Science.gov (United States)

A number of alloys of zirconium have been investigated as part of a program aimed at improving the high-temperature tensile and creep strength of zirconium. These alloys include aluminum, beryllium, lead, magnesium, molybdenum, niobium, tantalum, tin, titanium, tungsten, vanadium, and zinc, binary and ternary alloys. The data indicate that aluminum, lead, molybdenum niobium, tin, titanium, tungsten, and vanadium can be used successfully to harden zirconium, and that aluminum, tin, titanium, and vanadium are particularly effective in maintaining the strength of zirconium at elevated temperatures.

International Nuclear Information System (INIS)

A zirconium alloy comprising from 0.8 to 1.6wt% of Sn, from 0.17 to 0.25wt% of Fe, from 0.15 to 0.25wt% of Cr and from 0.01 to 0.08wt% of Ni and Si at a concentration of 120ppm or lower as an impurity and the balance of Zr is melted into cast pieces and then subjected to an #beta# annealing. It is controlled so as to satisfy Fe + Cr + Ni #<=# 0.52wt%. Then, rolling and annealing are applied so that the total heat injection amount #SIGMA#A_i to the materials is within a range of from 1 x 10"-"1"9 to 1 x 10"-"1"7. #SIGMA#A_i = #SIGMA#t_i #centre dot# exp(-Q/RT_i), in which t_i represents processing time (hour) at an ith heat treatment step after the #beta# annealing, T_i represents a processing temperature (K) in the step i. Q represents an activating energy, R represents a gas constant, and Q/R 40,000. (I.N.).

International Nuclear Information System (INIS)

Zirconium alloys have anisotropic mechanical properties depending on their physical orientations and are widely used as nuclear materials such as cladding tube material. An operation condition of the nuclear reactor requires a high creep resistance, because it is subjected to long period operations, high temperature and high pressure. Generally, it takes a few days or months to do the creep experiment, so it is difficult to get a data in short period. However, there is a way to predict a creep property by using the stress-relaxation in the short term. These studies realized the stress-relaxation through a compressive test of HANA-6 (Zr-1.1Nb-0.05Cu) alloy that was developed by KAERI (Korea Atomic Energy Research Institute), and then predicted the creep property

International Nuclear Information System (INIS)

The present invention concerns a method of evaluating corrosion resistance of a zirconium alloy easily and in a short period of time. An anode polarization curve of the zirconium alloy is measured to obtain an anode polarization curve expressed by logarithm. The curve is converted to a potential-current density curve expressed by absolute values. The peak area in the curve of the converted potential-current density is indicated by numerical values. Further, the corrosion resistance of the zirconium alloy is evaluated based on the peak area converted into the numerical values as a reference. This method is based on the finding that the peak area has a close relation with nodular corrosion resistance, and the corrosion resistance can be judged with respect to a specific zircaloy-2. (T.M.).

International Nuclear Information System (INIS)

Substantial roles of precipitates such as Zr-Fe-Cr type intermetallic compounds on uniform corrosion and hydrogen pickup of zirconium alloys in pure water autoclave tests were investigated from an electrochemical point of view. This paper describes the roles on corrosion. A corrosion test on precipitate-containing and precipitate-free materials made from pure zirconium and a small quantity of iron and chromium, rest potential measurements on an intermetallic compound of Zr(FeCr)_2 and zirconium matrix, and a galvanic coupling test of those were performed. Results showed that corrosion behavior of zirconium alloys could be attributed to the electrochemical properties of intermetallic compounds precipitated in each alloy. Namely, the cathodic and anodic polarization characteristics were associated with anodic protection provided by the ...

Energy Technology Data Exchange (ETDEWEB)

Alloying elements such as Fe and Cr are generally considered to be effective even in small quantities for corrosion resistance of Zircaloy-4. The maximum total solubility of Fe + Cr in a Zr-Sn matrix has been reported to be very low. Therefore, most of these elements are observed in the form of ternary Zr-Fe-Cr-type precipitates. To clarify the effects of precipitates on corrosion property, Zr-1.3 Sn-(Fe,Cr) alloys containing Fe + Cr from 45 up to 180 ppm (the Fe to Cr ratio is about 2) were melted from pure zirconium (X-bar Zr and EB-Zr) and pure alloying elements. They were subjected to corrosion testing in 633 K water and microstructural analysis. It was found that precipitate-free materials showed much larger weight gains than precipitate-containing materials even at the same alloy compositions. Subsequently, a corrosion test on the precipitate-free material ...

Energy Technology Data Exchange (ETDEWEB)

Substantial roles of precipitates such as Zr-Fe-Cr type intermetallic compounds on uniform corrosion and hydrogen pickup of zirconium alloys in pure water autoclave tests were investigated from an electrochemical point of view. In the previous paper, corrosion mechanism was elucidated by the anodic protection-precipitates degradation model. This paper describes the roles on hydrogen pickup. 633 K pure water autoclave test was performed on high purity zirconium, Zr-0.2Fe, Zr-0.2Cr, and Zr-0.1Fe-0.1Cr alloys. Hydrogen analysis after the corrosion test showed that hydrogen pickup ratio of Zr-0.2Fe alloy was about 80%. It was much higher than about 30% of pure Zr and about 10% of both Zr-0.2Cr and Zr-0.1Fe-0.1Cr alloys. Larger hydrogen content was introduced into Zr-0.2Fe alloy than the other ones by the cathodic hydrogen charging under ...

British Library Electronic Table of Contents (United Kingdom)

Zirconium and particularly Zr-2.5wt%Nb (Zr2.5Nb) alloy are useful for engineering bearing applications because they can be oxidized in air to form a hard surface ceramic. Oxidized zirconium (OxZr) due to its abrasion resistant ceramic surface and biocompatible substrate alloy has been used as a bearing surface in total joint arthroplasty for several years. OxZr is characterized by hard zirconium oxide (oxide) formed on Zr2.5Nb using one step thermal oxidation carried out in air. Because the oxide is only at the surface, the bulk material behaves like a metal, with high toughness. The oxide, furthermore, exhibits high adhesion to the substrate because of an oxygen-rich diffusion hardened zone (DHZ) interposing between the oxide and the substrate. In this study, we demonstrate a two step pro...

British Library Electronic Table of Contents (United Kingdom)

The review provides a general idea about the types of metallic alloys and the pure metals used as implant materials in dental and orthopedic surgery. Their corrosive behavior in both real solutions and various media that model human biological fluids is described. Based on the literature data, it is concluded that multicomponent alloys containing titanium, niobium, zirconium, tungsten, molybdenum, aluminum, and silicon are the most resistant to corrosion. Implants made of different types of stainless steel are preferred when manufacturing orthopedic devices for short-term use.

International Nuclear Information System (INIS)

Alloys of zirconium are widely used in various core components of power reactors. Nuclear assemblies require high degree of reliability and integrity for performing in radiation and corrosive atmosphere. The hostile environments of reactor core and inaccessibility for repairs make it mandatory to select only those joining techniques which produce not only superior quality but are also amenable to NDT methods and such other techniques which ensure acceptable performance. The author has worked on various types of welding of zirconium alloys for different applications. Modern techniques in electron beam (EB) welding, resistance welding, GTAW welding and laser welding have been developed for joining Zr alloys components for different types of reactors. Many of these have been standardized and successfully used in production. Several advancements have been made in the welding ...

International Nuclear Information System (INIS)

Zircaloy fabrication plant manufactures all the necessary Zr-2 components like fuel canning tubes, calandria tubes and other rod and sheet products. This plant is having a capacity of producing about 4 lakh nos. of PHWR fuel tubes per annum. These tubes are seamless, thin walled with close dimensional tolerances and stringent mechanical properties. The plant has established all the facilities required to produce these tubes with required quality.

International Nuclear Information System (INIS)

The electrochemical behavior of some zirconium alloys including Zry-2 with various #SIGMA#Ai from 2.5 x 10"-"2"0 to 1.2 x 10"-"1"7 (h), modified Zry-2 with iron contents of 0.15, 0.25, and 0.5%, and standard Zry-4 was studied by measuring anodic polarization curves in sulfuric acid solution. The results of these electrochemical tests were compared with those of steam autoclave tests. In Zry-2, the current peak was observed at 1250 mV (versus SCE) on the anodic polarization curve, and this peak area increased with #SIGMA#Ai and with the size of secondary precipitates. Also, this peak was closely correlated with nodular corrosion resistance as expected from the above results. As iron contents in modified Zry-2 increased, the current peak at 1,250 mV decreased and a new peak at 1,900 mV appeared. The former peak disappeared and the latter peak increased further at 0.5% iron. In Zry-4, the current peak was observed at 1,900 mV, but not at 1,250 mV, ...

International Nuclear Information System (INIS)

The cold-worked Zr-2.5%Nb alloy is used as material for the pressure tubes in CANDU nuclear reactors. During the service life in reactor, diffusion of hydrogen and/or deuterium in the pressure tubes wall occur. Below a certain temperature, a stable hydride of zirconium is formed, as a brittle phase which can lead to catastrophic failures. For this reason, it is very important to be able to investigate the hydrogen effect on the micro structural properties of zirconium alloys. In the present paper a non-destructive testing technique is used, known as ultrasonic spectral analysis. When an ultrasonic signal traverses a medium, the frequency components associated with the input signal are altered. By frequency analysing the reflected signals, it is possible to study and compare the material properties. The two major parameters measured in ultrasonic spectroscopy are the attenuation and the velocity of the ...

International Nuclear Information System (INIS)

Corrosion testings of model alloys, corresponding by chemical composition to simple and complex-alloyed #gamma#- and #gamma#'-phases of nickel heat-resistant alloys are conducted in sodium sulfate and chloride melts. It is ascertained that heat resistant nickel alloys containing over 50 % of hardening #gamma#'-phase, are subject to disastrous sulfide corrosion (SC). Resistance against SC alloys containing below 50 % of #gamma#'-phase is determined by the resistance of #gamma#-solid solution. 10 refs., 3 figs., 2 tabs.

International Nuclear Information System (INIS)

The description is presented of binary phase diagrams of titanium alloyed with the following elements: silver, aluminium, arsenic, gold, boron, barium, beryllium, bismuth, carbon, calcium, cadmium, cobalt, chromium, copper, iron, gallium, germanium, hydrogen, hafnium, indium, iridium, potassium, lithium, magnesium, manganese, molybdenum, nitrogen, sodium, niobium, nickel, oxygen, osmium, phosphorus, lead, palladium, platinum, plutonium, rhenium, lanthanium, cerium, preseodymium, neodymium, gadolinium, erbium, terbium, thulium, lutetium, rhodium, ruthenium, scandium, silicon, tin, strontium, tantalum, technetium, thorium, uranium, vanadium, tungsten, yttrium, ytterbium, zinc and zirconium.

Energy Technology Data Exchange (ETDEWEB)

At least quinary alloys form metallic glass upon cooling below the glass transition temperature at a rate less than 10.sup.3 K/s. Such alloys comprise zirconium and/or hafnium in the range of 45 to 65 atomic percent, titanium and/or niobium in the range of 4 to 7.5 atomic percent, and aluminum and/or zinc in the range of 5 to 15 atomic percent. The balance of the alloy compositions comprise copper, iron, and cobalt and/or nickel. The composition is constrained such that the atomic percentage of iron is less than 10 percent. Further, the ratio of copper to nickel and/or cobalt is in the range of from 1:2 to 2:1. The alloy composition formula is: (Zr,Hf).sub.a (Al,Zn).sub.b (Ti,Nb).sub.c (Cu.sub.x Fe.sub.y (Ni,Co).sub.z).sub.d wherein the constraints upon the formula are: a ranges from 45 to 65 atomic percent, b ranges from 5 to 15 atomic percent, c ranges from 4 to 7.5 atomic ...

International Nuclear Information System (INIS)

In association with periodic inspection of CANDU nuclear power plant components, Canadian Standards Association issued CSA N285.8 in 2005 as technical requirements for in-service evaluation of zirconium alloy pressure tubes in CANDU reactors. This first version, CSA N285.8 involves procedures for, firstly, the evaluation of pressure tube flaws, secondly, the evaluation of pressure tube to calandria tube contact and, thirdly, the assessment of a reactor core, and material properties and derived quantities. The evaluation of pressure tube flaws includes delayed hydride cracking evaluation the procedures of which are stipulated based on the existing delayed hydride cracking models. For example, the evaluation of flaw-tip hydride precipitation during reactor cooldown involves a procedure to calculate the equilibrium hydrogen equivalent concentration in solution at the flaw tip, Htipas follows: Htip=Hfexp[- (VH delta no.)/RT], where Hf is the total ...

International Nuclear Information System (INIS)

Uranium-aluminum alloys with a significant enrichment of uranium with "2"3"3U or "2"3"5U serve as nuclear fuels in research reactors. The quality assurance of this fuel requires, among other things, precise knowledge that all trace metal constituents that affect neutron economy, fuel integrity, and fuel fabrication process parameters are well within the specification limits. Trace metal characterization of "2"3"5U-Al alloy has been carried out by atomic spectrometry. The trace metal constituents of interest are grouped into common metals (silver, boron, calcium, cadmium, cobalt, chromium, copper, iron, magnesium, manganese, molybdenum, sodium, nickel, lead, silicon, tin, titanium, vanadium, tungsten, and zinc) and lanthanides (cerium, dysprosium, europium, gadolinium, holminium, lutetium, samarium, and terbium). The elements yttrium and zirconium are grouped with the latter in view of the chemical separation procedure used. ...

International Nuclear Information System (INIS)

Three types of titanium hydrides have been reported: #delta#, #epsilon# and #gamma# hydrides. The #delta# hydride forms in the composition range from TiH/sub 1.5/ to TiH/sub 1.99/ and has a CaF/sub 2/ structure with metal atoms on an fcc lattice and hydrogen atoms randomly occupying tetrahedral interstitial sites. At higher hydrogen concentrations, TiH/sub 2/, the fct (c/a # #epsilon# transformation is apparently diffusionless, similar to that operating in the cubic/tetragonal transformation in zirconium hydride. The metastable fct #gamma# hydride having a c/a value of 1.09 or 1.12 forms from solid solutions of hydrogen in the hcp #alpha# matrix. While the titanium hydride precipitation in #alpha#-Ti and its alloys has attracted extensive investigation, hydride formation in bcc #beta#-Ti alloys has rarely been studied because they have not been thought to be liable to hydride formation. This paper shows conclusive evidence ...

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With the ever increasing awareness of the toxicity of Pb, significant pressure has been put on the electronics industry to get the Pb out of solder. This work pertains to the development and characterization of an alloy which is Pb-free, yet retains the proven positive qualities of current Sn-Pb solders while enhancing the shortcomings of Sn-Pb solder. The solder studied is the Sn-4.7Ag-1.7Cu wt% alloy. By utilizing a variety of experimental techniques the alloy was characterized. The alloy has a melting temperature of 217{degrees}C and exhibits eutectic melting behavior. The solder was examined by subjecting to different annealing schedules and examining the microstructural stability. The effect of cooling rate on the microstructure of the solder was also examined. Overall, this solder alloy shows great promise as a viable alternative to Pb-bearing solders and, ...

J-STORE (Japan)

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The bibliography contains citations concerning the pitting corrosion of copper and copper alloys, in different media, with some references to methods for protecting against such corrosion. Included are factors contributing to the onset of pitting corrosion. Emphasis is placed on exposure to water, especially in tubing for heat exchangers and water conduits. Many of the citations present studies on exposure to sea water. Some references pertain to the detection of pitting corrosion in installations and the evaluation of the degree of pitting present. (Contains 250 citations and includes a subject term index and title list.)

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Experimental data on the material characteristics of structures subjected to thermal and mechanical cycling are needed for designing structural parts for creep and creep-fatigue interaction. Moreover, high-temperature low-cycle fatigue data are not sufficient to predict the fatigue creep lifetime. In order to check the reliability of steam generators, tests on pipe materials are conducted under cyclic thermal loading. The tests have been performed on an iron-nickel chromium alloy (alloy 800). Isothermal low-cycle fatigue tests have been conducted at 550 C. 15 refs.

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During 17 years since the start of operation of the first commercial LWR in Japan, many LWRs have experienced various corrosion damages, but the causes of them were clarified, and the counter-measures were executed effectively in actual plants, as the results, the cause of corrosion damage decreased remarkably, and now, the high rate of operation has become to be maintained. In this paper, the major cases of corrosion damage experienced in LWRs in Japan and foreign countries, the causes of them and the countermeasures, the problems of hereafter and so on are described. The corrosion damage of metallic materials in the environment of LWRs occurs in the parts in contact with high temperature, high pressure water and steam, such as stainless steel piping in the primary cooling system of BWRs, and nickel alloy heating tubes of steam generators, carbon steel feed water piping and zirconium alloy fuel cladding tubes in PWRs. ...

Energy Technology Data Exchange (ETDEWEB)

Alloy 800 has been proposed for use in the receiver tube panel arrays of advanced solar central receiver (SCR) designs. In this application the alloy will be exposed to a molten mixture of sodium and potassium nitrate salts at temperatures ranging up to approximately 600/sup 0/C While these salts are routinely used in a variety of applications including metal heat treating and process heat transfer, common industrial experience has been limited to maximum temperatures of 400/sup 0/C - 450/sup 0/C. There is, therefore, considerable interest in the compatibility of these salts with containment alloys at the higher temperatures associated with SCR designs. Additionally, the containment alloy may be subject to thermally induced fatigue damage resulting from intermittent cloud cover and diurnal cycling. Previous work has found that slower near-threshold fatigue crack growth rates (FCGR) ...

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International Nuclear Information System (INIS)

An Al-5%Mg-0.18%Mn-0.2%Sc-0.08%Zr-0.002%Be was subjected to equal-channel angular extrusion up to true strains of #approx#3 and #approx#8, that resulted in the formation of partially recrystallized and fully recrystallized structure, respectively. It was shown that the alloy with partially recrystallized structure exhibits highest strength and ductility. The material with fully recrystallized structure showed lowest fatigue crack growth rate and highest value of fracture toughness. Reasons of this unusual effect of microstructure on crack propagation resistance under fatigue are discussed.

International Nuclear Information System (INIS)

A one-nanometer scale transmission electron microscope electron probe X-ray microanalysis characterization of as-deposited and annealed aluminum--11.5 at.% zirconium multilayer samples in cross-section synthesized by magnetron sputtering is reported on here. Composition line profiles were acquired across Zr layers in as-deposited material and samples isochronally annealed in a differential scanning calorimeter to temperatures of 290 C and 485 C. A spatial resolution of approximately 1.5 to 2.0 nm was achieved in these experiments and will be improved by deconvolution of the instrumental electron probe function from the data. The as-deposited structure consisted of crystalline Al and Zr layers with thin amorphous layers at the Al/Zr interfaces. The amorphous interface layers increased in thickness upon annealing to 290 C. Additionally, at 290 C a metastable cubic alloy forms at the Zr deposited on Al interface. Upon heating to 485 C a multilayer ...

International Nuclear Information System (INIS)

The present design of Blanket Shield and Primary Wall for ITER envisages construction of the wall with a water cooled, stainless steel outer layer and a water cooled, copper liner on the inside plasma facing surface. Protection of the inner copper surface with an armour layer is necessary to cope with plasma to wall interaction. There are a number of armour materials under consideration, for this project beryllium was used. The scope of work was to produce a series of mock-ups, each consisting of a different combination of materials, which included Dispersion Strengthened Copper, Copper-Chrome-Zirconium alloy, Beryllium and Stainless Steel. Hot Isostatic Pressing (HIP) was the method used to ensure that a fully diffused bonded joint was achieved giving the necessary strength and thermal conductivity. The first five of the mock ups have been successfully completed and are being tested at the various laboratories in Europe. The remaining mock ups ...

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The electrochromatographic behavior of 25 metal ions on zirconium tungstate-impregnated papers is described. Six background electrolytes were used. On the basis of the differential mobilities of metal ions which depend on the ion-exchange properties of zirconium tungstate and the nature of complex formation with the electrolytes, some important binary and ternary separations have been achieved.

International Nuclear Information System (INIS)

The critical part of the trimetallic transition joint (type 304 stainless steel/Alloy 800/2.25 Cr-1 Mo steel), the Alloy 800/2.25 Cr-1 Mo steel joint welded with Inconel 182, was subjected to thermal cycling between room temperature and 873 K. The thermal cycling test procedure used produces accelerated failures in transition joints similar to those observed in steam generators of operating power plants. On thermal cycling, precipitation at the weld/ferritic steel interface decreased on post-weld heat treatment. This precipitation increased with increased prior ageing and applied stress. The results of these tests indicated a considerable improvement in performance of the trimetallic transition joint compared to the direct (bimetallic) transition joint. (orig.).

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Metallic components within or immediately adjacent to gasifiers, such as gas distributors, thermowells, transfer lines, and cyclones, are subjected to severe of temperature, pressure, and hostile multicomponent gas environments. Metallic heat exchangers/waste-heat boilers resistant to sulfidation, corrosion. and erosion in low- and medium-Btu gas environments are essential components in large-scale gasification schemes, in both dry ash and slogging type gasifiers. Components, in general. must be resistant to corrosion, erosion, and high-temperature creep. A substantial data base is needed on the mechanical properties of materials exposed to complex gas environments to provide a more viable basis for establishing long-term reliability of components. This work examines high-temperature creep of Alloy 800, a high-chromium alloy widely used in coal conversion systems, after exposure to oxygen and oxygen/sulfur mixed-gas ...

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In an HTR plant high temperature components of Alloy 800 materials are subjected to temperatures from about 550 to 850degC in the long term; higher temperatures may occur in the short term. Thus the creep and stress-rupture parameters govern the design of these components. Since in recent years the scope of experimental data available for Alloy 800 materials has considerably increased, a new evaluation of the creep and creep-rupture properties was performed using a data bank computer. The relationships between the characteristics of the creep and creep-rupture behaviour and the metallurgical parameters were investigated by multilinear regression analyses. On the basis of the results of these analyses and after discussion in material expert committees new material specifications were determined for different types of Alloy 800. They were included into the draft standards DIN 17459 and DIN 17460 under the ...

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The bibliography contains citations concerning the structural properties of sputtered tantalum and tantalum compounds. The preparation of thin film capacitors and resistors is described. The electrical properties of the sputtered films are also included. The influence of the substrate on the properties of the coatings is considered, including adherence of the coating to the substrate, and the effects of impurities on coating integrity. (Contains 250 citations and includes a subject term index and title list.)

British Library Electronic Table of Contents (United Kingdom)

Flame propagating through zirconium particle cloud in a small-scale vertical rectangle chamber was investigated experimentally. In the experiments, the zirconium quoted 99% purity was used and the diameter of particles was distributed 1?22 ?m. The zirconium dust was dispersed into the chamber by air flow and ignited by an electrode spark. A high-speed video camera was used to record the images of the propagating flame. Micro-thermocouples, schlieren optical system and microscopic lens were used to obtain temperature profiles and flame structure, respectively. Based on the experimental results, flame propagation characteristics and flame structure of zirconium particle cloud were analyzed. The propagation velocity of the flame is quite slow in the initial 14 ms and then accelerates to maxim...

Energy Technology Data Exchange (ETDEWEB)

Two austenitic steels, 316 Stainless Steel and Alloy 800, have been examined under conditions of both isothermal low cycle fatigue (LCF) and thermomechanical fatigue (TMF). The TMF tests were conducted between 649 and 360/sup 0/C with a carefully controlled triangular waveform. The LCF tests were performed at 649/sup 0/C and both kinds of tests were subjected to a strain range of 0.5%. TMF shortened life to 40% for 316 Stainless Steel and to 5% for Alloy 800. The microstructural evolution occurring in both alloys has been examined and we conclude these do not play a role in the life shortening caused by TMF. The TMF does produce asymmetric hysteresis loops with large tensile peak stresses in tests where the maximum temperature corresponded with the peak compressive stress. The influence of TMF on fatigue crack growth rates has been measured and it was found that TMF accelerated crack growth in ...

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The nucleation of microdamage under dynamic loading was investigated through planar impact experiments accomplished with a light gas gun. The microscopic observation of recovered and sectioned specimens showed that microcracks were nucleated only by cracking of brittle particles inside material. However, for comparison the in situ static tensile tests on the same material conducted with a scanning electron microscope showed that the microcracks were nucleated by many forms those were fracture of ductile matrix, debonding particles from matrix and cracking of brittle particles. The quantitative metallographic observations of the specimens subjected to impact loading showed that most of the cracked particles were situated on grain boundaries of the aluminum matrix. These facts suggested the concept of critical size and incubation time of submicroscopic cavities in the dynamic case and the mechanism of embryo-damage induced nucleation by fracture of brittle particles ...

International Nuclear Information System (INIS)

This paper presents the results of experimental study carried out to know whether the salicylic acid used as an additive during the precipitation of zirconium using ammonium hydroxide solution goes into the filtrate, remains in the hydrated zirconia or gets distributed between the both under the ambient conditions of precipitation. Keeping its simplicity and amenability to adopt on a routine basis, spectrophotometric method has been chosen for the purpose among the many methods available and the problems associated in determining salicylic acid in the presence of zirconium and the medial measures to circumvent the same have been brought out in detail. (author)

Energy Technology Data Exchange (ETDEWEB)

The goal of this program was to increase the high-temperature strength of the H-Series of cast austenitic stainless steels by 50% and upper use temperature by 86 to 140 F (30 to 60 C). Meeting this goal is expected to result in energy savings of 38 trillion Btu/year by 2020 and energy cost savings of $185 million/year. The higher strength H-Series of cast stainless steels (HK and HP type) have applications for the production of ethylene in the chemical industry, for radiant burner tubes and transfer rolls for secondary processing of steel in the steel industry, and for many applications in the heat-treating industry. The project was led by Duraloy Technologies, Inc. with research participation by the Oak Ridge National Laboratory (ORNL) and industrial participation by a diverse group of companies. Energy Industries of Ohio (EIO) was also a partner in this project. Each team partner had well-defined roles. Duraloy Technologies led the team by identifying the base ...

International Nuclear Information System (INIS)

The physical, chemical and mechanical properties of magnesium alloys make them attractive materials for automotive and aerospace applications. However, these materials are susceptible to corrosion and wear. This work discusses the potential of using sol-gel based coatings consisting of ZrO_2 and 15 wt.% of CeO_2. The CeO_2 component provides enhanced corrosion protection, while ZrO_2 impart corrosion as well as wear resistance. Coating deposition was performed by the dip coating technique on two magnesium alloy substrates with different surface finishes: AZ91D (as-casted, sand-blasted, and machined) and AZ31 (rolled and machined). All as-deposited coatings (xerogel coatings) were then subjected to 10 h annealing: a temperature of 180 C was applied to the AZ91D alloy and 140 C to the AZ31 alloy. Morphological and structural properties of the annealed coatings were investigated by ...

International Nuclear Information System (INIS)

Over the recent years the nuclear structure around the N = 50 shell closure, which is very pronounced in the strontium and zirconium isotopes, has been the subject of extensive experimental and theoretical work. On the proton side Z = 38 and Z = 40 provide fairly closed sub-shells. In the strontium isotopes the lg/sub 9/2/ neutron shell is closed at "8"8Sr, supplying relatively pure neutron-hole and neutron-particle states with large spectroscopic factors in "8"7Sr and "8"9Sr, as well as core-coupled states. The mass region is thus ideally suited to examine the transition from a correlated to an uncorrelated (chaotic?) excitational behavior. These two types are characterized e.g. by the density of excited states, the transition strengths, and the spectroscopic factors observed in transfer reactions. We conducted (n,#gamma#) and (d,p) reactions leading to /sup 87,88,89/Sr in addition to "8"8Sr(d,t)"8"7Sr and 24 keV neutron capture in "8"8Sr. The ...

Energy Technology Data Exchange (ETDEWEB)

The effect of warm rolling under various conditions on the microstructure and mechanical property was investigated using an AZ31 Mg alloy sheet. Several processing parameters such as initial thickness, thickness reduction by a single pass rolling, rolling temperature, roll speed, and roll temperature were varied to elicit an optimum condition for the warm rolling process of AZ31 Mg alloy. Microstructure and mechanical properties were measured for specimens subjected to rolling experiments of various conditions. Warm rolling of 30% thickness reduction per pass was possible without any side-crack at temperatures as low as 200 C under the roll speed of 30 m/min. The initial microstructure before rolling was the mixed one consisting of partially recrystallized and cast structures. Grain refinement was found to occur actively during the warm rolling, producing a very fine grain size of 7 {mu}m after 50% reduction in single pass ...

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Using the PMR method the interaction of zirconium and hafnium tetrachlorides with tri.tet.butylphenyl ester of 1,2- naphthoquinonediazide (2)-5-sulfonic acid is studied. The formation of MCl/sub 4/xNQD complexes is established, the equilibrium constants and thermodynamic parameters of complexing reaction are determined. The presence of rapid ligand exchange, proceeding according to associative mechanism, is detected. The rate constants and activation energies of the exchange reaction are calculated.

International Nuclear Information System (INIS)

A method has been developed for the adsorption of Sc"I"I"I employing inorganic ion exchanger zirconium phosphosilicate by batch method. Effects of various parameters have been evaluated on the percentage adsorption of Sc"I"I"I. Separation of Sc"I"I"I from various other elements is standardized. (author)

Energy Technology Data Exchange (ETDEWEB)

The kinetics of the reaction of zirconium phosphates with carbon tetrachloride in sodium and potassium chloride melt as well as the effect of temperature, gas flow, solubility and weight of the solid phase of the phosphate, and stirring of the melt on the chlorination rate has been studied. The kinetic parameters of the reaction (rate constants, activation energy, etc.) have been calculated.

International Nuclear Information System (INIS)

Ti-10V-2Fe-3Al is high strength, metastable beta titanium alloy developed by the Timet Division, Titanium Metals Corporation of America for enhanced forgeability and excellent mechanical property combinations, including deep hardening characteristics. Ti-10-2-3 has been the subject of intense thermomechanical processing (TMP) development and reduction to commercial practice for the full range of open die, closed-die and precision forged products utilized in aerospace and other applications. With commercially proven TMP, Ti-10-2-3 forgings provide a range of strength-fracture toughness combinations from 180 Ksi (1,240 MPa) minimum U.T.S. to 140 Ksi (965 MPa) minimum U.T.S with commensurate fracture toughness. With optimal TMP and these strength-toughness combinations, Ti-10-2-3 forgings are found provide superior smooth and notched fatigue properties critical to aerospace applications over incumbent alpha-beta alloys. The ...

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The divertor collector plate in the INTOR reactor will be subjected to high heat, particle, and neutron fluxes, making it the most severely damaged torus component. The collector plate is composed of a protection plate, which is directly exposed to the particle flux, and a heat sink which provides support for the protection plate and carries the water coolant. The high-Z refractory metals have been considered for use as the protection plate material, and austenitic stainless steels and copper alloys have been considered as the heat sink material. Tungsten and Type 316 stainless steels have been selected for the protection plate and heat sink, respectively. The protection plate has a sputtering lifetime of 1.75 y at a 50% duty factor, while the heat sink is expected to last the lifetime of the reactor.

Energy Technology Data Exchange (ETDEWEB)

For a new and practical {sup 99m}Tc generator using not (n, f){sup 99}Mo, but (n, {gamma}){sup 99}Mo, an inorganic polymer adsorbent framed with oxygen-zirconium-chlorine bonds with a high adsorption performance of Mo has been developed; the polymer adsorbent was named PZC. The amounts of {sup 99}Mo (Mo) adsorbed are stably more than 250 mg/g(PZC). But, the current experiments with 0.5 MBq to 1.85 GBq of {sup 99}Mo gave a subject that the breakthrough of {sup 99}Mo in the elution of {sup 99m}Tc from the adsorbent was 0.05-0.5 %, although the breakthrough of Zr was less than the detection limit of 5 x 10{sup -2} mg(Zr) to 1 g of PZC, and {sup 99m}Tc was eluted constantly with 78{+-}4%. To apply the adsorbent as a generator commercially in Japan, the {sup 99}Mo breakthroughed from the generator must be suppressed to less than 0.15 kBp({sup 99}Mo)/MBq({sup 99m}Tc) by law which is equivalent to 0.015 %, and the {sup 99}Mo breakthrough is controlled ...

UK PubMed Central (United Kingdom)

The management of the interim phase of a complete oral rehabilitation in patients with severely worn dentition is often challenging due to the loss of occlusal vertical dimension, loss of tooth structure,...Full Text Available

Science.gov (United States)

The corrosion behavior of Ta, Ti, and Zr in inorganic acids, bases, chlorides and miscellaneous salts, waters and gases, and organic acids and miscellaneous organic chemicals is summarized. (W.L.H)

International Science & Technology Center (ISTC)

The New Titanium Alloys With Increased Mechanical Properties and Corrosion Resistance for Medical Instruments and their Coatings

CERN Document Server

Metals and alloy - Atmospheric corrosion testing

International Nuclear Information System (INIS)

The "6"2Zn-"6"2Cu generator system is one of the few which yield a pure positron emitting daughter. The authors have developed a method for the preparation of this generator system following 32 MeV #alpha# particle bombardment of nickel targets. The chemical processing involves two stages: first a hydrous zirconium oxide column is used at pH 4-5 to separate the zinc and copper activities produced in the target nickel, and secondly, a conventional anion exchange column is used to retain the "6"2Zn and remove all copper activities in 2M HCl. This column serves as the "6"2Cu generator which will yield pure "6"2Cu repeatedly, free from "6"2Zn and other impurities, in a mixture of HCl and NaCl. A method is outlined also to obtain a solution of "6"2Zn using the hydrous zirconium oxide (HZO) column. "6"1Cu can be prepared as a by-product in the above procedure, but a method for the preparation of "6"1Cu alone using an 18 MeV #alpha# particle beam on a ...

Energy Technology Data Exchange (ETDEWEB)

This volume provides the subject index for the annual input to the Biomass Information Service of the IEA. (DT)

Science.gov (United States)

... MOLYBDENUM ALLOY GUN BARREL LINERS o0 in ... NEW POWDER TECHNOLOGIES FOR MOLYBDENUM ALLOY GUN BARREL LINERS ...

International Nuclear Information System (INIS)

... filters molybdenum alloys production sulfuric acid alloys chemical reactions ...

International Nuclear Information System (INIS)

This patent describes the producing of a refractory metal wherein a sponge refractory metal is produced as an intermediate product by the use of magnesium with the incidental production of magnesium chloride, and wherein residual magnesium is separated from the magnesium chloride and from refractory metal to a vacuum distillation step which fractionally distills the magnesium, the magnesium chloride, and the metal sub-chlorides; the steps of: recovering fractionally distilled vapors of magnesium chloride and metal sub-chlorides from a sponge refractory metal; separately condensing the vapors as separately recovered; and recycling the separately recovered magnesium at a purity of at least about 96%.

Energy Technology Data Exchange (ETDEWEB)

The incorporation of (a) Cs/Sr as simulated heat-generating isotopes contained in Purex reprocessing waste, (b) simulated actinides, and (c) simulated Purex waste in sodium zirconium phosphate (NZP) has been studied. The samples were prepared by sintering, by hot pressing and by hot isostatic pressing in metal bellows containers. The short-term chemical durability of the phosphate-based material containing Purex waste was within an order of magnitude of that for Synroc-C, as measured by 7-day MCC-1 tests at 90{degrees}C. The dissolution behavior showed evidence of re-precipitation phenomena, even after times as short as 28 days. Potential for improvement of NZP-based ceramics for HLW management is discussed. 19 refs., 4 figs., 3 tabs.

Energy Technology Data Exchange (ETDEWEB)

Fe-Ni-Mn martensitic steels are one of the major groups of ultra-high strength steels that have good mechanical properties and ductility in as annealed condition but they suffer from severe inter-granular embitterment after aging. In this paper, the effect of heavy shaped cold rolling and wire drawing on the mechanical properties of Fe-Ni-Mn steel was investigated. This process could provide a large strain deformation in this alloy. The total strain was {epsilon} {approx}7. Aging behavior and tensile properties of Fe-10Ni-7Mn were studied after aging at 753 K. The results showed that the ultimate tensile strength and ductility after cold rolling, wire drawing and aging increased up to 2540 MPa and 7.1 %, respectively, while the conventional steels show a premature fracture stress of 830 MPa with about zero ductility after aging.

International Nuclear Information System (INIS)

Results of hot cracking on welds with compositions between alloy 800 and AWS ER NiCr 3. Investigation of the influence of Si, Mn, Ti and Al on the hot cracking suscpetibility of the alloy 800. (orig.).

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

Energy Technology Data Exchange (ETDEWEB)

The topics of these short lectures on the subject of cyclic stress were: Microstructural mechanisms of damage accumulation under a multistage cyclic stress until incipient cracking; influence of surface decarbonizing phenomena on the failure behaviour of steel construction parts subjected to cyclic stress; thermocyclic fatigue of pipe samples of austenitic steel 1.4436; studies on surface structuring, microstructure and fatigue in LCF area. The short lectures on effects of quasi-static and creep stress were: Shear fracture in AlMg alloys as a result of local plastic instability; study of formation and growth of pores for an early recognition of damage and the course of damage in heat-resistant steels under creep test; experimental and numeric studies of the infuence of the microstructure on the course of damage during shear fractures of steel; numerical modelling of ductile fractures on the basis of micromechanical models. ...

Science.gov (United States)

Not Available

Energy Technology Data Exchange (ETDEWEB)

Alloys are described which contain nickel, aluminum, boron, iron and in some instances manganese, niobium and titanium.

Energy Technology Data Exchange (ETDEWEB)

The National Institute of Materials Science (NIMS) has utilized the in-house alloy design program to develop a 5{sup th} generation Ni-base single crystal superalloy, TMS-196 with superior high temperature creep, thermo mechanical fatigue (TMF) and oxidation resistance by incorporating further ruthenium (Ru) and chromium (Cr) content over the compositions of 4{sup th} generation superalloys. With Ru additions in advanced superalloys to enhance phase stability, higher content of refractory elements can be accommodated to provide further strengthening; the associated oxidation resistance can be improved by the increase in Cr additions. In present article, TMS-196 has been subjected to cyclic/isothermal oxidation tests at 1100 C and 900 C, creep at conditions between 800 C{proportional_to}1100 C/137MPa{proportional_to}735MPa and TMF cycles. Preliminary studies indicate that the surface of oxidized TMS-196 can exhibit continuous alumina layer ...

International Nuclear Information System (INIS)

This paper reviews the mill flowsheet applied at the SOMAIR (Societe des Mines de l'Air) uranium mill in Niger. It focuses on the yellow cake quality improvements achieved by molybdenum and zirconium elimination through double yellow cake precipitation in tanks at first stage and through size/density control in a fluidized bed precipitator at second stage. Water saving aspects in the plant are also presented. (author)

Energy Technology Data Exchange (ETDEWEB)

The evaluated data testing for Si, Zr, Nb and Fe materials has been performed through the analyses of the neutron leakage spectrum from spherical assemblies measured in integral benchmark experiments with (d,t) and Cf fission neutron sources. Intercomparisons of the calculated from BROND-2, ENDF/B-6 and JENDL-3 data files with experimental results are presented.

International Nuclear Information System (INIS)

Due to the well-establish corrosion problems of Alloy 600 as a steam-generator material and the subsequent focus on thermally treated (TT) Alloy 690 and Alloy 800 as alternative materials, a systematic analysis of the corrosion behavior of these two latter alloys is warranted. Corrosion test results for Alloys 690 TT and 800 were collected and organized in the form of corrosion mode diagrams. Selected data for mill annealed (MA) Alloy 600 were also included for reference. The corrosion mode diagrams correlate the modes of corrosion degradation observed in tests as functions of the environment pH and electrochemical potential (ECP). The diagrams confirm that Alloys 690TT shows some susceptibility in caustic environments, and Alloy 800 shows susceptibility in both caustic and highly acidic environments. (authors). 6 figs., ...

International Nuclear Information System (INIS)

Consideration is given to the process of the formation of a titanium sponge alloyed with niobium or tantalum, in the joint metallic reduction of titanium, niobium and tantanum chlorides. A percentage composition of the phases observed and the structure of the alloyed sponge have been studied. It is shown that after one remelting operation of the alloyed sponge the alloys of titanium with niobium and tantalum have a uniform component distribution. At the stage of chloride reduction there appear solid solutions based on titanium and an alloying component. The stage of vacuum separation of the reaction mass is associated with a mutual dissolution of the primary phases and the formation of the solid solutions of the alloyed titanium sponge, which, by their composition, are close to the desired alloy composition. The principal features of the ...

International Nuclear Information System (INIS)

The influence of various alloy elements on tensile strength of the eutectic, directionally solidified superalloy 73 C was determined. The tensile properties of the base alloy has been increased by Al, Y and C as alloying elements, while Ni and Ti showed a decreasing effect (alloy softening). However, ductility and thermo-fatigue behaviour had been influenced in a positive way by these elements. The specific meachanism caused by the different elements are discussed. (orig.).

Energy Technology Data Exchange (ETDEWEB)

The processing characteristics, tensile properties, and oxidation response of two Nb-Ti-Al-Cr alloys were investigated. One creep test at 650 C and 172 MPa was conducted on the base alloy, which contained 40Nb-40Ti-10Al-10Cr. A second alloy was modified with 0.11 at.% C and 0.07 at.% Y. Alloys were arc melted in a chamber backfilled with argon, drop cast into a water-cooled copper mold, and cold rolled to obtain a 0.8-mm sheet. The sheet was annealed at 1,100 C for 0.5 h. Longitudinal tensile specimens and oxidation specimens were obtained for both the base alloy and the modified alloy. Tensile properties were obtained for the base alloy at room temperature, 400, 600, 700, 800, 900, and 1,000 C and for the modified alloy at room temperature, 400, 600, 700, and 800 C. Oxidation tests the base alloy ...

Energy Technology Data Exchange (ETDEWEB)

The use of nickel alloys in Flue Gas Desulfurization (FGD) applications is described. Recently, nickel alloys 625 and C-276 have been clad to carbon steel plate. Production and properties of the clad plate are reviewed and a brief discussion is presented on production, fabrication and welding. Laboratory and field corrosion tests in SO/sub 2/ scrubber environments suggest that alloy 625 and C-276 clad steel plates are as corrosion resistant as the solid alloy plate.

International Nuclear Information System (INIS)

The relationships of hydrogen alloyed #beta#-titanium alloy deformation behaviour to its microstructure and texture are investigated. It is shown that plasticity increases and strain induced texture changes at low hydrogen contents (0.1-0.2 mass %). Possible mechanisms responsible for specific features of #beta#-Ti alloy deformation are discussed. The study is made using alloy VT35 doped with hydrogen

Energy Technology Data Exchange (ETDEWEB)

Three model boilers, manufactured to simulate full-size tube sheet crevices, were tested with various secondary side environments. The first was faulted with organics representative of the decomposition of humic acid. The second was faulted with sodium carbonate and sodium hydroxide, while the third was faulted with sodium sulfate and sodium hydroxide. Each model contained seven tubes, which included Alloy 600 in the mill-annealed (MA) and thermally-treated (TT) conditions and Alloy 690 in the thermally-treated condition. Two models contained Alloy 800 tubes in the mill-annealed condition and one had Alloy 800 in the mill-annealed/cold-worked/glass-bead-peened condition. Two different sizes of tubesheet crevices were used in all model boilers. In the organics-faulted boiler, tubes of Alloy 600MA, Alloy 690TT and Alloy 800MA experienced no ...

Energy Technology Data Exchange (ETDEWEB)

Theoretical assessment on the chromatographic {sup 99m}Tc generator preparation using (n, {gamma}) {sup 99}Mo produced ex-natural molybdenum was carried out. The relationship between the neutron flux for MoO{sub 3} target activation, Mo-content or Mo adsorption capacity of column packing material, {sup 99m}Tc pertechnetate concentration and/or {sup 99m}Tc radioactivity of eluate was established. The reasonably lower limit of neutron flux of reactor and Molybdenum content of column packing material were found out to estimate the production of portable chromatographic generators available for nuclear medicine application. The concentration of {sup 99m}Tc pertechnetate eluate of low {sup 99m}Tc concentration using the column elution technique was also evaluate theoretically and conducted successfully in practice. Three options of {sup 99m}Tc generator using Titanium-Molybdate, Zirconium-Molybdate and Zirconium Oxide as generator column-packing ...

International Nuclear Information System (INIS)

Reaction of formation of 3, 5, 7, 3', 4', 5' - hexaoxiflavone - myricetin complexes with zirconium and hafnium ions has been the basis for development of luminescent method of determining these elements. Optimum conditions for complexing have been determined. For Hf they are : 8-9 HCl concentration, maximum fluorescence wave length (lambda fl.)of 520 nm, wave length of exciting light (lambda el) of 436 nm, for Zr lambda fl = 536nm, lambda el = 436 nm. Stable fluorescence establishes after 25 min. for Zr and after 15 min for Hf in the presence of 40% ethanol. Usage of various camouflage agents has permitted to attain high selectivity of the method. Possibility for determination of Zr with myricetin in the presence of a 10-time excess of Hf, Cr, Cu, 50-time excess of Mo and Ti is shown. Sensitivity of Zr determination is 2.0x10 #mu#g"-"2/ml, for Hf it is 9.0x10 #mu#g"-"3 and mineral waters.

Energy Technology Data Exchange (ETDEWEB)

Laser surface alloying with gaseous nitrogen was utilized to improve the wear resistance of a Ti-6Al-4V alloy. Wear-resistant composite coatings reinforced by hard TiN dendrites were produced 'in-situ' on a substrate of a Ti-6Al-4V alloy. The hardness and wear resistance of the laser alloyed coating under two-body abrasive and block-on-ring full-sliding wear conditions were significantly enhanced. (orig.)

Energy Technology Data Exchange (ETDEWEB)

The CeO{sub 2}-ZrO{sub 2}-Bi{sub 2}O{sub 3} samples with different bismuth content were prepared in this study. By the doping of Bi{sub 2}O{sub 3} into the lattice, TPR profiles of the CeO{sub 2}-ZrO{sub 2} shifted to lower temperatures and oxygen storage capacity increased remarkably. It is concluded that the reason for such a behavior is probably due to both the formation of oxygen vacancies which enhance the oxygen mobility and the simultaneous reduction of Ce{sup 4+} and Bi{sup 3+} in the mixed oxides. (authors)

International Nuclear Information System (INIS)

The manufacturing of TRIGA fuel rods with low enriched uranium follows in principle the same route as high-enriched uranium. The high purity of the primary metals (uranium, zirconium and erbium) is important for determining the equilibrium metal-hydrogen phases. The impurities from the metal, on the surface and from hydrogen may have an important influence on the hydriding process. This paper presents the aspects of the fuel contamination with oxygen during the manufacturing process of the low enriched uranium fuel. The continuous control of the oxygen concentration in the working zone ensures avoidance of the accidental contamination. Key words: manufacturing, fuel, oxygen, contamination. (authors)

International Nuclear Information System (INIS)

In one of the first uses of high Tc superconductors in an end-use product, Lake Shore Cryotronics and a Swiss lab have developed a liquid nitrogen level sensor using a high Tc thin film. The probe is manufactured using a seamless stainless steel tube with an yttrium-based zirconium oxide flame-sprayed on the tube. A plasma-sprayed superconductor compound is deposited on top of that. The probe is coated with a sealant that protects the superconducting film from the atmosphere. This manufacturing method has yielded an extremely durable product. Unaffected by ice formation and related mechanical problems, the superconducting level sensor can be kept in the dewar for long periods of time.

Science.gov (United States)

... alloys--Lanthanum-- Magnesium--Magnasium &11oy8--Hagn*31Uft compounds--Manxganese--Manganes. alloys-- Mercury ...

Science.gov (United States)

Hilled Bend Spechene of an Alpha-Beta Titanium Alloy. Ti-6M14V. ..... The all beta titanium alloy was nllled from both sides; only the edges were taped. ...

Energy Technology Data Exchange (ETDEWEB)

The nickel-rich superalloys Alloy 600 and Alloy 800 have been corroded in mildly alkaline deuterated aqueous conditions typical of secondary coolant circuits in a nuclear power station. The oxide films and substrates of these alloys have been analysed by imaging SIMS depth profiling, which makes it possible to describe elemental distribution in all three dimensions. The measurement of the distribution of the secondary ions NiO[sup -], FeO[sup -] and CrO[sup -] appears useful for detailing the behaviour of nickel, iron and chromium within oxidized phases. The measurement of D[sup -] distribution outlines the extent of oxide hydration. For Alloy 800, evidence of sodium migration into the grain boundaries of the alloy substrate is found. For Alloy 600, no grain boundary sodium ingress can be identified under comparable corrosion conditions. (author).

Energy Technology Data Exchange (ETDEWEB)

The resistance to pitting of a Fe-17%Cr alloy in Cl[sup [minus

Energy Technology Data Exchange (ETDEWEB)

Welded Ni-base alloys and Alloy 800 were exposed under metal dusting conditions at 600 C and 650 C for up to 6000 hours. Alloy 800 was attacked very strongly already in the first days and Alloy 600 also rather soon and widespread, on both materials attack started mainly in the heat affected zone. Several surface states of Alloy 600: brushed, ground, sand-blasted and pickled were tried only grinding caused a modest delay and decrease of metal dusting attack. Generally the attack was less widespread but deeper at 650 C than at 600 C, also for Alloy 601 and 602. The latter alloys show minor, mainly local attack, but especially the welds are affected. TIG welding led to better resistance than hand-welding. (Abstract Copyright [2003], Wiley Periodicals, Inc.)

Science.gov (United States)

... Accession Number : ADD120492. Title : Environmental Cracking of the Alpha-Beta Titanium Alloy, Ti-6Al-6V-2Sn,. Corporate ...

CERN Document Server

Differences in synchrotron radiation induced gas desorption from stainless steel and aluminium alloy

Energy Technology Data Exchange (ETDEWEB)

In this project, graphite is used as a substitute for lead in order to maintain the machinability of plumbing components at the level of leaded brass. Graphite dispersed in Cu alloy was observed to impart good machinability and reduce the sizes of chips during machining of plumbing components in a manner similar to lead. Copper alloys containing dispersed graphite particles could be successfully cast in several plumbing fixtures which exhibited acceptable corrosion rate, solderability, platability, and pressure tightness. The power consumption for machining of composites was also lower than that of the matrix alloy. In addition, centrifugally cast copper alloy cylinders containing graphite particles were successfully made. These cylinders can therefore be used for bearing applications, as substitutes for lead-containing copper alloys. The results indicate that copper graphite ...

Science.gov (United States)

... Accession Number : ADD144314. Title : Beta-21S: A High Temperature Metastable Beta Titanium Alloy. Descriptive Note : Conference Proceedings, ...

Energy Technology Data Exchange (ETDEWEB)

Recognizing the importance of {sup 99m}Tc and {sup 99m}Tc-based radiopharmaceuticals in nuclear medicine, the Philippine Nuclear Research Institute has initiated research on the development of column-type generators for {sup 99m}Tc using {sup 99}Mo in the form of a gel. The use of reactor-produced {sup 99}Mo will reduce the country's dependence on the importation of commercial generators based on fission product molybdenum-99. However, the relatively low specific activity of {sup 99}Mo must be compensated by the high adsorption capacity of the column material for molybdenum. A procedure based on the incorporation of low activity {sup 99}Mo into a zirconium molybdate gel matrix was adopted with reasonable success. Because the properties of the gel vary considerably with conditions of synthesis, the following parameters were carefully controlled: pH, concentration, temperature, order of mixing of the reactant solutions and conditions of aging, washing and ...

KoreaScience (Korea)

Full Text Available

Science.gov (United States)

... cure. Descriptors : *Combustible cartridge cases, *Ammunition propellants, Patents, Binders, Curing agents, Additives. Subject ...

KoreaScience (Korea)

Full Text Available

Wastenet

society organisations (more than 30) in reaching the most vulnerable groups and dealing with a subject area as sensitive

Energy Technology Data Exchange (ETDEWEB)

Whereas supersaturated aluminum alloys demonstrate enhanced passivity, conventional aluminum alloys spontaneously pit in air-saturated chloride solutions. We have concentrated on three areas: evaluation and characterization of Al-W alloys, which exhibit the best corrosion performance of any alloy system studied to date; characterization of the passive-film structure of Al-Mo alloys; and production and characterization of Al-W and Al-Ta powders, which will be used for compaction into bulk material. Surface analysis of the Al-W passive films formed during polarization show surprising little oxidized solute compared to other alloys. These results indicate that the barrier layer formation and electrostatic repulsion mechanisms used to explain the passivity of other alloys are not involved here. Instead the W may act to stabilize the passive film ...

International Nuclear Information System (INIS)

In-reactor testing of bolt-loaded compact tension specimens was performed in 360 C water to determine the irradiation-assisted stress corrosion cracking (IASCC) behavior of HTH Alloy X-750 and direct-aged Alloy 625. New data confirm previous results showing that high irradiation levels reduce SCC resistance in Alloy X-750. Heat-to-heat variability correlates with boron content, with low boron heats showing improved IASCC properties. Alloy 625 is resistant to IASCC, as no cracking was observed in any Alloy 625 specimens. Microstructural, microchemical and deformation studies were performed to characterize the mechanisms responsible for IASCC in Alloy X-750 and the lack of an effect in Alloy 625. The mechanisms under investigation are: boron transmutation effects, radiation-induced changes in microstructure and deformation characteristics, and ...

Energy Technology Data Exchange (ETDEWEB)

To clarify the acidic and alkaline Intergranular Stress Corrosion Cracking (IGSCC) mechanism of thermally treated alloy 690 (alloy 690 TT) and shot peened alloy 800 (alloy 800 SP), C-ring tests were conducted in deaerated HCl solutions and in deaerated NaOH solutions at 350degC, compared with the acidic and the alkaline IGSCC susceptibilities of mill-annealed alloy 600 (alloy 600 MA), full-sensitized one (alloy 600 FS) and thermally treated one (alloy 600 TT). Grain boundary characteristics, such as chromium depleted zone and chromium carbide precipitation, were examined using modified Huey test and Transmission Electron Microscopy. Potential-pH diagram for Ni, Cr, Fe-H{sub 2}O system at 350degC was constructed and the solubilities of NiO, Cr{sub 2}O{sub 3} and Fe{sub 3}O{sub 4} were also calculated to evaluate the ...

KoreaScience (Korea)

Full Text Available

International Nuclear Information System (INIS)

The investigations carried out on Alloy 800 in aqueous high-temperature environments in France as well as in other countries are reviewed. These studies are mainly concerned with nuclear industry where Alloy 800 can be used as structural material for steam generators of PWR, breeders or HTR. As results referred to in the literature on cracking in caustic environmens do not always agree, a discussion is presented on the matter. The behaviour of Alloy 800 in superheated steam is examined. (Auth.).

International Nuclear Information System (INIS)

(Nov 1973). United States Greenfield, MA Pierce, CM Chicago, IL.

KoreaScience (Korea)

Full Text Available

International Science & Technology Center (ISTC)

Investigation of Destruction Mechanisms in Reactor Steels and Alloys under Cycling Deformation

Energy Technology Data Exchange (ETDEWEB)

Short communication. 6 refs., 2 figs.

Energy Technology Data Exchange (ETDEWEB)

General corrosion behavior of ALLOY 800 in high temperature water was studied in relation to its surface film structure. The surface film formed in water was found to decrease the corrosion rate of ALLOY 800. This film is composed of Ni ferrite, and can be obtained by oxidation in air or steam. Based on these results, air or steam oxidation treatment to inhibit Ni and Co release of ALLOY 800 into high temperature water is proposed. (author).

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

Energy Technology Data Exchange (ETDEWEB)

In the present work, electrochemical measurements and corrosion tests in NaCl solutions were carried out to study the effect of aging treatments on pitting corrosion behavior in a 8090 alloy and its high purity Al-Li binary alloy analogue. The pitting corrosion characteristics and corrosion resistance of the 8090 alloy have been determined in relation to precipitation microstructures. (orig.).

Science.gov (United States)

... THE STRENGTH, TOUGHNESS, AND STRESS-CORROSION CRACKING SUSCEPTIBILITY OF A METASTABLE BETA TITANIUM ALLOY (Ti-11. ...

Energy Technology Data Exchange (ETDEWEB)

Simulated atmospheric corrosion studies were performed to determine the corrosion protection provided by galvanized zinc coatings on depleted uranium, U-0.75 Ti alloy, and U-6 Nb alloys. The accelerated ASTM tests consisted of exposing the galvanized samples to aqueous and aqueous chloride environments. The test results showed that anodic protection was provided by the electronegative zinc coatings on uranium and uranium alloys. Treating zinc with chromate conversion coatings also provided more protection.

International Nuclear Information System (INIS)

A new high strength titanium alloy has been developed primarily intended for fastener applications. While Ti-6Al-4V is used extensively as a fastener alloy in the aerospace industry, its shear strength allowable is limited to 655 MPa (95 ksi). For higher shear strength requirements, various steels or nickel-based alloys are used (up to 860 MPa (125 ksi)), but with the attendant density penalty. This new alloy is intended to provide the 860 MPa shear strength at roughly a 40% weight savings. After screening various alloy systems, the optimum chemistry has been selected as follows: Ti-6.0V-6.2Mo-5.7Fe-3Al. In light of its 125 ksi shear strength goal, the alloy has been designated TIMETAL reg-sign 125.

International Nuclear Information System (INIS)

In order to substitute expensive cast titanium alloys by powder ones the possibility of introduction of powder additions by mechanical stock mixing is studied. It is shown that microstructure of powder alloys of Ti-Zr(1-9%) system is typical for one-phase cast #alpha#-alloys. The Ti-Mo(1-9%) and Ti-Nb(1-9%) system alloys have microstructure typical for two-phase (#alpha#+#beta#)-alloys. For homogeneous structure to be obtained the high temprature annealing is advisable after hot pressing. Alloying with Mo, Zr and Nb permits to increase considerable the strength of powder titanium products (at 9% Mo more than two times).

Energy Technology Data Exchange (ETDEWEB)

In this book over 250 alloys are organized by AISI number into 10 major sections: Irons, Carbon Steels, Alloy Steels, Low Alloy Constructional Steels, Ultra High Strength Steels, Tool Steels, Maraging Steels, Wrought Stainless Steels, Heat Resistnat Casting Alloys, and Iron Based Rought Superalloys. Each alloy record lists the designation, specifications, UNS number, composition, product forms and a comment on the high-temperature properties and applications. Referenced data is then given for physical properties such as density, specific heat, thermal conductivity, thermal expansion, electrical conductivity, Poisson's ratio, moduli of elasticity and rigidity, etc. Mechanical properties follow, and include tensile properties, shearing and bearing properties, impact properties, creep, stress rupture and stress relaxation and fatigue properties. The last part of the ...

Energy Technology Data Exchange (ETDEWEB)

Magnesium alloys show a high specific strength and are therefore increasingly used for light-weight constructions in transportation industry.{sup [1,2]} To predict the behaviour of the material under the influence of cyclic loading it is vital to understand the fatigue behaviour of magnesium alloys. Only when understood properly, it is possible to fully apply the potential weight reduction by using magnesium alloys. A very important aspect in fatigue of magnesium alloys is the influence of a corrosive media and elevated temperatures, of which both are relevant in automotive applications. These two factors tend to have deleterious effects on magnesium alloys and therefore also have to be considered in investigations on the fatigue behaviour of magnesium alloys. (Abstract Copyright [2004], Wiley Periodicals, Inc.)

International Nuclear Information System (INIS)

The threshold stress intensities for stress corrosion crack propagation in beta titanium alloy 38-6-44, Ti3Al-8V-6Cr-4Mo-4Zr, has been determined in salt water and methanolic solutions. The alloy was immune to stress corrosion cracking (SCC) in aqueous sodium chloride solutions (marine atmosphere). However, in methanolic solutions, the alloy was very susceptible to SCC. This marked susceptibility in methanolic solutions can be mitigated by the addition of an inhibitor: sodium nitrate. Crack extension in the alloy was transgranular and failure occurred by brittle quasi-cleavage in methanolic solutions.

International Nuclear Information System (INIS)

By the methods of microstructural and electron-microscopic analyses by the tension test and impact test studied is the effect of quenching conditions on structure and mechanical properties of the TS6 titanium-#beta# alloy. It is shown that low temperature quenching from 700 deg C, recommended earlier for analogous VT15 titanium alloy, leads to appearence of intercrystalline fracture and to sharp decrease of impact strength of the TS6 alloy. Established are optimum conditions for quenching of half-finished products and articles of the TS6 alloy depending on their subsequent working or operation.

International Nuclear Information System (INIS)

Cr_2O_3 scales are found to form on Alloy 800 and a similar pure ternary alloy in air, and 1 and 50 atm. helium containing oxidizing impurities typical of those in an SGHTR. The strong temperature dependence and neglibible helium overpressure dependence indicate that gas transport through the scales is not rate controlling. Surface oxidation rates are therefore controlled by solid state diffusion and the low oxygen partial pressure dependence of the oxidation rate in Alloy 800 is ascribed to the presence of extrinsic defects in the Cr_3O_3 (due to doping by alloying elements) or to the presence of short circuit diffusion paths. (Auth.).

British Library Electronic Table of Contents (United Kingdom)

There is evidence that aged normal subjects have more difficulty in achieving automaticity than young subjects. The underlying central neural mechanism for this phenomenon is unclear. In the present study, functional magnetic resonance imaging (fMRI) was used to investigate the effect of normal ageing on automaticity. Aged healthy subjects were asked to practice self-initiated, self-paced, memorized sequential finger movements with different complexity until they could perform the tasks automatically. Automaticity was evaluated by having subjects perform a secondary task simultaneously with the sequential movements. Although it took more time, most aged subjects eventually performed the tasks automatically at the same level as the young subjects. Functional MRI results showed that, for bot...

International Nuclear Information System (INIS)

The creep crack growth properties of two versions of Alloy 800 have been compared at 500 and 600"0C in the Grade II condition in tests up to 10"4 hours duration. The two alloys were a low carbon alloy containing (wt.%) 0.024 C, 0.5 Ti, 0.3 Al (Alloy B) and a higher carbon alloy containing (wt.%) 0.038 C, 0.2-0.3 Ti, 0.2-3.0 Al (Alloy J). At 600"0C, Alloy B attained maximum age hardening in 10"2 hours, whereas J did not harden significantly in time up to 10"4 hours. Both alloys age hardened at 550"0C with Alloy J hardening more rapidly than B. The creep displacements and displacement rates in small compact tension specimens at 600"0C were smaller than Alloy B than in Alloy J. However, failure times were shorter in Alloy B because of lower ...

International Nuclear Information System (INIS)

In order to investigate the role of amorphous SiO2 particles in corrosion and wear resistance of Ni-based metal matrix composite alloying layer, the amorphous nano-SiO2 particles reinforced Ni-based composite alloying layer has been prepared by double glow plasma alloying on AISI 316L stainless steel surface, where Ni/amorphous nano-SiO2 was firstly predeposited by brush plating. The composition and microstructure of the nano-SiO2 particles reinforced Ni-based composite alloying layer were analyzed by using SEM, TEM and XRD. The results indicated that the composite alloying layer consisted of ?-phase and amorphous nano-SiO2 particles, and under alloying temperature (1000 deg. C) condition, the nano-SiO2 particles were uniformly distributed in the alloying layer and still kept the amorphous structure. The corrosion resistance of composite ...

Energy Technology Data Exchange (ETDEWEB)

The purpose of this work was to investigate the role of chromium on hydrogen embrittlement of Ni-Cr-Fe alloys and thus to develop a better understanding of the low-temperature stress corrosion cracking (SCC) phenomenon. The effect of chromium on hydrogen embrittlement was examined using tensile tests followed by material evaluation via scanning electron microscopy (SEM) and light optical microscopy. Four alloys were prepared with chromium contents ranging from 6 to 35 wt pct. In the uncharged condition, ductility, as measured by the percent elongation or reduction in area, increased as the alloy chromium content increased. Hydrogen appeared to have only minor effects on the mechanical properties of the low-chromium alloys. The addition of hydrogen had a marked effect on the ductility of the higher-chromium alloys. In the 26 pct chromium alloy, the elongation to ...

Science.gov (United States)

The purpose of this communication is to determine whether the solubility enhancements for cold-worked Pd-Ni alloys increase or decrease with atom fraction of Ni. Substitutional Ni atoms contract and Pd lattice, in contrast to the lattice expansion resulting from substitutional Ag in Pd. The Pd-Ni alloy system forms a continuous series of fcc solid solution alloys over the whole composition range. The solubility enhancements will also be determined for a series of homogeneous, ternary Pd[sub 1[minus]x]Ni[sub 1/2x]Ag[sub 1/2x] alloys for x in the range from 0 to 0.2. For this series of ternary alloys the fcc lattice parameters do not change significantly from that of pure Pd. The alloys used in this research were purchased from Tanaka Kikinzoku Kogyo K.K. The detailed experimental procedure has been described previously. The alloys were all ...

UK PubMed Central (United Kingdom)

Although there have been numerous studies investigating subjective spatial impression in rooms, only a few of those studies have addressed the influence of visual cues on the judgment of auditory measures....Full Text Available

UK PubMed Central (United Kingdom)

Data from exposure of experimental animals and human subjects to sulfuric acid presents a consistent picture of its toxicology. Effects on airway resistance in asthmatic subjects were well predicted...Full Text Available

UK PubMed Central (United Kingdom)

A mesophilic yeast, Candida utilis, and a psychrophilic yeast, Leucosporidium stokesii, were subjected to freeze-thaw cycling over the range 25 to -60 C. Viability...Full Text Available

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... Author: Vets With A Mission Subjects: vietnam, vietnam war, warfare DeweyClass: 959.7043 Resource ... Subjects: vietnam, vietnam war DeweyClass: 959.7 Resource type: bibliography, index World Travel ...

Science.gov (United States)

...parents or guardians and for assent by children. 46.408 Section 46.408 Public...SUBJECTS Additional Protections for Children Involved as Subjects in Research ...parents or guardians and for assent by children. (a) In addition to the...

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... Title : Transverse Pumping with Diode Lasers. Descriptive Note : Technical rept. ... Subject Categories : LASERS AND MASERS. ...

British Library Electronic Table of Contents (United Kingdom)

ABSTRACT This article proposes a philosophical reconstruction of the subject of the educator as the agent of curriculum. Starting from recent work in critical theory and philosophy, it describes the process of the existential crisis of the educator as the first step toward a truly critical education. The article argues that philosophy of curriculum must be concerned not just with forms of thought but also with forms of being-with the very ground of the subject and its real. This political ontology of the subject suggests a process of reconstruction consisting of several stages: the disclosure of ideology and complicity, the investigation of the process of interpellation, and the creation of a fundamentally collective educational practice. It is only on the basis of the effective staging of...

International Nuclear Information System (INIS)

Studies of the gastrointestinal absorption of lead-203 chloride were carried out on 11 normal subjects, 7 males and 4 females. Whole body counting of these subjects after administration of 74 kBq (2 #mu#Ci) of cyclotron-produced lead-203 chloride showed a mean absorption of 21.3% of the dose with a range from 10.4 to 47.7%. The male subjects had a lower mean absorption of 18.1% of the dose compared with a mean of 26.9% in the females. Although this difference did not reach statistical significance, it is postulated that male/female differences in absorption may relate to differences in iron saturation of the subjects.

Energy Technology Data Exchange (ETDEWEB)

Certain radioiodine containing amides useful as brain imaging agents are disclosed. The compounds of the subject invention are represented by the formula

Science.gov (United States)

... fields, materials can be subjected to energy densities exceeding those realized in high explosives, a fact which forms the basis for magnetic forming ...

British Library Electronic Table of Contents (United Kingdom)

Gas nitridation has shown excellent promise to form dense, electrically conductive and corrosion-resistant Cr-nitride surface layers on Ni-Cr base alloys for use as proton exchange membrane fuel cell (PEMFC) bipolar plates. Due to the high cost of nickel, Fe-base bipolar plate alloys are needed to meet the cost targets for many PEMFC applications. Unfortunately, nitridation of Fe-base stainless steel alloys typically leads to internal Cr-nitride precipitation rather than the desired protective surface nitride layer formation, due to the high permeability of nitrogen in these alloys. This paper reports the finding that it is possible to form a continuous, protective Cr-nitride (CrN and Cr2N) surface layer through nitridation of Fe-base stainless steel alloys. The key to form a protective Cr...

Energy Technology Data Exchange (ETDEWEB)

In this work, we have investigated the capability of different bimetallic nanoparticle alloy combinations to be used in fibre optic sensors based on the technique of surface plasmon resonance. The metals considered for this analysis are silver, gold, copper and aluminium. The performance of the sensor with different bimetallic nanoparticle alloy combinations is evaluated and compared numerically. The performance is analysed in terms of three parameters: sensitivity, signal-to-noise ratio (SNR) and operating range for the sensing layer refractive index values. On the basis of the comparison and some logistic criteria, the best possible bimetallic alloy combinations along with a requisite alloy composition ratio are predicted. The bimetallic nanoparticle alloy combination is capable of simultaneously providing larger values of sensitivity, SNR and operating range, which is not ...

British Library Electronic Table of Contents (United Kingdom)

Statement of problem Because noble dental casting alloys for metal ceramic restorations have a wide range of mechanical properties, knowledge of these properties is needed for rational alloy selection in different clinical situations where cast metal restorations are indicated. Purpose The purpose of this study was to compare the mechanical properties and examine both the fracture and polished surfaces of 6 noble casting alloys that span many currently marketed systems. Five alloys were designed for metal ceramic restorations, and a sixth Type GPT has Type IV alloy for fixed prosthodontics (Maxigold KF) was included for comparison. Material and methods Specimens (n=6) meeting dimensional requirements for ISO Standards 9693 and 8891 were loaded to failure in tension using a universal testin...

Energy Technology Data Exchange (ETDEWEB)

Resistance of Alloy 800 as a PWR S/G tube material to IGC/IGSCC and Ni, Co release into water was evaluated as compared with Alloys 600 and 690. The study to improve the resistance to IGSCC and general corrosion was also made, including the effects of shot-peening on the distribution of the residual stress of the U-bent tubes and the susceptibility to SCC, the stabilizing elements on IGC/IGSCC, and prior oxidation on general corrosion. From the results, shot-peened Alloy 800 was estimated to be the most reliable S/G tube material among the high nickel alloys tested. In addition, the Alloy 800 tube would obtain further reliability in IGSCC and general corrosion resistance by the combined addition of Ti, and Nb, and the prior oxidation of the inner tube surface, respectively.

Energy Technology Data Exchange (ETDEWEB)

Results of strain controlled fatigue and tensile tests are presented for two nickel base solution hardened alloys which are reference structural alloys for use in several high temperature gas cooled reactor concepts. These alloys, Hastelloy X Inconel 617, were tested at temperatures ranging from room temperature to 871/sup 0/C in air and impure helium. Materials were tested in the solution annealed as well as in the pre-aged condition where aging consisted of isothermal exposure at one of several temperatures for periods of up to 20,000 h. Comparisons are also given between the strain controlled fatigue lives of these alloys and several other commonly used alloys all tested at 538/sup 0/C.

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In order to develop the filler metal for Hastelloy alloy XR structure with thick wall, the weldability and high temperature strength properties of Hastelloy alloy XR weldment were investigated using the filler metals, which were alloy-designed on the basis of multiple regression analysis. The former was examined through the chemical analysis in the deposited metal, bend test, FISCO cracking test, optical microscopy and hardness measurement. The latter was investigated by means of tensile and creep test. It was found from these results that the crack susceptibility in the weldment was apparent to be lowered without degrading the high temperature strength properties. Therefore, it is concluded that these filler metals possess excellent performance as the filler metal for Hastelloy alloy XR structure with thick wall. (author).

Energy Technology Data Exchange (ETDEWEB)

The effect of the composition of multicomponent Zr-Ti-V-Mn-Cr-Ni alloys on their hydrogen-storage capacity and on the rate of electrosorption/desorption hydrogen was investigated under potentiodynamics as well as single-pulse and long-term galvanostatic conditions. The main characteristics of alloys and alloy electrodes were determined by their structural analysis by means of X-ray diffraction and scanning electron microscope, by specific surface area test and by determination of the hydrogen absorption/desorption isotherms in the gas/solid phase system. It was found that only the alloys with a manganese content below a threshold could be used as electrode materials for Ni-MH batteries, whereas the modification of the electrode material by micro-encapsulation of alloy particles should limit the dissolution of manganese from the electrode material in a strong alkaline solution. ...

Energy Technology Data Exchange (ETDEWEB)

Recent developments on plastic forming technology of magnesium alloys are presented. Attempts have been undergoing with an aim at forming magnesium alloy parts at lower temperatures. It is believed that fine microstructure magnesium alloys usually have much higher plasticity at lower temperatures and even room temperatures. Extrusion is a method to form magnesium profile products and tube products, which is also one of the effective ways to make fine microstructure magnesium alloys. Superplasticity forming is another method to form high plasticity magnesium alloys. Hot forming of magnesium sheet parts is an important process to form magnesium products. Some developments related to above issues are discussed in the present paper. (orig.)

International Nuclear Information System (INIS)

The corrosion behavior of the sputter-deposited amorphous or nanocrystalline W-Nb alloys is studied in 10% NaCl, 0.1 and 1 M NaOH solutions at 24 deg. C, open to air using immersion tests and electrochemical measurements. Niobium metal acts synergistically with tungsten in enhancing the corrosion resistance of the W-Nb alloys so as to show lower corrosion rates than the corrosion rates of the alloy-constituting elements in almost all examined solutions. Corrosion rates of W-Nb alloys are about more than one order of magnitude less than that of the sputter-deposited tungsten and even lower than that of sputter-deposited niobium. The stability of the anodic passive films formed on the W-Nb alloys increase with niobium content.

British Library Electronic Table of Contents (United Kingdom)

A body-centered cubic (bcc) Mg-12Li-9Al-1Zn (wt.%) alloy was fabricated in air by electrolysis from LiCl-KCl molten salt at 500degreeC. Electrolytic deposition of Li atoms on cathode (Mg-Al-Zn alloy) and diffusion of the Li atoms formed the bcc Mg-Li-Al-Zn alloy with 12wt.% Li and only 0.264wt.% K. Low K concentration in the bcc Mg alloy strip after the electrolysis process resulted from 47% atomic size misfit between K and Mg atoms and low solubility of K in Mg matrix.

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The authors examine the relationship of the structure and mechanical properties of similar alloys of tungsten with rhenium produced by the powder metallurgy method by sintering powders. Since the alloys were deformed by rolling, we examine the effect of the resultant anisotropy of the structure on the properties of the metal in various directions. The tests were conducted on an alloy of tungsten with 2 wt.% rhenium and, for comparison purposes, an alloy of tungsten with additions of oxides of yttrium and hafnium. The mechanical properties of the alloys, i.e., strength, cracking resistance, cold shortness temperature, were determined in the bend test. Structural examination was carried out using an optical microscope, electron scanning microscopy, and the method of transmission electron microscopy.

International Nuclear Information System (INIS)

The cross section and activity profile of different radioisotopes produced by #alpha#-induced nuclear reaction on natural zirconium, have been obtained by stacked foil activation using 40 MeV #alpha#-particles from Variable Energy Cyclotron (VEC) machine at Calcutta. The activity profile would be used to study the surface loss of zircaloy materials of engineering components by thin layer activation (TLA) technique. Generally, isotopes with suitable #gamma#-rays and long half-lives are the most useful in TLA technique, e.g., "9"2Nb, "9"5"gNb and "9"5Zr. (author). 2 refs., 1 tab.

International Nuclear Information System (INIS)

Stable boiloff of core water during a severe LWR accident, that is, boiloff driven only by the decay power generated below the water level, is tractable analytically and is relatively insensitive to axial power distribution. As might be expected, calculated accident event times are sensitive to the fidelity of the decay power model. During later stages of boiloff, heat transfer or transport of energy from above the water level to the residual water can result in an unstable condition during which the boiloff rate increases greatly. The unstable boiloff phenomenon illustrates the highly nonlinear influence of core heat transfer during meltdown and emphasizes the great accuracy requirements which attend the modeling of the accident during periods of enhanced heat transfer when significant zirconium oxidation is possible.

International Nuclear Information System (INIS)

Zirconia-toughened sialon composites have been fabricated using conventional hot-pressing techniques. The fracture toughness and microstructure were determined for CeO_2- and Y_2O_3-stabilized ZrO_2 additives and also as a function of volume percent ZrO_2. The Yttria system showed a linear increase in fracture toughness with increasing volume fraction zirconia content while the ceria-stabilized system exhibited a peak in fracture toughness at 20 vol% ZrO_2 content. The fracture toughness at 800 C was measured and correlated with the microstructure. High-temperature stability was determined and it was found that the deleterious nitride phases of zirconium could be precluded from the microstructure.

British Library Electronic Table of Contents (United Kingdom)

Spherical nano-sized YSZ (yttria stabilized ZrO2) powders were successfully synthesized via a reverse microemulsion system. The water droplets in the microemulsion system of yclohexane/water/span85/Triton X-100/hexyl alcohol can act as the nano-reactors which solubilize zirconium oxychloride and ammonia water separately. The minute original reactors are favor to the formation of nano-sized spherical YSZ powders and the dispersibility of the powders can be controlled effectually by adjusting the weight ratio of the LiNO3 molten salt to the precursor. The phase transformation from cubic to monoclinic starts at and 500??C and finally monoclinic and cubic phase with increased crytallinity coexist at 800??C. The effect of LiNO3 molten salt in the formation of YSZ powders was also discussed.

International Nuclear Information System (INIS)

Ionizing radiations that differ in number, size, and distribution of energy deposition events might be expected to cause different effects for the same absorbed dose. Furthermore, microdosimetry calculations suggest that large variations in biological effectiveness might be expected for internally deposited alpha-emitting radionuclides for the same absorbed dose, depending upon the specific activity and spatial distribution of the sources in tissue. The study described in this article was designed to demonstrate these phenomena in vitro. Cultured Chinese hamster ovary (CHO-K1 BH4) cells were exposed in vitro to inert, insoluble ceramic microspheres in zirconium dioxide labeled with "2"3"9Pu. The average exit energy of the 5.15 MeV alpha particle was calculated to be 4.3 MeV. Exposure times varied from four to seven hours to achieve the desired dose level.

International Nuclear Information System (INIS)

During the service in nuclear power plants, steam generator (SG) tubing will suffer from a vibration with a frequency from 30-40 Hz. This means that SG tubing will undergo a very high cycle fatigue process during the design life time (25 years=about 3x10"1"0cycles). The material degradation and the very high cycle fatigue life of SG tubing materials due to the vibration are therefore of concern. In this investigation, the fatigue properties of Alloy 690 and Alloy 800 SG tubing in the very high cycle fatigue regime (higher than 10"7 cycles) and strain controlled fatigue at temperatures up to 330"oC have been investigated. The fatigue properties of SG tubing of Alloy 690 are comparable to that of wrought material. The strain controlled fatigue properties of Alloy 690 and Alloy 800 are slightly better at 288"oC than at room temperature (RT). At the stress near the fatigue endurance, ...

International Nuclear Information System (INIS)

Available data are presented which support the supposition that metals and alloys with a negative low-temperature Hall coefficient are apparently not superconducting. (author).

Energy Technology Data Exchange (ETDEWEB)

The possibility of rapid heat treatment (RHT) application to titanium castings has been studied. It was shown that such treatment provides a significant improvement of intragrain structure and mechanical properties of cast ({alpha}+{beta})-titanium alloys. ((orig.))

Energy Technology Data Exchange (ETDEWEB)

A process for the generation of halogens from halide-containing solutions includes the step of conducting electrolysis of the solutions in an electrolytic cell having a platinum based amorphous metal alloy anode.

Energy Technology Data Exchange (ETDEWEB)

The effect of concentration on the corrosion behavior of Mg-based alloy AZ91D was investigated in ethylene glycol-water solutions using electrochemical techniques i.e. potentiodynamic polarization, electrochemical impedance measurements (EIS) and surface examination via scanning electron microscope (SEM) technique. This can provide a basis for developing new coolants for magnesium alloy engine blocks. Corrosion behavior of AZ91D alloy by coolant is important in the automotive industry. It was found that the corrosion rate of AZ91D alloy decreased with increasing concentration of ethylene glycol. For AZ91D alloy in chloride >0.05 M or fluoride <0.05 M containing 30% ethylene glycol solution, they are more corrosive than the blank (30% ethylene glycol-70% water). However, at concentrations <0.05 for chloride or >0.05 M for fluoride containing ethylene ...

International Nuclear Information System (INIS)

The status of development and commercialization of a modified 9 Cr-1 Mo alloy is presented. The alloy is modified by the addition of 0.06 to 0.10% Nb and 0.18 to 0.25% V. The alloy is recommended for use in the normalized and tempered condition (1040"0C for 1 h, air cooled to room temperature; 760"0C for 1 h, air cooled to room temperature). Heat treatment, Charpy impact, tensile, and creep properties of the alloy are described in detail along with a brief description of other properties. The modified alloy has creep strength that exceeds that of standard 9 Cr-1 Mo and 2 1/4 Cr-1 Mo steels for the temperature range from 427 to 704"0C. The total-elongation and reduction-of-area values for all test temperatures and rupture times up to 22,500 h exceed 15 and 70%, respectively. The estimated design allowable stresses for this alloy are higher than those for standard ...

Science.gov (United States)

Quantitative metallography is often used to confirm the proper processing of aerospace metallic materials. A microstructural feature of great importance for titanium alloys processed in the alpha-beta phase field is the volume fraction of primary alpha. S...

Energy Technology Data Exchange (ETDEWEB)

The carbon transfer has been analyzed in the Alloy 800/sodium/stainless steel system by determining the carbon-uptake of Alloy 800 foils, which were exposed in liquid sodium of known carburizing potential. Under equilibrium conditions between 650 and 550/sup 0/C the measured total carbon concentrations in the Alloy 800 tabs were found to be roughly related to the carbon activities of the sodium environment by the equation already stated for the 18 Cr-8/10 Ni stainless steels, extrapolated to the chemical composition of the Ni-rich austenitic alloy. However the Alloy 800 was not found to undergo any decarburization in low-carbon activity environments. The carbon diffusion kinetics was determined as a function of temperature, it was found to be similar to that reported for the AISI-304 type of steel. The effects of sodium exposure on microstructural and mechanical properties of ...

Science.gov (United States)

The authors have presented results of an investigation of wettability of SiC particulates by liquid alloys of the Al-Si-Mg system. The evaluation of wetting has been carried out through the determination of the threshold pressure for infiltration of packed SiC particulates by the liquid alloy. The results indicate that whereas Si and Mg additions do not affect wetting, in the case of the ternary alloys the contact angle decreases in an amount proportional to the content of Mg[sub 2]Si.

International Nuclear Information System (INIS)

A series of ball-on-disc wear and friction measurements were made for surfaces which have a chemical vapour deposition carbon silicon alloy layer on a carbon substrate (fine grain POCO graphite). Nitrogen ion irradiation was used to improve the wear resistance of the carbon alloy surface. For comparison, measurements were also taken for alumina against alumina. It was found that the lowest friction coefficient and lowest wear occurred for ion irradiated coated samples containing 4% Si in the alloy and that the performance was superior to that of alumina. ((orig.)).

Energy Technology Data Exchange (ETDEWEB)

The exposure of heat-resistant alloys to high temperature can significantly change their mechanical properties. This paper presents and analyzes data on the effect of thermal exposure on the tensile and impact behavior of three cast materials -- the HK-40, HP-50, and 21Cr-32Ni-Fe alloys -- and of wrought material -- Alloy 800. The changes in tensile and impact properties caused by high-temperature exposure are reviewed. Reasons for these property changes and needs for considering them in the design, operation, and life assessment of high-temperature equipment are discussed.

Energy Technology Data Exchange (ETDEWEB)

The chemical properties of alloys in a given environment are to a large extent governed by the surface composition. Changes of the surface composition during passivation are important features in this respect. Previous studies of single crystal Ni-Mo alloys surfaces have been reported. The aim of this work was to obtain quantitative data, for the natural oxide and the passive films formed on Ni-6% Mo(100) and (110) alloys, using Rutherford backscattering spectroscopy and nuclear reaction analysis.

International Nuclear Information System (INIS)

Phase transformations occuring during cold deformation in hardened #alpha#+#beta# titanium alloy of the Ti-Al-Mo-Zr-Sn-Si system with 10% summary content of alloying elements are studied by X-ray diffraction analysis. Two stages of trapsformation of metastable #alpha#''-phase are found. A conclusiop is made that ability of the alloy containing #alpha#''-phase to cold deformation is determined by the presence of favourable texture, by high degree of metastability and by volume portion of #alpha#''-phase in the alloy structure.

International Nuclear Information System (INIS)

A computerized corrosion measuring system (EG and G model 350 A) was used to study the influence of Cr, Mo, Ti, Nb and W on the pitting corrosion of nickel base alloys in 3% NaCl at 90"0C. The electrochemical parameters under investigation are the corrosion potential E_c_o_r_r, pitting potential E_p and protection potential E_p_p. The corrosion behaviour of nickel base alloys were studied by using pitting scan and potentiostatic techniques. Values of corrosion potential, pitting potential and protection potential were used for a ranking of alloys for corrosion resistance.

International Nuclear Information System (INIS)

Formation of the soft magnetic nanostructure in amorphous Fe_1_4Ni_4_0Zr_7B_1_2 alloy due to heat treatment is studied by the Moessbauer, differential scanning calorimetry, and X-ray diffraction techniques. Annealing at temperatures 520-580 "oC leads to the formation of extremely soft nanocrystalline alloy as revealed by the rf-Moessbauer measurements. The superparamagnetic behaviour was observed for the alloy annealed at 620-640 "oC. At higher annealing temperatures good soft magnetic properties deteriorate. (author)

Energy Technology Data Exchange (ETDEWEB)

Experiments were conducted which established that the higher passivating capacity of Ni/sub 60/Nb/sub 40/ alloys in the amorphous state and higher efficiency of the anodic process of generation of chlorine (2 N NaCl + HCl to pH = 0) in comparison with the crystalline state are determined by higher homogeneity and density of the passive films formed on the amorphous alloy and by higher electron conduction which depends directly on the difference in the structure of the passive films formed on the alloys in the amorphous and crystalline states.

International Nuclear Information System (INIS)

The methods of optical and transmission electron microscopy were used to study the influence of different programmes of hot deformation on the structure formation of (#alpha#+#beta#) titanium alloy VT9. The #beta# alloy VT-15 was studied at the same time in order to simulate the dislocation structure generated in the process of hot deformation. During the hot deformation of two-phase titanium alloys in both #beta# and (#alpha#+#beta#) ranges there is found to be an optimum range of deformation in which a homogeneous, polygonized structure is formed.

International Nuclear Information System (INIS)

We propose a dissolution-passivation model to account for the electrochemical behavior of Alloy 800 and 316L stainless steel under steam generators operating conditions. This model is similar to the one defined for nickel, considering the known importance of this element on the studied alloys. The comparison of the rates of the elementary steps points out the favorable influence of dissolved oxygen and phosphate ions on the dissolution of Alloy 800, even in the presence of chloride ions. The sensitivity of 316L SS is greater, especially because of the lowest stability of oxide-like intermediate.

Energy Technology Data Exchange (ETDEWEB)

An experimental verification for long-term performance of a Pd-Ag permeation in ITER tritium fusion cleanup units (FCU) is needed. In addition, information is required on the influence of tritium and {sup 3}He decay on the physical and chemical properties of Pd-Ag alloys (V-1). The results of the investigations of alloys (V-1) (mechanical properties and microstructure) after long-term usage exposition in tritium are given in this report. The experimental conditions (temperature, pressure, clearance, {sup 3}He concentrations) and the previous conclusions on the V-1 alloy performance are presented. (orig.).

International Nuclear Information System (INIS)

Formation of basis type texture at rolling of Ti + 6.0% Al + 1.5% V + 1.0% Mo system alloy with initial prismatic texture is investigated by means of X-ray techniques. Variations of mechanical features in titanium alloy sheets depending on temperature-deformation conditions of rolling are investigated. Main conditions for formation of the intensive basis textute in the investigated alloy sheets which provides for isotropic properties in sheet plane and for increased ductility are determined.

Energy Technology Data Exchange (ETDEWEB)

The most typical kinds of corrosion of brasses are selective corrosion (dezincification) and stress corrosion. Prevention against these kinds of corrosion lies in application of arsenic alloy addition and appropriate heat treatment removing internal stresses as well as in maintaining the arsenic and phosphorus contents on a proper level. The most typical corrosion of cupronickels is the local corrosion. Selective corrosion occurs less often and corrosion cracking caused by stress corrosion in sea water does not usually occur. Crevice corrosion is found especially in places of an heterogeneous oxidation of the surface under inorganic deposits or under bio-film. Common corrosive phenomena for brasses and cupronickels are the effects caused by sea water flow and most often the impingement attack. Alloy additions improve resistance to the action of intensive sea water flow but situation in this field requires further improvement, especially if the ...

International Nuclear Information System (INIS)

Existing applications of Alloy 800 are summarized, with particular reference to its use in various types of reactor. The need for a co-ordinated research and development programme is stressed, and the variables to be explored are outlined. The papers relating to the problem of corrosion and cracking in water and steam are considered. the strength and ductility of Alloy 800 is considered. Finally, sections of the summary deal with the use of Alloy 800 for (a) sodium cooled fast reactor boiler tubes; (b) the high temperature gas cooled reactor; and (c) PWR steam generator tubes. (U.K.).

Energy Technology Data Exchange (ETDEWEB)

Two extruded magnesium alloys, AZ31 and AZ61 were selected to evaluate the influence of process parameters on the material forgeability. The processing parameters considered for forging magnesium alloys were: compression load in the range 55 KN to 60 KN and forging temperature, in the range of ambient temperature to 300 C. Uniaxial compression tests were conducted to establish the strain-temperature relationship. The influences of process parameters on the microstructure were also evaluated. (orig.)

International Nuclear Information System (INIS)

The optimum of strontium amount for good modification of AK7, AK9, AK11, AK52, AK104 alloys was determined on the base of the analysis of microstructural changes. The stability of the modifier was investigated on the way of successive remelting of billets. The influence of amount of modifier on the impact strength of the alloys was established. (author)

Energy Technology Data Exchange (ETDEWEB)

Using commercial AZ31 magnesium alloy sheets, we produced a foamable preform sheet containing titanium hydride (TiH{sub 2}) powder through diffusion-bonding and hot-rolling of four cycles. Heating the preform sheets in Ar atmosphere, we obtained closed-cell magnesium alloy foams with various porosities. The foamed specimen at 883 K showed the maximum porosities of 77%. (orig.)

Energy Technology Data Exchange (ETDEWEB)

One of the effective methods of deep modification of the surface of steels and alloys is the combination of ion implantation and plasma nitriding. In this work, the long-range effect is demonstrated in the case of combination of the effect of high- and low-energy ions of nitrogen on a martensitic steel for each ion implantation is usually not effective, and a titanium alloy used widely in industry.

International Nuclear Information System (INIS)

Cyclic strength of #alpha#+#beta#-titanium alloy BT3-1 is studied under load frequencies of 33 and 300 Hz. The increase in the cyclic strength with growing frequency is caused by formation of FCC interphase layers of titanium hydrides. Their formation is one of possible ways of raising the fatigue strength of titanium alloys. Peculiarities of FCC interlayer formation in #alpha#+#beta# phases under loading frequency variation are revealed.

Energy Technology Data Exchange (ETDEWEB)

The distribution of graphite particles in graphite containing copper alloy was further improved very significantly using several procedures and technological modifications. The developed techniques attacked the graphite distribution problem in two ways. Realizing that clustering of very fine (5um) graphite particles is one of the two major problems, a pretreatment process has been developed using aluminum powders to deagglomerate graphite particles. Along with this, a two-stage stirring technique was used to first incorporate and then to distribute uniformly the deagglomerated particles in the melt. During this year, based on these developments, several components were cast to evaluate the castability of Cu alloy-graphite melts. In addition, machinability tests were done to clearly established that addition of graphite particles improve the machinability of copper MMC alloys over and above that of monolithic copper ...

International Nuclear Information System (INIS)

Peculiarities of metastable #beta#-solid solution decmposition in titanium alloy VT30 in the process of isothermal ageing in the range 500-650 deg C are investigated. Using the methods of transmittion electron microscopy, X-ray diffraction analysis, etc., it is shown that in the case of alloy quenching from the temperature below the point of complete polymorphous transformation (T_t_._t_.), as well as after warm rolling the course of subsequent decomposition of solid solution can be consierably complicated.

International Nuclear Information System (INIS)

A historical overview of corrosion problems found in power plant condensers and mitigation procedures is presented. The paper is organized according to alloy type and failure mode. Alloys considered are copper-base alloys, stainless steels and titanium. Failure modes discussed include erosion-corrosion, sulfide attack, environmentally assisted cracking, galvanic corrosion, steam condensate corrosion, pitting corrosion, and dealloying. Mitigation procedures discussed include cathodic protection, ferrous ion injection, as well as tube cleaning and layup practices.

Energy Technology Data Exchange (ETDEWEB)

The present results indicate that maximum selectivity to acrylic acid can be reached over V-P-Zr-O catalysts. When the hydrocarbon concentration is 5.1 vol.% the selectivity is about 30% at quite high paraffin conversion. Conclusively, some explanations to the observed facts can be given. The V-P-O catalyst promotion with lanthanum by means of mechanochemical treatment is distinguished by the additive uniform spreading all over the matrix surface. Such twophase system is highly active in propane conversion (lanthanum oxide) and further oxidation of the desired products. The similar properties are attributed to V-P-Bi-La-O catalyst. Bismuth, tellurium and zirconium additives having clearly defined acidic properties provoke the surface acidity strengthening and make easier desorption of the acidic product (acrylic acid) from the surface lowering its further oxidation. Additionally, since bismuth and zirconium are able to form phosphates and, ...

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Purification parameters of the vacuum distillation process for AM50A and AZ31B magnesium alloy were studied. The vacuum distillation tests were kept at 580 C to 620 C up to 10 h under a vacuum pressure of about 1 Pa. The purification ratio for AM50A magnesium alloy increases with increasing the purification time. The chemical compositions of materials deposited purifying at 580 C for AM50A magnesium alloy almost satisfy the values for pure magnesium specified by JIS standard specification. The chemical compositions of deposited materials at 600 C for AZ31B magnesium alloy satisfy the values specified by the standard specification except for Zn. (orig.)