed for control form performance of cast iron spheroidizing by Inmold method was illustrated. Author, pointed out that amount of magnesium master alloy should obtain 0,8 ÷ 1,0% of mass in form at all. Such quantity of preliminary alloy assure of obtain of nodular graphite in cast iron. In consequence of this, is reduce the cast iron liquidus temperature and decrease of recalescence temperature of graphite-eutectic crystallization in compare with initial cast iron. Control of casts can be carried out by ultrasonic method. In plain cast iron, ferritic-pearlitic microstructure is obtaining. Additives of 1,5% Cu ensure pearlitic structure.

  20. Bainitic high-strength cast iron with globular graphite

    Science.gov (United States)

    Silman, G. I.; Makarenko, K. V.; Kamynin, V. V.; Zentsova, E. A.

    2013-07-01

    Special features of formation of bainitic structures in grayed cast irons are considered. The influence of the graphite phase and of the special features of chemical composition of the iron on the intermediate transformation in high-carbon alloys is allowed for. The range of application of high-strength cast irons with bainitic structure is determined. The paper is the last and unfinished work of G. I. Silman completed by his disciples as a tribute to their teacher.

  1. Ultrasmall iron particles prepared by use of sodium amalgam

    DEFF Research Database (Denmark)

    Linderoth, Søren; Mørup, Steen

    1990-01-01

    Ultrasmall magnetic particles containing iron have been prepared by reduction of iron ions by the use of sodium in mercury. Mössbauer studies at 12 K show that the magnetic hyperfine field is significantly larger than in bulk alpha-Fe, suggesting that an iron mercury alloy rather than alpha-Fe has...... been formed. The particles exhibit superparamagnetic relaxation above 120 K. Journal of Applied Physics is copyrighted by The American Institute of Physics....

  2. Exchange interactions in iron and dilute iron alloys

    NARCIS (Netherlands)

    Schurer, Pier Jouke

    1972-01-01

    In dit proefschrift is een onderzoek beschreven dat tot doel had meer inzicht te verschaffen in de oorsprong van het ferromagnetische gedrag van ijzer en verdunde ijzerlegeringen. Op grond van verschillende experimentele gegevens kan men vermoeden dat het ferromagnetisme in ijzer een tweeslachtig

  3. LASER CLADDING ON ALUMINIUM BASE ALLOYS

    OpenAIRE

    Pilloz , M.; Pelletier , J.; Vannes , A.; Bignonnet , A.

    1991-01-01

    laser cladding is often performed on iron or titanium base alloys. In the present work, this method is employed on aluminum alloys ; nickel or silicon are added by powder injection. Addition of silicon leads to sound surface layers, but with moderated properties, while the presence of nickel induces the formation of hard intermetallic compounds and then to an attractive hardening phenomena ; however a recovery treatment has to be carried out, in order to eliminate porosity in the near surface...

  4. Lubrication for hot working of titanium alloys

    International Nuclear Information System (INIS)

    Gotlib, B.M.

    1980-01-01

    The isothermal lubrication of the following composition is suggested, wt. %: aluminium powder 4-6, iron scale 15-25, vitreous enamel up to 100. The lubricant improves forming and decreases the danger of the metal fracture when titanium alloys working. It is advisable to use the suggested lubrication when stamping thin-walled products of titanium alloys at the blank temperature from 700 to 1000 deg C [ru

  5. Diffusion in ordered Fe-Si alloys

    International Nuclear Information System (INIS)

    Sepiol, B.; Vogl, G.

    1995-01-01

    The measurement of the diffusional Moessbauer line broadening in single crystalline samples at high temperatures provides microscopic information about atomic jumps. We can separate jumps of iron atoms between the various sublattices of Fe-Si intermetallic alloys (D0 3 structure) and measure their frequencies. The diffusion of iron in Fe-Si samples with Fe concentrations between 75 and 82 at% shows a drastic composition dependence: the jump frequency and the proportion between jumps on Fe sublattices and into antistructure (Si) sublattice positions change greatly. Close to Fe 3 Si stoichiometry iron diffusion is extremely fast and jumps are performed exclusively between the three Fe sublattices. The change in the diffusion process when changing the alloy composition from stoichiometric Fe 3 Si to the iron-rich side is discussed. (orig.)

  6. Swelling in several commercial alloys irradiated to very high neutron fluence

    International Nuclear Information System (INIS)

    Gelles, D.S.; Pintler, J.S.

    1984-01-01

    Swelling values have been obtained from a set of commercial alloys irradiated in EBR-II to a peak fluence of 2.5 x 10 23 n/cm 2 (E > 0.1 MeV) or approx. 125 dpa covering the range 400 to 650 0 C. The alloys can be ranked for swelling resistance from highest to lowest as follows: the martensitic and ferritic alloys, the niobium based alloys, the precipitation strengthened iron and nickel based alloys, the molybdenum alloys and the austenitic alloys

  7. IRON DOME

    African Journals Online (AJOL)

    6 Israeli Navy 'First Arm of the Sea: The Successful Interception of the Iron Dome Rocket .... sky to destroy them whilst in flight to minimise civilian casualties. ..... Including The Moon and Celestial Bodies.53 Demeyere further emphasises the.

  8. Iron overdose

    Science.gov (United States)

    ... tracing) X-ray to detect and track iron tablets through the stomach and intestines Treatment may include: ... BF, St. Geme JW, Schor NF, eds. Nelson Textbook of Pediatrics . 20th ed. Philadelphia, PA: Elsevier; 2016: ...

  9. VANADIUM ALLOYS

    Science.gov (United States)

    Smith, K.F.; Van Thyne, R.J.

    1959-05-12

    This patent deals with vanadium based ternary alloys useful as fuel element jackets. According to the invention the ternary vanadium alloys, prepared in an arc furnace, contain from 2.5 to 15% by weight titanium and from 0.5 to 10% by weight niobium. Characteristics of these alloys are good thermal conductivity, low neutron capture cross section, good corrosion resistance, good welding and fabricating properties, low expansion coefficient, and high strength.

  10. Influence of annealing temperature on properties of Cu(In,Ga)(Se,S){sub 2} thin films prepared by co-sputtering from quaternary alloy and In{sub 2}S{sub 3} targets

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Y.C., E-mail: ielinyc@cc.ncue.edu.t [Department of Mechatronics Engineering, National Changhua University of Education, No. 2, Shida Road, Changhua 50074, Taiwan (China); Yen, W.T.; Chen, Y.L.; Wang, L.Q. [Department of Mechatronics Engineering, National Changhua University of Education, No. 2, Shida Road, Changhua 50074, Taiwan (China); Jih, F.W. [Chung-Shan Institute of Science and Technology, No. 15, Shi Qi Zi, Gaoping village, Longtan Township, Taoyuan County, Taiwan (China)

    2011-02-15

    Pentanary Cu(In,Ga)(Se,S){sub 2} (CIGSS) thin films were deposited on soda-lime glass substrate by co-sputtering quaternary alloy, and In{sub 2}S{sub 3} targets. In this study, we investigated the influence of post-annealing temperature on structural, compositional, electrical, and optical properties of CIGSS films. Our experimental results show that the CIGS quaternary target had chalcopyrite characteristics. All CIGSS films annealed above 733 K exhibited a polycrystalline tetragonal chalcopyrite structure, with (1 1 2) preferred orientation. The carrier concentration and resistivity of the resultant CIGSS layer annealed above 763 K was 4.86x10{sup 16} cm{sup -3} and 32 {Omega} cm, respectively, and the optical band-gap of the CIGSS absorber layer was 1.18 eV. Raman spectral analysis demonstrated the existence of many different phases, including CuInSe{sub 2}, CuGaSe{sub 2}, and CuInS{sub 2}. This may be because the vibration frequencies of In-Se, In-S bonds are similar to the Ga-Se and Ga-S bonds, causing their absorption bands overlap. -- Research Highlights: {yields} We report a chalcopyrite Cu(In,Ga)(Se,S){sub 2} (CIGSS) thin films on soda lime glass substrate by co-sputtering quaternary single-phase chalcopyrite CIGS alloy, and In{sub 2}S{sub 3} targets. {yields} By incorporating sulfur into partly selenized CIGS films, researchers fabricated a chalcopyrite CIGSS layer with double-graded band-gap structure. {yields} The CIGS quaternary target and Raman spectra were analyzed for investigating the CIGSS structure and quality.

  11. Hydrogen solubility in austenite of Fe-Ni-Cr alloys

    International Nuclear Information System (INIS)

    Zhirnova, V.V.; Mogutnov, B.M.; Tomilin, I.A.

    1981-01-01

    Hydrogen solubility in Fe-Ni-Cr alloys at 600-1000 deg C is determined. Hydrogen solubility in ternary alloys can not be predicted on the basis of the data on its solubility in binary Fe-Ni, Fe-Cr alloys. Chromium and nickel effect on hydrogen solubility in iron is insignificant in comparison with the effect of these elements on carbon or nitrogen solubility [ru

  12. The Aging of Iron Man

    Directory of Open Access Journals (Sweden)

    Azhaar Ashraf

    2018-03-01

    Full Text Available Brain iron is tightly regulated by a multitude of proteins to ensure homeostasis. Iron dyshomeostasis has become a molecular signature associated with aging which is accompanied by progressive decline in cognitive processes. A common theme in neurodegenerative diseases where age is the major risk factor, iron dyshomeostasis coincides with neuroinflammation, abnormal protein aggregation, neurodegeneration, and neurobehavioral deficits. There is a great need to determine the mechanisms governing perturbations in iron metabolism, in particular to distinguish between physiological and pathological aging to generate fruitful therapeutic targets for neurodegenerative diseases. The aim of the present review is to focus on the age-related alterations in brain iron metabolism from a cellular and molecular biology perspective, alongside genetics, and neuroimaging aspects in man and rodent models, with respect to normal aging and neurodegeneration. In particular, the relationship between iron dyshomeostasis and neuroinflammation will be evaluated, as well as the effects of systemic iron overload on the brain. Based on the evidence discussed here, we suggest a synergistic use of iron-chelators and anti-inflammatories as putative anti-brain aging therapies to counteract pathological aging in neurodegenerative diseases.

  13. The Aging of Iron Man.

    Science.gov (United States)

    Ashraf, Azhaar; Clark, Maryam; So, Po-Wah

    2018-01-01

    Brain iron is tightly regulated by a multitude of proteins to ensure homeostasis. Iron dyshomeostasis has become a molecular signature associated with aging which is accompanied by progressive decline in cognitive processes. A common theme in neurodegenerative diseases where age is the major risk factor, iron dyshomeostasis coincides with neuroinflammation, abnormal protein aggregation, neurodegeneration, and neurobehavioral deficits. There is a great need to determine the mechanisms governing perturbations in iron metabolism, in particular to distinguish between physiological and pathological aging to generate fruitful therapeutic targets for neurodegenerative diseases. The aim of the present review is to focus on the age-related alterations in brain iron metabolism from a cellular and molecular biology perspective, alongside genetics, and neuroimaging aspects in man and rodent models, with respect to normal aging and neurodegeneration. In particular, the relationship between iron dyshomeostasis and neuroinflammation will be evaluated, as well as the effects of systemic iron overload on the brain. Based on the evidence discussed here, we suggest a synergistic use of iron-chelators and anti-inflammatories as putative anti-brain aging therapies to counteract pathological aging in neurodegenerative diseases.

  14. Nonswelling alloy

    Science.gov (United States)

    Harkness, S.D.

    1975-12-23

    An aluminum alloy containing one weight percent copper has been found to be resistant to void formation and thus is useful in all nuclear applications which currently use aluminum or other aluminum alloys in reactor positions which are subjected to high neutron doses.

  15. Nonswelling alloy

    International Nuclear Information System (INIS)

    Harkness, S.D.

    1975-01-01

    An aluminum alloy containing one weight percent copper has been found to be resistant to void formation and thus is useful in all nuclear applications which currently use aluminum or other aluminum alloys in reactor positions which are subjected to high neutron doses

  16. Low alloy steel versus ADI – differences and similarities

    Directory of Open Access Journals (Sweden)

    A. Krzyńska

    2009-01-01

    Full Text Available The results of comparison between the microstructure of selected bainitic low alloy steel and austempered ductile iron ADI are presented. The aim of the comparison was to find out differences and similarities existing in these iron carbon commercial alloys. In this paper our own results on ADI structure and literature data were used. It follows from discussion presented here that both microstructure and properties of ADI are very close that which are observed in low alloy carbon steel. Moreover, we suggest that there is no so doubt to treat ADI mechanical properties as steel containing nodular inclusions of graphite.

  17. Effects of alloying elements on nodular and uniform corrosion resistance of zirconium-based alloys

    International Nuclear Information System (INIS)

    Abe, Katsuhiro

    1992-01-01

    The effects of alloying and impurity elements (tin, iron, chromium, nickel, niobium, tantalum, oxygen, aluminum, carbon, nitrogen, silicon, and phosphorus) on the nodular and uniform corrosion resistance of zirconium-based alloys were studied. The improving effect of iron, nickel and niobium in nodular corrosion resistance were observed. The uniform corrosion resistance was also improved by nickel, niobium and tantalum. The effects of impurity elements, nitrogen, aluminum and phosphorus were negligibly small but increasing the silicon content seemed to improve slightly the uniform corrosion resistance. Hydrogen pick-up fraction were not changed by alloying and impurity elements except nickel. Nickel addition increased remarkably hydrogen pick-up fraction. Although the composition of secondary precipitates changed with contents of alloying elements, the correlation of composition of secondary precipitates to corrosion resistance was not observed. (author)

  18. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... iron-rich foods, especially during certain stages of life when more iron is needed, such as childhood and pregnancy. Good sources of iron are meat, poultry, fish, and iron- ...

  19. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... that are good sources of iron include dried beans, dried fruits, eggs, lean red meat, salmon, iron- ... of iron, including iron-fortified breads and cereals, beans, tofu, dried fruits, and spinach and other dark ...

  20. Iron in diet

    Science.gov (United States)

    ... Reasonable amounts of iron are also found in lamb, pork, and shellfish. Iron from vegetables, fruits, grains, ... strawberries, tomatoes, and potatoes) also increase iron absorption. Cooking foods in a cast-iron skillet can also ...

  1. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... from developing iron-deficiency anemia. Foods that are good sources of iron include dried beans, dried fruits, ... iron is needed, such as childhood and pregnancy. Good sources of iron are meat, poultry, fish, and ...

  2. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... you are diagnosed with iron-deficiency anemia. Risk Factors You may have an increased risk for iron- ... iron-deficiency anemia if you have certain risk factors , including pregnancy. To prevent iron-deficiency anemia, your ...

  3. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... for your body to absorb iron from the gastrointestinal tract (GI tract). Blood loss When you lose blood, ... iron deficiency. Endurance athletes lose iron through their gastrointestinal tracts. They also lose iron through the breakdown of ...

  4. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... iron in your body is low. For this reason, other iron tests are also done. Ferritin measure ... iron is needed, such as childhood and pregnancy. Good sources of iron are meat, poultry, fish, and ...

  5. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... develop new therapies for conditions that affect the balance of iron in the body and lead to ... Disease Control and Prevention) Iron - Health Professional Fact Sheet (NIH) Iron Dietary Supplement Fact Sheet (NIH) Iron- ...

  6. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... to moderate iron-deficiency anemia, or red blood cell transfusion for severe iron-deficiency anemia. You may ... body needs iron to make healthy red blood cells. Iron-deficiency anemia usually develops over time because ...

  7. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... enough iron-rich foods, such as meat and fish, may result in you getting less than the ... pregnancy. Good sources of iron are meat, poultry, fish, and iron-fortified foods that have iron added. ...

  8. Iron Dextran Injection

    Science.gov (United States)

    Iron dextran injection is used to treat iron-deficiency anemia (a lower than normal number of red blood cells ... treated with iron supplements taken by mouth. Iron dextran injection is in a class of medications called ...

  9. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... and severity. Treatments may include iron supplements, procedures, surgery, and dietary ... iron supplements, also called iron pills or oral iron, by mouth once or several times a ...

  10. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... developing iron-deficiency anemia. Foods that are good sources of iron include dried beans, dried fruits, eggs, ... is needed, such as childhood and pregnancy. Good sources of iron are meat, poultry, fish, and iron- ...

  11. Iron deficiency

    DEFF Research Database (Denmark)

    Schou, Morten; Bosselmann, Helle; Gaborit, Freja

    2015-01-01

    BACKGROUND: Both iron deficiency (ID) and cardiovascular biomarkers are associated with a poor outcome in heart failure (HF). The relationship between different cardiovascular biomarkers and ID is unknown, and the true prevalence of ID in an outpatient HF clinic is probably overlooked. OBJECTIVES.......043). CONCLUSION: ID is frequent in an outpatient HF clinic. ID is not associated with cardiovascular biomarkers after adjustment for traditional confounders. Inflammation, but not neurohormonal activation is associated with ID in systolic HF. Further studies are needed to understand iron metabolism in elderly HF...

  12. Dephosphorization of Levitated Silicon-Iron Droplets for Production of Solar-Grade Silicon

    Science.gov (United States)

    Le, Katherine; Yang, Yindong; Barati, Mansoor; McLean, Alexander

    2018-05-01

    The treatment of relatively inexpensive silicon-iron alloys is a potential refining route in order to generate solar-grade silicon. Phosphorus is one of the more difficult impurity elements to remove by conventional processing. In this study, electromagnetic levitation was used to investigate phosphorus behavior in silicon-iron alloy droplets exposed to H2-Ar gas mixtures under various experimental conditions including, refining time, temperature (1723 K to 1993 K), gas flow rate, iron content, and initial phosphorus concentration in the alloy. Thermodynamic modeling of the dephosphorization reaction permitted prediction of the various gaseous products and indicated that diatomic phosphorus is the dominant species formed.

  13. The solubility of metals in Pb-17Li liquid alloy

    International Nuclear Information System (INIS)

    Borgstedt, H.U.; Feuerstein, H.

    1992-01-01

    The solubility data of iron in the eutectic alloy Pb-17Li which were evaluated from corrosion tests in a turbulent flow of the molten alloy are discussed in the frame of solubilities of the transition metals in liquid lead. It is shown that the solubility of iron in the alloy is close to that in lead. This is also the fact for several other alloying elements of steels. A comparison of all known data shows that they are in agreement with generally shown trends for the solubility of the transition metals in low melting metals. These trends indicate comparably high solubilities of nickel and manganese in the liquid metals, lower saturation concentration of vanadium, chromium, iron, and cobalt, and extremely low solubility of molybdenum. (orig.)

  14. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... Research Home / < Back To Health Topics / Iron-Deficiency Anemia Iron-Deficiency Anemia Also known as Leer en español Iron-deficiency ... iron-deficiency anemia. Blood tests to screen for iron-deficiency anemia To screen for iron-deficiency anemia, your doctor ...

  15. The microstructure of steels and cast irons. History and interpretation

    International Nuclear Information System (INIS)

    Durand-Charre, M.

    2003-01-01

    The microstructure of steels and cast irons is a monograph on the history and interpretation of the microstructure of steels and iron alloys. Its 400 pages are illustrated by a lot of micrographies of commercial alloys or model alloys at each the available scales with the modern investigations means of electronic microscopy and the optical macro/microscopy. The first part of this book is an historical introduction on the development of the metallurgical structures manually forged for the iron knowledge, in particular the famous structures called damask. The second part of this book deals with the fundamental notions in order to give all the reasoning bases required on the phases equilibria and the transformations kinetics. Concerning the phases equilibria, a lot of diagrams are included. The reading of ternary systems is analyzed for six systems representative of the reactions encountered in steels, Fe-Cr-C, Fe-Ni-Cr, Fe-Mn-S, Fe-Co-Cu, Fe-Mo-Cr and Fe-C-V. The solidification structures are studied through all the classical cases but in others too as the markings of peritectic or metatectic reactions or transformations in series. Solid phases transformations are illustrated and commented with recent interpretations, in particular in the case of bainitic structures. A lot of references allow to deepen the non developed aspects. The third part is a guide to understand and discuss on scientific bases the role of alloy elements and those of different specific treatments resulting to the optimisation of steels and iron casts, to define the micrographic characteristics in relation with the use properties. Steels are classified in series for the very low alloy steels to steels with high amounts in alloy elements resulting of a very fine composition adjustment. Cast irons are presented naturally according to their microstructure, classified in white irons, lamellar grey and nodular irons. (O.M.)

  16. Electrical Resistance Alloys and Low-Expansion Alloys

    DEFF Research Database (Denmark)

    Kjer, Torben

    1996-01-01

    The article gives an overview of electrical resistance alloys and alloys with low thermal expansion. The electrical resistance alloys comprise resistance alloys, heating alloys and thermostat alloys. The low expansion alloys comprise alloys with very low expansion coefficients, alloys with very low...... thermoelastic coefficients and age hardenable low expansion alloys....

  17. Studies on the Production of NdFeB Alloy by Calciothermic Reduction of Neodymium Oxide

    International Nuclear Information System (INIS)

    Charoensri, Apisara

    2003-06-01

    Neodymium-Iron-Boron (NdFeB) is a class of permanent magnets having the highest energy product (BH max ). It has been used in various electronic devices of small size and light weight. This research is to study the preparation of Neodymium-Iron-Boron alloy by calciothermic reduction of neodymium oxide mixed with iron and iron-boron. The reduction process essentially involves the compaction of the charge mixture with calcium metal and then heating at 900-1200οC in argon atmosphere. The results show that charge blend compaction, temperature and time of reaction are important parameters of the process. It is found that at proper conditions, magnetic phase structure of Neodymium-Iron-Boron alloy can be prepared satisfactory although the alloy produced from the reduction contains higher impurities of oxygen and calcium than the alloy produced from the conventional method using Nd metal

  18. Iron and iron derived radicals

    International Nuclear Information System (INIS)

    Borg, D.C.; Schaich, K.M.

    1987-04-01

    We have discussed some reactions of iron and iron-derived oxygen radicals that may be important in the production or treatment of tissue injury. Our conclusions challenge, to some extent, the usual lines of thought in this field of research. Insofar as they are born out by subsequent developments, the lessons they teach are two: Think fast! Think small! In other words, think of the many fast reactions that can rapidly alter the production and fate of highly reactive intermediates, and when considering the impact of competitive reactions on such species, think how they affect the microenvironment (on the molecular scale) ''seen'' by each reactive molecule. 21 refs., 3 figs., 1 tab

  19. Iron binary and ternary coatings with molybdenum and tungsten

    Energy Technology Data Exchange (ETDEWEB)

    Yar-Mukhamedova, Gulmira, E-mail: gulmira-alma-ata@mail.ru [Institute Experimental and Theoretical Physics Al-Farabi Kazakh National University, 050038, Al-Farabi av., 71, Almaty (Kazakhstan); Ved, Maryna; Sakhnenko, Nikolay; Karakurkchi, Anna; Yermolenko, Iryna [National Technical University “Kharkov Polytechnic Institute”, Kharkov (Ukraine)

    2016-10-15

    Highlights: • High quality coatings of double Fe-Mo and ternary Fe-Mo-W electrolytic alloys can be produced both in a dc and a pulsed mode. • Application of unipolar pulsed current allows receiving an increased content of the alloying components and their more uniform distribution over the surface. • It is established that Fe-Mo and Fe-Mo-W coatings have an amorphous structure and exhibit improved corrosion resistance and microhardness as compared with the steel substrate due to the inclusion molybdenum and tungsten. - Abstract: Electrodeposition of Fe-Mo-W and Fe-Mo layers from a citrate solution containing iron(III) on steel and iron substrates is compared. The utilization of iron(III) compounds significantly improved the electrolyte stability eliminating side anodic redox reactions. The influence of concentration ratios and electrodeposition mode on quality, chemical composition, and functional properties of the alloys is determined. It has been found that alloys deposited in pulse mode have more uniform surface morphology and chemical composition and contain less impurities. Improvement in physical and mechanical properties as well as corrosion resistance of Fe-Mo and Fe-Mo-W deposits when compared with main alloy forming metals is driven by alloying components chemical passivity as well as by alloys amorphous structure. Indicated deposits can be considered promising materials in surface hardening technologies and repair of worn out items.

  20. Iron-57 and iridium-193 Moessbauer spectroscopic studies of supported iron-iridium catalysts

    International Nuclear Information System (INIS)

    Berry, F.J.; Jobson, S.

    1988-01-01

    57 Fe and 193 Ir Moessbauer spectroscopy shows that silica- and alumina-supported iron-iridium catalysts formed by calcination in air contain mixtures of small particle iron(III) oxide and iridium(IV) oxide. The iridium dioxide in both supported catalysts is reduced in hydrogen to metallic iridium. The α-Fe 2 O 3 in the silica supported materials is predominantly reduced in hydrogen to an iron-iridium alloy whilst in the alumina-supported catalyst the iron is stabilised by treatment in hydrogen as iron(II). Treatment of a hydrogen-reduced silica-supported iron catalyst in hydrogen and carbon monoxide is accompanied by the formation of iron carbides. Carbide formation is not observed when the iron-iridium catalysts are treated in similar atmospheres. The results from the bimetallic catalysts are discussed in terms of the hydrogenation of associatively adsorbed carbon monoxide and the selectivity of supported iron-iridium catalysts to methanol formation. (orig.)