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Sample records for aluminum die-casting plant

  1. Microstructures and properties of aluminum die casting alloys

    Energy Technology Data Exchange (ETDEWEB)

    M. M. Makhlouf; D. Apelian; L. Wang

    1998-10-01

    This document provides descriptions of the microstructure of different aluminum die casting alloys and to relate the various microstructures to the alloy chemistry. It relates the microstructures of the alloys to their main engineering properties such as ultimate tensile strength, yield strength, elongation, fatigue life, impact resistance, wear resistance, hardness, thermal conductivity and electrical conductivity. Finally, it serves as a reference source for aluminum die casting alloys.

  2. Die Casting Mold Design for Aluminum Alloy Shell of Instrument

    Directory of Open Access Journals (Sweden)

    Li Yuanyuan

    2015-01-01

    Full Text Available This paper is about die casting mold design for aluminum alloy shell of instrument. Three-dimensional model of the casting and mold are designed by using Pro/Engineer and AutoCad which can analyze forming quality. Digital design and theoretical calculation can greatly shorten product development cycle and mold design cycle, improve the accuracy of product design and mold design, and reduce the cost of mold design.

  3. Numerical simulation of low pressure die-casting aluminum wheel

    Directory of Open Access Journals (Sweden)

    Mi Guofa

    2009-02-01

    Full Text Available The FDM numerical simulation software, ViewCast system, was employed to simulate the low pressure die casting (LPDC of an aluminum wheel. By analyzing the mold-fi lling and solidifi cation stage of the LPDC process, the distribution of liquid fraction, temperature field and solidification pattern of castings were studied. The potential shrinkage defects were predicted to be formed at the rim/spoke junctions, which is in consistence with the X-ray detection result. The distribution pattern of the defects has also been studied. A solution towards reducing such defects has been presented. The cooling capacity of the mold was improved by installing water pipes both in the side mold and the top mold. Analysis on the shrinkage defects under forced cooling mode proved that adding the cooling system in the mold is an effective method for reduction of shrinkage defects.

  4. 3D scanning based mold correction for planar and cylindrical parts in aluminum die casting

    Directory of Open Access Journals (Sweden)

    Takashi Seno

    2015-04-01

    Full Text Available Aluminum die casting is an important manufacturing process for mechanical components. Die casting is known to be more accurate than other types of casting; however, post-machining is usually necessary to achieve the required accuracy. The goal of this investigation is to develop machining- free aluminum die casting. Improvement of the accuracy of planar and cylindrical parts is expected by correcting metal molds. In the proposed method, the shape of cast aluminum made with the initial metal molds is measured by 3D scanning. The 3D scan data includes information about deformations that occur during casting. Therefore, it is possible to estimate the deformation and correction amounts by comparing 3D scan data with product computer-aided design (CAD data. We corrected planar and cylindrical parts of the CAD data for the mold. In addition, we corrected the planar part of the metal mold using the corrected mold data. The effectiveness of the proposed method is demonstrated by evaluating the accuracy improvement of the cast aluminum made with the corrected mold.

  5. Tribological and Wear Performance of Nanocomposite PVD Hard Coatings Deposited on Aluminum Die Casting Tool

    Directory of Open Access Journals (Sweden)

    Jose Mario Paiva

    2018-02-01

    Full Text Available In the aluminum die casting process, erosion, corrosion, soldering, and die sticking have a significant influence on tool life and product quality. A number of coatings such as TiN, CrN, and (Cr,AlN deposited by physical vapor deposition (PVD have been employed to act as protective coatings due to their high hardness and chemical stability. In this study, the wear performance of two nanocomposite AlTiN and AlCrN coatings with different structures were evaluated. These coatings were deposited on aluminum die casting mold tool substrates (AISI H13 hot work steel by PVD using pulsed cathodic arc evaporation, equipped with three lateral arc-rotating cathodes (LARC and one central rotating cathode (CERC. The research was performed in two stages: in the first stage, the outlined coatings were characterized regarding their chemical composition, morphology, and structure using glow discharge optical emission spectroscopy (GDOES, scanning electron microscopy (SEM, and X-ray diffraction (XRD, respectively. Surface morphology and mechanical properties were evaluated by atomic force microscopy (AFM and nanoindentation. The coating adhesion was studied using Mersedes test and scratch testing. During the second stage, industrial tests were carried out for coated die casting molds. In parallel, tribological tests were also performed in order to determine if a correlation between laboratory and industrial tests can be drawn. All of the results were compared with a benchmark monolayer AlCrN coating. The data obtained show that the best performance was achieved for the AlCrN/Si3N4 nanocomposite coating that displays an optimum combination of hardness, adhesion, soldering behavior, oxidation resistance, and stress state. These characteristics are essential for improving the die mold service life. Therefore, this coating emerges as a novelty to be used to protect aluminum die casting molds.

  6. Tribological and Wear Performance of Nanocomposite PVD Hard Coatings Deposited on Aluminum Die Casting Tool.

    Science.gov (United States)

    Paiva, Jose Mario; Fox-Rabinovich, German; Locks Junior, Edinei; Stolf, Pietro; Seid Ahmed, Yassmin; Matos Martins, Marcelo; Bork, Carlos; Veldhuis, Stephen

    2018-02-28

    In the aluminum die casting process, erosion, corrosion, soldering, and die sticking have a significant influence on tool life and product quality. A number of coatings such as TiN, CrN, and (Cr,Al)N deposited by physical vapor deposition (PVD) have been employed to act as protective coatings due to their high hardness and chemical stability. In this study, the wear performance of two nanocomposite AlTiN and AlCrN coatings with different structures were evaluated. These coatings were deposited on aluminum die casting mold tool substrates (AISI H13 hot work steel) by PVD using pulsed cathodic arc evaporation, equipped with three lateral arc-rotating cathodes (LARC) and one central rotating cathode (CERC). The research was performed in two stages: in the first stage, the outlined coatings were characterized regarding their chemical composition, morphology, and structure using glow discharge optical emission spectroscopy (GDOES), scanning electron microscopy (SEM), and X-ray diffraction (XRD), respectively. Surface morphology and mechanical properties were evaluated by atomic force microscopy (AFM) and nanoindentation. The coating adhesion was studied using Mersedes test and scratch testing. During the second stage, industrial tests were carried out for coated die casting molds. In parallel, tribological tests were also performed in order to determine if a correlation between laboratory and industrial tests can be drawn. All of the results were compared with a benchmark monolayer AlCrN coating. The data obtained show that the best performance was achieved for the AlCrN/Si₃N₄ nanocomposite coating that displays an optimum combination of hardness, adhesion, soldering behavior, oxidation resistance, and stress state. These characteristics are essential for improving the die mold service life. Therefore, this coating emerges as a novelty to be used to protect aluminum die casting molds.

  7. Annealing of chromium oxycarbide coatings deposited by plasma immersion ion processing (PIIP) for aluminum die casting

    International Nuclear Information System (INIS)

    Peters, A.M.; He, X.M.; Trkula, M.; Nastasi, M.

    2001-01-01

    Chromium oxycarbide coatings have been investigated for use as non-wetting coatings for aluminum die casting. This paper examines Cr-C-O coating stability and non-wetability at elevated temperatures for extended periods. Coatings were deposited onto 304 stainless steel from chromium carbonyl [Cr(CO) 6 ] by plasma immersion ion processing. The coatings were annealed in air at an aluminum die casting temperature of 700 deg. C up to 8 h. Coatings were analyzed using resonant ion backscattering spectroscopy, nanoindentation and pin-on-disk tribometry. Molten aluminum was used to determine coating wetting and contact angle. Results indicate that the surface oxide layer reaches a maximum thickness of 900 nm. Oxygen concentrations in the coatings increased from 24% to 34%, while the surface concentration rose to almost 45%. Hardness values ranged from 22.1 to 6.7 GPa, wear coefficients ranged from 21 to 8x10 -6 mm 3 /Nm and contact angles ranged from 156 deg. to 127 deg

  8. Improved design and durability of aluminum die casting horizontal shot sleeves

    Science.gov (United States)

    Birceanu, Sebastian

    The design and performance of shot sleeves is critical in meeting the engineering requirements of aluminum die cast parts. Improvement in shot sleeve materials have a major impact on dimensional stability, reproducibility and quality of the product. This investigation was undertaken in order to improve the life of aluminum die casting horizontal shot sleeves. Preliminary pin tests were run to evaluate the soldering, wash-out and thermal fatigue behavior of commercially available materials and coatings. An experimental rig was designed and constructed for shot sleeve configuration evaluation. Fabrication and testing of experimental shot sleeves was based upon preliminary results and manufacturing costs. Three shot sleeve designs and materials were compared to a reference nitrided H13 sleeve. Nitrided H13 is the preferred material for aluminum die casting shot sleeves because of wear resistance, strength and relative good soldering and wash-out resistance. The study was directed towards damage evaluation on the area under the pouring hole. This area is the most susceptible to damage because of high temperatures and impingement of molten aluminum. The results of this study showed that tungsten and molybdenum had the least amount of soldering and wash-out damage, and the best thermal fatigue resistance. Low solubility in molten aluminum and stability of intermetallic layers are main factors that determine the soldering and wash-out behavior. Thermal conductivity and thermal expansion coefficient directly influence thermal fatigue behavior. TiAlN nanolayered coating was chosen as the material with the best damage resistance among several commercial PVD coatings, because of relatively large thickness and simple deposition conditions. The results show that molybdenum thermal sprayed coating provided the best protection against damage under the pouring hole. Improved bonding is however required for life extension of the coating. TiAlN PVD coating applied on H13 nitrided

  9. A process chain for integrating piezoelectric transducers into aluminum die castings to generate smart lightweight structures

    Directory of Open Access Journals (Sweden)

    Stefan Stein

    Full Text Available The application of piezoelectric transducers to structural body parts of machines or vehicles enables the combination of passive mechanical components with sensor and actuator functions in one single structure. According to Herold et al. [1] and Staeves [2] this approach indicates significant potential regarding smart lightweight construction. To obtain the highest yield, the piezoelectric transducers need to be integrated into the flux of forces (load path of load bearing structures. Application in a downstream process reduces yield and process efficiency during manufacturing and operation, due to the necessity of a subsequent process step of sensor/actuator application. The die casting process offers the possibility for integration of piezoelectric transducers into metal structures. Aluminum castings are particularly favorable due to their high quality and feasibility for high unit production at low cost (Brunhuber [3], Nogowizin [4]. Such molded aluminum parts with integrated piezoelectric transducers enable functions like active vibration damping, structural health monitoring or energy harvesting resulting in significant possibilities of weight reduction, which is an increasingly important driving force of automotive and aerospace industry (Klein [5], Siebenpfeiffer [6] due to increasingly stringent environmental protection laws. In the scope of those developments, this paper focuses on the entire process chain enabling the generation of lightweight metal structures with sensor and actuator function, starting from the manufacturing of piezoelectric modules over electrical and mechanical bonding to the integration of such modules into aluminum (Al matrices by die casting. To achieve this challenging goal, piezoceramic sensors/actuator modules, so-called LTCC/PZT modules (LPM were developed, since ceramic based piezoelectric modules are more likely to withstand the thermal stress of about 700 °C introduced by the casting process (Flössel et

  10. Mortality among workers in a die-casting and electroplating plant.

    Science.gov (United States)

    Silverstein, M; Mirer, F; Kotelchuck, D; Silverstein, B; Bennett, M

    1981-01-01

    A proportional mortality and case-referent analysis of 238 deaths among hourly employees in an automobile hardware manufacturing plant was conducted. The major operations of the plant were zinc die casting and electroplating. Chemical exposure included die-casting emissions and mists from chrome and nickel plating. The chief proportional mortality finding was a significant excess of lung cancer among both white men and women. A case-referent analysis indicated a possible association between lung cancer and work in certain departments. The findings support the hypothesis of a work-related carcinogenic risk. Follow-up recommendations have been made.

  11. Metallic Reinforcement of Direct Squeeze Die Casting Aluminum Alloys for Improved Strength and Fracture Resistance

    Energy Technology Data Exchange (ETDEWEB)

    D. Schwam: J.F. Wallace: Y. Zhu: J.W. Ki

    2004-10-01

    The utilization of aluminum die casting as enclosures where internal equipment is rotating inside of the casting and could fracture requires a strong housing to restrain the fractured parts. A typical example would be a supercharger. In case of a failure, unless adequately contained, fractured parts could injure people operating the equipment. A number of potential reinforcement materials were investigated. The initial work was conducted in sand molds to create experimental conditions that promote prolonged contact of the reinforcing material with molten aluminum. Bonding of Aluminum bronze, Cast iron, and Ni-resist inserts with various electroplated coatings and surface treatments were analyzed. Also toughening of A354 aluminum cast alloy by steel and stainless steel wire mesh with various conditions was analyzed. A practical approach to reinforcement of die cast aluminum components is to use a reinforcing steel preform. Such performs can be fabricated from steel wire mesh or perforated metal sheet by stamping or deep drawing. A hemispherical, dome shaped casting was selected in this investigation. A deep drawing die was used to fabricate the reinforcing performs. The tendency of aluminum cast enclosures to fracture could be significantly reduced by installing a wire mesh of austenitic stainless steel or a punched austenitic stainless steel sheet within the casting. The use of reinforcements made of austenitic stainless steel wire mesh or punched austenitic stainless steel sheet provided marked improvement in reducing the fragmentation of the casting. The best strengthening was obtained with austenitic stainless steel wire and with a punched stainless steel sheet without annealing this material. Somewhat lower results were obtained with the annealed punched stainless steel sheet. When the annealed 1020 steel wire mesh was used, the results were only slightly improved because of the lower mechanical properties of this unalloyed steel. The lowest results were

  12. Inventory of pollution reduction options for an aluminium pressure die casting plant

    NARCIS (Netherlands)

    Neto, B.A.F.; Kroeze, C.; Hordijk, L.; Costa, C.

    2009-01-01

    This study presents an overview of options aiming to reduce emissions to air, soil and water from an aluminium die casting plant located in Portugal. We identify eighteen pollution reduction options and then estimate their potential to reduce the pollution, and the costs associated with their

  13. Strategies to reduce the environmental impact of an aluminium pressure die casting plant: A scenario analysis

    NARCIS (Netherlands)

    Neto, B.; Kroeze, C.; Hordijk, L.; Costa, C.; Pulles, M.P.J.

    2009-01-01

    This study explores a model (MIKADO) to analyse scenarios for the reduction of the environmental impact of an aluminium die casting plant. Our model calculates the potential to reduce emissions, and the costs associated with implementation of reduction options. In an earlier paper [Neto, B., Kroeze,

  14. A process chain for integrating piezoelectric transducers into aluminum die castings to generate smart lightweight structures

    Science.gov (United States)

    Stein, Stefan; Wedler, Jonathan; Rhein, Sebastian; Schmidt, Michael; Körner, Carolin; Michaelis, Alexander; Gebhardt, Sylvia

    The application of piezoelectric transducers to structural body parts of machines or vehicles enables the combination of passive mechanical components with sensor and actuator functions in one single structure. According to Herold et al. [1] and Staeves [2] this approach indicates significant potential regarding smart lightweight construction. To obtain the highest yield, the piezoelectric transducers need to be integrated into the flux of forces (load path) of load bearing structures. Application in a downstream process reduces yield and process efficiency during manufacturing and operation, due to the necessity of a subsequent process step of sensor/actuator application. The die casting process offers the possibility for integration of piezoelectric transducers into metal structures. Aluminum castings are particularly favorable due to their high quality and feasibility for high unit production at low cost (Brunhuber [3], Nogowizin [4]). Such molded aluminum parts with integrated piezoelectric transducers enable functions like active vibration damping, structural health monitoring or energy harvesting resulting in significant possibilities of weight reduction, which is an increasingly important driving force of automotive and aerospace industry (Klein [5], Siebenpfeiffer [6]) due to increasingly stringent environmental protection laws. In the scope of those developments, this paper focuses on the entire process chain enabling the generation of lightweight metal structures with sensor and actuator function, starting from the manufacturing of piezoelectric modules over electrical and mechanical bonding to the integration of such modules into aluminum (Al) matrices by die casting. To achieve this challenging goal, piezoceramic sensors/actuator modules, so-called LTCC/PZT modules (LPM) were developed, since ceramic based piezoelectric modules are more likely to withstand the thermal stress of about 700 °C introduced by the casting process (Flössel et al., [7]). The

  15. Ageless Aluminum-Cerium-Based Alloys in High-Volume Die Casting for Improved Energy Efficiency

    Science.gov (United States)

    Stromme, Eric T.; Henderson, Hunter B.; Sims, Zachary C.; Kesler, Michael S.; Weiss, David; Ott, Ryan T.; Meng, Fanqiang; Kassoumeh, Sam; Evangelista, James; Begley, Gerald; Rios, Orlando

    2018-04-01

    Strong chemical reactions between Al and Ce lead to the formation of intermetallics with exceptional thermal stability. The rapid formation of intermetallics directly from the liquid phase during solidification of Al-Ce alloys leads to an ultrafine microconstituent structure that effectively strengthens as-cast alloys without further microstructural optimization via thermal processing. Die casting is a high-volume manufacturing technology that accounts for greater than 40% of all cast Al products, whereas Ce is highly overproduced as a waste product of other rare earth element (REE) mining. Reducing heat treatments would stimulate significant improvements in manufacturing energy efficiency, exceeding (megatonnes/year) per large-scale heat-treatment line. In this study, multiple compositions were evaluated with wedge mold castings to test the sensitivity of alloys to the variable solidification rate inherent in high-pressure die casting. Once a suitable composition was determined, it was successfully demonstrated at 800 lbs/h in a 600-ton die caster, after which the as-die cast parts performed similarly to ubiquitous A380 in the same geometry without requiring heat treatment. This work demonstrates the compatibility of Al REE alloys with high-volume die-casting applications with minimal heat treatments.

  16. Ageless Aluminum-Cerium-Based Alloys in High-Volume Die Casting for Improved Energy Efficiency

    Science.gov (United States)

    Stromme, Eric T.; Henderson, Hunter B.; Sims, Zachary C.; Kesler, Michael S.; Weiss, David; Ott, Ryan T.; Meng, Fanqiang; Kassoumeh, Sam; Evangelista, James; Begley, Gerald; Rios, Orlando

    2018-06-01

    Strong chemical reactions between Al and Ce lead to the formation of intermetallics with exceptional thermal stability. The rapid formation of intermetallics directly from the liquid phase during solidification of Al-Ce alloys leads to an ultrafine microconstituent structure that effectively strengthens as-cast alloys without further microstructural optimization via thermal processing. Die casting is a high-volume manufacturing technology that accounts for greater than 40% of all cast Al products, whereas Ce is highly overproduced as a waste product of other rare earth element (REE) mining. Reducing heat treatments would stimulate significant improvements in manufacturing energy efficiency, exceeding (megatonnes/year) per large-scale heat-treatment line. In this study, multiple compositions were evaluated with wedge mold castings to test the sensitivity of alloys to the variable solidification rate inherent in high-pressure die casting. Once a suitable composition was determined, it was successfully demonstrated at 800 lbs/h in a 600-ton die caster, after which the as-die cast parts performed similarly to ubiquitous A380 in the same geometry without requiring heat treatment. This work demonstrates the compatibility of Al REE alloys with high-volume die-casting applications with minimal heat treatments.

  17. Dimensional control of die castings

    Science.gov (United States)

    Karve, Aniruddha Ajit

    The demand for net shape die castings, which require little or no machining, is steadily increasing. Stringent customer requirements are forcing die casters to deliver high quality castings in increasingly short lead times. Dimensional conformance to customer specifications is an inherent part of die casting quality. The dimensional attributes of a die casting are essentially dependent upon many factors--the quality of the die and the degree of control over the process variables being the two major sources of dimensional error in die castings. This study focused on investigating the nature and the causes of dimensional error in die castings. The two major components of dimensional error i.e., dimensional variability and die allowance were studied. The major effort of this study was to qualitatively and quantitatively study the effects of casting geometry and process variables on die casting dimensional variability and die allowance. This was accomplished by detailed dimensional data collection at production die casting sites. Robust feature characterization schemes were developed to describe complex casting geometry in quantitative terms. Empirical modeling was utilized to quantify the effects of the casting variables on dimensional variability and die allowance for die casting features. A number of casting geometry and process variables were found to affect dimensional variability in die castings. The dimensional variability was evaluated by comparisons with current published dimensional tolerance standards. The casting geometry was found to play a significant role in influencing the die allowance of the features measured. The predictive models developed for dimensional variability and die allowance were evaluated to test their effectiveness. Finally, the relative impact of all the components of dimensional error in die castings was put into perspective, and general guidelines for effective dimensional control in the die casting plant were laid out. The results of

  18. Modeling of high temperature- and diffusion-controlled die soldering in aluminum high pressure die casting

    DEFF Research Database (Denmark)

    Domkin, Konstantin; Hattel, Jesper Henri; Thorborg, Jesper

    2009-01-01

    of the die lifetime based on a quantitative analysis of die soldering in the framework of the numerical simulations of the die-casting process. Full 3D simulations of the process, including the filling. solidification, and the die cooling, are carried out using the casting simulation software MAGMAsoft....... The resulting transient temperature fields on the die surface and in the casting are then post-processed to estimate the die soldering. The present work deals only with the metallurgical/chemical kind of soldering which occurs at high temperatures and involves formation and growth of intermetallic layers...

  19. Vacuum Die Casting Process and Simulation for Manufacturing 0.8 mm-Thick Aluminum Plate with Four Maze Shapes

    Directory of Open Access Journals (Sweden)

    Chul Kyu Jin

    2015-02-01

    Full Text Available Using vacuum die casting, 0.8 mm-thick plates in complicated shapes are manufactured with the highly castable aluminum alloy Silafont-36 (AlSi9MgMn. The sizes and shapes of the cavities, made of thin plates, feature four different mazes. To investigate formability and mechanical properties by shot condition, a total of six parameters (melt temperatures of 730 °C and 710 °C; plunger speeds of 3.0 m/s and 2.5 m/s; vacuum pressure of 250 mbar and no vacuum are varied in experiments, and corresponding simulations are performed. Simulation results obtained through MAGMA software show similar tendencies to those of the experiments. When the melt pouring temperature is set to 730 °C rather than 710 °C, formability and mechanical properties are superior, and when the plunger speed is set to 3.0 m/s rather than to 2.5 m/s, a fine, even structure is obtained with better mechanical properties. The non-vacuumed sample is half unfilled. The tensile strength and elongation of the sample fabricated under a melt temperature of 730 °C, plunger speed of 3.0 m/s, and vacuum pressure of 250 mbar are 265 MPa and 8.5%, respectively.

  20. Endurance in Al Alloy Melts and Wear Resistance of Titanium Matrix Composite Shot-Sleeve for Aluminum Alloy Die-casting

    International Nuclear Information System (INIS)

    Choi, Bong-Jae; Kim, Young-Jig; Sung, Si-Young

    2012-01-01

    The main purpose of this study was to evaluate the endurance against Al alloy melts and wear resistance of an in-situ synthesized titanium matrix composite (TMC) sleeve for aluminum alloy die-casting. The conventional die-casting shot sleeve material was STD61 tool steel. TMCs have great thermal stability, wear and oxidation resistance. The in-situ reaction between Ti and B4C leads to two kinds of thermodynamically stable reinforcements, such as TiBw and TiCp. To evaluate the feasibility of the application to a TMCs diecasting shot sleeve, the interfacial reaction behavior was examined between Al alloys melts with TMCs and STD61 tool steel. The pin-on-disk type dry sliding wear test was also investigated for TMCs and STD61 tool steel.

  1. Analysis of the Causes of Cracks in a Thick-Walled Bush Made of Die-Cast Aluminum Bronze

    Directory of Open Access Journals (Sweden)

    Pisarek B.P.

    2016-12-01

    Full Text Available For the die casting conditions of aluminium bronzes assumed based on the literature data, a thick-walled bush was cast, made of complex aluminium bronze (Cu-Al-Fe-Ni-Cr. After the cast was removed from the mould, cracks were observed inside it. In order to identify the stage in the technological production process at which, potentially, the formation of stresses damaging the continuity of the microstructure created in the cast was possible (hot cracking and/or cold cracking, a computer simulation was performed. The article presents the results of the computer simulation of the process of casting the material into the gravity die as well as solidifying and cooling of the cast in the shape of a thick-walled bush. The simulation was performed with the use of the MAGMA5 program and by application of the CuAl10Ni5,5Fe4,5 alloy from the MAGMA5 program database. The results were compared with the location of the defects identified in the actual cast. As a result of the simulation of the die-casting process of this bush, potential regions were identified where significant principal stresses accumulate, which can cause local hot and cold cracking. Until now, no research has been made of die-cast aluminium bronzes with a Cr addition. Correlating the results of the computer simulation validated by the analysis of the actual cast made it possible to clearly determine the critical regions in the cast exposed to cracking and point to the causes of its occurrence. Proposals of changes in the bush die casting process were elaborated, in order to avoid hot tearing and cold cracking. The article discusses the results of preliminary tests being a prologue to the optimization of the die-casting process parameters of complex aluminium bronze thick-walled bushs.

  2. Effect of Heat Treatment on Commercial AlSi12Cu1(Fe) and AlSi12(b) Aluminum Alloy Die Castings

    Science.gov (United States)

    Battaglia, E.; Bonollo, F.; Ferro, P.; Fabrizi, A.

    2018-03-01

    High-pressure die castings (HPDCs) cannot normally be heat-treated at a high temperature because of the presence of inner air/gas- or shrinkage-porosity that may lead to the formation of undesired surface blisters. In this paper, an unconventional heat treatment is proposed. Two secondary Al-Si alloys, AlSi12(b) and AlSi12Cu1(Fe), were stabilization heat-treated at 624 K (350 °C) with soaking times ranging from 1 to 8 hours. Enhancement of both static and dynamic mechanical properties was found to be related to the fragmentation of interconnected eutectic Si particles and the smoothing of coarser crystals. Increased ductility after heat treatment was correlated with a decrease in hardness and Si particle roundness. The formation of Si precipitates within the α-Al matrix was also observed.

  3. Energy Saving Melting and Revert Reduction Technology (E-SMARRT): Development of Surface Engineered Coating Systems for Aluminum Pressure Die Casting Dies: Towards a 'Smart' Die Coating

    Energy Technology Data Exchange (ETDEWEB)

    Dr. John J. Moore; Dr. Jianliang Lin,

    2012-07-31

    The main objective of this research program was to design and develop an optimal coating system that extends die life by minimizing premature die failure. In high-pressure aluminum die-casting, the die, core pins and inserts must withstand severe processing conditions. Many of the dies and tools in the industry are being coated to improve wear-resistance and decrease down-time for maintenance. However, thermal fatigue in metal itself can still be a major problem, especially since it often leads to catastrophic failure (i.e. die breakage) as opposed to a wear-based failure (parts begin to go out of tolerance). Tooling costs remain the largest portion of production costs for many of these parts, so the ability prevent catastrophic failures would be transformative for the manufacturing industry.The technology offers energy savings through reduced energy use in the die casting process from several factors, including increased life of the tools and dies, reuse of the dies and die components, reduction/elimination of lubricants, and reduced machine down time, and reduction of Al solder sticking on the die. The use of the optimized die coating system will also reduce environmental wastes and scrap parts. Current (2012) annual energy saving estimates, based on initial dissemination to the casting industry in 2010 and market penetration of 80% by 2020, is 3.1 trillion BTU's/year. The average annual estimate of CO2 reduction per year through 2020 is 0.63 Million Metric Tons of Carbon Equivalent (MM TCE).

  4. Tensile Properties and Fracture Behavior of Aluminum Alloy Foam Fabricated from Die Castings without Using Blowing Agent by Friction Stir Processing Route.

    Science.gov (United States)

    Hangai, Yoshihiko; Kamada, Hiroto; Utsunomiya, Takao; Kitahara, Soichiro; Kuwazuru, Osamu; Yoshikawa, Nobuhiro

    2014-03-21

    Al foam has been used in a wide range of applications owing to its light weight, high energy absorption and high sound insulation. One of the promising processes for fabricating Al foam involves the use of a foamable precursor. In this study, ADC12 Al foams with porosities of 67%-78% were fabricated from Al alloy die castings without using a blowing agent by the friction stir processing route. The pore structure and tensile properties of the ADC12 foams were investigated and compared with those of commercially available ALPORAS. From X-ray computed tomography (X-ray CT) observations of the pore structure of ADC12 foams, it was found that they have smaller pores with a narrower distribution than those in ALPORAS. Tensile tests on the ADC12 foams indicated that as their porosity increased, the tensile strength and tensile strain decreased, with strong relation between the porosity, tensile strength, and tensile strain. ADC12 foams exhibited brittle fracture, whereas ALPORAS exhibited ductile fracture, which is due to the nature of the Al alloy used as the base material of the foams. By image-based finite element (FE) analysis using X-ray CT images corresponding to the tensile tests on ADC12 foams, it was shown that the fracture path of ADC12 foams observed in tensile tests and the regions of high stress obtained from FE analysis correspond to each other. Therefore, it is considered that the fracture behavior of ADC12 foams in relation to their pore structure distribution can be investigated by image-based FE analysis.

  5. Tensile Properties and Fracture Behavior of Aluminum Alloy Foam Fabricated from Die Castings without Using Blowing Agent by Friction Stir Processing Route

    Directory of Open Access Journals (Sweden)

    Yoshihiko Hangai

    2014-03-01

    Full Text Available Al foam has been used in a wide range of applications owing to its light weight, high energy absorption and high sound insulation. One of the promising processes for fabricating Al foam involves the use of a foamable precursor. In this study, ADC12 Al foams with porosities of 67%–78% were fabricated from Al alloy die castings without using a blowing agent by the friction stir processing route. The pore structure and tensile properties of the ADC12 foams were investigated and compared with those of commercially available ALPORAS. From X-ray computed tomography (X-ray CT observations of the pore structure of ADC12 foams, it was found that they have smaller pores with a narrower distribution than those in ALPORAS. Tensile tests on the ADC12 foams indicated that as their porosity increased, the tensile strength and tensile strain decreased, with strong relation between the porosity, tensile strength, and tensile strain. ADC12 foams exhibited brittle fracture, whereas ALPORAS exhibited ductile fracture, which is due to the nature of the Al alloy used as the base material of the foams. By image-based finite element (FE analysis using X-ray CT images corresponding to the tensile tests on ADC12 foams, it was shown that the fracture path of ADC12 foams observed in tensile tests and the regions of high stress obtained from FE analysis correspond to each other. Therefore, it is considered that the fracture behavior of ADC12 foams in relation to their pore structure distribution can be investigated by image-based FE analysis.

  6. Energy and resource efficiency in aluminium die casting

    CERN Document Server

    Heinemann, Tim

    2016-01-01

    This monograph provides a field-proven approach to analyze industrial production with a cross-company scope as well as regarding all hierarchical system levels of manufacturing enterprises. The book exemplifies this approach in the context of aluminum  die casting, and presents a set of measures which allow a 30 percent energy reduction along the value chain. The target audience primarily comprises researchers and experts in the field but the book may also be beneficial for graduate students.

  7. Die casting copper motor rotors: mold materials and processing for cost-effective manufacturing

    Energy Technology Data Exchange (ETDEWEB)

    Peters, D.T.; Cowie, J.G.; Brush, E.F. Jr.

    2000-07-01

    This project seeks to demonstrate mold materials for copper pressure die-casting that are cost-effective and practical for production use in die-casting copper motor rotors. The incorporation of die-cast copper for conductor bars and end rings of the induction motor in place of aluminum would result in attractive improvements in motor energy efficiency through reductions in motor losses ranging from 15% to 20%. Die-cast motor rotors are produced in aluminum today because rotor fabrication by pressure die-casting is an established practice. Lack of a durable and cost-effective mold material has been the technical barrier preventing manufacture of the die-cast copper rotor. This project tested H-13 steel die inserts that establish the baseline. Nickel-, tungsten-, and molybdenum-based high temperature alloys were extensively tested. Results indicate that substantially extended die life is possible using high temperature die materials, pre-heated and operated at elevated temperatures. Pre-heating and high operating temperatures were shown to be critical in extending the die life by decreasing the cyclic stresses associated with thermal expansion. Extended die life provides the opportunity for economically viable copper motor rotor die-casting. (orig.)

  8. Development of Integrated Die Casting Process for Large Thin-Wall Magnesium Applications

    Energy Technology Data Exchange (ETDEWEB)

    Carter, Jon T. [General Motors LLC, Warren, MI (United States); Wang, Gerry [Meridian Lightweight Technologies, Plymouth MI (United States); Luo, Alan [General Motors LLC, Warren, MI (United States)

    2017-11-29

    improvement in tensile properties with vacuum casting. Plant trials with large castings revealed cavity fill issues attributed to cooling and partial solidification of metal in the shot sleeve while waiting for vacuum to be established in the die cavity. 6. Developed age-hardenable Mg-based alloys as potential alternatives to the AM60 and AZ91 alloys typically used in automotive applications. Mg-7%Al-based alloys having Sn or Sn+Si additions exhibited significant age hardening, but more work is needed to demonstrate significant improvement in tensile properties. Corrosion behavior of these alloys is between those of AM60 and AZ91 alloys. 7. Evaluated the die casting of magnesium directly onto either steel or aluminum tubes as a potential process to make large lightweight subassemblies. Samples were free of gross defects, but additional work is needed to increase the interfacial shear strength. Overall, the project demonstrated that an automotive door-in-white design incorporating a die cast magnesium inner panel and a stamped aluminum outer panel can achieve approximately 50% mass reduction compared to the stamped steel baseline door-in-white. This leads to reduced energy consumption when driving the vehicle, which should more than offset the increased embedded energy of manufacture associated with the lighter metals. However, additional design work would be needed in order to meet the mechanical performance required of a door. Development of high-strength, high-ductility magnesium alloy castings would help make this technology more attractive for potential use in the side doors on automobiles. Also, increased use of recycled magnesium and aluminum would reduce the embedded energy and greenhouse gas emissions associated with the manufacture of this type of lightweight door. Commercialization planning of the type of lightweight door technology addressed in this project would be contingent upon the doors meeting all technical performance requirements of the car maker. The

  9. Modeling and Analysis of The Pressure Die Casting Using Response Surface Methodology

    International Nuclear Information System (INIS)

    Kittur, Jayant K.; Herwadkar, T. V.; Parappagoudar, M. B.

    2010-01-01

    Pressure die casting is successfully used in the manufacture of Aluminum alloys components for automobile and many other industries. Die casting is a process involving many process parameters having complex relationship with the quality of the cast product. Though various process parameters have influence on the quality of die cast component, major influence is seen by the die casting machine parameters and their proper settings. In the present work, non-linear regression models have been developed for making predictions and analyzing the effect of die casting machine parameters on the performance characteristics of die casting process. Design of Experiments (DOE) with Response Surface Methodology (RSM) has been used to analyze the effect of effect of input parameters and their interaction on the response and further used to develop nonlinear input-output relationships. Die casting machine parameters, namely, fast shot velocity, slow shot to fast shot change over point, intensification pressure and holding time have been considered as the input variables. The quality characteristics of the cast product were determined by porosity, hardness and surface rough roughness (output/responses). Design of experiments has been used to plan the experiments and analyze the impact of variables on the quality of casting. On the other-hand Response Surface Methodology (Central Composite Design) is utilized to develop non-linear input-output relationships (regression models). The developed regression models have been tested for their statistical adequacy through ANOVA test. The practical usefulness of these models has been tested with some test cases. These models can be used to make the predictions about different quality characteristics, for the known set of die casting machine parameters, without conducting the experiments.

  10. Automatic inspection of surface defects in die castings after machining

    Directory of Open Access Journals (Sweden)

    S. J. Świłło

    2011-07-01

    Full Text Available A new camera based machine vision system for the automatic inspection of surface defects in aluminum die casting was developed by the authors. The problem of surface defects in aluminum die casting is widespread throughout the foundry industry and their detection is of paramount importance in maintaining product quality. The casting surfaces are the most highly loaded regions of materials and components. Mechanical and thermal loads as well as corrosion or irradiation attacks are directed primarily at the surface of the castings. Depending on part design and processing techniques, castings may develop surface discontinuities such as cracks or tears, inclusions due to chemical reactions or foreign material in the molten metal, and pores that greatly influence the material ability to withstand these loads. Surface defects may act as a stress concentrator initiating a fracture point. If a pressure is applied in this area, the casting can fracture. The human visual system is well adapted to perform in areas of variety and change; the visual inspection processes, on the other hand, require observing the same type of image repeatedly to detect anomalies. Slow, expensive, erratic inspection usually is the result. Computer based visual inspection provides a viable alternative to human inspectors. Developed by authors machine vision system uses an image processing algorithm based on modified Laplacian of Gaussian edge detection method to detect defects with different sizes and shapes. The defect inspection algorithm consists of three parameters. One is a parameter of defects sensitivity, the second parameter is a threshold level and the third parameter is to identify the detected defects size and shape. The machine vision system has been successfully tested for the different types of defects on the surface of castings.

  11. Energy Saving Melting and Revert Reduction Technology: Melting Efficiency in Die Casting Operations

    Energy Technology Data Exchange (ETDEWEB)

    David Schwam

    2012-12-15

    This project addressed multiple aspects of the aluminum melting and handling in die casting operations, with the objective of increasing the energy efficiency while improving the quality of the molten metal. The efficiency of melting has always played an important role in the profitability of aluminum die casting operations. Consequently, die casters need to make careful choices in selecting and operating melting equipment and procedures. The capital cost of new melting equipment with higher efficiency can sometimes be recovered relatively fast when it replaces old melting equipment with lower efficiency. Upgrades designed to improve energy efficiency of existing equipment may be well justified. Energy efficiency is however not the only factor in optimizing melting operations. Melt losses and metal quality are also very important. Selection of melting equipment has to take into consideration the specific conditions at the die casting shop such as availability of floor space, average quantity of metal used as well as the ability to supply more metal during peaks in demand. In all these cases, it is essential to make informed decisions based on the best available data.

  12. Thermal Fatigue of Die-Casting Dies: An Overview

    Directory of Open Access Journals (Sweden)

    Abdulhadi Hassan A.

    2016-01-01

    Full Text Available Coupled studies by experimental and numerical simulations are necessary for an increased understanding of the material behaviour as related to the interaction between the thermal and mechanical conditions. This paper focus on the mechanisms of thermal fatigue in the failure of dies and cores used in the die casting of aluminum alloys. The thermal fatigue resistance is expressed by two crack parameters which are the average maximum crack and the average cracked area. Samples of various types of H13 steel were compared with a standard H13 steel by testing under identical thermal fatigue cycles. To determine the thermal constraint developed in the sample during the test, a finite difference technique was used to obtain the temperature distribution, based on temperature measurements at the boundaries. The resulting stresses and strains were computed, and the strain calculated at the edge or weakest point of the sample was used to correlate the number of cycles to crack initiation. As the strain at the edge increased, the number of cycles to failure decreased. The influence of various factors on thermal fatigue behavior was studied including austenitizing temperature, surface condition, stress relieving, casting, vacuum melting, and resulfurization. The thermal fatigue resistance improved as the austenitizing temperature increased from 1750 to 2050ºF.

  13. New trends in cold-chamber die casting machine design

    Directory of Open Access Journals (Sweden)

    R. Dańko

    2015-07-01

    Full Text Available Larger and larger proportions of aluminium castings, especially those produced by the die casting process, can be observed during recent years in the automotive industry, house-hold articles and others. In case of the automotive industry, apart from the traditional elements produced by the die pressure method such as engine blocks or crank shaft bedplates, aluminium is displacing steel from structural parts of cars (‘body in white’. The current state and development directions of the structural solutions of cold-chamber die castings are analysed in this paper. These solutions drive the prospective development of these machines and die casting technology. The focus is mainly on essential functional systems such as: hydraulic drives of closing and locking units, as well as pressing in die machines of known companies present on the European market.

  14. Strength and deformation behaviour of magnesium die casting alloys

    International Nuclear Information System (INIS)

    Regener, D.; Schick, E.; Wagner, I.; Heyse, H.

    1999-01-01

    Modern magnesium die casting alloys are used for the manufacturing of automotive parts due to their low density, fortunate mechanical and physical properties as well as good castability and machinability. However, in comparison to other materials the automotive application of these alloys is still low. The reasons for this are among other things the shortage of relevant materials values, insufficient knowledge concerning the correlation between the microstructure and the mechanical properties as well as deficits in relation to the die cast technology. This paper investigates the influence of the microstructure and manufacture-induced defects like micro-shrinkage and gas pores on the strength and deformability of the alloys AZ91, AM50 and AE42 under tensile and bend loading. To characterise the microstructure in the dependence on the wall thickness, the investigations are mainly carried out using in situ specimens obtained from die castings. (orig.)

  15. Strength Estimation of Die Cast Beams Considering Equivalent Porous Defects

    Energy Technology Data Exchange (ETDEWEB)

    Park, Moon Shik [Hannam Univ., Daejeon (Korea, Republic of)

    2017-05-15

    As a shop practice, a strength estimation method for die cast parts is suggested, in which various defects such as pores can be allowed. The equivalent porosity is evaluated by combining the stiffness data from a simple elastic test at the part level during the shop practice and the theoretical stiffness data, which are defect free. A porosity equation is derived from Eshelby's inclusion theory. Then, using the Mori-Tanaka method, the porosity value is used to draw a stress-strain curve for the porous material. In this paper, the Hollomon equation is used to capture the strain hardening effect. This stress-strain curve can be used to estimate the strength of a die cast part with porous defects. An elastoplastic theoretical solution is derived for the three-point bending of a die cast beam by using the plastic hinge method as a reference solution for a part with porous defects.

  16. Study of protective coatings for aluminum die casting molds

    Energy Technology Data Exchange (ETDEWEB)

    Peter, Ildiko, E-mail: ildiko.peter@polito.it; Rosso, Mario; Gobber, Federico Simone

    2015-12-15

    Highlights: • Development and characterization of some protective coatings on steel substrate, realized by plasma spray techniques, were presented. • The substrate material used is a Cr–Mo–V based hot work tool steel. • The main attention is on the study of wear and on the characterization of the interface, because of their key role in determining the resistance of the coating layer. • Simulation of friction and wear processes is performed by pin-on-disk test and the tested samples are observed by scanning electron microscopy. - Abstract: In this paper, the development and characterization of some protective coatings on steel substrate are presented. The coatings are realized by plasma spray techniques. The substrate material used is a Cr–Mo–V based hot work tool steel, initially submitted to vacuum heat treatment to achieve homogeneous hardness. The main attention is focused on the study of wear and on the characterization of the interface between the substrate material and the coating layer, because of their key role in determining the resistance of the coating layer. Simulation of friction and wear processes is performed by pin-on-disk test and the tested samples are observed by scanning electron microscopy.

  17. Evaluation of porosity in Al alloy die castings

    Directory of Open Access Journals (Sweden)

    M. Říhová

    2012-01-01

    Full Text Available Mechanical properties of an Al-alloy die casting depend significantly on its structural properties. Porosity in Al-alloy castings is one of the most frequent causes of waste castings. Gas pores are responsible for impaired mechanical-technological properties of cast materials. On the basis of a complex evaluation of experiments conducted on AlSi9Cu3 alloy samples taken from the upper engine block which was die- cast with and without local squeeze casting it can be said that castings manufactured without squeeze casting exhibit maximum porosity in the longitudinal section. The area without local squeeze casting exhibits a certain reduction in mechanical properties and porosity increased to as much as 5%. However, this still meets the norms set by SKODA AUTO a.s.

  18. Modeling the Mechanical Performance of Die Casting Dies

    Energy Technology Data Exchange (ETDEWEB)

    R. Allen Miller

    2004-02-27

    The following report covers work performed at Ohio State on modeling the mechanical performance of dies. The focus of the project was development and particularly verification of finite element techniques used to model and predict displacements and stresses in die casting dies. The work entails a major case study performed with and industrial partner on a production die and laboratory experiments performed at Ohio State.

  19. Die design and process optimization of die cast V6 engine blocks

    Directory of Open Access Journals (Sweden)

    Henry Hu

    2005-02-01

    Full Text Available The use of aluminum, particularly for engine blocks, has grown considerably in the past ten years, and continues to rise in the automotive industry. In order to enhance the quality and engineering functionality of die cast engine blocks, die design and processes have to be optimized. In this study, a computer simulation software, MAGMAsoft, as an advanced tool for optimizing die design and casting process, was emplooyed to virtually visualize cavity filling and patterns of a V6 engine block. The original die design and process was simulated first to establish a baseline. A reality check was used to verify the predicted results. Then, the die modification with a different unner system was made by using a CAD software, Unigraphics (UG. The simulation on combinations of the modified die design and revised process was performed to examine the effect of die modification and process change on flow filling of V6 engine blocks. The simulated prediction indicateds that the enhancement of cavity filling due to the die and process modification minimizeds the occurrence of defects during casting, and consequently improves the quality of blocks. The results of mechanical testing show a significant increase in fatigue strengths, and a moderately improvement on tensile properties for the blocks die cast with the new die design and prpocess in comparison with those produced by the original ones.

  20. Microstructure and mechanical properties of AM50 alloy according to thickness and forming condition of the products by a high pressure die-casting process

    Energy Technology Data Exchange (ETDEWEB)

    Park, Joon Hong [Dong-A University, Busan (Korea, Republic of); Kang, Chung Gil [Pusan National University, Busan (Korea, Republic of)

    2013-10-15

    In recent years, Magnesium (Mg) and its alloys have become a center of special interest in the automotive industry. Due to their high specific mechanical properties, they offer a significant weight saving potential in modern vehicle constructions. Most Mg alloys show very good machinability and processability, and even the most complicated die casting parts can be easily produced. The die casting process is a fast production method capable of a high degree of automation for which certain Mg alloys are ideally suited. Although Mg alloys are fulfilling the demands for low specific weight materials with excellent machining and casting abilities, they are still not used in die casting process to the same extent as the competing material aluminum. One of the reasons is that effects of various forming variables for die casting process is not closely examined from the viewpoint of die design. In this study, step die and flowability tests for AM50 were performed by die casting process according to various combination of casting pressure and plunger velocity. Microstructure, Vickers hardness and tensile tests were examined and performed for each specimen to verify effects of forming conditions.

  1. Numerical simulation and optimization of Al alloy cylinder body by low pressure die casting

    Directory of Open Access Journals (Sweden)

    Mi Guofa

    2008-05-01

    Full Text Available Shrinkage defects can be formed easily at Critical location during low pressure die casting (LPDC of aluminum alloy cylinder body. It has harmful effect on the products. Mold fi lling and solidifi cation process of a cylinder body was simulated by using of Z-CAST software. The casting method was improved based on the simulation results. In order to create effective feeding passage, the structure of casting was modifi ed by changing the location of strengthening ribs at the bottom, without causing any adverse effect on the part’s performance. Inserting copper billet at suitable location of the die is a valid way to create suitable solidifi cation sequence that is benefi cial to the feeding. Using these methods, the shrinkage defect was completely eliminated at the critical location.

  2. Development of Thin Section Zinc Die Casting Technology

    Energy Technology Data Exchange (ETDEWEB)

    Goodwin, Frank [International Lead Zinc Research Org., Inc., Durham, NC (United States)

    2013-10-31

    A new high fluidity zinc high pressure die casting alloy, termed the HF alloy, was developed during laboratory trials and proven in industrial production. The HF alloy permits castings to be achieved with section thicknesses of 0.3 mm or less. Technology transfer activities were conducted to develop usage of the HF high fluidity alloy. These included production of a brochure and a one-hour webinar on the HF alloy. The brochure was then sent to 1,184 product designers in the Interzinc database. There was excellent reception to this mailing, and from this initial contact 5 technology transfer seminars were conducted for 81 participants from 30 companies across a wide range of business sectors. Many of the successful applications to date involve high quality surface finishes. Design and manufacturing assistance was given for development of selected applications.

  3. Effect of substituting cerium-rich mischmetal with lanthanum on high temperature properties of die-cast Mg-Zn-Al-Ca-RE alloys

    International Nuclear Information System (INIS)

    Anyanwu, Ifeanyi A.; Gokan, Yasuhiro; Suzuki, Atsuya; Kamado, Shigeharu; Kojima, Yo; Takeda, Suguru; Ishida, Taketoshi

    2004-01-01

    Mg-Zn-Al-Ca-RE alloys have been found to be promising materials for substituting aluminum alloys used for automatic transmission case applications in the automobile industry. Particularly, Mg-0.5%Zn-6%Al-1%Ca-3%RE (ZAXE05613) alloy exhibits comparable creep resistance as ADC12 die-casting aluminum alloy that is currently used for automatic transmission case applications. Changing the rare earth (RE) content of the alloy from mischmetal to lanthanum gives a further improvement in the creep properties of the alloy. Lanthanum addition results in the crystallization of a large amount of acicular Al 11 RE 3 (Al 11 La 3 ) compound along the grain boundaries as well as across the grain boundaries and this effectively controls grain boundary sliding and dislocation motion in the vicinity of the grain boundaries. As a result, die-cast ZAXLa05613 alloy exhibits a higher creep resistance than that of ZAXE05613 alloy

  4. National Metal Casting Research Institute final report. Volume 2, Die casting research

    Energy Technology Data Exchange (ETDEWEB)

    Jensen, D. [University of Northern Iowa, Cedar Falls, IA (United States). Dept. of Industrial Technology] [comp.

    1994-06-01

    Four subprojects were completed: development and evaluation of die coatings, accelerated die life characterization of die materials, evaluation of fluid flow and solidification modeling programs, selection and characterization of Al-based die casting alloys, and influence of die materials and coatings on die casting quality.

  5. Mathematical modeling of porosity formation in die cast A356 wheels

    International Nuclear Information System (INIS)

    Maijer, D.; Cockcroft, S.L.; Wells, M.A.; Luciuk, T.; Hermesmann, C.

    2000-01-01

    In an effort to leverage recent advances in modeling and process simulation tools, a mathematical model has been developed to predict porosity formation in die cast A356 wheels as part of a collaborative research agreement between researchers at the University of British Columbia and Canadian Autoparts Toyota Incorporated. The heat transfer model represents a three-dimensional, 30 o , slice of the wheel and die and is based on the commercial finite element code ABAQUS. Extensive temperature measurements in the die and in the wheel taken over several cycles in the casting process were used to fine tune and validate the model. Initial work on predicting porosity formation has focused on using the Niyama parameter as a measure of the probability of porosity. To date Niyama porosity predictions agree well with plant experience and show promise for reducing losses associated with porosity. (author)

  6. Energy Saving Melting and Revert Reduction Technology: Improved Die Casting Process to Preserve the Life of the Inserts

    Energy Technology Data Exchange (ETDEWEB)

    David Schwam, PI; Xuejun Zhu, Sr. Research Associate

    2012-09-30

    The goal of this project was to study the combined effects of die design, proper internal cooling and efficient die lubricants on die life. The project targeted improvements in die casting insert life by: Optomized Die Design for Reduced Surface Temperature: The life of die casting dies is significantly shorter when the die is exposed to elevated temperature for significant periods of time. Any die operated under conditions leading to surface temperature in excess of 1050oF undergoes structural changes that reduce its strength. Optimized die design can improve die life significantly. This improvement can be accomplished by means of cooling lines, baffles and bubblers in the die. A key objective of the project was to establish criteria for the minimal distance of the cooling lines from the surface. This effort was supported with alloys and machining by BohlerUddeholm, Dunn Steel, HH Stark and Rex Buckeye. In plant testing and evaluation was conducted as in-kind cost share at St. Clair Die Casting. The Uddeholm Dievar steel evaluated in this program showed superior resistance to thermal fatigue resistance. Based on the experimental evidence, cooling lines could be placed as close as 0.5" from the surface. Die Life Extension by Optimized Die Lubrication: The life of die casting dies is affected by additions made to its surface with the proper lubricants. These lubricants will protect the surface from the considerable temperature peaks that occur when the molten melt enters the die. Dies will reach a significantly higher temperature without this lubricant being applied. The amount and type of the lubricant are critical variables in the die casting process. However, these lubricants must not corrode the die surface. This effort was supported with alloys and machining by BohlerUddeholm, Dunn Steel, HH Stark and Rex Buckeye. In plant testing and evaluation was conducted as in-kind cost share at St. Clair Die Casting. Chem- Trend participated in the program with die

  7. High pressure die casting of Fe-based metallic glass

    Science.gov (United States)

    Ramasamy, Parthiban; Szabo, Attila; Borzel, Stefan; Eckert, Jürgen; Stoica, Mihai; Bárdos, András

    2016-01-01

    Soft ferromagnetic Fe-based bulk metallic glass key-shaped specimens with a maximum and minimum width of 25.4 and 5 mm, respectively, were successfully produced using a high pressure die casting (HPDC) method, The influence of die material, alloy temperature and flow rate on the microstructure, thermal stability and soft ferromagnetic properties has been studied. The results suggest that a steel die in which the molten metal flows at low rate and high temperature can be used to produce completely glassy samples. This can be attributed to the laminar filling of the mold and to a lower heat transfer coefficient, which avoids the skin effect in the steel mold. In addition, magnetic measurements reveal that the amorphous structure of the material is maintained throughout the key-shaped samples. Although it is difficult to control the flow and cooling rate of the molten metal in the corners of the key due to different cross sections, this can be overcome by proper tool geometry. The present results confirm that HPDC is a suitable method for the casting of Fe-based bulk glassy alloys even with complex geometries for a broad range of applications. PMID:27725780

  8. High pressure die casting of Fe-based metallic glass.

    Science.gov (United States)

    Ramasamy, Parthiban; Szabo, Attila; Borzel, Stefan; Eckert, Jürgen; Stoica, Mihai; Bárdos, András

    2016-10-11

    Soft ferromagnetic Fe-based bulk metallic glass key-shaped specimens with a maximum and minimum width of 25.4 and 5 mm, respectively, were successfully produced using a high pressure die casting (HPDC) method, The influence of die material, alloy temperature and flow rate on the microstructure, thermal stability and soft ferromagnetic properties has been studied. The results suggest that a steel die in which the molten metal flows at low rate and high temperature can be used to produce completely glassy samples. This can be attributed to the laminar filling of the mold and to a lower heat transfer coefficient, which avoids the skin effect in the steel mold. In addition, magnetic measurements reveal that the amorphous structure of the material is maintained throughout the key-shaped samples. Although it is difficult to control the flow and cooling rate of the molten metal in the corners of the key due to different cross sections, this can be overcome by proper tool geometry. The present results confirm that HPDC is a suitable method for the casting of Fe-based bulk glassy alloys even with complex geometries for a broad range of applications.

  9. High pressure die casting of Fe-based metallic glass

    Science.gov (United States)

    Ramasamy, Parthiban; Szabo, Attila; Borzel, Stefan; Eckert, Jürgen; Stoica, Mihai; Bárdos, András

    2016-10-01

    Soft ferromagnetic Fe-based bulk metallic glass key-shaped specimens with a maximum and minimum width of 25.4 and 5 mm, respectively, were successfully produced using a high pressure die casting (HPDC) method, The influence of die material, alloy temperature and flow rate on the microstructure, thermal stability and soft ferromagnetic properties has been studied. The results suggest that a steel die in which the molten metal flows at low rate and high temperature can be used to produce completely glassy samples. This can be attributed to the laminar filling of the mold and to a lower heat transfer coefficient, which avoids the skin effect in the steel mold. In addition, magnetic measurements reveal that the amorphous structure of the material is maintained throughout the key-shaped samples. Although it is difficult to control the flow and cooling rate of the molten metal in the corners of the key due to different cross sections, this can be overcome by proper tool geometry. The present results confirm that HPDC is a suitable method for the casting of Fe-based bulk glassy alloys even with complex geometries for a broad range of applications.

  10. 77 FR 6587 - PHB Die Casting a Subsidiary of PHB, Inc., Including On-Site Leased Workers From Career Concepts...

    Science.gov (United States)

    2012-02-08

    ... DEPARTMENT OF LABOR Employment and Training Administration [TA-W-64,292] PHB Die Casting a... 19, 2008, applicable to workers of PHB Die Casting, a subsidiary of PHB, Inc., including on-site... production of die castings. New information shows that a worker from Burns Industrial Group (BIG Inc) was...

  11. Study on interfacial heat transfer coefficient at metal/die interface during high pressure die casting process of AZ91D alloy

    Directory of Open Access Journals (Sweden)

    GUO Zhi-peng

    2007-02-01

    Full Text Available The high pressure die casting (HPDC process is one of the fastest growing and most efficient methods for the production of complex shape castings of magnesium and aluminum alloys in today’s manufacturing industry.In this study, a high pressure die casting experiment using AZ91D magnesium alloy was conducted, and the temperature profiles inside the die were Measured. By using a computer program based on solving the inverse heat problem, the metal/die interfacial heat transfer coefficient (IHTC was calculated and studied. The results show that the IHTC between the metal and die increases right after the liquid metal is brought into the cavity by the plunger,and decreases as the solidification process of the liquid metal proceeds until the liquid metal is completely solidified,when the IHTC tends to be stable. The interfacial heat transfer coefficient shows different characteristics under different casting wall thicknesses and varies with the change of solidification behavior.

  12. Thermal Stress Analysis for Ceramics Stalk in the Low Pressure Die Casting Machine

    Science.gov (United States)

    Noda, Nao-Aki; Hendra, Nao-Aki; Takase, Yasushi; Li, Wenbin

    Low pressure die casting (LPDC) is defined as a net shape casting technology in which the molten metal is injected at high speeds and pressure into a metallic die. The LPDC process is playing an increasingly important role in the foundry industry as a low-cost and high-efficiency precision forming technique. The LPDC process is that the permanent die and filling systems are placed over the furnace containing the molten alloy. The filling of the cavity is obtained by forcing the molten metal by means of a pressurized gas in order to rise into a ceramic tube, which connects the die to the furnace. The ceramics tube called stalk has high temperature resistance and high corrosion resistance. However, attention should be paid to the thermal stress when the stalk is dipped into the molten aluminum. It is important to develop the design of the stalk to reduce the risk of fracture because of low fracture toughness of ceramics. In this paper, therefore, the finite element method is applied to calculate the thermal stresses when the stalk is dipped into the crucible by varying the dipping speeds and dipping directions. It is found that the thermal stress can be reduced by dipping slowly if the stalk is dipped into the crucible vertically, while the thermal stress can be reduced by dipping fast if it is dipped horizontally.

  13. Reducing non value adding aluminium alloy in production of parts through high pressure die casting

    CSIR Research Space (South Africa)

    Pereira, MFVT

    2010-10-01

    Full Text Available in the cast part feed system, including overflows. CSIR intends using the results of this research for further development and application of high temperature die construction materials in high pressure die casting processes of light metal alloys...

  14. Die Casting Part Distortion: Prediction and Attenuation; FINAL

    International Nuclear Information System (INIS)

    Allen Miller, R.

    2002-01-01

    The goal of this research was to predict the part deformation and residual stresses after ejection from the die and cooling to room temperature. A finite element model was built to achieve this goal and several modeling techniques were investigated throughout this research. Die-casting is a very complex process and the researchers are faced with a large number of hard to solve physical problems when modeling the process. Several assumptions are made in our simulation model. The first significant assumption is the instantaneous cavity filling. This means that the cavity filling stage is not considered in our model. Considering the cavity filling stage increases the modeling complexity as a result of different flow patterns. expected in the shot sleeve, gate, runner and different cavity features. The flow of gas from the cavity through the vents is another problem that is ignored in our model as a result of this assumption. Our second assumption is that the cast metal has uniform temperature distribution inside the cavity, at the starting point of simulation. This temperature is assumed to be over liquidus limit, i.e. the solid fraction is 0.0% of the cast metal. The third assumption is due to ABAQUS (commercial software used in this research) limitations. ABAQUS cannot deal with multi-phase models; therefore we use solid elements to define the casting instead of multi-phase (liquid/solid) elements. Liquid elements can carry the hydrostatic pressure from the shot sleeve and apply it on the cavity surfaces, while the solid elements do not have this capability. To compensate for this assumption we add the cavity pressure as a boundary condition and apply it on the cavity surface separately from the part. Another issue with this assumption is that, liquid casting can follow the cavity shape when it distorts. With the use of solid elements to represent the casting during its liquid state, it loses this capability to follow the cavity. Several techniques were tested to

  15. Fabrication of ZnO Nanowires Arrays by Anodization and High-Vacuum Die Casting Technique, and Their Piezoelectric Properties

    Science.gov (United States)

    Kuo, Chin-Guo; Chang, Ho; Wang, Jian-Hao

    2016-01-01

    In this investigation, anodic aluminum oxide (AAO) with arrayed and regularly arranged nanopores is used as a template in the high-vacuum die casting of molten zinc metal (Zn) into the nanopores. The proposed technique yields arrayed Zn nanowires with an aspect ratio of over 600. After annealing, arrayed zinc oxide (ZnO) nanowires are obtained. Varying the anodizing time yields AAO templates with thicknesses of approximately 50 μm, 60 μm, and 70 μm that can be used in the fabrication of nanowires of three lengths with high aspect ratios. Experimental results reveal that a longer nanowire generates a greater measured piezoelectric current. The ZnO nanowires that are fabricated using an alumina template are anodized for 7 h and produce higher piezoelectric current of up to 69 pA. PMID:27023546

  16. Fabrication of ZnO Nanowires Arrays by Anodization and High-Vacuum Die Casting Technique, and Their Piezoelectric Properties

    Directory of Open Access Journals (Sweden)

    Chin-Guo Kuo

    2016-03-01

    Full Text Available In this investigation, anodic aluminum oxide (AAO with arrayed and regularly arranged nanopores is used as a template in the high-vacuum die casting of molten zinc metal (Zn into the nanopores. The proposed technique yields arrayed Zn nanowires with an aspect ratio of over 600. After annealing, arrayed zinc oxide (ZnO nanowires are obtained. Varying the anodizing time yields AAO templates with thicknesses of approximately 50 μm, 60 μm, and 70 μm that can be used in the fabrication of nanowires of three lengths with high aspect ratios. Experimental results reveal that a longer nanowire generates a greater measured piezoelectric current. The ZnO nanowires that are fabricated using an alumina template are anodized for 7 h and produce higher piezoelectric current of up to 69 pA.

  17. Fabrication of ZnO Nanowires Arrays by Anodization and High-Vacuum Die Casting Technique, and Their Piezoelectric Properties.

    Science.gov (United States)

    Kuo, Chin-Guo; Chang, Ho; Wang, Jian-Hao

    2016-03-24

    In this investigation, anodic aluminum oxide (AAO) with arrayed and regularly arranged nanopores is used as a template in the high-vacuum die casting of molten zinc metal (Zn) into the nanopores. The proposed technique yields arrayed Zn nanowires with an aspect ratio of over 600. After annealing, arrayed zinc oxide (ZnO) nanowires are obtained. Varying the anodizing time yields AAO templates with thicknesses of approximately 50 μm, 60 μm, and 70 μm that can be used in the fabrication of nanowires of three lengths with high aspect ratios. Experimental results reveal that a longer nanowire generates a greater measured piezoelectric current. The ZnO nanowires that are fabricated using an alumina template are anodized for 7 h and produce higher piezoelectric current of up to 69 pA.

  18. Corrosion behavior of die-cast Mg-4Al-2Sn-xCa alloy

    Energy Technology Data Exchange (ETDEWEB)

    Park, Kyung Chul; Kim, Byeong Ho; Kim, Kyung Ro [Defence Agency for Technology and Quality, Jinju (Korea, Republic of); Cho, Dae Hyun; Park, Ik Min [Pusan National University, Busan (Korea, Republic of)

    2016-05-15

    In the present work, the effect of Ca additions on microstructure and corrosion characteristics of high pressure die-cast Mg-4Al-2Sn alloy has been investigated. Mg-4Al-2Sn-xCa (x= 0, 0.3 and 0.7wt.%) alloy was prepared by using a high pressure die-casting method. Results indicated that the microstructure of Mg-4Al-2Sn alloy consisted of α-Mg, Mg{sub 17}Al{sub 12} and Mg{sub 2}Sn phase. With increase of Ca additions, CaMgSn phase was newly formed and grain size was sharply decreased. From the test results, the corrosion resistance of die-cast Mg-4Al-2Sn alloy was significantly improved by Ca addition. It is considered that stabilization of Mg(OH){sub 2} layer and refinements of microstructure with increase of Ca additions.

  19. Aluminum exclusion and aluminum tolerance in woody plants.

    Science.gov (United States)

    Brunner, Ivano; Sperisen, Christoph

    2013-01-01

    The aluminum (Al) cation Al(3) (+) is highly rhizotoxic and is a major stress factor to plants on acid soils, which cover large areas of tropical and boreal regions. Many woody plant species are native to acid soils and are well adapted to high Al(3) (+) conditions. In tropical regions, both woody Al accumulator and non-Al accumulator plants occur, whereas in boreal regions woody plants are non-Al accumulators. The mechanisms of these adaptations can be divided into those that facilitate the exclusion of Al(3) (+) from root cells (exclusion mechanisms) and those that enable plants to tolerate Al(3) (+) once it has entered the root and shoot symplast (internal tolerance mechanisms). The biochemical and molecular basis of these mechanisms have been intensively studied in several crop plants and the model plant Arabidopsis. In this review, we examine the current understanding of Al(3) (+) exclusion and tolerance mechanisms from woody plants. In addition, we discuss the ecology of woody non-Al accumulator and Al accumulator plants, and present examples of Al(3) (+) adaptations in woody plant populations. This paper complements previous reviews focusing on crop plants and provides insights into evolutionary processes operating in plant communities that are widespread on acid soils.

  20. Microstructural analysis of the creep resistance of die-cast Mg-4Al-2RE alloy

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, S.M. [CAST CRC, Department of Materials Engineering, Monash University, Victoria 3800 (Australia)], E-mail: suming.zhu@eng.monash.edu.au; Gibson, M.A. [CAST CRC, CSIRO Materials Science and Engineering, Private Bag 33, Clayton South MDC, Clayton, Victoria 3169 (Australia); Nie, J.F.; Easton, M.A. [CAST CRC, Department of Materials Engineering, Monash University, Victoria 3800 (Australia); Abbott, T.B. [Advanced Magnesium Technologies, Milton, Queensland 4064 (Australia)

    2008-03-15

    The microstructure and microstructural stability of die-cast AE42 (Mg-4Al-2RE) alloy were investigated by transmission electron microscopy. It is shown that the formation of Mg{sub 17}Al{sub 12} after ageing at 200 deg. C is not due to the decomposition of A1{sub 11}RE{sub 3} as reported in the literature, but, rather, is associated with the supersaturation of Al solute in the {alpha}-Mg matrix. The level of Al solute retained in the {alpha}-Mg matrix after die-casting is suggested to be an important factor in influencing creep resistance.

  1. The simulation of magnesium wheel low pressure die casting based on PAM-CASTTM

    International Nuclear Information System (INIS)

    Peng Yinghong; Wang Yingchun; Li Dayong; Zeng Xiaoqin

    2004-01-01

    Magnesium is the lightest metal commonly used in engineering, with various excellent characteristics such as high strength and electromagnetic interference shielding capability. Particularly, the usage of magnesium in automotive industry can meet better the need to reduce fuel consumption and CO2 emissions. Nowadays, most current magnesium components in automobiles are made by die casting. In this paper, commercial software for die casting, PAM-CAST TM , was utilized to simulate the low pressure die casting process of magnesium wheel. Through calculating temperature field and velocity field during filling and solidification stages, the evolution of temperature distribution and liquid fraction was analyzed. Then, the potential defects including the gas entrapments in the middle of the spokes, shrinkages between the rim and the spokes were forecasted. The analytical results revealed that the mold geometry and die casting parameters should be improved in order to get the sound magnesium wheel. The reasons leading to these defects were also analyzed and the solutions to eliminate them were put forward. Furthermore, through reducing the pouring velocity, the air gas entrapments and partial shrinkages were eliminated effectively

  2. Low cycle fatigue behavior of die cast Mg-Al-Mn-Ce magnesium alloy

    Directory of Open Access Journals (Sweden)

    Wu Wei

    2013-11-01

    Full Text Available Fatigue failure is a main failure mode for magnesium and other alloys. It is beneficial for fatigue design and fatigue life improvement to investigate the low cycle fatigue behavior of magnesium alloys. In order to investigate the low cycle fatigue behavior of die cast Mg-Al-Mn-Ce magnesium alloy, the strain controlled fatigue experiments were performed at room temperature and fatigue fracture surfaces of specimens were observed with scanning election microscopy for the alloys under die-cast and aged states. Cyclic stress response curves, strain amplitude versus reversals to failure curve, total strain amplitude versus fatigue life curves and cyclic stress-strain curves of Mg-Al-Mn-Ce alloys were analyzed. The results show that the Mg-Al-Mn-Ce alloys under die-cast (F and aged (T5 states exhibit cyclic strain hardening under the applied total strain amplitudes, and aging treatment could greatly increase the cyclic stress amplitudes of die cast Mg-Al-Mn-Ce alloys. The relationships between the plastic strain amplitude, the elastic strain amplitude and reversals to failure of Mg-Al-Mn-Ce magnesium alloy under different treatment states could be described by Coffin-Manson and Basquin equations, respectively. Observations on the fatigue fracture surface of specimens reveal that the fatigue cracks initiate on the surface of specimens and propagate transgranularly.

  3. Semi-solid high pressure die casting of metal matrix composites produced by liquid state processing

    CSIR Research Space (South Africa)

    Ivanchev, L

    2012-10-01

    Full Text Available stirring. The composite was then transferred to a High Pressure Die Casting (HPDC) machine in the semi-solid state. The micron size particles were found to be predominantly in the intergranular eutectic while the nano-particles were predominantly...

  4. Metallographic assessment of Al-12Si high-pressure die casting escalator steps.

    Science.gov (United States)

    Vander Voort, George Frederic; Suárez-Peña, Beatriz; Asensio-Lozano, Juan

    2014-10-01

    A microstructural characterization study was performed on high-pressure die cast specimens extracted from escalator steps manufactured from an Al-12 wt.% Si alloy designed for structural applications. Black and white, color light optical imaging and scanning electron microscopy techniques were used to conduct the microstructural analysis. Most regions in the samples studied contained globular-rosette primary α-Al grains surrounded by an Al-Si eutectic aggregate, while primary dendritic α-Al grains were present in the surface layer. This dendritic microstructure was observed in the regions where the melt did not impinge directly on the die surface during cavity filling. Consequently, microstructures in the surface layer were nonuniform. Utilizing physical metallurgy principles, these results were analyzed in terms of the applied pressure and filling velocity during high-pressure die casting. The effects of these parameters on solidification at different locations of the casting are discussed.

  5. Age hardening in die-cast Mg–Al–RE alloys due to minor Mn additions

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, S.M., E-mail: suming.zhu@rmit.edu.au [School Engineering, RMIT University, Carlton, Victoria 3053 (Australia); Department of Materials Science and Engineering, Monash University, Victoria 3800 (Australia); Abbott, T.B. [School Engineering, RMIT University, Carlton, Victoria 3053 (Australia); Department of Materials Science and Engineering, Monash University, Victoria 3800 (Australia); Magontec Limited, Sydney, New South Wales 2000 (Australia); Gibson, M.A. [School Engineering, RMIT University, Carlton, Victoria 3053 (Australia); Department of Materials Science and Engineering, Monash University, Victoria 3800 (Australia); CSIRO Manufacturing Flagship, Clayton, Victoria 3168 (Australia); Nie, J.F. [Department of Materials Science and Engineering, Monash University, Victoria 3800 (Australia); Easton, M.A. [School Engineering, RMIT University, Carlton, Victoria 3053 (Australia)

    2016-02-22

    Die-cast Mg–Al–rare earth (RE) alloys are normally used in the as-cast condition without the application of heat treatment because it is a common perception that heat treatment will not provide benefit to these alloys. This paper reports, for the first time, that enhanced age hardenability can be achieved in die-cast Mg–Al–RE alloys with minor Mn additions. For example, the yield strength of Mg–4 wt%Al–3 wt%La alloy with 0.32 wt% Mn is increased by ∼34 MPa (∼26%) after ageing at 200 °C for 32 h (T5). The enhanced age hardenability is associated with the precipitation of nanoscale Al–Mn particles during ageing.

  6. Dislocation analysis of die-cast Mg-Al-Ca alloy after creep deformation

    International Nuclear Information System (INIS)

    Terada, Yoshihiro; Itoh, Daigo; Sato, Tatsuo

    2009-01-01

    Tensile creep tests were combined with detailed transmission electron microscopy in order to characterize the dislocation movements during creep and to explain the creep properties of the Mg-Al-Ca AX52 die-cast alloy at 473 K and stresses from 15 to 70 MPa. TEM observations indicate that dislocations are generated within the primary α-Mg grain in the die-casting process, which consist of both the basal and non-basal segments. The basal segments of dislocations are able to bow out and glide on the basal planes under the influence of a stress, and the jogs follow the basal segments with the help of climb during creep. The creep mechanism for the alloy is deduced as dislocation climb due to the formation of sub-boundaries during creep, while the easy glide of the basal segments of dislocations is controlling the creep rates immediately after the stress application of creep tests.

  7. Influence of refining process on the porosity of high pressure die casting alloy Al-Si

    Directory of Open Access Journals (Sweden)

    A.W. Orlowicz

    2009-04-01

    Full Text Available This study presents research results of the influence that refining and transfer of AlSi12S alloy on the porosity of high pressure diecastings.Tests were conducted under production conditions of Die-casting Foundry META-ZEL Sp z o.o. The operation of refining was conducted in a melting furnace, with the use of an FDU Mini Degasser. Decay of the refining effect was assessed by evaluating the porosity content and metallographic examination.

  8. Modeling of microstructure evolution of magnesium alloy during the high pressure die casting process

    International Nuclear Information System (INIS)

    Wu Mengwu; Xiong Shoumei

    2012-01-01

    Two important microstructure characteristics of high pressure die cast magnesium alloy are the externally solidified crystals (ESCs) and the fully divorced eutectic which form at the filling stage of the shot sleeve and at the last stage of solidification in the die cavity, respectively. Both of them have a significant influence on the mechanical properties and performance of magnesium alloy die castings. In the present paper, a numerical model based on the cellular automaton (CA) method was developed to simulate the microstructure evolution of magnesium alloy during cold-chamber high pressure die casting (HPDC) process. Modeling of dendritic growth of magnesium alloy with six-fold symmetry was achieved by defining a special neighbourhood configuration and calculating of the growth kinetics from complete solution of the transport equations. Special attention was paid to establish a nucleation model considering both of the nucleation of externally solidified crystals in the shot sleeve and the massive nucleation in the die cavity. Meanwhile, simulation of the formation of fully divorced eutectic was also taken into account in the present CA model. Validation was performed and the capability of the present model was addressed by comparing the simulated results with those obtained by experiments.

  9. Casting defects and mechanical properties of high pressure die cast Mg-Zn-Al-RE alloys

    Energy Technology Data Exchange (ETDEWEB)

    Xiao, Wenlong; Easton, Mark A.; Zhu, Suming; Nie, Jianfeng [CAST Cooperative Research Centre, Department of Materials Engineering Monash University, Melbourne, VIC (Australia); Dargusch, Matthew S. [School of Mechanical and Mining Engineering, University of Queensland, Brisbane, QLD (Australia); Gibson, Mark A. [CSIRO Process Science and Engineering, Melbourne, VIC (Australia); Jia, Shusheng [Key Laboratory of Automobile Materials, Ministry of Education, Department of Materials Science and Engineering Jilin University, Changchun (China)

    2012-02-15

    The die casting defects and tensile properties of high pressure die cast (HPDC) Mg-Zn-Al-RE alloys with various combinations of Zn and Al were studied. The results show that die casting defects in Mg-Zn-Al-RE alloys are affected by the percentage of Zn and Al contents. The hot tearing susceptibility (HTS) of Mg-Zn-Al-RE alloys tends to increase with increasing Zn content up to 6 wt%, while a further increase of Al and/or Zn content reduces the HTS. In tensile tests, the yield strength (YS) is generally improved by increasing Zn or Al content, whereas the tensile strength (TS) and ductility appear to depend largely on the presence of casting defects. Compared with Mg-Zn-Al alloys, the mechanical properties of the Mg-Zn-Al-RE alloy are significantly improved. The Mg-4Zn-4Al-4RE alloy is found to have few casting defects and the optimal tensile properties. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  10. Study on the Surface Microstructure of a Modified STD61 Steel Mold Used for the Die Casting Process

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Ha-Young; Lee, Seung-Joon; Kang, Minwoo; Lee, Suk-Jin; Lee, Young-Kook [Yonsei University, Seoul (Korea, Republic of); Yang, Won Jon [Korea Institute of Materials Science, Changwon (Korea, Republic of); Jeong, Jae Suk; Kim, Byung-Hoon [Doosan Heavy Industries and Construction, Changwon (Korea, Republic of)

    2016-09-15

    The surface microstructure and crack formation of an aluminum die-casting mold were investigated. The mold was made of a modified STD61 steel, and was used for more than 165,000 cycles. The mold surface consisted of four layers; an oxidized layer, a decarburized layer, a network carbide layer and a tempered martensite matrix. The depth down to the hardest network carbide layer was ⁓200 μm. Inside the matrix, M{sub 3}C transition carbides were dissolved so that solute C joined pre-existing M{sub 2}3C{sub 6} and MC carbides to make them coarse. About 60% of thermal fatigue cracks had a depth less than 200 μm due to the hard network carbide layer, which obstructed the propagation of cracks. Cracks of over 200 μm were filled with oxide wedges of Al and Si which was which flown from the molten alloy as well as the Fe oxide.

  11. Development of materials for the rapid manufacture of die cast tooling

    Science.gov (United States)

    Hardro, Peter Jason

    The focus of this research is to develop a material composition that can be processed by rapid prototyping (RP) in order to produce tooling for the die casting process. Where these rapidly produced tools will be superior to traditional tooling production methods by offering one or more of the following advantages: reduced tooling cost, shortened tooling creation time, reduced man-hours for tool creation, increased tool life, and shortened die casting cycle time. By utilizing RP's additive build process and vast material selection, there was a prospect that die cast tooling may be produced quicker and with superior material properties. To this end, the material properties that influence die life and cycle time were determined, and a list of materials that fulfill these "optimal" properties were highlighted. Physical testing was conducted in order to grade the processability of each of the material systems and to optimize the manufacturing process for the downselected material system. Sample specimens were produced and microscopy techniques were utilized to determine a number of physical properties of the material system. Additionally, a benchmark geometry was selected and die casting dies were produced from traditional tool materials (H13 steel) and techniques (machining) and from the newly developed materials and RP techniques (selective laser sintering (SLS) and laser engineered net shaping (LENS)). Once the tools were created, a die cast alloy was selected and a preset number of parts were shot into each tool. During tool creation, the manufacturing time and cost was closely monitored and an economic model was developed to compare traditional tooling to RP tooling. This model allows one to determine, in the early design stages, when it is advantageous to implement RP tooling and when traditional tooling would be best. The results of the physical testing and economic analysis has shown that RP tooling is able to achieve a number of the research objectives, namely

  12. An establish attempt of reasons of machining splinter formation in AC44200 alloy high pressure die castings

    OpenAIRE

    J. Mutwil

    2008-01-01

    A problem of splinter formation during machining the AC44200 alloy high pressure die casting has been experimental investigated. Inorder to establish the reason of this occurrence a set of 200 high pressure die casting of the tensile strength samples have been prepared. The tensile tests were carried out using a Zwick Z050 universal testing machine. JM-SPC program has been used for statistical analysis of test results. A large variability of tensile strength results has been found. In order t...

  13. Treatment of Aluminum Die Casting Operations for the Purposes of NSR Applicability

    Science.gov (United States)

    This document may be of assistance in applying the New Source Review (NSR) air permitting regulations including the Prevention of Significant Deterioration (PSD) requirements. This document is part of the NSR Policy and Guidance Database. Some documents in the database are a scanned or retyped version of a paper photocopy of the original. Although we have taken considerable effort to quality assure the documents, some may contain typographical errors. Contact the office that issued the document if you need a copy of the original.

  14. The effect of equipment efficiency on occurrence of non-conforming products in die casting

    Directory of Open Access Journals (Sweden)

    S. Borkowski

    2010-01-01

    Full Text Available This study focuses on determination of the relationships between equipment efficiency in casting machines and the level of quality. The determination was made based on coefficients of Total Productive Maintenance and r correlation coefficient. The degree at which break-downs and downtime affect the occurrence of non-conforming products was also evaluated. The goal of further investigations is to deter-mine the structure of downtime and finding which downtime types have greatest impact on the quality of die-casting products.

  15. Technical-economic modelling of an aluminium high pressure die casting system for automotive parts fabrication

    International Nuclear Information System (INIS)

    Faura, F.

    1997-01-01

    In the present paper a technical-economic model for an aluminium high pressure die casting system has been developed. In order to obtain the necessary data for correlations utilized by the model, has been analyzed the production systems of companies that use these processes. This has allowed to determine the most important technological variables that affect to the economical aspect of the process. A computer application has been developed which allows to explore easily the influence of different system parameters. (Author) 12 refs

  16. Simulation of Stress Distribution in a Thick- Walled Bushing Produced by Die-Casting

    Directory of Open Access Journals (Sweden)

    Pisarek B.P.

    2017-12-01

    Full Text Available Metallographic investigations and a computer simulation of stresses in a gravity die-casting bushing were performed. Simulation of the casting process, solidification of the thick-walled bushing and calculations of the stress was performed using MAGMA5.3 software. The size variability of phases κII affecting the formation of phase stresses σf, depending on the location of the metallographic test area, was identified. The distribution of thermal σt and shrinkage stresses σs, depending on the location of the control point SC in the bushing's volume, was estimated. Probably the nature of these stresses will change slightly even after machining. This can cause variations in operating characteristics (friction coefficient, wear. Due to the strong inhomogeneity of the stress distribution in the bushing's casting, it is necessary to perform further tests of the possibility to conduct thermal treatment guaranteeing homogenization of the internal stresses in the casting, as well as to introduce changes in the bushing' s construction and the casting technology. The paper presents the continuation of the results of research aimed at identifying the causes of defects in the thick-walled bushing, die-casting made of CuAl10Fe5Ni5Cr aluminium bronze.

  17. Fatigue Life Prediction in Rapid Die Casting - Preliminary Work in View of Current Research

    International Nuclear Information System (INIS)

    Chuan Huat Ng; Grote, Karl-Heinrich; Baehr, Ruediger

    2007-01-01

    Numerical simulation technique as a prediction tool is slowly adopted in metal casting industry for predicting design modelling solidification analysis. The reasons for this activity is found in the need to further enhance the geometrical design and mechanical properties of the tool design and the correct prediction methodology to fulfil industrial needs. The present state of numerical simulation capabilities in rapid die casting technologies is reviewed and the failure mode mechanisms of thermal fatigue, aimed at developing a numerical simulation with a systematic design guidance for predicting the thermal cyclic loading analysis and improvement is presented along with several other methods. The economic benefits of a numerical simulation technique in die casting are limited to tool life time, mechanical properties and design guidance. The extensive computer capabilities of a numerical simulation with a systematic design guidance methodology are exploited to provide a solution for flexible design, mechanical properties and mould life time. Related research carried out worldwide by different organisations and academic institutions are discussed

  18. Economical surface treatment of die casting dies to prevent soldering in high pressure casting

    International Nuclear Information System (INIS)

    Fraser, D.T.; Jahedi, M.Z.

    2001-01-01

    This paper describes the use of a gas oxidation treatment of H13 tool steel to develop a compact iron oxide layer at the surface of core pins to prevent soldering in high pressure die casting. The performance of oxide layers in the protection of die steel against soldering during high pressure die casting was tested in a specially designed die using removable core pins and Al-11 Si-3 Cu casting alloy. The gas oxidation treatment can be applied at low temperatures and to large areas of the die surface. In addition this process is very cost effective compared to other coating processes such as physical vapour deposition (PVD), or thermo-reactive diffusion (TRD) coatings. This work demonstrated that surface treatment producing pure magnetite (Fe 3 O 4 ) layers are more protective than oxide layers containing a combination of Fe 3 O 4 (magnetite) and Fe 3 O 3 (haematite). The magnetite layer acts as a barrier between the die steel/casting alloy interface and prevents the formation of inter-metallic phases. Optical microscopy and scanning electron microscope were used to determine the thickness of the oxide layer, while X-ray diffraction was performed to determine the oxide phase structure

  19. Differential response of plants to aluminum. A review

    OpenAIRE

    Valencia R, Rubén A; Ligarreto M, Gustavo A

    2012-01-01

    Aluminum toxicity is a major limiting factor to the growth and development of plants in acidic soils worldwide, occurring in 40% of arable soils. The root seems to be the object of aluminum toxicity, particularly the apex, producing a rapid inhibition of cell division and elongation of the root. Fortunately, plants differ in their ability to tolerate aluminum and grow in acidic soils. Tolerance mechanisms have commonly been defined in genetic and physiological terms, however, tolerance mechan...

  20. Determining the optimal index of heat stress in foundry, die casting and road construction industries using FAHP_Topsis

    Directory of Open Access Journals (Sweden)

    Maryam Dehghanipoor

    2016-12-01

    Full Text Available Introduction: Heat stress is one of the harmful risks in casting and die casting industries, which can not only cause work-related diseases but also can impair the performance and safety of workers. Since the indicators that are used to evaluate heat stress are very different, it is very difficult to choose a suitable index. The aim of this study was to determine the optimum heat stress index in foundry, die-cast, and road construction industries using FAHP and Topsis methods. Material and Method: In order to determine optimum heat stress index in foundry, die-cast, and road construction industries, first, the prioritization criteria were defined by experts (including ease of measurement, measurement accuracy, comprehensiveness, time, cost, and correlation. Then, considering these criteria, the best heat stress index was determined based on experts’ opinions and using FAHP and Topsis methods. Result: The results of this study suggest that given the current conditions and criteria, WBGT and P4SR is the best indices for foundry, die casting and construction. Conclusion: The results showed that according to comprehensiveness, accuracy and correlation criteria, the WBGT index is considered as the best indicator of heat stress assessment in foundry, die-cast and road construction industries. Moreover, the HSI ranked in the last place due to the complexity and cost of its calculation.

  1. Microstructure and Properties of Cobalt-and Zinc-Containing Magnetic Magnesium Alloys Processed by High-Pressure Die Casting

    Science.gov (United States)

    Klose, Christian; Demminger, Christian; Maier, Hans Jürgen

    The inherent magnetic properties of lightweight alloys based on magnesium and cobalt offer a novel way in order to measure mechanical loads throughout the entire structural component using the magnetoelastic effect. Because the solubility of cobalt in the magnesium matrix is negligible, the magnetic properties mainly originate from Co-rich precipitates. Thus, the size and distribution of Co-containing phases within the alloy's microstructure wields a major influence on the amplitude of the load-sensitive properties which can be measured by employing the harmonic analysis of eddy-current signals. In this study, Mg-Co-based alloys are produced by several casting methods which allow the application of different cooling rates, e.g. gravity die casting and high-pressure die casting. The differences between the manufactured alloys' micro- and phase structures are compared depending on the applied cooling rate and the superior magnetic and mechanical properties of the high-pressure die cast material are demonstrated.

  2. Case study of lean manufacturing application in a die casting manufacturing company

    Science.gov (United States)

    Ching, Ng Tan; Hoe, Clarence Chan Kok; Hong, Tang Sai; Ghobakhloo, Morteza; Pin, Chen Kah

    2015-05-01

    The case study of lean manufacturing aims to study the application of lean manufacturing in a die casting manufacturing company located in Pulau Penang, Malaysia. This case study describes mainly about the important concepts and applications of lean manufacturing which could gradually help the company in increasing the profit by studying and analyzing their current manufacturing process and company culture. Many approaches of lean manufacturing are studied in this project which includes: 5S housekeeping, Kaizen, and Takt Time. Besides, the lean tools mentioned, quality tool such as the House of Quality is being used as an analysis tool to continuously improve the product quality. In short, the existing lean culture in the company is studied and analyzed, with recommendations written at the end of this paper.

  3. SPH based modelling of oxide and oxide film formation in gravity die castings

    International Nuclear Information System (INIS)

    Ellingsen, K; M'Hamdi, M; Coudert, T

    2015-01-01

    Gravity die casting is an important casting process which has the capability of making complicated, high-integrity components for e.g. the automotive industry. Oxides and oxide films formed during filling affect the cast product quality. The Smoothed particle hydrodynamics (SPH) method is particularly suited to follow complex flows. The SPH method has been used to study filling of a gravity die including the formation and transport of oxides and oxide films for two different filling velocities. A low inlet velocity leads to a higher amount of oxides and oxide films in the casting. The study demonstrates the usefulness of the SPH method for an increased understanding of the effect of different filling procedures on the cast quality. (paper)

  4. A Study on Development of High Strength Al-Zn Based alloy for Die Casting

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Sang-Soo; Park, Ik-Min [Pusan National University, Busan (Korea, Republic of); Yeom, Gil-Young; Lim, Kyoung-Mook [Korea Institute of Industrial Technology, Incheon (Korea, Republic of); Son, Hyun-Jin [Oh-Sung Co. Ltd., Siheung (Korea, Republic of)

    2015-09-15

    In this study, the microstructural evolution and various characteristics of Al-20⁓45wt%Zn alloys were investigated. In terms of microstructure, as the amount of Zn addition to the alloys increased, the α-phase size decreased and the α+η non-equilibrium solidification phase fraction increased. Also, increasing Zn content improved the wear resistance of the alloys, but reduced the damping capacity and toughness of the alloys. Their physical properties of the Al-Zn alloy with high Zn content, specifically the wear resistance and toughness, were superior to those of commercial ALDC12 alloys for die-casting. Based on these results, we considered the possibility of application of the developed Al-Zn alloy as a structural material.

  5. Evaluations of antimony and strontium interaction in an Al–Si–Cu–Zn die cast alloy

    Energy Technology Data Exchange (ETDEWEB)

    Farahany, Saeed, E-mail: saeedfarahany@gmail.com; Idris, Mohd Hasbullah; Ourdjini, Ali

    2014-05-01

    Graphical abstract: - Highlights: • Probable interactions between Sb and Sr in a complex Al–Si alloy were evaluated. • Sequence of addition did not affect thermal and microscopical characteristics. • Threshold ratio for the Sb and Sr interaction is proposed. - Abstract: The interaction between antimony and strontium in an ADC12 die casting alloy is investigated comprehensively by using a computer aided cooling curve thermal analysis coupled with microstructure inspection. The results of the thermal analysis show significant changes in Al–Si eutectic reaction based on different concentrations of Sb and Sr. Sb reduces the efficiency of Sr in modifying the eutectic Si. Based upon the data obtained in this study, the threshold Sr/Sb ratio should exceed about 0.5 in order to obtain fully modified structure. Moreover, a pre-eutectic reaction of Al{sub 2}Si{sub 2}Sr intermetallic was detected for high concentrations of Sr.

  6. A Study on Development of High Strength Al-Zn Based alloy for Die Casting

    International Nuclear Information System (INIS)

    Shin, Sang-Soo; Park, Ik-Min; Yeom, Gil-Young; Lim, Kyoung-Mook; Son, Hyun-Jin

    2015-01-01

    In this study, the microstructural evolution and various characteristics of Al-20⁓45wt%Zn alloys were investigated. In terms of microstructure, as the amount of Zn addition to the alloys increased, the α-phase size decreased and the α+η non-equilibrium solidification phase fraction increased. Also, increasing Zn content improved the wear resistance of the alloys, but reduced the damping capacity and toughness of the alloys. Their physical properties of the Al-Zn alloy with high Zn content, specifically the wear resistance and toughness, were superior to those of commercial ALDC12 alloys for die-casting. Based on these results, we considered the possibility of application of the developed Al-Zn alloy as a structural material.

  7. Optimization of die filling in high pressure die cast part using MAGMAsoft®

    DEFF Research Database (Denmark)

    Kotas, Petr; Hattel, Jesper Henri

    2008-01-01

    Integrated modeling of an entire casting process has become a tool which favors design and optimization of manufactured parts. The aim of this project was to examine and optimize a high-pressure die cast part and its production process with respect to die filling and issues of residual stresses...... in the process and machine parameters were done and assessed. All simulations revealed that, the main causes of the problems were: a poor geometry of the casting leading to an improper filling pattern, and a massive gating system bringing thermal imbalance into the solidification process. Thus deformations due...... to residual stresses occurred. The numerical results were evaluated and appeared to be in agreement with the results from the actual manufacturing process. Based on these findings, proposals for improvements were given. In order to avoid distortions and cold shuts further geometrical adjustments should...

  8. Numerical modeling of the thickness dependence of zinc die-cast materials

    Science.gov (United States)

    Page, Maria Angeles Martinez; Ruf, Matthias; Hartmann, Stefan

    2017-11-01

    Zinc die casting alloys show varying material properties over the thickness in their final solid state, which causes a change in the mechanical response for specimens with different thicknesses. In this article, we propose a modeling concept to account for the varying porosity in the constitutive modeling. The material properties are effectively incorporated by combining a partial differential equation describing the distribution of the pores by a structural parameter with the Mori-Tanaka approach for linear elasticity. The distribution of the porosity is determined by polished cut images, for which the procedure is explained in detail. Finite element simulations of the coupled system incorporating the thickness dependence show the applicability of this approach.

  9. Comparative study on laser welding and TIG welding of semi-solid high pressure die cast A356 aluminium alloy

    CSIR Research Space (South Africa)

    Govender, G

    2007-07-01

    Full Text Available components. The low porosity levels in SSM high pressure die castings (HPDC) improves the weldability of these components. The aim of the current research was to perform a comparative study of laser and TIG welding of SSM HPDC aluminium alloy A356. SSM...

  10. Microstructure investigation and first-principle analysis of die-cast AZ91 alloy with calcium addition

    International Nuclear Information System (INIS)

    Lin, L.; Wang, F.; Yang, L.; Chen, L.J.; Liu, Z.; Wang, Y.M.

    2011-01-01

    Highlights: → Die-cast AZ91 with Ca addition was investigated experimentally and theoretically. → Precipitation sequence was confirmed with increasing Ca addition. → Phase stability difference was verified by first-principle calculation. → Valence configurations were associated with alloying effects of Al, Mg and Ca. - Abstract: In order to get improved mechanical properties of die-cast AZ91 alloy under elevated temperatures, Ca element was added as a cost-effective alloying constituent. It appeared that minor Ca addition less than 0.5 wt% would result in no apparent change in microstructure, but the tensile strength at elevated temperatures was improved considerably. When increasing Ca addition to more than 1.0 wt%, Al 2 Ca phase will precipitate during solidification, no Mg 2 Ca phase was discovered. Homogeneous microstructure and high temperature stability in tensile strength of die-cast AZ91 alloy with Ca addition was mainly attributed to the precipitation of Al 2 Ca phase, which considerably refined the bulky β-Mg 17 Al 12 phase distributed originally at the grain boundaries of die-cast AZ91 alloy with no Ca addition. The priority of Al 2 Ca phase compared to Mg 2 Ca phase in precipitation sequence was verified by first-principle calculation of their cohesive energy and formation enthalpy, and can also be associated with more bounding electrons between Al and Ca atoms.

  11. Fluorine in plants in the areas of Yugoslav aluminum factories

    Energy Technology Data Exchange (ETDEWEB)

    Ivos, J.; Ciszek, H.; Rezek, A.; Marjanovic, L.

    1970-01-01

    Distribution of fluorine in the areas around aluminum production facilities was investigated. The plants in areas around the factories did indeed show increased levels of fluorine. Distribution patterns were found to be affected by wind and precipitation patterns.

  12. Progress in Aluminum Electrolysis Control and Future Direction for Smart Aluminum Electrolysis Plant

    Science.gov (United States)

    Zhang, Hongliang; Li, Tianshuang; Li, Jie; Yang, Shuai; Zou, Zhong

    2017-02-01

    The industrial aluminum reduction cell is an electrochemistry reactor that operates under high temperatures and highly corrosive conditions. However, these conditions have restricted the measurement of key control parameters, making the control of aluminum reduction cells a difficult problem in the industry. Because aluminum electrolysis control systems have a significant economic influence, substantial research has been conducted on control algorithms, control systems and information systems for aluminum reduction cells. This article first summarizes the development of control systems and then focuses on the progress made since 2000, including alumina concentration control, temperature control and electrolyte molecular ratio control, fault diagnosis, cell condition prediction and control system expansion. Based on these studies, the concept of a smart aluminum electrolysis plant is proposed. The frame construction, key problems and current progress are introduced. Finally, several future directions are discussed.

  13. Microstructural and mechanical properties of gravity-die-cast A356 alloy inoculated with yttrium and Al-Ti-B grain refiner simultaneously

    Directory of Open Access Journals (Sweden)

    Y.P. Lim

    2011-10-01

    Full Text Available In the present work, the effect of inoculating yttrium and Al-5Ti-1B simultaneously on A356 aluminum alloy has been studied. Gravity die casting process is used to cast the ASTM tensile test specimens for analysis. In each experiment, the Ti and B contents were maintained constantly at 0.1 and 0.02 wt% respectively. The addition of yttrium was manipulated at the amount of 0, 0.1, 0.2, 0.3, 0.4 and 0.5 wt%. Microstructural characterization of the as-cast A356 alloy was investigated by means of optical microscope and its phases are detected by XRD. The mechanical properties tested are tensile strength and hardness. The inoculation of yttrium was found to enhance the grain refinement effect of Al-5Ti-1B grain refiner and improve the mechanical properties. The optimal weight percentage of yttrium was found to be 0.3. The grain refining efficiency of combining yttrium and Al-5Ti-1B on A356 aluminum alloy was mainly attributed to the heterogeneous nucleation of TiB2 and TiAl3 particles which were dispersed more evenly in the presence of yttrium and the grain growth restriction effected by the accumulation of Al-Y compound at grain boundaries.

  14. Analysis of the creep behaviour of die-cast Mg–3Al–1Si alloy

    International Nuclear Information System (INIS)

    Zhu, S.M.; Easton, M.A.; Gibson, M.A.; Dargusch, M.S.; Nie, J.F.

    2013-01-01

    The creep behaviour of die-cast Mg–3Al–1Si (AS31) alloy has been studied at 125 °C, 150 °C and 175 °C with stresses ranging 50–110 MPa. The alloy exhibits anomalously high stress exponents, i.e. 14.4 at 125 °C, 11.6 at 150 °C and 9.5 at 175 °C. Contrary to work reported previously, these high stress exponents cannot be rationalised using the threshold stress approach that is commonly adopted in analysing creep behaviour of dispersion strengthened alloys or metal matrix composites. It is shown that the observed high stress exponents are associated with the dominance of power-law breakdown creep in this study, and the stress dependence can be well described by the Garofalo sinh relationship with the natural exponent of 5. Transmission electron microscopy (TEM) observations reveal that cross-slip of 〈a〉 type dislocations is probably the controlling creep mechanism

  15. Aluminium Foam and Magnesium Compound Casting Produced by High-Pressure Die Casting

    Directory of Open Access Journals (Sweden)

    Iban Vicario

    2016-01-01

    Full Text Available Nowadays, fuel consumption and carbon dioxide emissions are two of the main focal points in vehicle design, promoting the reduction in the weight of vehicles by using lighter materials. The aim of the work is to evaluate the influence of different aluminium foams and injection parameters in order to obtain compound castings with a compromise between the obtained properties and weight by high-pressure die cast (HPDC using aluminium foams as cores into a magnesium cast part. To evaluate the influence of the different aluminium foams and injection parameters on the final casting products quality, the type and density of the aluminium foam, metal temperature, plunger speed, and multiplication pressure have been varied within a range of suitable values. The obtained compound HPDC castings have been studied by performing visual and RX inspections, obtaining sound composite castings with aluminium foam cores. The presence of an external continuous layer on the foam surface and the correct placement of the foam to support injection conditions permit obtaining good quality parts. A HPDC processed magnesium-aluminium foam composite has been developed for a bicycle application obtaining a suitable combination of mechanical properties and, especially, a reduced weight in the demonstration part.

  16. Failure behavior of high pressure die casting AZ91D magnesium alloy

    Energy Technology Data Exchange (ETDEWEB)

    Li, X.; Xiong, S.M. [School of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); Key Laboratory for Advanced Materials Processing Technology, Ministry of Education, Tsinghua University, Beijing 100084 (China); Guo, Z., E-mail: zhipeng_guo@mail.tsinghua.edu.cn [School of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); Key Laboratory for Advanced Materials Processing Technology, Ministry of Education, Tsinghua University, Beijing 100084 (China)

    2016-08-30

    The failure behavior of high pressure die casting AZ91D magnesium alloy during both tensile and fatigue tests was studied in situ by using scanning electron microscope. Attention was focused on the role of microstructure played in crack initiation and propagation. Results showed that the defects in castings, including gas pore, shrinkage pore and defect band, were the crack initiation sources. In tensile test, the crack propagated in a combination of intergranular and transgranular modes, and the specimen fractured by connecting defects at the section with minimum effective force bearing area. In fatigue test, the crack propagated in a transgranular mode at specific crystalline planes. When the crack was in contact with the β-phase, the crack would pass through, and fracture the network β-phase, whereas bypass the island β-phase by detaching it from the surrounding α-Mg grains. Besides, defects in front of the crack would act as the secondary crack initiation sources, from which new cracks would initiate and propagate. With the propagation of the fatigue crack, the actual maximum cyclic stress would increase to the fracture stress of the left cross section and lead to the final fracture of the specimen.

  17. Assessment of Computer Simulation Software and Process Data for High Pressure Die Casting of Magnesium

    Energy Technology Data Exchange (ETDEWEB)

    Sabau, Adrian S [ORNL; Hatfield, Edward C [ORNL; Dinwiddie, Ralph Barton [ORNL; Kuwana, Kazunori [University of Kentucky; Viti, Valerio [University of Kentucky, Lexington; Hassan, Mohamed I [University of Kentucky, Lexington; Saito, Kozo [University of Kentucky

    2007-09-01

    Computer software for the numerical simulation of solidification and mold filling is an effective design tool for cast structural automotive magnesium components. A review of commercial software capabilities and their validation procedures was conducted. Aside form the software assessment, the program addressed five main areas: lubricant degradation, lubricant application, gate atomization, and heat transfer at metal mold interfaces. A test stand for lubricant application was designed. A sensor was used for the direct measurement of heat fluxes during lubricant application and casting solidification in graphite molds. Spray experiments were conducted using pure deionized water and commercial die lubricants. The results show that the sensor can be used with confidence for measuring heat fluxes under conditions specific to the die lube application. The data on heat flux was presented in forms suitable for use in HPDC simulation software. Severe jet breakup and atomization phenomena are likely to occur due to high gate velocities in HPDC. As a result of gate atomization, droplet flow affects the mold filling pattern, air entrapment, skin formation, and ensuing defects. Warm water analogue dies were designed for obtaining experimental data on mold filling phenomena. Data on break-up jet length, break-up pattern, velocities, and droplet size distribution were obtained experimentally and was used to develop correlations for jet break-up phenomena specific to die casting gate configurations.

  18. New high pressure die cast magnesium alloy AM-HP2 for powertrain applications

    Energy Technology Data Exchange (ETDEWEB)

    Gibson, M.A. [Queensland Univ., Brisbane (Australia). CAST CRC]|[CSIRO Manufacturing and Materials Technology, Clayton (Australia); Zhu, S.M.; Nie, J.F. [Queensland Univ., Brisbane (Australia). CAST CRC]|[Monash Univ., Monash (Australia). Dept. of Materials Engineering

    2007-07-01

    In order to improve the benefits available through weight savings on engine emissions, magnesium alloys must gain wider acceptance in transmission and engine applications. This paper provided details of a new alloy with exceptional creep properties developed for automotive powertrain applications. The AM-HP2 alloy was developed as part of a broader research program investigating the relationship between the composition, structure and properties of magnesium rare earth (Mg-RE) based alloys and high-pressure die casting (HPDC). Cylindrical test specimens of various alloys were produced on a cold chamber HPDC machine. Tensile creep tests were then conducted under a constant load at 177 degrees C for a period of 600 hours. Microstructures of specimens were characterized using a CM20 transmission electron microscope. Results of the tests indicated that near-grain boundary microstructure was an important parameter in securing optimum elevated temperature properties. The RE element had a significant effect on the creep behaviour of the HPDC Mg-RE alloys. It was concluded that further research is needed to investigate the influence of the RE mixture in improving creep performance. 15 refs., 2 tabs., 6 figs.

  19. Analysis of the creep behaviour of die-cast Mg–3Al–1Si alloy

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, S.M., E-mail: suming.zhu@monash.edu [CAST Cooperative Research Centre, Department of Materials Engineering, Monash University, Victoria 3800 (Australia); ARC Centre of Excellence for Design in Light Metals, Department of Materials Engineering, Monash University, Victoria 3800 (Australia); Easton, M.A. [CAST Cooperative Research Centre, Department of Materials Engineering, Monash University, Victoria 3800 (Australia); Gibson, M.A. [CAST Cooperative Research Centre, CSIRO Process Science and Engineering, Clayton, Victoria 3169 (Australia); Dargusch, M.S. [Centre for Advanced Materials Processing and Manufacturing, School of Mechanical and Mining Engineering, The University of Queensland, Queensland 4075 (Australia); Defence Materials Technology Centre, The University of Queensland, Queensland 4075 (Australia); Nie, J.F. [ARC Centre of Excellence for Design in Light Metals, Department of Materials Engineering, Monash University, Victoria 3800 (Australia)

    2013-08-20

    The creep behaviour of die-cast Mg–3Al–1Si (AS31) alloy has been studied at 125 °C, 150 °C and 175 °C with stresses ranging 50–110 MPa. The alloy exhibits anomalously high stress exponents, i.e. 14.4 at 125 °C, 11.6 at 150 °C and 9.5 at 175 °C. Contrary to work reported previously, these high stress exponents cannot be rationalised using the threshold stress approach that is commonly adopted in analysing creep behaviour of dispersion strengthened alloys or metal matrix composites. It is shown that the observed high stress exponents are associated with the dominance of power-law breakdown creep in this study, and the stress dependence can be well described by the Garofalo sinh relationship with the natural exponent of 5. Transmission electron microscopy (TEM) observations reveal that cross-slip of 〈a〉 type dislocations is probably the controlling creep mechanism.

  20. Microstructural effects of phosphorus on pressure die cast Al-12Si components

    Directory of Open Access Journals (Sweden)

    Suárez-Peña, B.

    2007-10-01

    Full Text Available The refinement of cuboidal silicon in eutectic Al-Si alloys by phosphorus additions used to manufacture pressure die cast components was studied. The results show that the addition of phosphorus in the form of AlFeP mother alloy before process degassing, leads to the best refinement of the size of the Si-cuboids phase, among several phosphorus additions analysed in the present research.

    Se ha estudiado el afino del silicio cuboidal en aleaciones eutécticas Al-Si por acción del fósforo, en piezas obtenidas mediante la técnica de fundición a presión. Tras la adición de fósforo en pruebas industriales, en las que dicho elemento se incorpora al baño con diversas composiciones, los mejores resultados se obtienen con la adición de la aleación madre AlFeP, previa al desgasificado industrial.

  1. Simulation of distortion and residual stress in high pressure die casting – modelling and experiments

    International Nuclear Information System (INIS)

    Hofer, P; Kaschnitz, E; Schumacher, P

    2012-01-01

    Two individual high-pressure die-casting geometries were developed in order to study the influence of process parameters and different alloys on the distortion behaviour of castings. These geometries were a stress lattice and a V-shaped sample tending to form residual stress due to different wall thickness respectively by a deliberate massive gating system. In the experimental castings the influence of the most important process parameters such as die temperature and die opening time and the cooling regime was examined. The time evolution of process temperatures was measured using thermal imaging. The heat transfer coefficients were adapted to the observed temperature distributions. Castings were produced from the two alloys AlSi12 and AlSi10MnMg. The distortion of the castings was measured by means of a tactile measuring device. For the alloy AlSi10MnMg thermo-physical and thermo-mechanical data were obtained using differential scanning calorimetry, laser flash technique, dilatometry and tensile testing at elevated temperatures. These data were used for modelling the material behaviour of the AlSi10MnMg alloy in the numerical model while for the alloy AlSi12(Fe) literature data were used. Process and stress simulation were conducted using the commercial FEM software ANSYS Workbench. A survey on the results of the comparison between simulation and experiment is given for both alloys.

  2. An establish attempt of reasons of machining splinter formation in AC44200 alloy high pressure die castings

    Directory of Open Access Journals (Sweden)

    J. Mutwil

    2008-10-01

    Full Text Available A problem of splinter formation during machining the AC44200 alloy high pressure die casting has been experimental investigated. Inorder to establish the reason of this occurrence a set of 200 high pressure die casting of the tensile strength samples have been prepared. The tensile tests were carried out using a Zwick Z050 universal testing machine. JM-SPC program has been used for statistical analysis of test results. A large variability of tensile strength results has been found. In order to find the reason of this variability the fracture surface investigations (macrographs for all of samples and SEM micrographs for chosen samples have been carried out. It has been establish that in all cases a significant decrease of tensile strength was caused by presence of inclusions or porosity. In lot of cases the inclusions have a form of oxide film.

  3. The Influence of Pressure Die Casting Parameters on the Castability of AlSi11-SiCp Composites

    Directory of Open Access Journals (Sweden)

    Konopka Z.

    2015-03-01

    Full Text Available The paper presents the method of preparing a composite slurry composed of AlSi11 alloy matrix and 10 vol.% of SiC particles, as well as the method of its high-pressure die casting and the measurement results concerning the castability of the obtained composite. Composite castings were produced at various values of the piston velocity in the second stage of injection, diverse intensification pressure values, and various injection gate width values. There were found the regression equations describing the change of castability of the examined composite as a function of pressure die casting process parameters. The conclusion gives the analysis and the interpretation of the obtained results.

  4. Vacuum die casting of silicon sheet for photovoltaic applications. First quarterly report, March 16-June 30, 1979

    Energy Technology Data Exchange (ETDEWEB)

    None

    1979-01-01

    The obtective of this program is to develop a vacuum die-casting process for producing silicon sheet suitable for photovoltaic cells and to develop production techniques for optimization of polycrystallie silicon solar cell output. Efforts will examine process methods which are directed toward minimum cost processing of silicon into a quality suitable for producing solar cells with a terrestrial efficiency greater than 12% and having the potential to be scaled for large quantity production. In the vacuum die casting technique, silicon is melted under vacuum, and an evacuated die with a thin rectangular cavity is inserted into the melt. Liquid silicon is then injected into the die using a positive pressure of an inert gas. The major portion of the die casting work will be performed at Stanford Research Institute International under subcontract. The initial approach will follow parallel tracks: (1) obtain mechanical design parameters by using boron nitride, which has been shown to be non-wetting to silicon; (2) optimize silicon nitride material composition and coatings by sessile drop experiments; (3) test effectiveness of fluoride salt interfacial media with a graphite mold; and (4) test effect of surface finish using both boron nitride and graphite. Having established the material and mechanical boundary conditions, a finalized version of the prototype assembly will be constructed and the casting varibles determined. Polycrystalline silicon solar cells, with and without impurities, will be fabricated, characterized, and optimized at ARCCO Solar. The major activities will focus on the use of Wacker SILCO, HEM and in-house materials until vacuum die cast wafers are available. A baseline process with vacuum metallized contacts will be established and a reference mass production process with screen-printed metallization and high-throughput diffusions will also be obtained.

  5. Modelling the Cast Component Weight in Hot Chamber Die Casting using Combined Taguchi and Buckingham's π Approach

    Science.gov (United States)

    Singh, Rupinder

    2018-02-01

    Hot chamber (HC) die casting process is one of the most widely used commercial processes for the casting of low temperature metals and alloys. This process gives near-net shape product with high dimensional accuracy. However in actual field environment the best settings of input parameters is often conflicting as the shape and size of the casting changes and one have to trade off among various output parameters like hardness, dimensional accuracy, casting defects, microstructure etc. So for online inspection of the cast components properties (without affecting the production line) the weight measurement has been established as one of the cost effective method (as the difference in weight of sound and unsound casting reflects the possible casting defects) in field environment. In the present work at first stage the effect of three input process parameters (namely: pressure at 2nd phase in HC die casting; metal pouring temperature and die opening time) has been studied for optimizing the cast component weight `W' as output parameter in form of macro model based upon Taguchi L9 OA. After this Buckingham's π approach has been applied on Taguchi based macro model for the development of micro model. This study highlights the Taguchi-Buckingham based combined approach as a case study (for conversion of macro model into micro model) by identification of optimum levels of input parameters (based on Taguchi approach) and development of mathematical model (based on Buckingham's π approach). Finally developed mathematical model can be used for predicting W in HC die casting process with more flexibility. The results of study highlights second degree polynomial equation for predicting cast component weight in HC die casting and suggest that pressure at 2nd stage is one of the most contributing factors for controlling the casting defect/weight of casting.

  6. The role of aluminum sensing and signaling in plant aluminum resistance

    Science.gov (United States)

    As researchers have gained a better understanding in recent years into the physiological, molecular and genetic basis of how plants deal with aluminum (Al) toxicity in acid soils prevalent in the tropics and sub-tropics, it has become clear that an important component of these responses is the trigg...

  7. Polyphenol-aluminum complex formation: Implications for aluminum tolerance in plants

    Science.gov (United States)

    Natural polyphenols may play an important role in aluminum detoxification in some plants. We examined the interaction between Al3+ and the purified high molecular weight polyphenols pentagalloyl glucose (940 Da) and oenothein B (1568 Da), and the related compound methyl gallate (184 Da) at pH 4 and ...

  8. Interlocking multi-material components made of structured steel sheets and high-pressure die cast aluminium

    Science.gov (United States)

    Senge, S.; Brachmann, J.; Hirt, G.; Bührig-Polaczek, A.

    2017-10-01

    Lightweight design is a major driving force of innovation, especially in the automotive industry. Using hybrid components made of two or more different materials is one approach to reduce the vehicles weight and decrease fuel consumption. As a possible way to increase the stiffness of multi-material components, this paper presents a process chain to produce such components made of steel sheets and high-pressure die cast aluminium. Prior to the casting sequence the steel sheets are structured in a modified rolling process which enables continuous interlocking with the aluminium. Two structures manufactured by this rolling process are tested. The first one is a channel like structure and the second one is a channel like structure with undercuts. These undercuts enable the formation of small anchors when the molten aluminium fills them. The correlation between thickness reduction during rolling and the shape of the resulting structure was evaluated for both structures. It can be stated that channels with a depth of up to 0.5 mm and a width of 1 mm could be created. Undercuts with different size depending on the thickness reduction could be realised. Subsequent aluminium high-pressure die casting experiments were performed to determine if the surface structure can be filled gap-free with molten aluminium during the casting sequence and if a gap-free connection can be achieved after contraction of the aluminium. The casting experiments showed that both structures could be filled during the high-pressure die casting. The channel like structure results in a gap between steel and aluminium after contraction of the cast metal whereas the structure with undercuts leads to a good interlocking resulting in a gap-free connection.

  9. The correlation between microstructure and mechanical properties of high-pressure die-cast AM50 alloy

    International Nuclear Information System (INIS)

    Song Jie; Xiong Shoumei; Li Mei; Allison, John

    2009-01-01

    Scanning acoustic microscopy was used to characterize the micro-voids distribution for specimens in non-destructive mode. In addition, the in-situ scanning electron microscopy observation was performed during tensile deformation of high-pressure die-cast (HPDC) of AM50 alloy to obtain the mechanism of fracture induced by micro-voids. The effects of micro-voids on the mechanical properties were discussed. The results obtained from the examination suggest that fracture tends to occur at bigger micro-voids or in the cluster micro-voids area.

  10. Tribological Properties of AlSi11-SiCp Composite Castings Produced by Pressure Die Casting Method

    Directory of Open Access Journals (Sweden)

    Konopka Z.

    2014-08-01

    Full Text Available The measurement results concerning the abrasive wear of AlSi11-SiC particles composites are presented in paper. The method of preparing a composite slurry composed of AlSi11 alloy matrix and 10, 20% vol.% of SiC particles, as well as the method of its high-pressure die casting was described. Composite slurry was injected into metal mould of cold chamber pressure die cast machine and castings were produced at various values of the piston velocity in the second stage of injection, diverse intensification pressure values, and various injection gate width values. Very good uniform arrangement of SiC particles in volume composite matrix was observed and these results were publicated early in this journal. The kinetics of abrasive wear and correlation with SiC particles arrangement in composite matrix were presented. Better wear resistance of composite was observed in comparison with aluminium alloy. Very strong linear correlation between abrasive wear and particle arrangement was observed. The conclusion gives the analysis and the interpretation of the obtained results.

  11. Simple visualization techniques for die casting part and die design. Final report, July 1, 1995--September 30, 1997

    Energy Technology Data Exchange (ETDEWEB)

    Miller, R.A.; Lu, S.C.; Rebello, A.B.

    1998-05-01

    The objective of this work was to develop and test die casting design evaluation techniques based on the visualization of geometric data that is related to potential defects of problems. Specifically, thickness information is used to provide insight into potential thermal problems in the part and die. Distance from the gate and a special type of animation of the fill pattern is used to provide an assessment of gate, vent and overflow locations. Techniques have been developed to convert part design information in the form of STL files to a volume-based representation called a voxel model. The use of STL files makes the process CAD system independent. Once in voxel form, methods that were developed in this work are used to identify thick regions in the part, thin regions in the part and/or die, distance from user specified entry locations (gates), and the qualitative depiction of the fill pattern. The methods were tested with a prototype implementation on the UNIX platform. The results of comparisons with numerical simulation and field reported defects were surprisingly good. The fill-related methods were also compared against short-shots and a water analog study using high speed video. The report contains the results of the testing plus detailed background material on the construction of voxel models, the methods used for displaying results, and the computational geometric reasoning methods used to create die casting-related information from the voxel model for display to the user.

  12. Simple visualization techniques for die casting part and die design. Final report, July 1, 1995--September 30, 1997

    Energy Technology Data Exchange (ETDEWEB)

    Miller, R.A.; Lu, S.C.; Rebello, A.B.

    1998-05-01

    The objective of this work was to develop and test die casting design evaluation techniques based on the visualization of geometric data that is related to potential defects of problems. Specifically, thickness information is used to provide insight into potential thermal problems in the part and die. Distance from the gate and a special type of animation of the fill pattern is used to provide an assessment of gate, vent and overflow locations. Techniques have been developed to convert part design information in the form of STL files to a volume-based representation called a voxel model. The use of STL files makes the process CAD system independent. Once in voxel form, methods that were developed in this work are used to identify thick regions in the part, thin regions in the part and/or die, distance from user specified entry locations (gates), and the qualitative depiction of the fill pattern. The methods were tested with a prototype implementation on the UNIX platform. The results of comparisons with numerical simulation and field reported defects were surprisingly good. The fill-related methods were also compared against short-shots and a water analog study using high speed video. The report contains the results of the testing plus detailed background material on the construction of voxel models, the methods used for displaying results, and the computational geometric reasoning methods used to create die casting-related information form the voxel model for display to the user.

  13. REDUCING REJECTION/REWORK IN PRESSURE DIE CASTING PROCESS BY APPLICATION OF DMAIC METHODOLOGY OF SIX SIGMA

    Directory of Open Access Journals (Sweden)

    Javedhusen Malek

    2015-12-01

    Full Text Available In today's ever-changing customer driven market, industries are needed to improve their products and processes to satisfy customer requirements. The Six Sigma approach has set a new paradigm of business excellence. Six Sigma as a process driven improvement methodology has been adopted successfully by many industries. From the review of various literatures, it is revealed that Six Sigma is well adopted in large scale enterprise but having less evidence of adoption in Indian SMEs. This paper is focused on providing path to Indian SMEs for initiating Six Sigma approach in their industries. The paper discusses the real life case where Six Sigma has been successfully applied at one of the Indian small-scale unit to improve rejection/rework rate in manufacturing products by pressure die casting process. This paper describes phase wise application of all the phases of define-measure-analyse-improve-control (DMAIC which also shows impact of Six Sigma in quality improvement.

  14. Microstructural stability of heat-resistant high-pressure die-cast Mg-4Al-4Ce alloy

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Wei; Zhang, Jinghuai; Li, Guoqiang; Feng, Yan; Su, Minliang; Wu, Ruizhi; Zhang, Zhongwu [Harbin Engineering Univ. (China). Key Laboratory of Superlight Material and Surface Technology; Jiao, Yufeng [Jiamusi Univ. (China). College of Materials Science and Engineering

    2017-05-15

    The thermal stability of Al-RE (rare earth) intermetallic phases with individual RE for heat-resistant high-pressure die-casting Mg-Al-RE alloys is investigated. The results of this study show that the main strengthening phase of Mg-4Al-4Ce alloy is Al{sub 11}Ce{sub 3}, whose content is about 5 wt.% according to quantitative X-ray diffraction phase analysis. The Al{sub 11}Ce{sub 3} phase appears to have high thermal stability at 200 C and 300 C, while phase morphology change with no phase structure transition could occur for Al{sub 11}Ce{sub 3} when the temperature reaches 400 C. Furthermore, besides the kinds of rare earths and temperature, stress is also an influencing factor in the microstructural stability of Mg-4Al-4Ce alloy.

  15. An eco design strategy for high pressure die casting components: microstructural analysis applied to mass reducing processes

    International Nuclear Information System (INIS)

    Suarez-Pena, B.; Asensio-Lozano, J.

    2009-01-01

    In this work the study focused on the possibility of use of new aluminium alloys with optimized microstructures that ensure the mechanical properties requested for cast components made by high pressure die casting. The objective was to check the possibility of manufacture of structurally sound eco-steps for escalators with reduced structural integrity. The former arises as a result of a new redesign of the traditional steps aiming at a significant weight reduction. The experimental results show that it is feasible to cut the use of materials during processing and therefore to reduce the impact of the components during its lifetime, whilst the performance and safety standards are kept identical or even improved. (Author) 17 refs

  16. 76 FR 76259 - National Emissions Standards for Hazardous Air Pollutants: Primary Aluminum Reduction Plants

    Science.gov (United States)

    2011-12-06

    ... Emissions From Maleic Anhydride Plants, Ethylbenzene/Styrene Plants, Benzene Storage Vessels, Benzene...). The rule is applicable to facilities with affected sources associated with the production of aluminum... are subject to the requirements of this NESHAP: 14 primary aluminum production plants and one carbon...

  17. Die-cast of a hypo-eutectic AL-SI alloy: influence of injection temperature on microstructure and mechanical properties

    International Nuclear Information System (INIS)

    Santos, Silvano Leal dos; Santos, Sydney Ferreira

    2014-01-01

    Die-casting is widely used for manufacturing light alloy components for automotive industry. Among others, hypo-eutectic Al-Si alloys are currently processed by die-casting. To obtain high quality die-cast components, a better understanding on the correlations between processing parameters, microstructures, and mechanical properties are of utmost importance. In this study, we investigate the effect of injection temperature of liquid metal on the microstructure and mechanical properties of Al-Si alloy EN AC 46000 (DIN designation). The injection temperatures were 579, 589, 643, and 709 deg C. As-cast components had their microstructures analyzed by X-ray diffraction, optical and scanning electron microscopy, and X-ray energy dispersive spectroscopy. The mechanical properties were examined by micro-hardness and tensile tests. It was observed that the ultimate tensile strength slightly increased with the increase of injection temperature. The same trend was observed for micro-hardness. The amount of porosity in the samples varies in a small amount for different injection temperatures. On the other hand, the microstructure of the alloys seems more refined for higher temperatures of injection. This refinement in microstructure might play a major role on the mechanical properties of the Al-Si die-cast alloy. (author)

  18. The effect of natural pre-ageing on the mechanical properties of Rheo-High pressure die cast aluminium alloy 2139

    CSIR Research Space (South Africa)

    Chauke, L

    2015-07-01

    Full Text Available -high pressure die casting process (R-HPDC). Alloy 2139 is a Ag-containing aluminium alloy from the Al-Cu-Mg 2xxx series family. The addition of Ag enhances the age hardening response through the formation of co-clusters that act as precursors to the formation...

  19. The role of aluminum sensing and signaling in plant aluminum resistance.

    Science.gov (United States)

    Liu, Jiping; Piñeros, Miguel A; Kochian, Leon V

    2014-03-01

    As researchers have gained a better understanding in recent years into the physiological, molecular, and genetic basis of how plants deal with aluminum (Al) toxicity in acid soils prevalent in the tropics and sub-tropics, it has become clear that an important component of these responses is the triggering and regulation of cellular pathways and processes by Al. In this review of plant Al signaling, we begin by summarizing the understanding of physiological mechanisms of Al resistance, which first led researchers to realize that Al stress induces gene expression and modifies protein function during the activation of Al resistance responses. Subsequently, an overview of Al resistance genes and their function provides verification that Al induction of gene expression plays a major role in Al resistance in many plant species. More recent research into the mechanistic basis for Al-induced transcriptional activation of resistance genes has led to the identification of several transcription factors as well as cis-elements in the promoters of Al resistance genes that play a role in greater Al-induced gene expression as well as higher constitutive expression of resistance genes in some plant species. Finally, the post-transcriptional and translational regulation of Al resistance proteins is addressed, where recent research has shown that Al can both directly bind to and alter activity of certain organic acid transporters, and also influence Al resistance proteins indirectly, via protein phosphorylation. Published 2014. This article is a U.S. Government work and is in the public domain in the USA.

  20. Cancer risk in aluminum reduction plant workers (Canada)

    Energy Technology Data Exchange (ETDEWEB)

    Spinelli, J.J.; Demers, P.A.; Le, N.D.; Friesen, M.D.; Lorenzi, M.F.; Fang, R.; Gallagher, R.P. [British Columbia Cancer Agency, Vancouver, BC (Canada)

    2006-09-15

    A 14-year update to a previously published historical cohort study of aluminum reduction plant workers was conducted. All men with three or more years at an aluminum reduction plant in British Columbia (BC), Canada between the years 1954 and 1997 were included; a total of 6,423 workers. A total of 662 men were diagnosed with cancer, representing a 400% increase from the original study. Standardized mortality and incidence ratios were used to compare the cancer mortality and incidence of the cohort to that of the BC population. Poisson regression was used to examine risk by cumulative exposure to coal tar pitch volatiles (CTPV) measured as benzene soluble materials (BSM) and benzo(a)pyrene (BaP). The risk for bladder cancer was related to cumulative exposure to CTPV measured as BSM and BaP (p trends < 0.001), and the risk for stomach cancer was related to exposure measured by BaP (p trend BaP < 0.05). The risks for lung cancer (p trend < 0.001), non-Hodgkin lymphoma (p trend < 0.001), and kidney cancer (p trend < 0.01) also increased with increasing exposure, although the overall rates were similar to that of the general population. Analysis of the joint effect of smoking and CTPV exposure on cancer showed the observed dose-response relationships to be independent of smoking.

  1. Environmental hazards of aluminum to plants, invertebrates, fish, and wildlife

    Science.gov (United States)

    Sparling, D.W.; Lowe, T.P.

    1996-01-01

    Aluminum is extremely common throughout the world and is innocuous under circumneutral or alkaline conditions. However, in acidic environments, it can be a maJor limiting factor to many plants and aquatic organisms. The greatest concern for toxicity in North America occurs in areas that are affected by wet and dry acid deposition, such as eastern Canada and the northeastern U.S. Acid mine drainage, logging, and water treatment plant effluents containing alum can be other maJor sources of Al. In solution, the metal can combine with several different agents to affect toxicity. In general, Al hydroxides and monomeric Al are the most toxic forms. Dissolved organic carbons, F, PO(3)3- and SO(4)2- ameliorate toxicity by reducing bioavailability. Elevated metal levels in water and soil can cause serious problems for some plants. Algae tend to be both acid- and Al tolerant and, although some species may disappear with reduced pH, overall algae productivity and biomass are seldom affected if pH is above 3.0. Aluminum and acid toxicity tend to be additive to some algae when pH is less than 4.5. Because the metal binds with inorganic P, it may reduce P availability and reduce productivity. Forest die-backs in North America involving red spruce, Fraser fir, balsam fir, loblolly pine, slash pine, and sugar maples have been ascribed to Al toxicity, and extensive areas of European forests have died because of the combination of high soil Al and low pH. Extensive research on crops has produced Al-resistant cultivars and considerable knowledge about mechanisms of and defenses against toxicity. Very low Al levels may benefit some plants, although the metal is not recognized as an essential nutrient. Hyperaccumulator species of plants may concentrate Al to levels that are toxic to herbivores. Toxicity in aquatic invertebrates is also acid dependent. Taxa such as Ephemeroptera, Plecoptera, and Cladocera are sensitive and may perish when Al is less than 1 mg.L-1 whereas dipterans

  2. The ‘full sleeve’ application in the horizontal cold-chamber machine for pressure die casting of aluminium alloys

    Directory of Open Access Journals (Sweden)

    Z. Konopka

    2008-04-01

    Full Text Available The ‘full sleeve’ construction has been designed and accomplished in the horizontal cold-chamber pressure die casting machine. Main part of this solution is a counter plunger placed in a movable die half which allows for full filling of the shot sleeve and precisely fixes the metal quantity needed for casting. The purpose of this new construction solution is mainly the reduction of the casting porosity caused by air entrapment and the improvement of both castability and accuracy of the die cavity reproduction. For such a redesigned machine there have been performed examinations consisting in pressure casting of AlSi9Cu alloy (EN AC-46000 at varying plunger velocity in the second stage of injection and varying intensification pressure. The alloy castability (the die filling ability has been measured for each parameter setting. For the purpose of comparison, similar measurements have been performed also for the conventional system without a counter plunger. The castability examination has been done by means of a specially designed die with an impression of a trial casting of variable wall thickness. The experiments have been held according to the assumed factor design 22, what allowed for determining the mathematical models describing the influence of die filling parameters on the castability and the die cavity reproduction level. Both alternatives of the experiment confirmed the positive influence of plunger velocity and intensification pressure increase on the improvement of castability, the measure of the latter being the filled length of the impression. Applying of the new ‘full sleeve’ solution has improved castability for each experiment by about 20% as compared with conventional alternative. Castability in the ‘full sleeve’ system has been increased even for low values of plunger velocity and intensification pressure. For both alternative systems the influence of plunger velocity has been found, as an average, by four times

  3. Ejection Performance of Coated Core Pins Intended for Application on High Pressure Die Casting Tools for Aluminium Alloys Processing

    Directory of Open Access Journals (Sweden)

    P. Terek

    2017-09-01

    Full Text Available In high pressure die casting (HPDC process of aluminium alloys cast alloy soldering severely damages tool surfaces. It hampers casting ejection, reduces the casting quality and decreases the overall production efficiency. Thin ceramic PVD (physical vapor deposition coatings applied on tool surfaces successfully reduce these effects. However, their performance is still not recognised for surfaces with various topographies. In this investigation, soldering tendency of Al-Si-Cu alloy toward EN X27CrMoV51 steel, plasma nitrided steel, CrN and TiAlN duplex PVD coatings is evaluated using ejection test. The coatings were prepared to a range of surface roughness and topographies. After the tests sample surfaces were analysed by different microscopy techniques and profilometry. It was found that the ejection performance is independent of the chemical composition of investigated materials. After the ejection, the cast alloy soldering layer was found on surfaces of all tested materials. This built-up layer formed by effects of mechanical soldering, without corrosion reactions. Coated samples displayed a pronounced dependence of ejection force on surface roughness and topography. By decreasing roughness, ejection force increased, which is a consequence of intensified adhesion effects. Presented findings are a novel information important for efficient application of PVD coatings intendent for protection of HPDC tools.

  4. Morphology transition of the primary silicon particles in a hypereutectic A390 alloy in high pressure die casting.

    Science.gov (United States)

    Wang, J; Guo, Z; Song, J L; Hu, W X; Li, J C; Xiong, S M

    2017-11-03

    The microstructure of a high-pressure die-cast hypereutectic A390 alloy, including PSPs, pores, α-Al grains and Cu-rich phases, was characterized using synchrotron X-ray tomography, together with SEM, TEM and EBSD. The Cu-rich phases exhibited a net morphology and distributed at the boundaries of the α-Al grains, which in turn surrounded the PSPs. Statistical analysis of the reconstructed 1000 PSPs showed that both equivalent diameter and shape factor of the PSPs exhibited a unimodal distribution with peaks corresponding to 25 μm and 0.78, respectively.) PSPs morphology with multiple twinning were observed and morphological or growth transition of the PSPs from regular octahedral shape (with a shape factor of 0.85 was mainly caused by the constraint of the Cu-rich phases. In particular, the presence of the Cu-rich phases restricted the growth of the α-Al grains, inducing stress on the internal silicon particles, which caused multiple twinning occurrence with higher growth potential and consequently led to growth transitions of the PSPs.

  5. Microstructure, Tensile Properties, and Corrosion Behavior of Die-Cast Mg-7Al-1Ca- xSn Alloys

    Science.gov (United States)

    Wang, Feng; Dong, Haikuo; Sun, Shijie; Wang, Zhi; Mao, Pingli; Liu, Zheng

    2018-02-01

    The microstructure, tensile properties, and corrosion behavior of die-cast Mg-7Al-1Ca- xSn ( x = 0, 0.5, 1.0, and 2.0 wt.%) alloys were studied using OM, SEM/EDS, tensile test, weight loss test, and electrochemical test. The experimental results showed that Sn addition effectively refined grains and intermetallic phases and increased the amount of intermetallic phases. Meanwhile, Sn addition to the alloys suppressed the formation of the (Mg,Al)2Ca phase and resulted in the formation of the ternary CaMgSn phase and the binary Mg2Sn phase. The Mg-7Al-1Ca-0.5Sn alloy exhibited best tensile properties at room temperature, while Mg-7Al-1Ca-1.0Sn alloy exhibited best tensile properties at elevated temperature. The corrosion resistance of studied alloys was improved by the Sn addition, and the Mg-7Al-1Ca-0.5Sn alloy presented the best corrosion resistance.

  6. Investigation of microporosity in die-cast AlSi12(Cu) alloys by neutron- and X-ray radiography

    International Nuclear Information System (INIS)

    Zsolt, S.; Marton, B.

    1999-01-01

    The porosity of the casting can dramatically reduce the solidity and reliability of the objects made from aluminum alloys. The X-ray radiography is able to find the placement of the porosity of the aluminum devices. After a special 'water saturation' process the dynamic neutron radiography is available to discover the 'dangerous' surface nearporosity in the aluminum samples. The X-ray and neutron radiography were used as complementary examination techniques to study the porosity of the aluminum castings.(author)

  7. Procedure of a secure design calculation for transmission housings made of aluminium die cast; Ablauf einer sicheren Auslegungsberechnung von Getriebegehaeusen aus Aluminiumdruckguss

    Energy Technology Data Exchange (ETDEWEB)

    Varenkamp, Marco; Schoen, Michael [ZF Friedrichshafen AG, Friedrichshafen (Germany). Fachbereich Berechnung und Simulation

    2011-07-01

    The challenges in life time calculation of transmission housings made of aluminium die cast are on the one hand the complex geometry of the parts and on the other hand the defects in the material such as pores resulting from the die-cast process. The calculations are carried out using the finite element method and the local strain approach. The problem of transferability within the local strain approach is mastered by comparison with component tests and improvement of the transfer functions based on statistical evaluation. The secure design is assured by a safety factor derived from the confidence probability. With the help of an example the procedure will be explained. In addition it will be shown that under uniaxial variable amplitude loading the calculation result can be improved using the damage parameter PJ. (orig.)

  8. The Influence of Pressure Die Casting Parameters on the Mechanical Properties of AlSi11/10 Vol.% SiC Composite

    Directory of Open Access Journals (Sweden)

    Konopka Z.

    2014-03-01

    Full Text Available The paper presents the method of preparing a composite slurry composed of AlSi11 alloy matrix and 10 vol.% of SiC particles, as well as the method of its high-pressure die casting and the measurement results concerning the tensile strength, the yield point, the elongation and hardness of the obtained composite. Composite castings were produced at various values of the piston velocity in the second stage of injection, diverse intensification pressure values, and various injection gate width values. There were found the regression equations describing the change of mechanical properties of the examined composite as a function of pressure die casting process parameters. The conclusion gives the analysis and the interpretation of the obtained results.

  9. The Influence of Pressure Die Casting Parameters on Distribution of Reinforcing Particles in the AlSi11/10% SiC Composite

    Directory of Open Access Journals (Sweden)

    Pasieka A.

    2013-09-01

    Full Text Available The method of pressure die casting of composites with AlSi11 alloy matrix reinforced with 10 vol. % of SiC particles and the analysis of the distribution of particles within the matrix is presented. The composite castings were produced at various values of the piston velocity in the second stage of injection, at diverse intensification pressure values, and various injection gate width values. The distribution of particles over the entire cross-section of the tensile specimen is shown. The index of distribution was determined on the basis of particle count in elementary measuring fields. The regression equation describing the change of the considered index was found as a function of the pressure die casting parameters. The conclusion presents an analysis of the obtained results and their interpretation.

  10. Aluminum stress and its role in the phospholipid signaling pathway in plants and possible biotechnological applications.

    Science.gov (United States)

    Poot-Poot, Wilberth; Hernandez-Sotomayor, Soledad M Teresa

    2011-10-01

    An early response of plants to environmental signals or abiotic stress suggests that the phospholipid signaling pathway plays a pivotal role in these mechanisms. The phospholipid signaling cascade is one of the main systems of cellular transduction and is related to other signal transduction mechanisms. These other mechanisms include the generation of second messengers and their interactions with various proteins, such as ion channels. This phospholipid signaling cascade is activated by changes in the environment, such as phosphate starvation, water, metals, saline stres, and plant-pathogen interactions. One important factor that impacts agricultural crops is metal-induced stress. Because aluminum has been considered to be a major toxic factor for agriculture conducted in acidic soils, many researchers have focused on understanding the mechanisms of aluminum toxicity in plants. We have contributed the last fifteen years in this field by studying the effects of aluminum on phospholipid signaling in coffee, one of the Mexico's primary crops. We have focused our research on aluminum toxicity mechanisms in Coffea arabica suspension cells as a model for developing future contributions to the biotechnological transformation of coffee crops such that they can be made resistant to aluminum toxicity. We conclude that aluminum is able to not only generate a signal cascade in plants but also modulate other signal cascades generated by other types of stress in plants. The aim of this review is to discuss possible involvement of the phospholipid signaling pathway in the aluminum toxicity response of plant cells. Copyright © 2011 Wiley Periodicals, Inc.

  11. Determining casting defects in near-net shape casting aluminum parts by computed tomography

    Science.gov (United States)

    Li, Jiehua; Oberdorfer, Bernd; Habe, Daniel; Schumacher, Peter

    2018-03-01

    Three types of near-net shape casting aluminum parts were investigated by computed tomography to determine casting defects and evaluate quality. The first, second, and third parts were produced by low-pressure die casting (Al-12Si-0.8Cu-0.5Fe-0.9Mg-0.7Ni-0.2Zn alloy), die casting (A356, Al-7Si-0.3Mg), and semi-solid casting (A356, Al-7Si-0.3Mg), respectively. Unlike die casting (second part), low-pressure die casting (first part) significantly reduced the formation of casting defects (i.e., porosity) due to its smooth filling and solidification under pressure. No significant casting defect was observed in the third part, and this absence of defects indicates that semi-solid casting could produce high-quality near-net shape casting aluminum parts. Moreover, casting defects were mostly distributed along the eutectic grain boundaries. This finding reveals that refinement of eutectic grains is necessary to optimize the distribution of casting defects and reduce their size. This investigation demonstrated that computed tomography is an efficient method to determine casting defects in near-net shape casting aluminum parts.

  12. Toxicity and tolerance of aluminum in plants: tailoring plants to suit to acid soils.

    Science.gov (United States)

    Sade, Hemalatha; Meriga, Balaji; Surapu, Varalakshmi; Gadi, Jogeswar; Sunita, M S L; Suravajhala, Prashanth; Kavi Kishor, P B

    2016-04-01

    Aluminum (Al) stress is one of the serious limiting factors in plant productivity in acidic soils, which constitute about 50 % of the world's potentially arable lands and causes anywhere between 25 and 80 % of yield losses depending upon the species. The mechanism of Al toxicity and tolerance has been examined in plants, which is vital for crop improvement and enhanced food production in the future. Two mechanisms that facilitate Al tolerance in plants are Al exclusion from the roots and the ability to tolerate Al in the symplast or both. Although efforts have been made to unravel Al-resistant factors, many aspects remain unclear. Certain gene families such as MATE, ALMT, ASR, and ABC transporters have been implicated in some plants for resistance to Al which would enhance the opportunities for creating crop plants suitable to grow in acidic soils. Though QTLs have been identified related to Al-tolerance, no crop plant that is tolerant to Al has been evolved so far using breeding or molecular approaches. The remarkable changes that plants experience at the physiological, biochemical and molecular level under Al stress, the vast array of genes involved in Al toxicity-tolerance, the underlying signaling events and the holistic image of the molecular regulation, and the possibility of creating transgenics for Al tolerance are discussed in this review.

  13. Tolerance of physic nut plants to aluminum activity in nutrient solution

    OpenAIRE

    Lana, Maria do Carmo; Steiner, Fábio [UNESP; Zoz, Tiago [UNESP; Fey, Rubens; Frandoloso, Jucenei Fernando

    2013-01-01

    Plants have different levels of tolerance to phytotoxic effects of aluminum and the exploitation of this characteristic is of significant importance to the use of acid soils. This research aimed to evaluate the effect of aluminum activity in nutrient solution on growth of physic nut young plant. After seven days of adaptation, plants were submitted to Al concentrations of 0; 200; 400; 600; 800 and 1,000 μmol L-1, corresponding to Al3+ activity solution, of: 14.5, 21.4; 46.6; 75.6; 108.3 e 144...

  14. Evaluation of interlocking bond strength between structured 1.0338 steel sheets and high pressure die cast AlMg5Si2

    Science.gov (United States)

    Senge, S.; Brachmann, J.; Hirt, G.; Bührig-Polaczek, A.

    2018-05-01

    Multi-material components open up new possibilities for functional design. Such components combine beneficial physical properties of different materials in a single component as for instance chemical resistance, high strength or low density. The challenge is a reliable bond between both materials to enable a long term usage. This paper deals with a form closure connection to ensure a solid connection between steel strips and high pressure die cast aluminium. Two different sizes of channel structures with width ratios of 1.0 and 1.35 are produced on a steel sheet. An ensuing flat rolling pass is performed to create undercuts with a width of up to 50 µm, enabling an interlocking of the molten aluminium in the concluding casting process. For both rolling processes the resulting geometry is analysed depending on the thickness reduction. In a subsequent high pressure die casting process, aluminium is applied resulting in a complete form filling for the coarser structure. Comparing structures with and without undercuts, only structures suited with undercuts remain gap-free after solidification contraction. The finer structure could not be filled completely; nevertheless these structures result in shear strength of up to 45 MPa transversal to the channel-direction.

  15. Correlations Between Arrangement of Reinforcing Particles and Mechanical Properties in Pressure Die Cast AlSi11-SiC Composites

    Directory of Open Access Journals (Sweden)

    Konopka Z.

    2014-06-01

    Full Text Available The work presents the investigation results concerning the structure of composite pressure die castings with AlSi11 alloy matrix reinforced with SiC particles. Examination has been held for composites containing 10 and 20 volume percent of SiC particles. The arrangement of the reinforcing particles within the matrix has been qualitatively assessed in specimens cut out of the castings. The index of distribution was determined on the basis of particle count in elementary measuring fields. The tensile strength, the yield point and elongation of the obtained composite were measured. Composite castings were produced at various values of the piston velocity in the second stage of injection, diverse intensification pressure values, and various injection gate width values. The regression equation describing the change of the considered arrangement particles index and mechanical properties were found as a function of the pressure die casting parameters. The infuence of particle arrangement in composite matrix on mechanical properties these material was examined and the functions of correlations between values were obtained. The conclusion gives the analysis and the interpretation of the obtained results.

  16. Comparative study on microstructures and mechanical properties of the heat-treated Al–5.0Cu–0.6Mn–xFe alloys prepared by gravity die casting and squeeze casting

    International Nuclear Information System (INIS)

    Lin, Bo; Zhang, WeiWen; Lou, ZhaoHui; Zhang, DaTong; Li, YuanYuan

    2014-01-01

    Highlights: • Only two kind Fe-rich intermetallics are found in the heat-treated Al–5.0Cu–0.6Mn–xFe alloys. • Squeeze cast Al–5.0Cu–0.6Mn alloys containing 1.5% Fe have desirable mechanical properties. • The difference between gravity die cast and squeeze cast Al–5.0Cu–0.6Mn–xFe alloys. - Abstract: The Al–5.0 wt% Cu–0.6 wt% Mn alloys with different Fe contents were prepared by gravity die casting and squeeze casting. The difference in microstructures and mechanical properties of the T5 heat-treated alloys was examined by tensile test, optical microscopy, deep etching technique, scanning electron microscope and electron probe micro-analyzer. The results show that both β-Fe and α (CuFe) are observed in T5 heat-treated gravity die cast alloy and only α (CuFe) appears in the squeeze cast alloy when the Fe content is 0.5 wt%. When the Fe content is more than 1.0 wt%, the main Fe-rich intermetallics is α (CuFe) in both squeeze cast and gravity die cast alloys. The mechanical properties of both the gravity die cast and squeeze cast alloys decrease gradually with the increase of Fe content due to the decreased volume fraction of precipitation particles, the increased volume fraction of Fe-rich intermetallics and the increased size of α (Al) dendrites. The squeeze cast alloys with different Fe contents have superior mechanical properties compared to the gravity die cast alloys, which is mainly attributed to the reduction of porosity and refinement of Fe-rich intermetallics and α (Al) dendrite. In particularly, the elongation of the squeeze cast alloys is less sensitive to the Fe content than that of the gravity die cast alloys. An elongation level of 13.7% is obtained in squeeze cast alloy even when the Fe content is as high as 1.5%, while that of the gravity die cast alloy is only 5.3%

  17. A new approach to assess the effects of Sr and Bi interaction in ADC12 Al–Si die casting alloy

    Energy Technology Data Exchange (ETDEWEB)

    Farahany, Saeed, E-mail: saeedfarahany@gmail.com; Ourdjini, Ali; Abu Bakar, Tuty Asma; Idris, Mohd Hasbullah

    2014-01-10

    Highlights: • Interactive effect between Bi and Sr has been invesitigated comprehensively. • Sequence of addition did not affect thermal and microscopical characteristics. • A new map has been established to assess the final microstructure of castings. - Abstract: In the present paper, the possible interaction between bismuth and strontium in ADC12 die casting alloy was investigated comprehensively by using in situ thermal analysis technique. The characteristic temperatures including nucleation, minimum and growth temperatures of eutectic Al–Si were also analyzed. The results show that with Bi present in the Al–Si alloy melt the efficiency of Sr in modifying the eutectic Si is reduced. A threshold Sr/Bi ratio of at least 0.5 is required for a fully modified Si structure to form. A new map based on the characteristic temperatures, Sr/Bi ratio and microstructure, was established to assess the microstructure of fully solidified Al–Si castings.

  18. A new approach to assess the effects of Sr and Bi interaction in ADC12 Al–Si die casting alloy

    International Nuclear Information System (INIS)

    Farahany, Saeed; Ourdjini, Ali; Abu Bakar, Tuty Asma; Idris, Mohd Hasbullah

    2014-01-01

    Highlights: • Interactive effect between Bi and Sr has been invesitigated comprehensively. • Sequence of addition did not affect thermal and microscopical characteristics. • A new map has been established to assess the final microstructure of castings. - Abstract: In the present paper, the possible interaction between bismuth and strontium in ADC12 die casting alloy was investigated comprehensively by using in situ thermal analysis technique. The characteristic temperatures including nucleation, minimum and growth temperatures of eutectic Al–Si were also analyzed. The results show that with Bi present in the Al–Si alloy melt the efficiency of Sr in modifying the eutectic Si is reduced. A threshold Sr/Bi ratio of at least 0.5 is required for a fully modified Si structure to form. A new map based on the characteristic temperatures, Sr/Bi ratio and microstructure, was established to assess the microstructure of fully solidified Al–Si castings

  19. Proteome modification in tomato plants upon long-term aluminum treatment

    Science.gov (United States)

    This study aimed to identify the aluminum (Al)-induced proteomes in tomato (Solanum lycopersicum, “Micro-Tom”) after long-term exposure to the stress factor. Plants were treated in Magnavaca’s solution (pH 4.5) supplemented with 7.5 uM Al3+ ion activity over a 4 month period beginning at the emergen...

  20. SOIL EXCHANGEABLE ALUMINUM INFLUENCING THE GROWTH AND LEAF TISSUE MACRONUTRIENTS CONTENT OF CASTOR PLANTS

    Directory of Open Access Journals (Sweden)

    ROSIANE DE LOURDES SILVA DE LIMA

    2014-01-01

    Full Text Available Three castor ( Ricinus communis genotypes were studied regarding tolerance to high exchange factorial distribution of five doses of exchangeable aluminum added to the soil (0, 0.15, 0.30, 0.60, and 1.20 cmol c dm - 3 and three castor genotypes (BRS Nordestina, BRS Paraguaçu, and Lyra. The plants were raised in pots in a greenhouse. At 53 days after emergence, data were taken on plant height, leaf area, dry mass of shoot and root, and leaf tissue content of macronutrients. The most sensitive genotype was the cv. BRS Nordestina, in which the shoot and root dry weight in the highest aluminum content were reduced to 12.9% and 16.2% of the control treatment, respectively. The most tolerant genotype was the hybrid Lyra, in which the shoot and root dry weight in the maximum content of aluminum were reduced to 43.5% and 42.7% of the control treatment, respectively.The increased exchangeable aluminum affected the leaf nutrient content, and the intensity of the response was different among cultivars. The aluminum toxicity increased N, Ca, and Mg contents and reduced on P, K, and S contents. The cv. BRS Nordestina had a drastic shoot dry weight reduction associated with an intense increment in the N leaf content. Thus, the N increment was caused by a concentration effect caused by the limited growth.

  1. Die-cast of a hypo-eutectic AL-SI alloy: influence of injection temperature on microstructure and mechanical properties; Fundicao sob pressao das ligas de AL-SI: influencia da temperatura de injecao nas microestruturas e propriedades mecanicas

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Silvano Leal dos; Santos, Sydney Ferreira, E-mail: silvano_lleal@yahoo.com.br [Universidade Federal do ABC (UFABC), SP (Brazil)

    2014-07-01

    Die-casting is widely used for manufacturing light alloy components for automotive industry. Among others, hypo-eutectic Al-Si alloys are currently processed by die-casting. To obtain high quality die-cast components, a better understanding on the correlations between processing parameters, microstructures, and mechanical properties are of utmost importance. In this study, we investigate the effect of injection temperature of liquid metal on the microstructure and mechanical properties of Al-Si alloy EN AC 46000 (DIN designation). The injection temperatures were 579, 589, 643, and 709 deg C. As-cast components had their microstructures analyzed by X-ray diffraction, optical and scanning electron microscopy, and X-ray energy dispersive spectroscopy. The mechanical properties were examined by micro-hardness and tensile tests. It was observed that the ultimate tensile strength slightly increased with the increase of injection temperature. The same trend was observed for micro-hardness. The amount of porosity in the samples varies in a small amount for different injection temperatures. On the other hand, the microstructure of the alloys seems more refined for higher temperatures of injection. This refinement in microstructure might play a major role on the mechanical properties of the Al-Si die-cast alloy. (author)

  2. Utilization of power plant bottom-ash particles as stabilizer in aluminum foams

    Energy Technology Data Exchange (ETDEWEB)

    Asavavisithchai, Seksak; Prapajaraswong, Attanadol [Chulalongkorn Univ., Bangkok (Thailand). Dept. of Metallurgical Engineering

    2013-07-01

    Aluminum foams, produced via powder metallurgical (PM) process, normally require the addition of ceramic particles in compaction stage, in order to increase both foamability of precursors and mechanical properties of the final foam products. Bottom ash particles are a by-product waste obtained from thermoelectric power plants which are commonly found to be used in landfill facilities. The major chemical constituent, approximately between 30 wt.-% and 60 wt.-%, of bottom ash particles is SiO{sub 2}, depending on chemical composition in coal, sintering condition and environment, and other process parameters. In this study, we explore the feasibility of utilizing bottom ash particles of thermoelectric power plant wastes as stabilizer in aluminum foams. A small amount of two-size bottom ash particles (mean size of 78 {mu}m and 186 {mu}m), between 1 wt.-% and 5 wt.-%, have been added to aluminum foams. Foam expansion, macro- and microstructures as well as mechanical properties, such as compressive strength and microhardness, were investigated. The results from the present study suggest that bottom ash particles can be used as a stabilizing material which can improve both cellular structure and mechanical properties of aluminum foams. (orig.)

  3. Role of Accumulated Calcium in Alleviating Aluminum Injury in Wheat Plants

    Directory of Open Access Journals (Sweden)

    M. Alamgir Hossain

    2014-01-01

    Full Text Available Aluminum (Al sensitive wheat cultivar kalyansona was grown for 14 d in a range of Ca solution (125, 625, and 2500 μM plus other nutrients without Al. At 14 d after Ca treatment, half of these plants were harvested (H1, and the rest of the plants were exposed to 100 μM Al for additional 6 d and harvested (H2. Severe Al injury was found only in the plants with the lowest supply of Ca before Al treatment. Aluminum concentration in the apoplastic fluid was very high at 125 μM Ca probably because the plasma membrane of some of the cells was destroyed due to the attack of 100 μM Al. Aluminum content in roots decreased with increasing supply of Ca before Al treatment. Calcium content decreased drastically at harvest (H2 in the plants with 100 μM Al. Under Al stress conditions, the plant responded to Al in different ways due to not only the different Ca supply but also the variation of Ca content in the plant tissues. Actually, the plants having the largest Ca content in the roots before Al treatment can receive less Al injury during Al treatment. To substantiate this idea, a companion study was conducted to investigate the effects of 2500 μM Ca supply during, before, and after 100 μM Al treatment on root growth. The results indicated clearly that exogenous Ca supply before Al treatment is able to alleviate Al injury but less effective than Ca supply during Al treatment.

  4. Operating experience with aluminum bearings at the Portsmouth Gaseous Diffusion Plant

    International Nuclear Information System (INIS)

    Langebrake, C.O.

    1975-01-01

    Considerable operating experience has been gained at the Portsmouth Gaseous Diffusion Plant over the last 15 years in the use of aluminum bearings in process related and auxiliary equipment. All of this experience has been excellent and, in several cases, the use of this type of bearing material has solved significant operating problems. Aluminum 850-T101 alloy was first used as a bearing material in purge cascade (PC-9) centrifugal compressors where a fatigue problem was being experienced with babbitt-type bearings. Good experience in this application led to the extended use of this bearing material in other equipment including process related as well as auxiliary equipment. Since 1961 aluminum bearings have been installed in approximately 21 Type PC-9 (centrifugal), 97 Type 9 (centrifugal), 262 Type X-29 (axial), and 101 Type 31 (axial) compressors, and 3 speed increasers in the X-330 Evacuation Booster Station. Based on successful operation of these bearings, continued and expanded use of aluminum bearings is recommended as a means of obtaining a high fatigue resistant bearing at a cost lower than that for babbitt-type bearings. (U.S.)

  5. [Roles of organic acid metabolism in plant adaptation to nutrient deficiency and aluminum toxicity stress].

    Science.gov (United States)

    Wang, Jianfei; Shen, Qirong

    2006-11-01

    Organic acids not only act as the intermediates in carbon metabolism, but also exert key roles in the plant adaptation to nutrient deficiency and metal stress and in the plant-microbe interactions at root-soil interface. From the viewpoint of plant nutrition, this paper reviewed the research progress on the formation and physiology of organic acids in plant, and their functions in nitrogen metabolism, phosphorus and iron uptake, aluminum tolerance, and soil ecology. New findings in the membrane transport of organic acids and the biotechnological manipulation of organic acids in transgenic model were also discussed. This novel perspectives of organic acid metabolism and its potential manipulation might present a possibility to understand the fundamental aspects of plant physiology, and lead to the new strategies to obtain crop varieties better adapted to environmental and metal stress.

  6. [Process and mechanism of plants in overcoming acid soil aluminum stress].

    Science.gov (United States)

    Zhao, Tian-Long; Xie, Guang-Ning; Zhang, Xiao-Xia; Qiu, Lin-Quan; Wang, Na; Zhang, Su-Zhi

    2013-10-01

    Aluminum (Al) stress is one of the most important factors affecting the plant growth on acid soil. Currently, global soil acidification further intensifies the Al stress. Plants can detoxify Al via the chelation of ionic Al and organic acids to store the ionic Al in vacuoles and extrude it from roots. The Al extrusion is mainly performed by the membrane-localized anion channel proteins Al(3+)-activated malate transporter (ALMT) and multi-drug and toxin extrusion (MATE). The genes encoding ABC transporter and zinc-finger protein conferred plant Al tolerance have also been found. The identification of these Al-resistant genes makes it possible to increase the Al resistance of crop plants and enhance their production by the biological methods such as gene transformation and mark-associated breeding. The key problems needed to be solved and the possible directions in the researches of plant Al stress resistance were proposed.

  7. Synergistic effects of composition and heat treatment on microstructure and properties of vacuum die cast Al-Si-Mg-Mn alloys

    Directory of Open Access Journals (Sweden)

    Jun-jie Xu

    2018-03-01

    Full Text Available The purpose of this study was to prepare high-quality Al-Si-Mg-Mn alloy with a good combination of strength and ductility employing the vacuum-assisted high-pressure die cast process. An orthogonal study of heat treatments was conducted to design an optimized T6 heat treatment process for both Al-10%Si-0.3%Mg-Mn and Al-11%Si-0.6%Mg-Mn alloys. The results demonstrate that no obvious blisters and warpage were observed in these two alloys with solid solution treatment. After the optimal T6 heat treatment of 530°C×3h + 165°C×6h, Al-11%Si-0.6%Mg-Mn alloy has better mechanical properties, of which tensile strength, yield strength and elongation reached 377.3 MPa, 307.8 MPa and 9%, respectively. The improvement of mechanical properties can be attributed to the high density of needle-like β″(Mg5Si6 precipitation after aging treatment and the fine and spherical eutectic Si particles uniformly distributed in the α-Al matrix.

  8. Microstructure, Mechanical and Surface Morphological Properties of Al5Ti5Cr Master Alloy as Friction Material Prepared by Stir Die Casting

    Science.gov (United States)

    Ahmed, Syed Faisal; Srivastava, Sanjay; Agarwal, Alka Bani

    2018-04-01

    Metal matrix composite offers outstanding properties for better performance of disc brakes. In the present study, the composite of AlTiCr master alloy was prepared by stir die casting method. The developed material was reinforced with (0-10 wt%) silicon carbide (SiC) and boron carbide (B4C). The effects of SiC reinforcement from 0 to 10 wt% on mechanical, microstructure and surface morphological properties of Al MMC was investigated and compared with B4C reinforcement. Physical properties like density and micro Vickers hardness number show an increasing trend with an increase in the percentage of SiC and B4C reinforcement. Mechanical properties viz. UTS, yield strength and percentage of elongation are improved with increasing the fraction of reinforcement. The surface morphology and phase were identified from scanning electron microscopy (SEM) and X-ray diffraction analysis and the oxidized product formed during the casting was investigated by Fourier transformation infrared spectroscopy. This confirms the presence of crystallization of corundum (α-Al2O3) in small traces as one of the alumina phases, within casting sample. Micro-structural characterization by SEM depicted that the particles tend to be more agglomerated more and more with the percentage of the reinforcement. The AFM results reveal that the surface roughness value shows a decreasing trend with SiC reinforcement while roughness increases with increase the percentage of B4C.

  9. Effect of parameters of high-pressure die casting on occurrence of casting nonconformities in sleeves of silumin alloy EN AB 47100

    Directory of Open Access Journals (Sweden)

    Pałyga Ł.

    2017-03-01

    Full Text Available The paper presents a research on the effect of extreme - for the technology of the considered silumin EN AB 47100 - parameters of high-pressure die casting on occurrence of casting nonconformities. Considered was influence of the way of assembling the mould cooled-down to 140-160°C, non-standard for the selected casting, and pouring temperature in the range of 705 to 720°C (higher than the recommended of non-refined alloy. The castings were prepared with use of a high-pressure casting machine made by Kirov with mould closing force of 2500 kN. Occurrence of nonconformities was evaluated on properly prepared specimens taken from the castings manufactured with various parameters of the injection piston and various multiplication pressures. The results were subjected to quantitative and qualitative analyses of casting nonconformities and distribution of major alloying elements. It was found that proper selection of working parameters of the casting machine, in spite of disadvantageous pouring conditions, makes it possible to reduce occurrence of some casting defects, like shrinkage cavities and porosity, to improve tightness of castings even when the alloy refining process is omitted.

  10. On the microstructural factors affecting creep resistance of die-cast Mg–La-rare earth (Nd, Y or Gd) alloys

    Energy Technology Data Exchange (ETDEWEB)

    Gavras, S. [Magnesium Innovation Centre, Helmholtz-Zentrum Geesthacht, Max-Planck-Straße 1, Geesthacht (Germany); Zhu, S.M. [School of Aerospace, Mechanical and Manufacturing Engineering, RMIT University, Carlton, Victoria 3053 (Australia); Nie, J.F. [Department of Materials Science and Engineering, Monash University, Victoria 3800 (Australia); Gibson, M.A. [School of Aerospace, Mechanical and Manufacturing Engineering, RMIT University, Carlton, Victoria 3053 (Australia); Department of Materials Science and Engineering, Monash University, Victoria 3800 (Australia); CSIRO Manufacturing, Clayton, Victoria 3168 (Australia); Easton, M.A. [School of Aerospace, Mechanical and Manufacturing Engineering, RMIT University, Carlton, Victoria 3053 (Australia)

    2016-10-15

    Creep properties of high-pressure die-cast Mg–La-RE (Nd, Y or Gd) alloys, varying in ternary RE additions and in different heat treatment conditions, have been investigated. Through the use of short-term solution treatments (1 h at 520 °C) it was shown that the continuous intermetallic phase present in the eutectic at grain boundaries became discontinuous. This effect, in combination with the likely removal of the localised region of supersaturated solute in solid solution near grain boundaries, reduced the creep resistance. When relatively high concentrations of ternary alloying additions were used, solid solution strengthening and precipitation hardening appeared to compensate for the negative effect of reduced grain boundary reinforcement. Microstructural investigation revealed that Nd-containing alloys had fewer and larger dynamic precipitates present in the α-Mg matrix following creep testing at 177 °C and 90 MPa. It was concluded that grain boundary reinforcement in combination with the thermal stability of the precipitates formed, which is ultimately related to the diffusivity of solute in solid solution, are also contributing factors to creep resistance.

  11. Strengthening effect of nano-scale precipitates in a die-cast Mg–4Al–5.6Sm–0.3Mn alloy

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Qiang [State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China); Bu, Fanqiang [State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Qiu, Xin [State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China); Yangzhou Hongfu Aluminium Co. Ltd, Yangzhou 100049 (China); Li, Yangde; Li, Weirong [E-ande Scientific & Technology Co. Ltd, Dongguan 523000 (China); Sun, Wei [State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China); Liu, Xiaojuan, E-mail: lxjuan@ciac.ac.cn [State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China); Meng, Jian, E-mail: jmeng@ciac.jl.cn [State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China)

    2016-04-25

    In this paper we report a quantitative study of the age-hardening in the high-pressure die-cast Mg–4Al−5.6Sm−0.3Mn alloy. The results indicate that a number of nano-scale spherical precipitates identified as Al{sub 3}Sm using high-angle annular dark-field scanning transmission electron microscopy, precipitated in Mg matrix after aging at 150–225 °C, with no obvious changes on grain sizes, intermetallic phases formed during solidification, and dislocation densities. From the existing strengthening theory equations in which some lacking parameters were taken from the first-principles density functional theory (DFT) calculations, a quantitative insight into the strengthening mechanisms of the nano-scale precipitate was formulated. The results are in reasonable agreement with the experimental values, and the operative mechanism of precipitation strengthening was revealed as Orowan dislocation bypassing. - Highlights: • The yield strength of Mg–Al–Sm alloy was improved by aging treatment. • A number of nano-scale precipitates formed in matrix after aging treatments. • The nanoscale precipitate was confirmed as Al{sub 3}Sm based on the data of HAADF-STEM study. • The strengthening mechanisms of the nano-scale precipitate were quantitatively formulated. • The operative mechanism of precipitate strengthening is Orowan dislocation bypassing.

  12. Corrosion Behavior of High Pressure Die Cast Al-Ni and Al-Ni-Ca Alloys in 3.5% NaCl Solution

    Energy Technology Data Exchange (ETDEWEB)

    Arthanari, Srinivasan; Jang, Jae Cheol; Shin, Kwang Seon [Seoul National University, Seoul (Korea, Republic of)

    2017-06-15

    In this investigation corrosion behavior of newly developed high-pressure die cast Al-Ni (N15) and Al-Ni-Ca (NX1503) alloys was studied in 3.5% NaCl solution. The electrochemical corrosion behavior was evaluated using open circuit potential (OCP) measurement, potentiodynamic polarization, and electrochemical impedance spectroscopy (EIS) techniques. Potentiodynamic polarization results validated that NX1503 alloy exhibited lower corrosion current density (i{sub corr}) value (5.969 μA/cm{sup 2}) compared to N15 (7.387 μA/cm{sup 2}). EIS-Bode plots revealed a higher impedance (|Z|) value and maximum phase angle value for NX1503 than N15 alloy. Equivalent circuit curve fitting analysis revealed that surface layer (R{sub 1}) and charge transfer resistance (R{sub ct}) values of NX1503 alloy was higher compared to N15 alloy. Immersion corrosion studies were also conducted for alloys using fishing line specimen arrangement to simultaneously measure corrosion rates from weight loss (P{sub W}) and hydrogen volume (P{sub H}) after 72 hours and NX1503 alloy had lower corrosion rate compared to N15 alloy. The addition of Ca to N15 alloy significantly reduced the Al{sub 3}Ni intermetallic phase and further grain refinement may be attributed for reduction in the corrosion rate.

  13. Microstructure and property evaluation of high-pressure die-cast Mg–La–rare earth (Nd, Y or Gd) alloys

    International Nuclear Information System (INIS)

    Gavras, Serge; Easton, Mark A.; Gibson, Mark A.; Zhu, Suming; Nie, Jian-Feng

    2014-01-01

    Highlights: • Different rare earth elements have remarkably different effects on Mg castability. • For the addition of each RE element, the alloy castability follows a unique pattern. • The effects of RE elements on the castability can be modelled. - Abstract: Microstructure, castability and tensile properties were investigated in high-pressure die-cast Mg–La–Nd, Mg–La–Y and Mg–La–Gd alloy series, with a constant La concentration at approximately 2.5 wt.% and the concentrations of Nd, Y or Gd were varied. All three alloy series had a dendritic microstructure with a Mg–La-rich eutectic with increasing Nd, Y or Gd content and containing a Mg 12 RE intermetallic phase. The morphology of the eutectic at ternary alloying additions of equal to or less than 1.0 wt.% was lamellar but became increasingly divorced at higher ternary concentrations. This was however more obvious in Mg–La–Y and Mg–La–Gd than Mg–La–Nd alloys. The hot tearing susceptibility in all three alloy series increased markedly with even micro-alloying additions of Nd, Y or Gd, and began to decrease again in alloys with more than 0.5 wt.% Y or 1.0 wt.% Gd, but did not decrease significantly for Mg–La–Nd. A model using the temperature–fraction solid curves as input parameters was used to estimate hot tearing susceptibility for Mg–La–Nd alloys. Tensile testing at room temperature showed that Mg–La–Nd alloy series had higher 0.2% proof stress and lower elongation to failure than either the Mg–La–Y or the Mg–La–Gd alloy series for Nd concentrations greater than 1 wt.% due to a greater effectiveness of grain boundary reinforcement

  14. Improved Life of Die Casting Dies of H13 Steel by Attaining Improved Mechanical Properties and Distortion Control During Heat Treatment

    Energy Technology Data Exchange (ETDEWEB)

    J. F. Wallace; D. Schwam

    1998-10-01

    The ultimate goal of this project is to increase die casting die life by using fast enough quenching rates to obtain good toughness and fatigue resistance in premium grade H-13 steel dies. The main tasks of the project were to compile a database on physical and mechanical properties of H-13; conduct gas quenching experiments to determine cooling rates of dies in difference vacuum furnaces; measure the as-quenched distortion of dies and the residual stresses; generate finite element analysis models to predict cooling rates, distortion, and residual stress of gas quenched dies; and establish rules and create PC-based expert system for prediction of cooling rates, distortion, and residual stress in vacuum/gas quenched H-13 dies. Cooling curves during gas quenching of H-13 blocks and die shapes have been measured under a variety of gas pressure. Dimensional changes caused by the gas quenching processes have been determined by accurate mapping of all surfaces with coordinate measuring machines before and after the quench. Residual stresses were determined by the ASTM E837 hole-drilling strain gage method. To facilitate the computer modeling work, a comprehensive database of H-13 mechanical and physical properties has been compiled. Finite element analysis of the heat treated shapes has been conducted using the TRAST/ABAQUS codes. There is a good fit between the predicted and measured distortion contours. However, the magnitude of the predicted distortion and residual stresses does not match well the measured values. Further fine tuning of the model is required before it can be used to predict distortion and residual stress in a quantitative manner. This last step is a prerequisite to generating rules for a reliable expert system.

  15. Leaching of aluminum and iron from boiler slag generated from a typical Chinese Steel Plant.

    Science.gov (United States)

    Li, Jinping; Gan, Jinhua; Li, Xianwang

    2009-07-30

    This paper presents a new way of recycling aluminum and iron in boiler slag derived from coal combustion plants, which integrates efficient extraction and reuse of the leached pellets together. The boiler slag was pelletized together with washed coal and lime prior to sintering and then was sintered at 800-1200 degrees C for different periods to produce sintered pellets for the leaching test. An elemental analysis of aqueous solutions leached by sulfuric acid was determined by EDTA-Na(2)-ZnCl(2) titration method. The components and microstructures of the samples, sintered pellets and leached residue were examined by means of XRF, XRD and SEM. XRD analysis indicates that predominate minerals such as kaolinite, quartz, calcium silicide, hematate and metakoalin exist in the boiler slag. An aluminum extraction efficiency of 86.50% was achieved. The maximum extraction efficiency of Fe was 94.60% in the same conditions of that for the maximum extraction efficiency of Al. The extraction efficiencies of Al and Fe increased with an increase in temperature, leaching time and acidity. High Al extraction efficiency was obtained for pellets with high CaO content. The final product of alumina would be used directly for the production of metallic aluminum.

  16. Effect of aluminum treatment on proteomes of radicles of seeds derived from Al-treated tomato plants

    Science.gov (United States)

    Aluminum (Al) toxicity is a major constraint to plant growth and crop yield in acid soils. Tomato cultivars are especially susceptible to excessive A1 3+ accumulated in the root zone. In this study, tomato plants were grown in a hydroponic culture system supplemented with 50 uM AlK(SO4)2. Seeds harv...

  17. Comparison of tolerance to soil acidity among crop plants. II. Tolerance to high levels of aluminum and manganese. Comparative plant nutrition

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, A; Hayakawa, Y

    1975-01-01

    Research was conducted by growing various species of plants in solutions containing high concentrations of manganese or aluminum. A comparison was made of the tolerance of these plants to low pH and to the manganese and aluminum. In addition, the element content of the plants was compared. Plants high in calcium were found to have an intermediate tolerance to high concentrations of manganese and aluminum. Gramineae had a high tolerance to these elements and to low pH. They also accumulated high levels of these elements. Legumes had a high tolerance to manganese and aluminum and to low pH. However, they also accumulated high levels of these elements. Legumes had a high tolerance to manganese and aluminum and to low pH. However, they also accumulated high levels of these elements. Cruciferae had a low tolerance to the elements and to low pH. They contained low levels of manganese and aluminum. Chenopodiaceae had a low tolerance to the elements as well as low element contents. However, they were highly tolerant to low pH.

  18. The Role of the Plasma Membrane H+-ATPase in Plant Responses to Aluminum Toxicity

    Directory of Open Access Journals (Sweden)

    Jiarong Zhang

    2017-10-01

    Full Text Available Aluminum (Al toxicity is a key factor limiting plant growth and crop production on acid soils. Increasing the plant Al-detoxification capacity and/or breeding Al-resistant cultivars are a cost-effective strategy to support crop growth on acidic soils. The plasma membrane H+-ATPase plays a central role in all plant physiological processes. Changes in the activity of the plasma membrane H+-ATPase through regulating the expression and phosphorylation of this enzyme are also involved in many plant responses to Al toxicity. The plasma membrane H+-ATPase mediated H+ influx may be associated with the maintenance of cytosolic pH and the plasma membrane gradients as well as Al-induced citrate efflux mediated by a H+-ATPase-coupled MATE co-transport system. In particular, modulating the activity of plasma membrane H+-ATPase through application of its activators (e.g., magnesium or IAA or using transgenics has effectively enhanced plant resistance to Al stress in several species. In this review, we critically assess the available knowledge on the role of the plasma membrane H+-ATPase in plant responses to Al stress, incorporating physiological and molecular aspects.

  19. Closing plant stomata requires a homolog of an aluminum-activated malate transporter.

    Science.gov (United States)

    Sasaki, Takayuki; Mori, Izumi C; Furuichi, Takuya; Munemasa, Shintaro; Toyooka, Kiminori; Matsuoka, Ken; Murata, Yoshiyuki; Yamamoto, Yoko

    2010-03-01

    Plant stomata limit both carbon dioxide uptake and water loss; hence, stomatal aperture is carefully set as the environment fluctuates. Aperture area is known to be regulated in part by ion transport, but few of the transporters have been characterized. Here we report that AtALMT12 (At4g17970), a homolog of the aluminum-activated malate transporter (ALMT) of wheat, is expressed in guard cells of Arabidopsis thaliana. Loss-of-function mutations in AtALMT12 impair stomatal closure induced by ABA, calcium and darkness, but do not abolish either the rapidly activated or the slowly activated anion currents previously identified as being important for stomatal closure. Expressed in Xenopus oocytes, AtALMT12 facilitates chloride and nitrate currents, but not those of organic solutes. Therefore, we conclude that AtALMT12 is a novel class of anion transporter involved in stomatal closure.

  20. Proteome Modification in Tomato Plants upon Long-Term Aluminum Treatment.

    Science.gov (United States)

    Zhou, Suping; Okekeogbu, Ikenna; Sangireddy, Sasikiran; Ye, Zhujia; Li, Hui; Bhatti, Sarabjit; Hui, Dafeng; McDonald, Daniel W; Yang, Yong; Giri, Shree; Howe, Kevin J; Fish, Tara; Thannhauser, Theodore W

    2016-05-06

    This study aimed to identify the aluminum (Al)-induced proteomes in tomato (Solanum lycopersicum, "Micro-Tom") after long-term exposure to the stress factor. Plants were treated in Magnavaca's solution (pH 4.5) supplemented with 7.5 μM Al(3+) ion activity over a 4 month period beginning at the emergence of flower buds and ending when the lower mature leaves started to turn yellow. Proteomes were identified using a 8-plex isobaric tags for relative and absolute quantification (iTRAQ) labeling strategy followed by a two-dimensional (high- and low-pH) chromatographic separation and final generation of tandem mass spectrometry (MS/MS) spectra of tryptic peptides on an LTQ-Orbitrap Elite mass spectrometer. Principal component analysis revealed that the Al-treatment had induced systemic alterations in the proteomes from roots and leaves but not seed tissues. The significantly changed root proteins were shown to have putative functions in Al(3+) ion uptake and transportation, root development, and a multitude of other cellular processes. Changes in the leaf proteome indicate that the light reaction centers of photosynthetic machinery are the primary targets of Al-induced stress. Embryo and seed-coat tissues derived from Al-treated plants were enriched with stress proteins. The biological processes involving these Al-induced proteins concur with the physiological and morphological changes, such as the disturbance of mineral homeostasis (higher contents of Al, P, and Fe and reduced contents of S, Zn, and Mn in Al-treated compared to nontreated plants) in roots and smaller sizes of roots and the whole plants. More importantly, the identified significant proteins might represent a molecular mechanism for plants to develop toward establishing the Al tolerance and adaptation mechanism over a long period of stress treatment.

  1. Impression creep properties of a semi-solid processed magnesium-aluminum alloy containing calcium and rare earth elements

    International Nuclear Information System (INIS)

    Nami, B.; Razavi, H.; Miresmaeili, S.M.; Mirdamadi, Sh.; Shabestari, S.G.

    2011-01-01

    The creep properties of a thixoformed magnesium-aluminum alloy containing calcium and rare earth elements were studied under shear modulus-normalized stresses ranging from 0.0225 to 0.035 at temperatures of 150-212 o C using the impression creep technique. Analysis of the creep mechanism based on a power-law equation indicated that pipe diffusion-controlled dislocation climb is the dominant mechanism during creep. The alloy has a better creep resistance than high-pressure die-cast magnesium-aluminum alloy.

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

    Science.gov (United States)

    Rebak, Raul B.

    2017-12-01

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

  3. Plant Adaptation to Acid Soils: The Molecular Basis for Crop Aluminum Resistance.

    Science.gov (United States)

    Kochian, Leon V; Piñeros, Miguel A; Liu, Jiping; Magalhaes, Jurandir V

    2015-01-01

    Aluminum (Al) toxicity in acid soils is a significant limitation to crop production worldwide, as approximately 50% of the world's potentially arable soil is acidic. Because acid soils are such an important constraint to agriculture, understanding the mechanisms and genes conferring resistance to Al toxicity has been a focus of intense research interest in the decade since the last article on crop acid soil tolerance was published in this journal. An impressive amount of progress has been made during that time that has greatly increased our understanding of the diversity of Al resistance genes and mechanisms, how resistance gene expression is regulated and triggered by Al and Al-induced signals, and how the proteins encoded by these genes function and are regulated. This review examines the state of our understanding of the physiological, genetic, and molecular bases for crop Al tolerance, looking at the novel Al resistance genes and mechanisms that have been identified over the past ten years. Additionally, it examines how the integration of molecular and genetic analyses of crop Al resistance is starting to be exploited for the improvement of crop plants grown on acid soils via both molecular-assisted breeding and biotechnology approaches.

  4. An eco design strategy for high pressure die casting components: microstructural analysis applied to mass reducing processes; Una estrategia de ecodiseno de piezas obtenidas mediante moldeo a presion: analisis microestructrual aplicado a la desmaterializacion

    Energy Technology Data Exchange (ETDEWEB)

    Suarez-Pena, B.; Asensio-Lozano, J.

    2009-07-01

    In this work the study focused on the possibility of use of new aluminium alloys with optimized microstructures that ensure the mechanical properties requested for cast components made by high pressure die casting. The objective was to check the possibility of manufacture of structurally sound eco-steps for escalators with reduced structural integrity. The former arises as a result of a new redesign of the traditional steps aiming at a significant weight reduction. The experimental results show that it is feasible to cut the use of materials during processing and therefore to reduce the impact of the components during its lifetime, whilst the performance and safety standards are kept identical or even improved. (Author) 17 refs.

  5. Expression of Aluminum-Induced Genes in Transgenic Arabidopsis Plants Can Ameliorate Aluminum Stress and/or Oxidative Stress1

    Science.gov (United States)

    Ezaki, Bunichi; Gardner, Richard C.; Ezaki, Yuka; Matsumoto, Hideaki

    2000-01-01

    To examine the biological role of Al-stress-induced genes, nine genes derived from Arabidopsis, tobacco (Nicotiana tabacum L.), wheat (Triticum aestivum L.), and yeast (Saccharomyces cerevisiae) were expressed in Arabidopsis ecotype Landsberg. Lines containing eight of these genes were phenotypically normal and were tested in root elongation assays for their sensitivity to Al, Cd, Cu, Na, Zn, and to oxidative stresses. An Arabidopsis blue-copper-binding protein gene (AtBCB), a tobacco glutathione S-transferase gene (parB), a tobacco peroxidase gene (NtPox), and a tobacco GDP-dissociation inhibitor gene (NtGDI1) conferred a degree of resistance to Al. Two of these genes, AtBCB and parB, and a peroxidase gene from Arabidopsis (AtPox) also showed increased resistance to oxidative stress induced by diamide, while parB conferred resistance to Cu and Na. Al content of Al-treated root tips was reduced in the four Al-resistant plant lines compared with wild-type Ler-0, as judged by morin staining. All four Al-resistant lines also showed reduced staining of roots with 2′,7′-dichloro fluorescein diacetate (H2DCFDA), an indicator of oxidative stress. We conclude that Al-induced genes can serve to protect against Al toxicity, and also provide genetic evidence for a link between Al stress and oxidative stress in plants. PMID:10712528

  6. Dissolution Rate And Mechanism Of Metals In Molten Aluminum Alloy A380

    OpenAIRE

    Zhu, Hengyu

    2014-01-01

    Shot sleeve is a very easily worn out part in a high-pressure die-casting machine due to serious dissolution of the area underneath the pouring hole. It is because during a normal pouring process, the high temperature molten aluminum will impact and dissolve that area of the shot sleeve by complex chemical and physical process. Rotation experiment was carried out to H13 and four kinds of refractory metal samples. SEM and EDS pictures were taken in order to investigate the microstructure and t...

  7. REPORT ON QUALITATIVE VALIDATION EXPERIMENTS USING LITHIUM-ALUMINUM LAYERED DOUBLE-HYDROXIDES FOR THE REDUCTION OF ALUMINUM FROM THE WASTE TREATMENT PLANT FEEDSTOCK

    International Nuclear Information System (INIS)

    Huber, H.J.; Duncan, J.B.; Cooke, G.A.

    2010-01-01

    A process for removing aluminum from tank waste simulants by adding lithium and precipitating Li-Al-dihydroxide (Lithiumhydrotalcite, (LiAl 2 (OH) 6 ) + X - ) has been verified. The tests involved a double-shell tank (DST) simulant and a single-shell tank (SST) simulant. In the case of the DST simulant, the product was the anticipated Li-hydrotalcite. For the SST simulant, the product formed was primarily Li-phosphate. However, adding excess Li to the solution did result in the formation of traces of Li-hydrotalcite. The Li-hydrotalcite from the DST supernate was an easily filterable solid. After four water washes the filter cake was a fluffy white material made of < 100 (micro)m particles made of smaller spheres. These spheres are agglomerates of ∼ 5 (micro)m diameter platelets with < 1 (micro)m thickness. Chemical and mineralogical analyses of the filtrate, filter cake, and wash waters indicate a removal of 90+ wt% of the dissolved Al for the DST simulant. For the SST simulant, the main competing reaction to the formation of lithium hydrotalcite appears to be the formation of lithium phosphate. In case of the DST simulant, phosphorus co-precipitated with the hydrotalcite. This would imply the added benefit of the removal of phosphorus along with aluminum in the pre-treatment part of the waste treatment and immobilization plant (WTP). For this endeavor to be successful, a serious effort toward process parameter optimization is necessary. Among the major issues to be addressed are the dependency of the reaction yield on the solution chemistry, as well as residence times, temperatures, and an understanding of particle growth.

  8. Red mud a byproduct of aluminum production contains soluble vanadium that causes genotoxic and cytotoxic effects in higher plants

    Energy Technology Data Exchange (ETDEWEB)

    Mišík, Miroslav [Institute of Cancer Research, Department of Medicine I, Comprehensive Cancer Center, Medical University of Vienna, Vienna (Austria); Burke, Ian T. [Earth Surface Science Institute, School of Earth and Environment, University of Leeds, Leeds LS2 9JT (United Kingdom); Reismüller, Matthias; Pichler, Clemens; Rainer, Bernhard [Institute of Cancer Research, Department of Medicine I, Comprehensive Cancer Center, Medical University of Vienna, Vienna (Austria); Mišíková, Katarina [Department of Botany, Faculty of Natural Sciences, Comenius University, Bratislava (Slovakia); Mayes, William M. [Centre for Environmental and Marine Sciences, University of Hull, Scarborough YO11 3AZ (United Kingdom); Knasmueller, Siegfried, E-mail: siegfried.knasmueller@meduniwien.ac.at [Institute of Cancer Research, Department of Medicine I, Comprehensive Cancer Center, Medical University of Vienna, Vienna (Austria)

    2014-09-15

    Red mud (RM) is a byproduct of aluminum production; worldwide between 70 and 120 million tons is produced annually. We analyzed RM which was released in the course of the Kolontar disaster in Hungary into the environment in acute and genotoxicity experiments with plants which are widely used for environmental monitoring. We detected induction of micronuclei which reflect chromosomal damage in tetrads of Tradescantia and in root cells of Allium as well as retardation of root growth with contaminated soils and leachates. Chemical analyses showed that RM contains metals, in particular high concentrations of vanadium. Follow-up experiments indicated that vanadate causes the effects in the plants. This compound causes also in humans DNA damage and positive results were obtained in carcinogenicity studies. Since it was found also in RM from other production sites our findings indicate that its release in the environment is a global problem which should be studied in more detail. Capsule abstract: Our findings indicate that the red mud causes genotoxic effect in plants probably due to the presence of vanadate which is contained at high concentrations in the residue. - Highlights: • Red mud, a by-product of aluminum production, causes DNA-damage in higher plants. • We showed that this effect is caused by vanadate a known carcinogenic genotoxin. • Vanadate is contained in high concentrations in the residue. • Release of red mud may cause adverse effects in ecosystems and affect human health.

  9. Physiological and Biochemical Responses to Aluminum Stress in the Root of a Biodiesel Plant Jatropha curcas L.

    Directory of Open Access Journals (Sweden)

    RADITE TISTAMA

    2012-03-01

    Full Text Available We investigated J. curcas responses to aluminum stress, histochemically and biochemically. Histochemical stainings were observed to analysis aluminum accumulation, lipid peroxidation and the loss of plasma membrane integrity on the surface and tissue of the root apex. Enzymatic analysis was conducted to measure malate content in leaf, root and malate efflux in the medium. We used M. malabathricum as a comparison for Al-tolerance plant. J. curcas root elongation was inhibited by 0.4 mM AlCl3, while M. malabathricum root elongation was inhibited by 0.8 mM AlCl3 treatment. Inhibition of root elongation has high correlation with Al accumulation in the root apex, which caused lipid degradation and cell death. Generally, malate content in J. curcas leaf and root was higher than that in M. malabathricum. In the contrary malate efflux from the root into the medium was lower. J. curcas root has a different pattern compared to M. malabathricum in malate synthesis and malate secretion when treated with a different Al concentration. We categorized J. curcas acc IP3 as more sensitive to aluminum than M. malabathricum.

  10. Plant adaptation to acid soils: the molecular basis for crop aluminum resistance

    Science.gov (United States)

    Aluminum (Al) toxicity on acid soils is a significant limitation to crop production worldwide, as approximately 50% of the world’s potentially arable soils are acidic. Because acid soils are such an important constraint to agriculture, understanding the mechanisms and genes conferring resistance to ...

  11. A molecular, genetic and physiological analysis of plant aluminum tolerance (abstract)

    International Nuclear Information System (INIS)

    Pineros, M.

    2005-01-01

    Aluminum (Al) toxicity is an important agronomic trait, limiting crop production on acid soils that comprise up to 50% of the world's potentially arable lands. A significant genetic variation in Al tolerance exists in both crop plants and Arabidopsis. The exploitation of this genetic variation to breed crops with increased Al tolerance has been a productive and active area of research, however, the underlying molecular, genetic and physiological bases are still not well understood. Only very recently was the first Al tolerance gene, ALMT1, isolated in wheat and shown to be a novel Al-activated malate transporter. Work in our laboratory has focused on using integrated genomic (gene and protein expression profiling), molecular genetic and physiological approaches to identify novel Al tolerance genes and the physiological mechanisms they control in the cereal crops maize and sorghum, and also in arabidopsis. In sorghum we had previously shown that Al tolerance is the result of a single locus, Alt/sub SB/ which maps to the top of sorghum chromosome 3 in a region totally distinct from where the major Al tolerance maps in wheat and other related members of the Triticeae. Very recently, we have used map-based cloning techniques in sorghum to clone Alt/sub SB/ and have found it is a novel Al tolerance gene. Here we will present a molecular characterization of the Alt/sub SB/ gene and also the physiological mechanism of sorghum Al tolerance it controls. In arabidopsis, we have previously shown that Al tolerance is a quantitative trait and have identified two major Al tolerance QTL on chromosomes 1 and 5. These genes function to confer tolerance via Al via activated root malate release. We found that a member of the arabidopsis gene family that is a close homolog to wheat ALMT1 maps near the largest tolerance QTL on chromosome 1 and have also found this gene encodes the Al-activated malate transport involved in arabidopsis Al tolerance. However, we have clear molecular

  12. 32. The scheme of quality control of technical purity aluminum in electrolysis shop of Tajik aluminium Plant in accordance with the requirements of State Standards

    International Nuclear Information System (INIS)

    Ivanov, A.V.

    1993-01-01

    The scheme of quality control of technical purity aluminum in electrolysis shop of Tajik aluminium Plant in accordance with the requirements of State Standards was discussed. The place of sampling or control was defined. The periodicity of sampling or control was defined as well. The characteristics of probe were studied.

  13. Impact properties of zinc die cast alloys

    Energy Technology Data Exchange (ETDEWEB)

    Schrems, Karol K.; Dogan, Omer N.; Manahan, M.P. (MPM Technologies, Inc.); Goodwin, F.E. (ILZRO)

    2005-01-01

    Alloys 3, 5, AcuZinc 5, and ZA-8 were tested at five temperatures between -40 C and room temperature to determine impact properties. Izod impact energy data was obtained in accordance with ASTM D256. Unlike ASTM E23, these samples were tested with a milled notch in order to compare with plastic samples. In addition, flexural data was obtained for design use.

  14. Fabrication of Aluminum Tubes Filled with Aluminum Alloy Foam by Friction Welding

    Directory of Open Access Journals (Sweden)

    Yoshihiko Hangai

    2015-10-01

    Full Text Available Aluminum foam is usually used as the core of composite materials by combining it with dense materials, such as in Al foam core sandwich panels and Al-foam-filled tubes, owing to its low tensile and bending strengths. In this study, all-Al foam-filled tubes consisting of ADC12 Al-Si-Cu die-cast aluminum alloy foam and a dense A1050 commercially pure Al tube with metal bonding were fabricated by friction welding. First, it was found that the ADC12 precursor was firmly bonded throughout the inner wall of the A1050 tube without a gap between the precursor and the tube by friction welding. No deformation of the tube or foaming of the precursor was observed during the friction welding. Next, it was shown that by heat treatment of an ADC12-precursor-bonded A1050 tube, gases generated by the decomposition of the blowing agent expand the softened ADC12 to produce the ADC12 foam interior of the dense A1050 tube. A holding time during the foaming process of approximately tH = 8.5 min with a holding temperature of 948 K was found to be suitable for obtaining a sound ADC12-foam-filled A1050 tube with sufficient foaming, almost uniform pore structures over the entire specimen, and no deformation or reduction in the thickness of the tube.

  15. Effect of Aluminum Treatment on Proteomes of Radicles of Seeds Derived from Al-Treated Tomato Plants

    Directory of Open Access Journals (Sweden)

    Ikenna Okekeogbu

    2014-03-01

    Full Text Available Aluminum (Al toxicity is a major constraint to plant growth and crop yield in acid soils. Tomato cultivars are especially susceptible to excessive Al3+ accumulated in the root zone. In this study, tomato plants were grown in a hydroponic culture system supplemented with 50 µM AlK(SO42. Seeds harvested from Al-treated plants contained a significantly higher Al content than those grown in the control hydroponic solution. In this study, these Al-enriched tomato seeds (harvested from Al-treated tomato plants were germinated in 50 µM AlK(SO42 solution in a homopiperazine-1,4-bis(2-ethanesulfonic acid buffer (pH 4.0, and the control solution which contained the buffer only. Proteomes of radicles were analyzed quantitatively by mass spectrometry employing isobaric tags for relative and absolute quantitation (iTRAQ®. The proteins identified were assigned to molecular functional groups and cellular metabolic pathways using MapMan. Among the proteins whose abundance levels changed significantly were: a number of transcription factors; proteins regulating gene silencing and programmed cell death; proteins in primary and secondary signaling pathways, including phytohormone signaling and proteins for enhancing tolerance to abiotic and biotic stress. Among the metabolic pathways, enzymes in glycolysis and fermentation and sucrolytic pathways were repressed. Secondary metabolic pathways including the mevalonate pathway and lignin biosynthesis were induced. Biological reactions in mitochondria seem to be induced due to an increase in the abundance level of mitochondrial ribosomes and enzymes in the TCA cycle, electron transport chains and ATP synthesis.

  16. Analysis of molecular responses in plants under the conditions of excess-aluminum stress

    International Nuclear Information System (INIS)

    Masaoka, Yoshikuni; Arakawa, Yusuke; Asanuma, Shuichi

    1998-01-01

    Development of a measuring method for the amount of 26 aluminum (Al) incorporated into the root of Brachiaria ruziziensis which is a highly Al-resistant gramineous grass was attempted. After incubation of the root in 10 mM AlCl 3 solution for 5 hrs, mitochondrial fraction was prepared by an ordinary method and applied to tandem-accelerator mass spectrometry (t-AMS). Thus, super-sensitive Al-detection method which allows to detect 10 7 -10 8 atoms of Al was established. Using this method it was found that 26 Al incorporated from the root is transferred into the leaves and mitochondria at first and it was accumulated in mitochondria up to 70 ng/mg protein. Aiming to construct new Al-resistant leguminous cells utilizing a lot of genetic sources, a screening of Al-resistant leguminous bacteria was conducted to investigate the resistance mechanism. Thus, 5 resistant strains of B. japonicum, 3 of R. huakuii and 2 of R. meliloti were obtained. Then, the effects of Al, phosphorous and pH on the growth were compared among these bacteria. (M.N.)

  17. Effects of toxic levels of sodium, arsenic, iron and aluminum on the rice plant

    Energy Technology Data Exchange (ETDEWEB)

    Lockard, R G; McWalter, A R

    1956-01-01

    The results of two sand culture experiments on rice plants are described. In one, the toxic effects of sodium, as sodium chloride, and of arsenic, as sodium arsenate, were tested; in the other, iron, chelated with the disodium salt of ethylene-diamine-tetra-acetic acid, and aluminium, as aluminium sulfate, were tried out. The former was undertaken because of the existence of these sub

  18. Tonoplast- and plasma membrane-localized aquaporin-family transporters in blue hydrangea sepals of aluminum hyperaccumulating plant.

    Directory of Open Access Journals (Sweden)

    Takashi Negishi

    Full Text Available Hydrangea (Hydrangea macrophylla is tolerant of acidic soils in which toxicity generally arises from the presence of the soluble aluminum (Al ion. When hydrangea is cultivated in acidic soil, its resulting blue sepal color is caused by the Al complex formation of anthocyanin. The concentration of vacuolar Al in blue sepal cells can reach levels in excess of approximately 15 mM, suggesting the existence of an Al-transport and/or storage system. However, until now, no Al transporter has been identified in Al hyperaccumulating plants, animals or microorganisms. To identify the transporter being responsible for Al hyperaccumulation, we prepared a cDNA library from blue sepals according to the sepal maturation stage, and then selected candidate genes using a microarray analysis and an in silico study. Here, we identified the vacuolar and plasma membrane-localized Al transporters genes vacuolar Al transporter (VALT and plasma membrane Al transporter 1 (PALT1, respectively, which are both members of the aquaporin family. The localization of each protein was confirmed by the transient co-expression of the genes. Reverse transcription-PCR and immunoblotting results indicated that VALT and PALT1 are highly expressed in sepal tissue. The overexpression of VALT and PALT1 in Arabidopsis thaliana conferred Al-tolerance and Al-sensitivity, respectively.

  19. Conditions of Thermal Reclamation Process Realization on a Sample of Spent Moulding Sand from an Aluminum Alloy Foundry Plant

    Directory of Open Access Journals (Sweden)

    Łucarz M.

    2017-06-01

    Full Text Available The results of investigations of thermal reclamation of spent moulding sands originating from an aluminum alloy foundry plant are presented in this paper. Spent sands were crushed by using two methods. Mechanical fragmentation of spent sand chunks was realized in the vibratory reclaimer REGMAS. The crushing process in the mechanical device was performed either with or without additional crushing-grinding elements. The reclaimed material obtained in this way was subjected to thermal reclamations at two different temperatures. It was found that a significant binder gathering on grain surfaces favors its spontaneous burning, even in the case when a temperature lower than required for the efficient thermal reclamation of furan binders is applied in the thermal reclaimer. The burning process, initiated by gas burners in the reclaimer chamber, generates favorable conditions for self-burning (at a determined amount of organic binders on grain surfaces. This process is spontaneously sustained and decreases the demand for gas. However, due to the significant amount of binder, this process is longer than in the case of reclaiming moulding sand prepared with fresh components.

  20. Aluminum Hydroxide

    Science.gov (United States)

    Aluminum hydroxide is used for the relief of heartburn, sour stomach, and peptic ulcer pain and to ... Aluminum hydroxide comes as a capsule, a tablet, and an oral liquid and suspension. The dose and ...

  1. Cast Aluminum Alloys for High Temperature Applications Using Nanoparticles Al2O3 and Al3-X Compounds (X = Ti, V, Zr)

    Science.gov (United States)

    Lee, Jonathan A.

    2009-01-01

    In this paper, the effect of nanoparticles Al2O3 and Al3-X compounds (X = Ti, V, Zr) on the improvement of mechanical properties of aluminum alloys for elevated temperature applications is presented. These nanoparticles were selected based on their low cost, chemical stability and low diffusions rates in aluminum at high temperatures. The strengthening mechanism at high temperature for aluminum alloy is based on the mechanical blocking of dislocation movements by these nanoparticles. For Al2O3 nanoparticles, the test samples were prepared from special Al2O3 preforms, which were produced using ceramic injection molding process and then pressure infiltrated by molten aluminum. In another method, Al2O3 nanoparticles can also be homogeneously mixed with fine aluminum powder and consolidated into test samples through hot pressing and sintering. With the Al3-X nanoparticles, the test samples are produced as precipitates from in-situ reactions with molten aluminum using conventional permanent mold or die casting techniques. It is found that cast aluminum alloy using nanoparticles Al3-X is the most cost effective method to produce high strength aluminum alloys for high temperature applications in comparison to nanoparticles Al2O3. Furthermore, significant mechanical properties retention in high temperature environment could be achieved with Al3-X nanoparticles, resulting in tensile strength of nearly 3 times higher than most 300- series conventional cast aluminum alloys tested at 600 F.

  2. Processing of Aluminum-Graphite Particulate Metal Matrix Composites by Advanced Shear Technology

    Science.gov (United States)

    Barekar, N.; Tzamtzis, S.; Dhindaw, B. K.; Patel, J.; Hari Babu, N.; Fan, Z.

    2009-12-01

    To extend the possibilities of using aluminum/graphite composites as structural materials, a novel process is developed. The conventional methods often produce agglomerated structures exhibiting lower strength and ductility. To overcome the cohesive force of the agglomerates, a melt conditioned high-pressure die casting (MC-HPDC) process innovatively adapts the well-established, high-shear dispersive mixing action of a twin screw mechanism. The distribution of particles and properties of composites are quantitatively evaluated. The adopted rheo process significantly improved the distribution of the reinforcement in the matrix with a strong interfacial bond between the two. A good combination of improved ultimate tensile strength (UTS) and tensile elongation (ɛ) is obtained compared with composites produced by conventional processes.

  3. Determinação rápida de alumínio em plantas Rapid determination of aluminum in plant material

    Directory of Open Access Journals (Sweden)

    J. Romano Gallo

    1962-01-01

    Full Text Available Um método rápido e sensível espectrofotométrico de determinação do sistema alumínio-hematoxilina pode ser usado para se conhecer o teor de alumínio em tecidos de plantas. Êste trabalho descreve o método analítico com modificações introduzidos, estuda as interferências e inclui sua adaptação para plantas. Depois do incineração do material orgânico, o alumínio é dosado usualmente numa alíquota do extrato de cinzas equivalente a 0,005 a 0,020 g de material sêco. A côr é obtida em condições controladas de pH com solução buffer de acetato e alcalinização com carbonato de amônio. No processo podem ser determinadas, rapidamente, pequenas quantidades de alumínio, sem interferência de outros elementos, nos concentrações que usualmente ocorrem nas plantas.A procedure is described for the spectrophotometric determination of aluminum in ash extracts of plant tissue using the organic dye hematoxylin, without removal of iron. It has been devised by modifying and incorporating previously published procedures for water and uranium materials. The proposed method provides a rapid determination of small amounts of aluminum up to 5 micrograms, with a recovery error smaller than ±5 per cent, as tested for several plant materials. Manganese, copper, molybdenum, vanadium, cobalt, and chromium in quantities usually encountered in plant tissue do not interfere with the method.

  4. Semi-solid metal forming of beryllium-reinforced aluminum alloys

    International Nuclear Information System (INIS)

    Haws, W.; Lane, L.; Marder, J.; Nicholas, N.

    1995-01-01

    A Powder Metallurgy (PM) based, Semi-Solid Metal (SSM) forming process has been developed to produce low cost near-net shapes of beryllium-reinforced aluminum alloys. Beryllium acts as a reinforcing additive to the aluminum, in which there is nearly no mutual solid solubility. The modulus of elasticity of the alloy dramatically increases, while the density and thermal expansion coefficient decrease with increasing beryllium content. The material is suitable for complex thermal management and vibration resistance applications, as well as for airborne components which are density and stiffness sensitive. The forming process involves heating a blank of the material to a temperature at which the aluminum is semi-solid and the beryllium is solid. The semi-solid blank is then injected without turbulence into a permanent mold. High quality, near net shape components can be produced which are functionally superior to those produced by other permanent mold processes. Dimensional accuracy is equivalent to or better than that obtained in high pressure die casting. Cost effectiveness is the primary advantage of this technique compared to other forming processes. The advantages and limitations of the process are described. Physical and mechanical property data are presented, as well as directions for future investigation

  5. Characterization of Ti6Al4V for integral transition structures in FRP-aluminum compounds

    Energy Technology Data Exchange (ETDEWEB)

    Schimanski, Kai; Schumacher, Jens; Von Hehl, Axel; Zoch, Hans-Werner [Stiftung Institut fuer Werkstofftechnik, Bremen (Germany); Wottschel, Vitalij; Vollertsen, Frank [Bremer Institut fuer Angewandte Strahltechnik, Bremen (Germany)

    2012-08-15

    Components in hybrid design become more and more important in terms of their lightweight potential. In this context, the demand for weight saving in aerospace industry leads to increase numbers of applications of fiber reinforced composites for primary structural components. In consequence, the use of FRP-metal compounds is necessary. In the context of the investigations of the researcher group named ''Black-Silver'' (''Schwarz Silber'', FOR 1224) founded by the DFG (German Research Foundation) material optimized interface structures for advanced carbon fiber reinforced plastic (CFRP)-aluminum compounds are currently being studied. Within their work the researcher group focussed on three concepts realizing the transition structures: the usage of wires (titanium), foils (titanium), and fibers (glass fiber) as transition elements between CFRP and aluminum. For the connection of the aluminum sheet and the transition element die-casting and laser beam welding are basically used. The paper concentrates on the characterization of suitable materials for transition structures. Due to their high strength and low density (in comparison to steel) and the resulting potential in view on light-weight design Ti-alloys were investigated. Because of the increased availability of Ti-wires compared to Ti-foils in suitable thickness the former were used for the basic investigations on Ti-alloys which are suitable for integral transition structures. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  6. Aluminum industry options paper

    International Nuclear Information System (INIS)

    1999-10-01

    In 1990, Canada's producers of aluminum (third largest in the world) emitted 10 million tonnes of carbon dioxide and equivalent, corresponding to 6.4 tonnes of greenhouse gas intensity per tonne of aluminum. In 2000, the projection is that on a business-as-usual (BAU) basis Canadian producers now producing 60 per cent more aluminum than in 1990, will emit 10.7 million tonnes of carbon dioxide and equivalent, corresponding to a GHG intensity of 4.2 tonnes per tonne of aluminum. This improvement is due to production being based largely on hydro-electricity, and partly because in general, Canadian plants are modern, with technology that is relatively GHG-friendly. The Aluminum Association of Canada estimates that based on anticipated production, and under a BAU scenario, GHG emissions from aluminum production will rise by 18 per cent by 2010 and by 30 per cent by 2020. GHG emissions could be reduced below the BAU forecast first, by new control and monitoring systems at some operations at a cost of $4.5 to 7.5 million per smelter. These systems could reduce carbon dioxide equivalent emissions by 0.8 million tonnes per year. A second alternative would require installation of breaker feeders which would further reduce perfluorocarbon (PFC) emissions by 0.9 million tonnes of carbon dioxide equivalent. Cost of the breakers feeders would be in the order of $200 million per smelter. The third option calls for the the shutting down of some of the smelters with older technology by 2015. In this scenario GHG emissions would be reduced by 2010 by 0.8 million tonnes per year of carbon dioxide equivalent. However, the cost in this case would be about $1.36 billion. The industry would support measures that would encourage the first two sets of actions, which would produce GHG emissions from aluminum production in Canada of about 10.2 million tonnes per year of carbon dioxide equivalent, or about two per cent above 1990 levels with double the aluminum production of 1990. Credit for

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

    Science.gov (United States)

    Lemieux, Alain

    wrought alloy AA6061. At present, there is simply no known application for pressure die-cast alloy with 206 (Liquid Die-casting). This is mainly due to the high propensity to hot cracking and limitations facing the part geometry and the subsequent assembly. This study demonstrated that in addition to pieces produced by semi-solid die-casting using large variations in chemical composition, the SEED process allows obtaining spare sound (sound part) and more complex geometry. Moreover, as the semi-solid parts have less porosity, they can also be machined and welded for some applications. The conclusions of this study demonstrate significant progress in identifying the main issues related to the feasibility of die-casting good parts with high performance using the modified 206 alloy combined with SEED process. This work is therefore a baseline work in the development of new Al-Cu alloys for industries of semi-solid and, at the same time, for the expansion of aluminum for high performance applications in the industry. N.B. This thesis is part of a research project developed by the NSERC / Rio Tinto Akan Industrial Research Chair in Metallurgy of Innovative Aluminum Transformation (CIMTAL).

  8. EFFECT OF ALUMINUM ON PLANT GROWTH, PHOSPORUS AND CALCIUM UPTAKE OF TROPICAL RICE (Oryza sativa, MAIZE (Zea mays, AND SOYBEAN (Glycine max

    Directory of Open Access Journals (Sweden)

    D. Nursyamsi

    2018-01-01

    Full Text Available Aluminum toxicity is the most limiting factor to plant growth on acid soils. Structural and functional damages in the root system by Al decrease nutrient uptake and lead to reduce plant growth and mineral deficiency in shoot. Greenhouse experiment was conducted to study the effect of Al on plant growth, and P and Ca uptake of rice, maize, and soybean. The plants were grown in hydroponic solution added with 0, 5, 10, and 30 ppm Al, at pH 4.0. The results showed that relative growth of shoots and roots of upland rice, lowland rice, maize, and soybean decreased with an increase of Al level. However, sometimes the low Al level (5 ppm stimulated shoot and root growth of some varieties in these species. According to total AlRG30 values, which is Al concentration in solution when relative growth decreased to 50%, Al tolerance of species was in order of barley < maize < soybean < lowland rice < upland rice. For maize, Al tolerance was in the order of Arjuna < Kalingga < P 3540 < SA 5 < SA 4 < PM 95 A < SA 3 < Antasena; for soybean was Wilis < INPS < Galunggung < Kerinci < Kitamusume; for lowland rice was RD 23 < Kapuas < Cisadane < KDML 105 < IR 66 < RD 13, and for upland rice was Dodokan < JAC165 < Cirata < Orizyca sabana 6 < Danau Tempe < Laut Tawar. Based on the rank of Al tolerance, rice was the useful crop to be planted in acid soils. Antasena (maize, Kitamusume ( soybean , RD 13 (lowland rice, and Laut Tawar (upland rice were also recommended for acid soils. P and Ca concentration in shoots and roots commonly decreased with an increase of Al level. However, the low Al level stimulated absorption of P and Ca concentrations in shoots and roots.

  9. Efficiency of electrical coagulation process using aluminum electrodes for municipal wastewater treatment: a case study at Karaj wastewater treatment plant

    Directory of Open Access Journals (Sweden)

    Samad Gholami Yengejeh

    2017-05-01

    Full Text Available Background: The reuse of treated municipal wastewater is an important source of water for different purposes. This study evaluated the efficiency of the electrocoagulation process in removing turbidity, total suspended solids (TSS, chemical oxygen demand (COD, nitrate, and phosphate from wastewater at the treatment facility in Karaj, Iran. Methods: This experimental study was performed at a pilot scale and in a batch system. A 4-liter tank made from safety glass with 4 plate electrodes made from aluminum was unipolarly connected to a direct current power supply with a parallel arrangement. Wastewater samples were taken from the influent at the Karaj wastewater treatment facility. Rates of turbidity, TSS, COD, nitrate, and phosphate removal under different conditions were determined. Results: The highest efficiency of COD, TSS, nitrate, turbidity, and phosphate elimination was achieved at a voltage of 30 volts and a reaction time of 30 minutes. The rates were 88.43%, 87.39%, 100%, 80.52%, and 82.69%, respectively. Conclusion: Based on the results of this study, electrocoagulation is an appropriate method for use in removing nitrate, phosphate, COD, turbidity, and TSS from wastewater.

  10. Aluminum nitrate recrystallization and recovery from liquid extraction raffinates

    International Nuclear Information System (INIS)

    Griffith, W.L.; Compere, A.L.; Googin, J.M.; Huxtable, W.P.

    1991-09-01

    The solid sludges resulting form biodenitrification of discarded aluminum nitrate are the largest Y-12 Plant process solid waste. Aluminum nitrate feedstocks also represent a major plant materials cost. The chemical constraints on aluminum nitrate recycle were investigated to determine the feasibility of increasing recycle while maintaining acceptable aluminum nitrate purity. Reported phase behavior of analogous systems, together with bench research, indicated that it would be possible to raise the recycle rate from 35% to between 70 and 90% by successive concentration and recrystallization of the mother liquor. A full scale pilot test successfully confirmed the ability to obtain 70% recycle in existing process equipment

  11. ALUMINUM BOX BUNDLING PRESS

    Directory of Open Access Journals (Sweden)

    Iosif DUMITRESCU

    2015-05-01

    Full Text Available In municipal solid waste, aluminum is the main nonferrous metal, approximately 80- 85% of the total nonferrous metals. The income per ton gained from aluminum recuperation is 20 times higher than from glass, steel boxes or paper recuperation. The object of this paper is the design of a 300 kN press for aluminum box bundling.

  12. Graphene-aluminum nanocomposites

    International Nuclear Information System (INIS)

    Bartolucci, Stephen F.; Paras, Joseph; Rafiee, Mohammad A.; Rafiee, Javad; Lee, Sabrina; Kapoor, Deepak; Koratkar, Nikhil

    2011-01-01

    Highlights: → We investigated the mechanical properties of aluminum and aluminum nanocomposites. → Graphene composite had lower strength and hardness compared to nanotube reinforcement. → Processing causes aluminum carbide formation at graphene defects. → The carbides in between grains is a source of weakness and lowers tensile strength. - Abstract: Composites of graphene platelets and powdered aluminum were made using ball milling, hot isostatic pressing and extrusion. The mechanical properties and microstructure were studied using hardness and tensile tests, as well as electron microscopy, X-ray diffraction and differential scanning calorimetry. Compared to the pure aluminum and multi-walled carbon nanotube composites, the graphene-aluminum composite showed decreased strength and hardness. This is explained in the context of enhanced aluminum carbide formation with the graphene filler.

  13. Associated mechanisms of aluminum tolerance in plants/ Mecanismos associados à tolerância ao alumínio em plantas

    Directory of Open Access Journals (Sweden)

    Cecília Estima Sacramento dos Reis

    2007-10-01

    Full Text Available Aluminum toxicity is one of the major limiting factor regarding plant development in acid soils. The use of liming for correcting soil pH is not viable for some of acid soil areas (technique or economic reasons, making the development of Al tolerant genotypes the best alternative. Thus, the tolerance mechanisms as well as the genetic basis of Al tolerance has deserved special attention in the scientific community. In the last years, a significant progress has been achieved towards these goals, as well as in developing cultivars adapted to acid soils. The Al tolerance mechanisms are divided basically in two classes: the exclusion mechanisms that act after absorption or blocking its entry in the root system and those involved in detoxification, complexing the Al in specific organelles, mainly in the vacuoles. In many species, physiological mechanisms have been reported as responsible for the activation of organic acids (mainly citrate and malate that act as Al quelating agents, however many process are not yet understood and cleared. Currently, the basis for the internal detoxification is becoming clear through organic acid complexes and there sequestering by the vacuoles. Other potential mechanisms are the target for discussions.A toxicidade do alumínio é um dos principais fatores limitantes do desenvolvimento das plantas em solos ácidos. Pelo fato da utilização de corretivos da acidez do solo não ser a estratégia mais viável em muitas situações com solos ácidos (por razões técnicas e econômicas, o desenvolvimento de genótipos tolerantes ao Al tem sido o caminho mais focado, assim a investigação dos mecanismos de tolerância bem como as bases genéticas da tolerância ao Al têm merecido atenção especial pela pesquisa científica. Nos últimos anos, foi gerado um significativo progresso no entendimento das bases dos mecanismos de tolerância ao Al, assim como no desenvolvimento de cultivares mais adaptados as condições de

  14. Decontamination and reuse of ORGDP aluminum scrap

    International Nuclear Information System (INIS)

    Compere, A.L.; Griffith, W.L.; Hayden, H.W.; Wilson, D.F.

    1996-12-01

    The Gaseous Diffusion Plants, or GDPs, have significant amounts of a number of metals, including nickel, aluminum, copper, and steel. Aluminum was used extensively throughout the GDPs because of its excellent strength to weight ratios and good resistance to corrosion by UF 6 . This report is concerned with the recycle of aluminum stator and rotor blades from axial compressors. Most of the stator and rotor blades were made from 214-X aluminum casting alloy. Used compressor blades were contaminated with uranium both as a result of surface contamination and as an accumulation held in surface-connected voids inside of the blades. A variety of GDP studies were performed to evaluate the amounts of uranium retained in the blades; the volume, area, and location of voids in the blades; and connections between surface defects and voids. Based on experimental data on deposition, uranium content of the blades is 0.3%, or roughly 200 times the value expected from blade surface area. However, this value does correlate with estimated internal surface area and with lengthy deposition times. Based on a literature search, it appears that gaseous decontamination or melt refining using fluxes specific for uranium removal have the potential for removing internal contamination from aluminum blades. A melt refining process was used to recycle blades during the 1950s and 1960s. The process removed roughly one-third of the uranium from the blades. Blade cast from recycled aluminum appeared to perform as well as blades from virgin material. New melt refining and gaseous decontamination processes have been shown to provide substantially better decontamination of pure aluminum. If these techniques can be successfully adapted to treat aluminum 214-X alloy, internal and, possibly, external reuse of aluminum alloys may be possible

  15. Effect of Contact Time on Interface Reaction between Aluminum Silicon (7% and 11% Alloy and Steel Dies SKD 61

    Directory of Open Access Journals (Sweden)

    Bambang Suharno

    2010-10-01

    Full Text Available Die soldering (die sticking is a defect of metal casting in which molten metal “welds” to the metallic die mold surface during casting process. Die soldering is the result of an interface reaction between the molten aluminum and the die material. Aluminum alloy with 7 and 11% silicon and SKD 61 die steel are the most common melt and die material used in aluminum die casting. This research is done to study the morphology and the characteristics of the formed AlxFeySiz intermetallic layer during interface reaction at dipping test. The samples of as-anneal SKD 61 tool steel was dipped into the molten of Al-7%Si held at temperature 680oC and into molten Al-11%Si held at temperature 710oC with the different contact time of 10 minutes; 30 minutes; and 50 minutes. The research results showed that the interface reaction can form a compact intermetallic layer with AlxFey phase and a broken intermetallic layer with AlxFeySiz phase on the surface of SKD 61 tool steel. The increasing of the contact time by the immersion of material SKD 61 tool steel in both of molten Al-7%Si and Al-11%Si will increase the thickness of the AlxFeySiz intermetallic layer until an optimum point and then decreasing. The micro hardness of the AlxFeySiz intermetallic layer depends on the content of the iron. Increasing of the iron content in intermetallic layer will increase the micro hardness of the AlxFeySiz. This condition happened because the increasing of Fe content will cause forming of intermetallic AlxFeySiz phase becomes quicker.

  16. BONDING ALUMINUM METALS

    Science.gov (United States)

    Noland, R.A.; Walker, D.E.

    1961-06-13

    A process is given for bonding aluminum to aluminum. Silicon powder is applied to at least one of the two surfaces of the two elements to be bonded, the two elements are assembled and rubbed against each other at room temperature whereby any oxide film is ruptured by the silicon crystals in the interface; thereafter heat and pressure are applied whereby an aluminum-silicon alloy is formed, squeezed out from the interface together with any oxide film, and the elements are bonded.

  17. Aluminum powder metallurgy processing

    Energy Technology Data Exchange (ETDEWEB)

    Flumerfelt, J.F.

    1999-02-12

    The objective of this dissertation is to explore the hypothesis that there is a strong linkage between gas atomization processing conditions, as-atomized aluminum powder characteristics, and the consolidation methodology required to make components from aluminum powder. The hypothesis was tested with pure aluminum powders produced by commercial air atomization, commercial inert gas atomization, and gas atomization reaction synthesis (GARS). A comparison of the GARS aluminum powders with the commercial aluminum powders showed the former to exhibit superior powder characteristics. The powders were compared in terms of size and shape, bulk chemistry, surface oxide chemistry and structure, and oxide film thickness. Minimum explosive concentration measurements assessed the dependence of explosibility hazard on surface area, oxide film thickness, and gas atomization processing conditions. The GARS aluminum powders were exposed to different relative humidity levels, demonstrating the effect of atmospheric conditions on post-atomization processing conditions. The GARS aluminum powders were exposed to different relative humidity levels, demonstrating the effect of atmospheric conditions on post-atomization oxidation of aluminum powder. An Al-Ti-Y GARS alloy exposed in ambient air at different temperatures revealed the effect of reactive alloy elements on post-atomization powder oxidation. The pure aluminum powders were consolidated by two different routes, a conventional consolidation process for fabricating aerospace components with aluminum powder and a proposed alternative. The consolidation procedures were compared by evaluating the consolidated microstructures and the corresponding mechanical properties. A low temperature solid state sintering experiment demonstrated that tap densified GARS aluminum powders can form sintering necks between contacting powder particles, unlike the total resistance to sintering of commercial air atomization aluminum powder.

  18. Comparison of the Performance of Poly Aluminum Chloride (PACl, Ferric Chloride (FeCl3, in Turbidity and Organic Matter Removal; from Water Source, Case-Study: Karaj River, in Tehran Water Treatment Plant No. 2

    Directory of Open Access Journals (Sweden)

    Mohammad Abdolah zadeh

    2009-06-01

    Full Text Available Coagulation and flocculation are the principal units in water treatment processes. In this study, the Jar test was used to investigate the effects of the pH and TOC on FeCl3 and PACl coagulants for further removal of turbidity, organic matter, aluminum, total organic carbon (TOC, dissolved organic carbon (DOC, organic Aadsorption at a wavelength of 254 nm (UV254 nm , alkalinity, residual aluminum and ferric, total trihalomethans (TTHMs in the Karaj River in the year 2007- 2008. These experiments were conducted through a bench scale study using conventional coagulation in the influent to Tehran Water Treatment Plant No. 2 (TWTP2.With normal pH levels, PACl demonstrated more efficiency than FeCl3 in removing turbidity, TOC, UV254 nm, and TTHMs. The lower coagulant consumption, high floc size, lower floc detention time, lower sludge production, lack of the need for pH adjustment in turbidity of 25 NTU and the lower alum consumption were the advantages of PACl application instead of FeCl3 as a coagulant. Also, PACl application was efficient at low turbidity (2 NTU, average turbidity (6 NTU, and high turbidity (100 NTU in TOC, turbidity, UV254 nm , and DOC removal. Thus, PACl is an economical alternative as a coagulant in TWTP2.

  19. R-HPDC Process with Forced Convection Mixing Device for Automotive Part of A380 Aluminum Alloy

    Directory of Open Access Journals (Sweden)

    Bing Zhou

    2014-04-01

    Full Text Available The continuing quest for cost-effective and complex shaped aluminum castings with fewer defects for applications in the automotive industries has aroused the interest in rheological high pressure die casting (R-HPDC. A new machine, forced convection mixing (FCM device, based on the mechanical stirring and convection mixing theory for the preparation of semisolid slurry in convenience and functionality was proposed to produce the automotive shock absorber part by R-HPDC process. The effect of barrel temperature and rotational speed of the device on the grain size and morphology of semi-solid slurry were extensively studied. In addition, flow behavior and temperature field of the melt in the FCM process was investigated combining computational fluid dynamics simulation. The results indicate that the microstructure and pore defects at different locations of R-HPDC casting have been greatly improved. The vigorous fluid convection in FCM process has changed the temperature field and composition distribution of conventional solidification. Appropriately increasing the rotational speed can lead to a uniform temperature filed sooner. The lower barrel temperature leads to a larger uniform degree of supercooling of the melt that benefits the promotion of nucleation rate. Both of them contribute to the decrease of the grain size and the roundness of grain morphology.

  20. A comparison of aluminum levels in tea products from Hong Kong markets and in varieties of tea plants from Hong Kong and India.

    Science.gov (United States)

    Fung, K F; Carr, H P; Poon, B H T; Wong, M H

    2009-05-01

    This study project aimed to investigate the concentrations of aluminum (Al) in tea products available in Hong Kong markets. Tea samples consisting of 47 different tea bags and 28 samples of tea leaves were analysed for concentrations of Al. All tea samples released Al (0.70-5.93 mg L(-1)) during a standard infusion period. In comparison to the Joint FAO/WHO Provisional Tolerable Weekly Intake guideline of 7 mg Al kg(-1) body weight, it was concluded that tea made with these tea leaves will not impose adverse human health impacts. The relative effects of age, soil available Al, and genetic differences on the levels of Al accumulated by tea bushes were investigated. It was found that there was no definite trend between the amount of Al accumulated and the age of tea bushes. The soil available Al influenced the levels of Al in Camellia sinensis to a certain extent, but it was evident that the ability of different varieties of C. sinensis to accumulate Al was variable. C. sinensis accumulated Al in all stages of growth. Young seedlings had lower contents of Al while the mobility of Al within the tea bushes was high. In a manner typical of hyperaccumulators, Al was not retained in the roots, but was consistently transported to the shoots. Aluminum in the tea bush was distributed between the different parts in the following order: mature leaves>roots>branches>young leaves.

  1. Utilization of Aluminum Waste with Hydrogen and Heat Generation

    Science.gov (United States)

    Buryakovskaya, O. A.; Meshkov, E. A.; Vlaskin, M. S.; Shkolnokov, E. I.; Zhuk, A. Z.

    2017-10-01

    A concept of energy generation via hydrogen and heat production from aluminum containing wastes is proposed. The hydrogen obtained by oxidation reaction between aluminum waste and aqueous solutions can be supplied to fuel cells and/or infrared heaters for electricity or heat generation in the region of waste recycling. The heat released during the reaction also can be effectively used. The proposed method of aluminum waste recycling may represent a promising and cost-effective solution in cases when waste transportation to recycling plants involves significant financial losses (e.g. remote areas). Experiments with mechanically dispersed aluminum cans demonstrated that the reaction rate in alkaline solution is high enough for practical use of the oxidation process. In theexperiments aluminum oxidation proceeds without any additional aluminum activation.

  2. Anodizing Aluminum with Frills.

    Science.gov (United States)

    Doeltz, Anne E.; And Others

    1983-01-01

    "Anodizing Aluminum" (previously reported in this journal) describes a vivid/relevant laboratory experience for general chemistry students explaining the anodizing of aluminum in sulfuric acid and constrasting it to electroplating. Additions to this procedure and the experiment in which they are used are discussed. Reactions involved are…

  3. Effect of zirconium addition on the ductility and toughness of cast zinc-aluminum alloy5, zamak5, grain refined by titanium plus boron

    International Nuclear Information System (INIS)

    Adnan, I.O.

    2007-01-01

    Zinc-aluminum casting alloys are frequently employed in design. They are inexpensive and have mechanical properties in many respects superior to aluminum and copper alloys. Common applications of zinc-aluminum alloys are in the automobile industry for manufacturing carburetors bodies, fuel pump bodies, driving wheels and door handles. They are mainly used for die casting due to their low melting points which ranges from 375 to 487 degree C, good fluidity, pollution free melting in addition to their high corrosion resistance. Against these advantages there exists the deficiency as these alloys solidify in a coarse dentititic structure which tends to deteriorate the mechanical properties and impact strength. It was found that addition of some rare earth materials e.g. titanium or titanium plus boron results in modifying its structure into a petal-like or nodular type. The available literature reveals that most of the published work is directed towards the metallurgical aspects and little or no work is published on the effect of those elements on its mechanical strength, ductility, toughness and impact strength. In this paper, the effect of addition of Zirconium on the microstructure, mechanical behavior, hardness, ductility and impact strength of zinc-aluminum alloy5, Zamak5, is investigated. It was found that addition of Ti+B or Zr or Ti+B+Zr resulted in modifying the coarse dentritic structure of the Zamak5 alloy into a fine nodular one. Further more, addition of any of these elements alone or together resulted in enhancement of the mechanical strength, hardness, ductility, toughness and impact strength of this alloy, for example an increase of 11% in hardness was achieved in case of Zr addition and 100% increase of ductility and 12.5% increase in impact strength were achieved in case of Ti+B addition. (author)

  4. Is the Aluminum Hypothesis Dead?

    Science.gov (United States)

    2014-01-01

    The Aluminum Hypothesis, the idea that aluminum exposure is involved in the etiology of Alzheimer disease, dates back to a 1965 demonstration that aluminum causes neurofibrillary tangles in the brains of rabbits. Initially the focus of intensive research, the Aluminum Hypothesis has gradually been abandoned by most researchers. Yet, despite this current indifference, the Aluminum Hypothesis continues to attract the attention of a small group of scientists and aluminum continues to be viewed with concern by some of the public. This review article discusses reasons that mainstream science has largely abandoned the Aluminum Hypothesis and explores a possible reason for some in the general public continuing to view aluminum with mistrust. PMID:24806729

  5. The aluminum smelting process.

    Science.gov (United States)

    Kvande, Halvor

    2014-05-01

    This introduction to the industrial primary aluminum production process presents a short description of the electrolytic reduction technology, the history of aluminum, and the importance of this metal and its production process to modern society. Aluminum's special qualities have enabled advances in technologies coupled with energy and cost savings. Aircraft capabilities have been greatly enhanced, and increases in size and capacity are made possible by advances in aluminum technology. The metal's flexibility for shaping and extruding has led to architectural advances in energy-saving building construction. The high strength-to-weight ratio has meant a substantial reduction in energy consumption for trucks and other vehicles. The aluminum industry is therefore a pivotal one for ecological sustainability and strategic for technological development.

  6. Solidification behavior and rheo-diecasting microstructure of A356 aluminum alloy prepared by self-inoculation method

    Directory of Open Access Journals (Sweden)

    Ming Li

    2017-01-01

    Full Text Available Semisolid slurry of A356 aluminum alloy was prepared by self-inoculation method, and the microstructure and solidification behavior during rheo-diecasting process were investigated. The results indicate that the semisolid slurry of A356 aluminum alloy can be prepared by self-inoculation method at 600 °C. Primary α-Al particles with fine and spherical morphologies are uniformly distributed when the isothermal holding time of slurry is 3 min. Liquid phase segregation occurs during rheo-diecasting process of semisolid slurry and the primary particles (α1 show obvious plastic deformation in the area of high stress and low cooling rate. A small amount of dendrites resulting from the relatively low temperature of the shot chamber at the initial stage of secondary solidification are fragmented as they pass through the in-gate during the mould filling process. The amount of dendrite fragments decreases with the increase of filling distance. During the solidification process of the remaining liquid, the nucleation rate of secondary particles (α2 increases with the increase of cooling rate, and the content of Si in secondary particles (α2 are larger than primary particles (α1. With the increase of cooling rate, the content of Si in secondary particles (α2 gradually increases. The morphologies of eutectic Si in different parts of die casting are noticeably different. The low cooling rate in the first filling positions leads to coarse eutectic structures, while the high cooling rate in the post filling positions promotes small and compact eutectic structures.

  7. Advances in aluminum anodizing

    Science.gov (United States)

    Dale, K. H.

    1969-01-01

    White anodize is applied to aluminum alloy surfaces by specific surface preparation, anodizing, pigmentation, and sealing techniques. The development techniques resulted in alloys, which are used in space vehicles, with good reflectance values and excellent corrosive resistance.

  8. Corrosion Inhibitors for Aluminum.

    Science.gov (United States)

    Muller, Bodo

    1995-01-01

    Describes a simple and reliable test method used to investigate the corrosion-inhibiting effects of various chelating agents on aluminum pigments in aqueous alkaline media. The experiments that are presented require no complicated or expensive electronic equipment. (DDR)

  9. Corrosion Protection of Aluminum

    Science.gov (United States)

    Dalrymple, R. S.; Nelson, W. B.

    1963-07-01

    Treatment of aluminum-base metal surfaces in an autoclave with an aqueous chromic acid solution of 0.5 to 3% by weight and of pH below 2 for 20 to 50 hrs at 160 to 180 deg C produces an extremely corrosion-resistant aluminum oxidechromium film on the surface. A chromic acid concentration of 1 to 2% and a pH of about 1 are preferred.

  10. Mesoporous aluminum phosphite

    International Nuclear Information System (INIS)

    El Haskouri, Jamal; Perez-Cabero, Monica; Guillem, Carmen; Latorre, Julio; Beltran, Aurelio; Beltran, Daniel; Amoros, Pedro

    2009-01-01

    High surface area pure mesoporous aluminum-phosphorus oxide-based derivatives have been synthesized through an S + I - surfactant-assisted cooperative mechanism by means of a one-pot preparative procedure from aqueous solution and starting from aluminum atrane complexes and phosphoric and/or phosphorous acids. A soft chemical extraction procedure allows opening the pore system of the parent as-prepared materials by exchanging the surfactant without mesostructure collapse. The nature of the pore wall can be modulated from mesoporous aluminum phosphate (ALPO) up to total incorporation of phosphite entities (mesoporous aluminum phosphite), which results in a gradual evolution of the acidic properties of the final materials. While phosphate groups in ALPO act as network building blocks (bridging Al atoms), the phosphite entities become basically attached to the pore surface, what gives practically empty channels. The mesoporous nature of the final materials is confirmed by X-ray diffraction (XRD), transmission electron microscopy (TEM) and N 2 adsorption-desorption isotherms. The materials present regular unimodal pore systems whose order decreases as the phosphite content increases. NMR spectroscopic results confirm the incorporation of oxo-phosphorus entities to the framework of these materials and also provide us useful information concerning the mechanism through which they are formed. - Abstract: TEM image of the mesoporous aluminum phosphite showing the hexagonal disordered pore array that is generated by using surfactant micelles as template. Also a scheme emphasizing the presence of an alumina-rich core and an ALPO-like pore surface is presented.

  11. Squeeze casting of aluminum alloy A380: Microstructure and tensile behavior

    Directory of Open Access Journals (Sweden)

    Li Fang

    2015-09-01

    Full Text Available A380 alloy with a relatively thick cross-section of 25 mm was squeeze cast using a hydraulic press with an applied pressure of 90 MPa. Microstructure and tensile properties of the squeeze cast A380 were characterized and evaluated in comparison with the die cast counterpart. Results show that the squeeze cast A380 possesses a porosity level much lower than the die cast alloy, which is disclosed by both optical microscopy and the density measurement technique. The results of tensile testing indicate the improved tensile properties, specifically ultimate tensile strength (UTS: 215.9 MPa and elongation (Ef: 5.4%, for the squeeze cast samples over those of the conventional high-pressure die cast part (UTS: 173.7 MPa, Ef: 1.0%. The analysis of tensile behavior shows that the squeeze cast A380 exhibits a high tensile toughness (8.5 MJ·m-3 and resilience (179.3 kJ·m-3 compared with the die cast alloy (toughness: 1.4 MJ·m-3, resilience: 140.6 kJ·m-3, despite that, during the onset of plastic deformation, the strain-hardening rate of the die cast specimen is higher than that of the squeeze cast specimens. The microstructure analyzed by the scanning electron microscopy (SEM shows that both the squeeze and die cast specimens contain the primary α-Al, Al2Cu, Al5FeSi phase and the eutectic Si phase. But, the Al2Cu phase present in the squeeze cast alloy is relatively large in size and quantity. The SEM fractography evidently reveals the ductile fracture features of the squeeze cast A380 alloy.

  12. Regeneration of aluminum hydride

    Science.gov (United States)

    Graetz, Jason Allan; Reilly, James J; Wegrzyn, James E

    2012-09-18

    The present invention provides methods and materials for the formation of hydrogen storage alanes, AlH.sub.x, where x is greater than 0 and less than or equal to 6 at reduced H.sub.2 pressures and temperatures. The methods rely upon reduction of the change in free energy of the reaction between aluminum and molecular H.sub.2. The change in free energy is reduced by lowering the entropy change during the reaction by providing aluminum in a state of high entropy, and by increasing the magnitude of the change in enthalpy of the reaction or combinations thereof.

  13. Regeneration of aluminum hydride

    Science.gov (United States)

    Graetz, Jason Allan; Reilly, James J.

    2009-04-21

    The present invention provides methods and materials for the formation of hydrogen storage alanes, AlH.sub.x, where x is greater than 0 and less than or equal to 6 at reduced H.sub.2 pressures and temperatures. The methods rely upon reduction of the change in free energy of the reaction between aluminum and molecular H.sub.2. The change in free energy is reduced by lowering the entropy change during the reaction by providing aluminum in a state of high entropy, by increasing the magnitude of the change in enthalpy of the reaction or combinations thereof.

  14. ALUMINUM TOXICITY VS SALICYLIC ACID EFFECTS IN PEARL MILLET METHYLOME.

    OpenAIRE

    Baba Ngom; Edward Mamati; Ibrahima Sarr; Josphert Kimatu.

    2018-01-01

    Aluminum toxicity is one of most distributed plant abiotic stress in the world, causing root inhibition and therefore crop losses. Plants continuously adapt its defense to abiotic stresses through different mechanisms including DNA methylation. The methylome variation is influenced by external cues from environment or by hormonal signals. Salicylic acid is one of the most important hormones in plants, directing growth and defense. Its application is seen having the capacity to elicit plant de...

  15. Aluminum Hydroxide and Magnesium Hydroxide

    Science.gov (United States)

    Aluminum Hydroxide, Magnesium Hydroxide are antacids used together to relieve heartburn, acid indigestion, and upset stomach. They ... They combine with stomach acid and neutralize it. Aluminum Hydroxide, Magnesium Hydroxide are available without a prescription. ...

  16. Electrically conductive anodized aluminum coatings

    Science.gov (United States)

    Alwitt, Robert S. (Inventor); Liu, Yanming (Inventor)

    2001-01-01

    A process for producing anodized aluminum with enhanced electrical conductivity, comprising anodic oxidation of aluminum alloy substrate, electrolytic deposition of a small amount of metal into the pores of the anodized aluminum, and electrolytic anodic deposition of an electrically conductive oxide, including manganese dioxide, into the pores containing the metal deposit; and the product produced by the process.

  17. Fluxless aluminum brazing

    Science.gov (United States)

    Werner, W.J.

    1974-01-01

    This invention relates to a fluxless brazing alloy for use in forming brazed composites made from members of aluminum and its alloys. The brazing alloy consists of 35-55% Al, 10--20% Si, 25-60% Ge; 65-88% Al, 2-20% Si, 2--18% In; 65--80% Al, 15-- 25% Si, 5- 15% Y. (0fficial Gazette)

  18. Aluminum Corrosion and Turbidity

    International Nuclear Information System (INIS)

    Longtin, F.B.

    2003-01-01

    Aluminum corrosion and turbidity formation in reactors correlate with fuel sheath temperature. To further substantiate this correlation, discharged fuel elements from R-3, P-2 and K-2 cycles were examined for extent of corrosion and evidence of breaking off of the oxide film. This report discusses this study

  19. Aluminum concentration in hydrangeas

    International Nuclear Information System (INIS)

    Yanagawa, M.; Haruyama, Y.; Saito, M.

    2008-01-01

    We have been trying to measure concentration of aluminum in Ajisai, Hydrangea macrophylla for these days. But due to bad luck, we have encountered detector trouble for two years in a low. Thus, we have few data to analyze and obtained quite limited results. (author)

  20. ALUMINUM AND CHROMIUM LEACHING WORKSHOP WHITEPAPER

    International Nuclear Information System (INIS)

    McCabe, D; Jeff Pike, J; Bill Wilmarth, B

    2007-01-01

    A workshop was held on January 23-24, 2007 to discuss the status of processes to leach constituents from High Level Waste (HLW) sludges at the Hanford and Savannah River Sites. The objective of the workshop was to examine the needs and requirements for the HLW flowsheet for each site, discuss the status of knowledge of the leaching processes, communicate the research plans, and identify opportunities for synergy to address knowledge gaps. The purpose of leaching of non-radioactive constituents from the sludge waste is to reduce the burden of material that must be vitrified in the HLW melter systems, resulting in reduced HLW glass waste volume, reduced disposal costs, shorter process schedules, and higher facility throughput rates. The leaching process is estimated to reduce the operating life cycle of SRS by seven years and decrease the number of HLW canisters to be disposed in the Repository by 1000 [Gillam et al., 2006]. Comparably at Hanford, the aluminum and chromium leaching processes are estimated to reduce the operating life cycle of the Waste Treatment Plant by 20 years and decrease the number of canisters to the Repository by 15,000-30,000 [Gilbert, 2007]. These leaching processes will save the Department of Energy (DOE) billions of dollars in clean up and disposal costs. The primary constituents targeted for removal by leaching are aluminum and chromium. It is desirable to have some aluminum in glass to improve its durability; however, too much aluminum can increase the sludge viscosity, glass viscosity, and reduce overall process throughput. Chromium leaching is necessary to prevent formation of crystalline compounds in the glass, but is only needed at Hanford because of differences in the sludge waste chemistry at the two sites. Improving glass formulations to increase tolerance of aluminum and chromium is another approach to decrease HLW glass volume. It is likely that an optimum condition can be found by both performing leaching and improving

  1. Borated aluminum alloy manufacturing technology

    International Nuclear Information System (INIS)

    Shimojo, Jun; Taniuchi, Hiroaki; Kajihara, Katsura; Aruga, Yasuhiro

    2003-01-01

    Borated aluminum alloy is used as the basket material of cask because of its light weight, thermal conductivity and superior neutron absorbing abilities. Kobe Steel has developed a unique manufacturing process for borated aluminum alloy using a vacuum induction melting method. In this process, aluminum alloy is melted and agitated at higher temperatures than common aluminum alloy fabrication methods. It is then cast into a mold in a vacuum atmosphere. The result is a high quality aluminum alloy which has a uniform boron distribution and no impurities. (author)

  2. Effects of aluminum on plant growth and nutrient uptake in young physic nut plantsEfeitos do alumínio no crescimento e na absorção de nutrientes em plantas jovens de pinhão-manso

    Directory of Open Access Journals (Sweden)

    João Alexandre Lopes Dranski

    2012-10-01

    Full Text Available Aluminum (Al3+ toxicity is a major limiting factor to crop productivity in acid soils. The effects of aluminum on root and shoot growth of physic nut (Jatropha curcas L. young plants and, the uptake and distribution of phosphorus, calcium, magnesium and aluminum in the roots and shoots were investigated in the present study. Plants were grown in 2.5L pots in a greenhouse. After fourteen days of adaptation to nutrient solution, plants were exposed to Al concentrations of 0, 370, 740, 1,100 and 1,480 ?mol L–1, corresponding to an active Al3+ solution of 13.3, 35.3, 90.0, 153.3 and 220.7 ?mol L–1, respectively. The dry matter partitioning between roots, stems and leaves, and the concentrations of P, Ca, Mg and Al in plant tissue, were measured after 75 days exposure to Al. The increasing level of Al3+ activity in solution progressively decreased the growth of the shoot and root of physic nut plants, and at the two highest active Al3+ levels, plants showed morphological abnormalities typical of the toxicity caused by this metal. Higher Al3+ activity reduced P concentrations in leaves and Ca and Mg in leaves and roots of physic nut, demonstrating the effect of Al on the uptake, transport and use of these nutrients by plants. The Al accumulated preferentially in the roots of physic nut, whereas only a small amount was transported to shoots.A toxicidade de alumínio (Al3+ é um dos principais fatores que limitam a produtividade das culturas em solos ácidos. O objetivo deste estudo foi avaliar o efeito do alumínio no crescimento e na absorção de fósforo, cálcio, magnésio e alumínio em plantas jovens de pinhão-manso, cultivadas em solução nutritiva. O experimento foi conduzido em vasos de 2,5 L e as plantas crescidas em casa de vegetação. Após 14 dias de adaptação em solução nutritiva, as plantas foram submetidas a concentrações de Al de: 0; 370; 740; 1.110 e 1.480 ?mol L–1, que corresponderam a atividade de Al3+ em solução de

  3. Analysis and Countermeasures of Wind Power Accommodation by Aluminum Electrolysis Pot-Lines in China

    Science.gov (United States)

    Zhang, Hongliang; Ran, Ling; He, Guixiong; Wang, Zhenyu; Li, Jie

    2017-10-01

    The unit energy consumption and its price have become the main obstacles for the future development of the aluminum electrolysis industry in China. Meanwhile, wind power is widely being abandoned because of its instability. In this study, a novel idea for wind power accommodation is proposed to achieve a win-win situation: the idea is for nearby aluminum electrolysis plants to absorb the wind power. The features of the wind power distribution and aluminum electrolysis industry are first summarized, and the concept of wind power accommodation by the aluminum industry is introduced. Then, based on the characteristics of aluminum reduction cells, the key problems, including the bus-bar status, thermal balance, and magnetohydrodynamics instabilities, are analyzed. In addition, a whole accommodation implementation plan for wind power by aluminum reduction is introduced to explain the theoretical value of accommodation, evaluation of the reduction cells, and the industrial experiment scheme. A numerical simulation of a typical scenario proves that there is large accommodation potential for the aluminum reduction cells. Aluminum electrolysis can accommodate wind power and remain stable under the proper technique and accommodation scheme, which will provide promising benefits for the aluminum plant and the wind energy plant.

  4. Water requirements of the aluminum industry

    Science.gov (United States)

    Conklin, Howard L.

    1956-01-01

    Aluminum is unique among metals in the way it is obtained from its ore. The first step is to produce alumina, a white powder that bears no resemblance to the bauxite from which it is derived or to the metallic aluminum to which it is reduced by electrolytic action in a second step. Each step requires a complete plant facility, and the plants may be adjacent or separated by as much as the width of the North American continent. Field investigations sf every alumina plant and reduction works in the United States were undertaken to determine the industry's water use. Detailed studies were made of process and plant layout so that a water balance could be made for each plant to determine not only the gross water intake but also an approximation of the consumptive use of water. Water requirements of alumina plants range from 0.28 to 1.10 gallons per pound of alumina; the average for the industry is 0.66 gallon. Water requirements of reduction works vary considerably more, ranging from 1.24 to 36.33 gallons per pound of aluminum, and average 14.62 gallons. All alumina plants in the United States derive alumina from bauxite by the Bayer process or by the Combination process, a modification of the Bayer process. Although the chemical process for obtaining alumina from bauxite is essentially the same at all plants, different procedures are employed to cool the sodium aluminate solution before it enters the precipitating tanks and to concentrate it by evaporation of some of the water in the solution. Where this evaporation takes place in a cooling tower, water in the solution is lost to the atmosphere as water vapor and so is used consumptively. In other plants, the quantity of solution in the system is controlled by evaporation in a multiple-effect evaporator where practically all vapor distilled out of the solution is condensed to water that may be reused. The latter method is used in all recently constructed alumina plants, and some older plants are replacing cooling towers

  5. Semi-solid near-net shape rheocasting of heat treatable wrought aluminum alloys

    CSIR Research Space (South Africa)

    Curle, UA

    2010-09-01

    Full Text Available Flexibility of the CSIR-RCS, induction stirring with simultaneous air cooling process, in combination with high pressure die casting is successfully demonstrated by semi-solid rheocasting of plates performed on commercial 2024, 6082 and 7075 wrought...

  6. 21 CFR 73.1645 - Aluminum powder.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Aluminum powder. 73.1645 Section 73.1645 Food and... ADDITIVES EXEMPT FROM CERTIFICATION Drugs § 73.1645 Aluminum powder. (a) Identity. (1) The color additive aluminum powder shall be composed of finely divided particles of aluminum prepared from virgin aluminum. It...

  7. Influence of aluminum on growth, mineral nutrition and organic acid exudation of rambutan (Nephelium lappaceum)

    Science.gov (United States)

    A randomized complete block design experiment with six aluminum (Al) concentrations was carried out to evaluate the effect of aluminum on nutrient content, plant growth, dry matter production and Al-induced organic acid exudation in rambutan (Nephelium lappaceum). One rambutan cultivar was grown in...

  8. Aluminum fin-stock alloys

    International Nuclear Information System (INIS)

    Gul, R.M.; Mutasher, F.

    2007-01-01

    Aluminum alloys have long been used in the production of heat exchanger fins. The comparative properties of the different alloys used for this purpose has not been an issue in the past, because of the significant thickness of the finstock material. However, in order to make fins lighter in weight, there is a growing demand for thinner finstock materials, which has emphasized the need for improved mechanical properties, thermal conductivity and corrosion resistance. The objective of this project is to determine the effect of iron, silicon and manganese percentage increment on the required mechanical properties for this application by analyzing four different aluminum alloys. The four selected aluminum alloys are 1100, 8011, 8079 and 8150, which are wrought non-heat treatable alloys with different amount of the above elements. Aluminum alloy 1100 serve as a control specimen, as it is commercially pure aluminum. The study also reports the effect of different annealing cycles on the mechanical properties of the selected alloys. Metallographic examination was also preformed to study the effect of annealing on the precipitate phases and the distribution of these phases for each alloy. The microstructure analysis of the aluminum alloys studied indicates that the precipitated phase in the case of aluminum alloys 1100 and 8079 is beta-FeAI3, while in 8011 it is a-alfa AIFeSi, and the aluminum alloy 8150 contains AI6(Mn,Fe) phase. The comparison of aluminum alloys 8011 and 8079 with aluminum alloy 1100 show that the addition of iron and silicon improves the percent elongation and reduces strength. The manganese addition increases the stability of mechanical properties along the annealing range as shown by the comparison of aluminum alloy 8150 with aluminum alloy 1100. Alloy 8150 show superior properties over the other alloys due to the reaction of iron and manganese, resulting in a preferable response to thermal treatment and improved mechanical properties. (author)

  9. Exergy analysis of aluminum recovery from municipal solid waste incineration

    DEFF Research Database (Denmark)

    Vyzinkarova, Dana; Allegrini, Elisa; Laner, D.

    Two main challenges, associated with the recovery of aluminum from state-of-the-art municipal solid waste (MSW) incineration plants, are yield as well as quality losses of metallic aluminum due to particle surface oxidation and presence of impurities. Yet, in the framework of life cycle assessment...... (LCA) a direct measure for expressing the quality of primary and secondary resources is missing. In view of a possible solution, exergy has been proposed as a concept to evaluate the quality of resources. In this paper, LCA and exergy analyses for two waste treatment approaches are conducted...... in parallel to each other, with a goal to evaluate the added value of exergy for LCA studies in the resource recovery context. The functional unit is the treatment of 1 ton MSW. Two alternative approaches for recovering aluminum from MSW directed to a waste-to-energy plant are considered. A) MSW is treated...

  10. Production of aluminum metal by electrolysis of aluminum sulfide

    Science.gov (United States)

    Minh, Nguyen Q.; Loutfy, Raouf O.; Yao, Neng-Ping

    1984-01-01

    Production of metallic aluminum by the electrolysis of Al.sub.2 S.sub.3 at 700.degree.-800.degree. C. in a chloride melt composed of one or more alkali metal chlorides, and one or more alkaline earth metal chlorides and/or aluminum chloride to provide improved operating characteristics of the process.

  11. Applied Electrochemistry of Aluminum

    DEFF Research Database (Denmark)

    Li, Qingfeng; Qiu, Zhuxian

    Electrochemistry of aluminum is of special importance from both theoretical and technological point of view. It covers a wide range of electrolyte systems from molten fluoride melts at around 1000oC to room temperature molten salts, from aqueous to various organic media and from liquid to solid...... electrolytes. The book is an updated review of the technological advances in the fields of electrolytic production and refining of metals, electroplating, anodizing and other electrochemical surface treatments, primary and secondary batteries, electrolytic capacitors; corrosion and protection and others....

  12. Helium trapping in aluminum and sintered aluminum powders

    International Nuclear Information System (INIS)

    Das, S.K.; Kaminsky, M.; Rossing, T.

    1975-01-01

    The surface erosion of annealed aluminum and of sintered aluminum powder (SAP) due to blistering from implantation of 100-keV 4 He + ions at room temperature has been investigated. A substantial reduction in the blistering erosion rate in SAP was observed from that in pure annealed aluminum. In order to determine whether the observed reduction in blistering is due to enhanced helium trapping or due to helium released, the implanted helium profiles in annealed aluminum and in SAP have been studied by Rutherford backscattering. The results show that more helium is trapped in SAP than in aluminum for identical irradiation conditions. The observed reduction in erosion from helium blistering in SAP is more likely due to the dispersion of trapped helium at the large Al-Al 2 O 3 interfaces and at the large grain boundaries in SAP than to helium release

  13. Selective Adsorption of Sodium Aluminum Fluoride Salts from Molten Aluminum

    Energy Technology Data Exchange (ETDEWEB)

    Leonard S. Aubrey; Christine A. Boyle; Eddie M. Williams; David H. DeYoung; Dawid D. Smith; Feng Chi

    2007-08-16

    Aluminum is produced in electrolytic reduction cells where alumina feedstock is dissolved in molten cryolite (sodium aluminum fluoride) along with aluminum and calcium fluorides. The dissolved alumina is then reduced by electrolysis and the molten aluminum separates to the bottom of the cell. The reduction cell is periodically tapped to remove the molten aluminum. During the tapping process, some of the molten electrolyte (commonly referred as “bath” in the aluminum industry) is carried over with the molten aluminum and into the transfer crucible. The carryover of molten bath into the holding furnace can create significant operational problems in aluminum cast houses. Bath carryover can result in several problems. The most troublesome problem is sodium and calcium pickup in magnesium-bearing alloys. Magnesium alloying additions can result in Mg-Na and Mg-Ca exchange reactions with the molten bath, which results in the undesirable pickup of elemental sodium and calcium. This final report presents the findings of a project to evaluate removal of molten bath using a new and novel micro-porous filter media. The theory of selective adsorption or removal is based on interfacial surface energy differences of molten aluminum and bath on the micro-porous filter structure. This report describes the theory of the selective adsorption-filtration process, the development of suitable micro-porous filter media, and the operational results obtained with a micro-porous bed filtration system. The micro-porous filter media was found to very effectively remove molten sodium aluminum fluoride bath by the selective adsorption-filtration mechanism.

  14. Reactions of aluminum with uranium fluorides and oxyfluorides

    Energy Technology Data Exchange (ETDEWEB)

    Leitnaker, J.M.; Nichols, R.W.; Lankford, B.S. [Martin Marietta Energy Systems, Inc., Oak Ridge, TN (United States)

    1991-12-31

    Every 30 to 40 million operating hours a destructive reaction is observed in one of the {approximately}4000 large compressors that move UF{sub 6} through the gaseous diffusion plants. Despite its infrequency, such a reaction can be costly in terms of equipment and time. Laboratory experiments reveal that the presence of moderate pressures of UF{sub 6} actually cools heated aluminum, although thermodynamic calculations indicate the potential for a 3000-4000{degrees}C temperature rise. Within a narrow and rather low (<100 torr; 1 torr = 133.322 Pa) pressure range, however, the aluminum is seen to react with sufficient heat release to soften an alumina boat. Three things must occur in order for aluminum to react vigorously with either UF{sub 6} or UO{sub 2}F{sub 2}. 1. An initiating source of heat must be provided. In the compressors, this source can be friction, permitted by disruption of the balance of the large rotating part or by creep of the aluminum during a high-temperature treatment. In the absence of this heat source, compressors have operated for 40 years in UF{sub 6} without significant reaction. 2. The film protecting the aluminum must be breached. Melting (of UF{sub 5} at 620 K or aluminum at 930 K) can cause such a breach in laboratory experiments. In contrast, holding Al samples in UF{sub 6} at 870 K for several hours produces only moderate reaction. Rubbing in the cascade can undoubtedly breach the protective film. 3. Reaction products must not build up and smother the reaction. While uranium products tend to dissolve or dissipate in molten aluminum, AIF{sub 3} shows a remarkable tendency to surround and hence protect even molten aluminum. Hence the initial temperature rise must be rapid and sufficient to move reactants into a temperature region in which products are removed from the reaction site.

  15. Primary Aluminum Reduction Industry - National Emission Standards for Hazardous Air Pollutants (NESHAP)

    Science.gov (United States)

    National emission standards for each new or existing potline, paste production operation, and anode bake furnace associated with a primary aluminum reduction plant. Includes rule history, implementation information and additional resources.

  16. Metallic aluminum in combustion; Metalliskt aluminium i foerbraenningen

    Energy Technology Data Exchange (ETDEWEB)

    Backman, Rainer; Berg, Magnus; Bostroem, Dan; Hirota, Catherine; Oehman, Marcus; Oehrstroem, Anna

    2007-06-15

    Although aluminum is easily oxidized and melts at temperatures lower than those common in combustion, it can pass through the combustion chamber almost unscathed. If one performs calculations of thermodynamic equilibriums, conditions under which this could happen are extreme in comparison to those generally found in a furnace. Metallic aluminum may yet be found in rather large concentrations in fly ashes. There are also indications that metallic aluminum is present in deposits inside the furnaces. The objectives for the present investigation are better understanding of the behavior of the metallic aluminum in the fuel when it passes through an incinerator and to suggest counter/measures that deal with the problems associated with it. The target group is primary incineration plants using fuel that contains aluminum foil, for example municipal waste, industrial refuse or plastic reject from cardboard recycling. Combustion experiments were performed in a bench scale reactor using plastic reject obtained from the Fiskeby Board mill. First the gas velocity at which a fraction of the reject hovers was determined for the different fuel fractions, yielding a measure for their propensity to be carried over by the combustion gases. Second fractions rich in aluminum foils were combusted with time, temperature and gas composition as parameters. The partially combusted samples were analyzed using SEM/EDS. The degree of oxidation was determined using TGA/DTA. Reference material from full scale incinerators was obtained by collecting fly ash samples from five plants and analyzing them using XRD and SEM/EDS. The results show that thin aluminum foils may easily be carried over from the furnace. Furthermore, it was very difficult to fully oxidize the metallic flakes. The oxide layer on the surface prevents further diffusion of oxygen to the molten core of the flake. The contribution of these flakes to the build of deposits in a furnace is confirmed by earlier investigations in pilot

  17. Aluminum anode for aluminum-air battery - Part I: Influence of aluminum purity

    Science.gov (United States)

    Cho, Young-Joo; Park, In-Jun; Lee, Hyeok-Jae; Kim, Jung-Gu

    2015-03-01

    2N5 commercial grade aluminum (99.5% purity) leads to the lower aluminum-air battery performances than 4N high pure grade aluminum (99.99% purity) due to impurities itself and formed impurity complex layer which contained Fe, Si, Cu and others. The impurity complex layer of 2N5 grade Al declines the battery voltage on standby status. It also depletes discharge current and battery efficiency at 1.0 V which is general operating voltage of aluminum-air battery. However, the impurity complex layer of 2N5 grade Al is dissolved with decreasing discharge voltage to 0.8 V. This phenomenon leads to improvement of discharge current density and battery efficiency by reducing self-corrosion reaction. This study demonstrates the possibility of use of 2N5 grade Al which is cheaper than 4N grade Al as the anode for aluminum-air battery.

  18. Invisible Display in Aluminum

    DEFF Research Database (Denmark)

    Prichystal, Jan Phuklin; Hansen, Hans Nørgaard; Bladt, Henrik Henriksen

    2005-01-01

    Bang & Olufsen a/s has been working with ideas for invisible integration of displays in metal surfaces. Invisible integration of information displays traditionally has been possible by placing displays behind transparent or semitransparent materials such as plastic or glass. The wish for an integ......Bang & Olufsen a/s has been working with ideas for invisible integration of displays in metal surfaces. Invisible integration of information displays traditionally has been possible by placing displays behind transparent or semitransparent materials such as plastic or glass. The wish...... for an integrated display in a metal surface is often ruled by design and functionality of a product. The integration of displays in metal surfaces requires metal removal in order to clear the area of the display to some extent. The idea behind an invisible display in Aluminum concerns the processing of a metal...

  19. [Microbiological corrosion of aluminum alloys].

    Science.gov (United States)

    Smirnov, V F; Belov, D V; Sokolova, T N; Kuzina, O V; Kartashov, V R

    2008-01-01

    Biological corrosion of ADO quality aluminum and aluminum-based construction materials (alloys V65, D16, and D16T) was studied. Thirteen microscopic fungus species and six bacterial species proved to be able to attack aluminum and its alloys. It was found that biocorrosion of metals by microscopic fungi and bacteria was mediated by certain exometabolites. Experiments on biocorrosion of the materials by the microscopic fungus Alternaria alternata, the most active biodegrader, demonstrated that the micromycete attack started with the appearance of exudate with pH 8-9 on end faces of the samples.

  20. Aluminum hydroxide issue closure package

    International Nuclear Information System (INIS)

    Bergman, T.B.

    1998-01-01

    Aluminum hydroxide coatings on fuel elements stored in aluminum canisters in K West Basin were measured in July and August 1998. Good quality data was produced that enabled statistical analysis to determine a bounding value for aluminum hydroxide at a 99% confidence level. The updated bounding value is 10.6 kg per Multi-Canister Overpack (MCO), compared to the previously estimated bounding value of 8 kg/MCO. Thermal analysis using the updated bounding value, shows that the MCO generates oxygen concentrate that are below the lower flammability limits during the 40-year interim storage period and are, therefore, acceptable

  1. Packaging material and aluminum. Hoso zairyo to aluminum

    Energy Technology Data Exchange (ETDEWEB)

    Itaya, T [Mitsubishi Aluminum Co. Ltd., Tokyo (Japan)

    1992-02-01

    The present paper introduces aluminum foil packaging materials among the relation between packing materials and aluminum. The characteristics of aluminum foil in the packaging area are in its barrier performance, non-toxicity, tastelessness and odorlessness. Its excellent functions and processibility suit best as functional materials for food, medicine and industrial material packaging. While an aluminum foil may be used as a single packing material as in foils used in homes, many of it as a packaging material are used in combination with adhesives, papers or plastic films, or coated or printed. It is used as composite materials laminated or coated with other materials according to their use for the purpose of complementing the aluminum foil as the base material. Representative method to laminate aluminum foils include the wet lamination, dry lamination, thermally dissolved lamination and extruded lamination. The most important quality requirement in lamination is the adhesion strength, which requires a close attention in selecting the kinds of adhesive, laminating conditions, and aging conditions. 8 figs., 6 tabs.

  2. Heated Aluminum Tanks Resist Corrosion

    Science.gov (United States)

    Johnson, L. E.

    1983-01-01

    Simple expedient of heating foam-insulated aluminum alloy tanks prevents corrosion by salt-laden moisture. Relatively-small temperature difference between such tank and surrounding air will ensure life of tank is extended by many years.

  3. Chrome - Free Aluminum Coating System

    Science.gov (United States)

    Bailey, John H.; Gugel, Jeffrey D.

    2010-01-01

    This slide presentation concerns the program to qualify a chrome free coating for aluminum. The program was required due to findings by OSHA and EPA, that hexavalent chromium, used to mitigate corrosion in aerospace aluminum alloys, poses hazards for personnel. This qualification consisted of over 4,000 tests. The tests revealed that a move away from Cr+6, required a system rather than individual components and that the maximum corrosion protection required pretreatment, primer and topcoat.

  4. "Ripples" in an Aluminum Pool?

    Science.gov (United States)

    Rohr, James; Wang, Si-Yin; Nesterenko, Vitali F.

    2018-05-01

    Our motivation for this article is for students to realize that opportunities for discovery are all around them. Discoveries that can still puzzle present day researchers. Here we explore an observation by a middle school student concerning the production of what appears to be water-like "ripples" produced in aluminum foil when placed between two colliding spheres. We both applaud and explore the student's reasoning that the ripples were formed in a melted aluminum pool.

  5. A Virtual Aluminum Reduction Cell

    Science.gov (United States)

    Zhang, Hongliang; Zhou, Chenn Q.; Wu, Bing; Li, Jie

    2013-11-01

    The most important component in the aluminum industry is the aluminum reduction cell; it has received considerable interests and resources to conduct research to improve its productivity and energy efficiency. The current study focused on the integration of numerical simulation data and virtual reality technology to create a scientifically and practically realistic virtual aluminum reduction cell by presenting complex cell structures and physical-chemical phenomena. The multiphysical field simulation models were first built and solved in ANSYS software (ANSYS Inc., Canonsburg, PA, USA). Then, the methodology of combining the simulation results with virtual reality was introduced, and a virtual aluminum reduction cell was created. The demonstration showed that a computer-based world could be created in which people who are not analysis experts can see the detailed cell structure in a context that they can understand easily. With the application of the virtual aluminum reduction cell, even people who are familiar with aluminum reduction cell operations can gain insights that make it possible to understand the root causes of observed problems and plan design changes in much less time.

  6. Anodized aluminum on LDEF

    Science.gov (United States)

    Golden, Johnny L.

    1993-01-01

    A compilation of reported analyses and results obtained for anodized aluminum flown on the Long Duration Exposure Facility (LDEF) was prepared. Chromic acid, sulfuric acid, and dyed sulfuric acid anodized surfaces were exposed to the space environment. The vast majority of the anodized surface on LDEF was chromic acid anodize because of its selection as a thermal control coating for use on the spacecraft primary structure, trays, tray clamps, and space end thermal covers. Reports indicate that the chromic acid anodize was stable in solar absorptance and thermal emittance, but that contamination effects caused increases in absorptance on surfaces exposed to low atomic oxygen fluences. There were some discrepancies, however, in that some chromic acid anodized specimens exhibited significant increases in absorptance. Sulfuric acid anodized surfaces also appeared stable, although very little surface area was available for evaluation. One type of dyed sulfuric acid anodize was assessed as an optical baffle coating and was observed to have improved infrared absorptance characteristics with exposure on LDEF.

  7. Divorced eutectic in a HPDC magnesium-aluminum alloy

    International Nuclear Information System (INIS)

    Barbagallo, S.; Laukli, H.I.; Lohne, O.; Cerri, E.

    2004-01-01

    The morphology of the eutectic in a thin-wall high pressure die cast (HPDC) U-shape AM60 magnesium box was investigated by light microscope, SEM, TEM and EPMA. The extremely fast cooling rate taking place in the solidification process produces a highly segregated zone near the boundaries of small grains and a fine distribution of β particles, which is typical of a completely divorced eutectic. It was shown that the segregated zone is coherent with the primary α-Mg grain core even if the increased aluminium content produces a deformation of the hexagonal crystal lattice, which was estimated through diffraction patterns (SADP). The variation of the alloying elements content through the grain boundaries was shown by means of EPMA line scanning. The β particle composition was quantitatively investigated and the results show that, in comparison with the equilibrium phase diagram, the non-equilibrium phase boundary of the Mg 17 Al 12 region is moved some percent towards the lower aluminium content, at the high cooling rate that occurs in high pressure die castings. The cubic structure of the β phase was revealed by diffraction pattern. The presence of small Al-Mn particles both inside the grain and in the boundary region was also put in evidence by TEM

  8. Soft-sensing model of temperature for aluminum reduction cell on improved twin support vector regression

    Science.gov (United States)

    Li, Tao

    2018-06-01

    The complexity of aluminum electrolysis process leads the temperature for aluminum reduction cells hard to measure directly. However, temperature is the control center of aluminum production. To solve this problem, combining some aluminum plant's practice data, this paper presents a Soft-sensing model of temperature for aluminum electrolysis process on Improved Twin Support Vector Regression (ITSVR). ITSVR eliminates the slow learning speed of Support Vector Regression (SVR) and the over-fit risk of Twin Support Vector Regression (TSVR) by introducing a regularization term into the objective function of TSVR, which ensures the structural risk minimization principle and lower computational complexity. Finally, the model with some other parameters as auxiliary variable, predicts the temperature by ITSVR. The simulation result shows Soft-sensing model based on ITSVR has short time-consuming and better generalization.

  9. Gas evolution behavior of aluminum in mortar

    Energy Technology Data Exchange (ETDEWEB)

    Hashizume, Shuji; Matsumoto, Junko; Banba, Tsunetaka [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1996-10-01

    As a part of study of leaching behavior for solidified dry low level radioactive waste, gas evolution behavior of aluminum in mortar was investigated, and a plan of our research was proposed. The effect of pH on corrosion rate of aluminum, corrosion product, time dependency of corrosion rate of aluminum in mortar, change of corrosion mechanism, the effects of Na, Ca and Cl ions on corrosion rate of aluminum in mortar and corrosion behavior of aluminum when aluminum was used as sacrificed anode in reinforced concrete were previously clarified. Study of the effects of environmental factors such as pH, kind of ions and temperature on gas evolution behavior of aluminum and the effect of aluminum/carbon steel surface ratio no gas evolution behavior of aluminum were planed. (author). 75 refs.

  10. Gas evolution behavior of aluminum in mortar

    International Nuclear Information System (INIS)

    Hashizume, Shuji; Matsumoto, Junko; Banba, Tsunetaka

    1996-10-01

    As a part of study of leaching behavior for solidified dry low level radioactive waste, gas evolution behavior of aluminum in mortar was investigated, and a plan of our research was proposed. The effect of pH on corrosion rate of aluminum, corrosion product, time dependency of corrosion rate of aluminum in mortar, change of corrosion mechanism, the effects of Na, Ca and Cl ions on corrosion rate of aluminum in mortar and corrosion behavior of aluminum when aluminum was used as sacrificed anode in reinforced concrete were previously clarified. Study of the effects of environmental factors such as pH, kind of ions and temperature on gas evolution behavior of aluminum and the effect of aluminum/carbon steel surface ratio no gas evolution behavior of aluminum were planed. (author). 75 refs

  11. Weld Repair of Thin Aluminum Sheet

    Science.gov (United States)

    Beuyukian, C. S.; Mitchell, M. J.

    1986-01-01

    Weld repairing of thin aluminum sheets now possible, using niobium shield and copper heat sinks. Refractory niobium shield protects aluminum adjacent to hole, while copper heat sinks help conduct heat away from repair site. Technique limits tungsten/inert-gas (TIG) welding bombardment zone to melt area, leaving surrounding areas around weld unaffected. Used successfully to repair aluminum cold plates on Space Shuttle, Commercial applications, especially in sealing fractures, dents, and holes in thin aluminum face sheets or clad brazing sheet in cold plates, heat exchangers, coolers, and Solar panels. While particularly suited to thin aluminum sheet, this process also used in thicker aluminum material to prevent surface damage near weld area.

  12. MIKADO: a decision support tool for pollution reduction in aluminium pressure die casting

    NARCIS (Netherlands)

    Neto, B.A.F.

    2007-01-01

    Industrial activities cause a variety of environmental problems. These are largely caused by emissions of air pollutants, the production of waste and depletion of natural resources. As a consequence, industrial managers face a complex problem when assessing the overall environmental pressure on the

  13. Die-cast heterophase composites with AlSi13Mg1CuNi matrix

    Directory of Open Access Journals (Sweden)

    M. Dyzia

    2010-01-01

    Full Text Available On the basis of the performed tests, an advantageous interaction of glassy carbon particles in a couple consisting of a heterophase composite and a spheroidal cast iron has been corroborated. It was found that, the presence of glassy carbon in the heterophase composite (SiC+C affects the stabilization of the friction coefficient value as a function of the friction distance and reduces the intensity of the wearing-in stage of the interacting surfaces. Both a decrease of the friction coefficient and the wear of the heterophase composites may be connected with the carbon particles' chipping effect and the deposition of its fragments on the surface of the interacting components of the friction couple, which forms a kind of a solid lubricating agent in the system. This should allow applying of this material to the composite piston - cylinder sleeve system in piston air-compressors. Further works will concern the selection of the matrix alloy composition with the purpose of reducing the phenomenon of particles chipping during machining. It seems that one of the possibilities is the application of a more plastic matrix and optimizing the fraction of reinforcing phases and their gradient distribution in the casting.

  14. Application of laser additive manufacturing to produce dies for aluminium high pressure die casting

    CSIR Research Space (South Africa)

    Pereira, MFVT

    2012-07-01

    Full Text Available through immersion in liquid aluminium. The dipping cycle closely resembles the heating and cooling cycle of a typical aluminium die under casting conditions. The suitability of any LAM technology, that can produce fully dense metallic components... cost vs wrought manufactured 5.2 1,7 2. 2 Average cost Very High Medium High Table 3: Processing and finishing costs of test coupons 3.1 Cyclic Immersion in Molten Aluminium Figure 3 below shows the testing apparatus developed to simulate...

  15. Characterization of metal powder based rapid prototyping components under aluminium high pressure die casting process conditions

    CSIR Research Space (South Africa)

    Pereira, MFVT

    2009-11-01

    Full Text Available periodic inspections, monitoring crack formation and evidence of surface washout. At the end of the thermal tests, mechanical strength and hardness tests were performed to assess toughness and core resistance variations in relation to the initial conditions...

  16. Ion Flux in Roots of Chinese Fir (Cunninghamia lanceolata (Lamb.) Hook) under Aluminum Stress

    Science.gov (United States)

    Ma, Zhihui; Huang, Binlong; Xu, Shanshan; Chen, Yu; Cao, Guangqiu; Ding, Guochang; Lin, Sizu

    2016-01-01

    Chinese fir is a tall, fast-growing species that is unique to southern China. In Chinese fir plantations, successive plantings have led to a decline in soil fertility, and aluminum toxicity is thought to be one of the main reasons for this decline. In this study, Non-invasive Micro-test Technology was used to study the effect of aluminum stress on the absorption of 4 different ions in the roots of the Chinese fir clone FS01. The results are as follows: with increased aluminum concentration and longer periods of aluminum stress, the H+ ion flow gradually changed from influx into efflux; there was a large variation in the K+ efflux, which gradually decreased with increasing duration of aluminum stress; and 1 h of aluminum stress uniformly resulted in Ca2+ influx, but it changed from influx to efflux after a longer period of aluminum stress. Changes in the different concentrations of aluminum had the largest influence on Mg2+. PMID:27270726

  17. Recrystallization in Commercially Pure Aluminum

    DEFF Research Database (Denmark)

    Bay, Bent; Hansen, Niels

    1984-01-01

    Recrystallization behavior in commercial aluminum with a purity of 99.4 pct was studied by techniques such as high voltage electron microscopy, 100 kV transmission electron microscopy, and light microscopy. Sample parameters were the initial grain size (290 and 24 microns) and the degree of defor......Recrystallization behavior in commercial aluminum with a purity of 99.4 pct was studied by techniques such as high voltage electron microscopy, 100 kV transmission electron microscopy, and light microscopy. Sample parameters were the initial grain size (290 and 24 microns) and the degree...... are discussed and compared with results from an earlier study1 covering the recrystallization behavior of commercial aluminum of the same purity deformed at higher degrees of deformation (50 to 90 pct reduction in thickness by cold-rolling)....

  18. Aluminum-air battery crystallizer

    Science.gov (United States)

    Maimoni, A.

    1987-01-01

    A prototype crystallizer system for the aluminum-air battery operated reliably through simulated startup and shutdown cycles and met its design objectives. The crystallizer system allows for crystallization and removal of the aluminium hydroxide reaction product; it is required to allow steady-state and long-term operation of the aluminum-air battery. The system has to minimize volume and maintain low turbulence and shear to minimize secondary nucleation and energy consumption while enhancing agglomeration. A lamella crystallizer satisfies system constraints.

  19. Aluminum-carbon composite electrode

    Science.gov (United States)

    Farahmandi, C. Joseph; Dispennette, John M.

    1998-07-07

    A high performance double layer capacitor having an electric double layer formed in the interface between activated carbon and an electrolyte is disclosed. The high performance double layer capacitor includes a pair of aluminum impregnated carbon composite electrodes having an evenly distributed and continuous path of aluminum impregnated within an activated carbon fiber preform saturated with a high performance electrolytic solution. The high performance double layer capacitor is capable of delivering at least 5 Wh/kg of useful energy at power ratings of at least 600 W/kg.

  20. Aluminum nitride insulating films for MOSFET devices

    Science.gov (United States)

    Lewicki, G. W.; Maserjian, J.

    1972-01-01

    Application of aluminum nitrides as electrical insulator for electric capacitors is discussed. Electrical properties of aluminum nitrides are analyzed and specific use with field effect transistors is defined. Operational limits of field effect transistors are developed.

  1. The aluminum anode in deep ocean environments

    International Nuclear Information System (INIS)

    Schreiber, C.F.

    1989-01-01

    Results of field and mini-plant studies are presented for A1 + 0.045% Hg + 0.1% Si + 0.45% Zn* and A1 + 0.015% In + 0.1% Si + 3% Zn** anodes in varying depths of natural seawater. Current capacity and potential information are presented. In addition to information on anode current capacity and potential, polarization curves were obtained on both aluminum alloys using potentiostatic techniques at a simulated ocean depth of 1090 ft. (332 m). These data were compared with similarly run experiments at ocean surface pressures. As a basis of comparison, zinc anodes (U.S. Mil-A-18001H) were included as a companion alloy. Information gained on zinc is sufficient to accurately represent the behavior of this alloy. Results conclude that conditions of high pressure (and low temperature) associated with the alloys under test did not alter their galvanic behavior from that noted at the ocean surface

  2. Pressing Speed, Specific Pressure and Mechanical Properties of Aluminium Cast

    Directory of Open Access Journals (Sweden)

    Gaspar S.

    2016-06-01

    Full Text Available Recent research in the process of aluminum alloy die castings production, which is nowadays deeply implemented into the rapidly growing automobile, shipping and aircraft industries, is aimed at increasing the useful qualitative properties of the die casting in order to obtain its high mechanical properties at acceptable economic cost. Problem of technological factors of high pressure die casting has been a subject of worldwide research (EU, US, Japan, etc.. The final performance properties of die castings are subjected to a large number of technological factors. The main technological factors of high pressure die casting are as follows: plunger pressing speed, specific (increase pressure, mold temperature as well as alloy temperature. The contribution discusses the impact of the plunger pressing speed and specific (increase pressure on the mechanical properties of the casting aluminum alloy.

  3. The effect of zinc on the aluminum anode of the aluminum-air battery

    Science.gov (United States)

    Tang, Yougen; Lu, Lingbin; Roesky, Herbert W.; Wang, Laiwen; Huang, Baiyun

    Aluminum is an ideal material for batteries, due to its excellent electrochemical performance. Herein, the effect of zinc on the aluminum anode of the aluminum-air battery, as an additive for aluminum alloy and electrolytes, has been studied. The results show that zinc can decrease the anodic polarization, restrain the hydrogen evolution and increase the anodic utilization rate.

  4. 75 FR 70689 - Kaiser Aluminum Fabricated Products, LLC; Kaiser Aluminum-Greenwood Forge Division; Currently...

    Science.gov (United States)

    2010-11-18

    ... DEPARTMENT OF LABOR Employment and Training Administration [TA-W-70,376] Kaiser Aluminum Fabricated Products, LLC; Kaiser Aluminum- Greenwood Forge Division; Currently Known As Contech Forgings, LLC..., applicable to workers of Kaiser Aluminum Fabricated Products, LLC, Kaiser Aluminum-Greenwood Forge Division...

  5. 75 FR 80527 - Aluminum Extrusions From China

    Science.gov (United States)

    2010-12-22

    ...)] Aluminum Extrusions From China AGENCY: United States International Trade Commission. ACTION: Scheduling of... of subsidized and less-than-fair-value imports from China of aluminum extrusions, primarily provided... contained in Aluminum Extrusions From the People's Republic of China: Notice of Preliminary Determination of...

  6. 21 CFR 73.2645 - Aluminum powder.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Aluminum powder. 73.2645 Section 73.2645 Food and... ADDITIVES EXEMPT FROM CERTIFICATION Cosmetics § 73.2645 Aluminum powder. (a) Identity and specifications. The color additive aluminum powder shall conform in identity and specifications to the requirements of...

  7. 21 CFR 582.1125 - Aluminum sulfate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Aluminum sulfate. 582.1125 Section 582.1125 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1125 Aluminum sulfate. (a) Product. Aluminum sulfate. (b) Conditions of use. This substance...

  8. 21 CFR 182.1125 - Aluminum sulfate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Aluminum sulfate. 182.1125 Section 182.1125 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR... Substances § 182.1125 Aluminum sulfate. (a) Product. Aluminum sulfate. (b) Conditions of use. This substance...

  9. Characterization of ultrafine aluminum nanoparticles

    International Nuclear Information System (INIS)

    Sandstrom, Mary M.; Jorgensen, Betty S.; Mang, Joseph T.; Smith, Bettina L.; Son, Steven F.

    2004-01-01

    Aluminum nanopowders with particle sizes ranging from ∼25 nm to 80 nm were characterized by a variety of methods. We present and compare the results from common powder characterization techniques including transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM), BET gas adsorption surface area analysis, thermogravimetric analysis (TGA), photon correlation spectroscopy (PCS), and low angle laser light scattering (LALLS). Aluminum nanoparticles consist of an aluminum core with an aluminum oxide coating. HRTEM measurements of both the particle diameter and oxide layer thickness tend to be larger than those obtained from BET and TGA. LALLS measurements show a large degree of particle agglomeration in solution; therefore, primary particle sizes could not be determined. Furthermore, results from small-angle scattering techniques (SAS), including small-angle neutron (SANS) and x-ray (SAXS) scattering are presented and show excellent agreement with the BET, TGA, and HRTEM. The suite of analytical techniques presented in this paper can be used as a powerful tool in the characterization of many types of nanosized powders.

  10. Aluminum break-point contacts

    NARCIS (Netherlands)

    Heinemann, Martina; Groot, R.A. de

    1997-01-01

    Ab initio molecular dynamics is used to study the contribution of a single Al atom to an aluminum breakpoint contact during the final stages of breaking and the initial stages of the formation of such a contact. A hysteresis effect is found in excellent agreement with experiment and the form of the

  11. Decarbonization process for carbothermically produced aluminum

    Science.gov (United States)

    Bruno, Marshall J.; Carkin, Gerald E.; DeYoung, David H.; Dunlap, Sr., Ronald M.

    2015-06-30

    A method of recovering aluminum is provided. An alloy melt having Al.sub.4C.sub.3 and aluminum is provided. This mixture is cooled and then a sufficient amount of a finely dispersed gas is added to the alloy melt at a temperature of about 700.degree. C. to about 900.degree. C. The aluminum recovered is a decarbonized carbothermically produced aluminum where the step of adding a sufficient amount of the finely dispersed gas effects separation of the aluminum from the Al.sub.4C.sub.3 precipitates by flotation, resulting in two phases with the Al.sub.4C.sub.3 precipitates being the upper layer and the decarbonized aluminum being the lower layer. The aluminum is then recovered from the Al.sub.4C.sub.3 precipitates through decanting.

  12. Behaviour of aluminum foam under fire conditions

    Directory of Open Access Journals (Sweden)

    J. Grabian

    2008-07-01

    Full Text Available Taking into account fire-protection requirements it is advantageous for aluminum foam, after melting at a temperature considerably exceeding the melting point, to have a structure of discontinuous suspension of solid inclusions to liquid metal instead of liquid consistency. Continuity of the suspension depends on the solid phase content. The boundary value of the phase determined by J. Śleziona, above which the suspension becomes discontinuous, is provided by the formula (1. Figure 1 presents the relationship graphically. Boundary values of the vs content resulting from the above relationship is too low, taking into account the data obtained from the technology of suspension composites [4]. Therefore, based on the structure assumed for the suspension shown in Figure 2 these authors proposed another way of determining the contents, the value of which is determined by the relationship (3 [5].For purposes of the experimental study presented in the paper two foams have been molten: a commercially available one, made by aluminum foaming with titanium hydride, and a foam manufactured in the Marine Materials Plant of the Maritime University of Szczecin by blowing the AlSi7 +20% SiC composite with argon. Macrophotographs of foam cross-sections are shown in Figure 3. The foams have been molten in the atmosphere of air at a temperature of 750ºC. The products of melting are presented in Figure 4. It appears that molten aluminum foam may have no liquid consistency, being unable to flow, which is a desired property from the point of view of fire-protection. The above feature of the molten foam results from the fact that it may be a discontinuous suspension of solid particles in a liquid metal. The suspended particles may be solid particles of the composite that served for making the foam or oxide membranes formed on extended metal surface of the bubbles included in the foam. The desired foam ability to form a discontinuous suspension after melting may be

  13. Aluminum precipitation from Hanford DSSF

    International Nuclear Information System (INIS)

    Borgen, D.; Frazier, P.; Staton, G.

    1994-01-01

    A series of pilot scale tests using simulated Double Shell Slurry Feed (DSSF) showed that well-settled aluminum precipitate can be produced in Hanford double shell tank (DST) high level waste by slow neutralization with carbon dioxide. This pretreatment could provide an early grout feed and free tank space, as well as facilitate downstream processes such as ion exchange by providing a less caustic feed. A total of eight test runs were completed using a 10-ft tall 3-in i.d. glass column. The 10-ft height corresponds to about one third of the vertical height of a DST, hence providing a reasonable basis for extrapolating the observed precipitate settling and compaction to the actual waste tank environment. Four runs (three with a simplified simulant and one with a chemically complete simulant) produced well settled precipitates averaging 1.5 to 2 feet high. Aluminum gel rather than settled precipitate resulted from one test where neutralization was too rapid

  14. Electrically Conductive Anodized Aluminum Surfaces

    Science.gov (United States)

    Nguyen, Trung Hung

    2006-01-01

    Anodized aluminum components can be treated to make them sufficiently electrically conductive to suppress discharges of static electricity. The treatment was conceived as a means of preventing static electric discharges on exterior satin-anodized aluminum (SAA) surfaces of spacecraft without adversely affecting the thermal-control/optical properties of the SAA and without need to apply electrically conductive paints, which eventually peel off in the harsh environment of outer space. The treatment can also be used to impart electrical conductivity to anodized housings of computers, medical electronic instruments, telephoneexchange equipment, and other terrestrial electronic equipment vulnerable to electrostatic discharge. The electrical resistivity of a typical anodized aluminum surface layer lies between 10(exp 11) and 10(exp 13) Omega-cm. To suppress electrostatic discharge, it is necessary to reduce the electrical resistivity significantly - preferably to anodized surface becomes covered and the pores in the surface filled with a transparent, electrically conductive metal oxide nanocomposite. Filling the pores with the nanocomposite reduces the transverse electrical resistivity and, in the original intended outer-space application, the exterior covering portion of the nanocomposite would afford the requisite electrical contact with the outer-space plasma. The electrical resistivity of the nanocomposite can be tailored to a value between 10(exp 7) and 10(exp 12) Omega-cm. Unlike electrically conductive paint, the nanocomposite becomes an integral part of the anodized aluminum substrate, without need for adhesive bonding material and without risk of subsequent peeling. The electrodeposition process is compatible with commercial anodizing production lines. At present, the electronics industry uses expensive, exotic, electrostaticdischarge- suppressing finishes: examples include silver impregnated anodized, black electroless nickel, black chrome, and black copper. In

  15. Investigation of the effects of aluminum stress on some macro and micro-nutrient contents of the seedlings of lycopersicon esculentum mill. by using scanning electron microscope

    International Nuclear Information System (INIS)

    Colak, G.; Catak, E.; Baykul, M.C.

    2014-01-01

    This study was planned to see the affect of aluminum stress on plant nutrition and metabolism. The effects of aluminum stress on uptake level of some macro- and micro-nutrients from the nutrition solution into the seedlings of Lycopersicon esculentum Mill. and on mobilization of some nutrient elements in the seedlings were examined at the level of epidermal cells. The elemental structure of root, hypocotyl and cotyledon epidermal cells were determined by Energy Dispersive Xray Microanalysis (EDX) performed in a local area 50 nm in diameter at the level of a single epidermal cell cytoplasm by using low vacuum (24 pascal ) Scanning Electron Microscope. EDX analysis revealed that aluminum content of the cells was increasing with the increased concentrations of aluminum in the nutrient solution and that aluminum largelyaccumulated in the roots. Aluminum concentration was much higher in the root epidermal cells of the seedlings incubated in aluminum containing media for 17 days without adding any nutrient solution; it was also true for the local EDX analysis of radicle epidermal cells from the same series. Aluminum stress was found to tend to modify the plant nutritional element content of the cells and this was particularly of critical importance in terms of some macro- and micro-nutrients. The assessments performed at the level of epidermal cells of young seedlings of Lycopersicon esculentum suggest that aluminum stress leads to an absolute change in the plant nutritional element composition of the cells and in the mobilization of some nutritional elements in the seedlings. (author)

  16. Infrared radiation properties of anodized aluminum

    Energy Technology Data Exchange (ETDEWEB)

    Kohara, S. [Science Univ. of Tokyo, Noda, Chiba (Japan). Dept. of Materials Science and Technology; Niimi, Y. [Science Univ. of Tokyo, Noda, Chiba (Japan). Dept. of Materials Science and Technology

    1996-12-31

    The infrared radiation heating is an efficient and energy saving heating method. Ceramics have been used as an infrared radiant material, because the emissivity of metals is lower than that of ceramics. However, anodized aluminum could be used as the infrared radiant material since an aluminum oxide film is formed on the surface. In the present study, the infrared radiation properties of anodized aluminum have been investigated by determining the spectral emissivity curve. The spectral emissivity curve of anodized aluminum changed with the anodizing time. The spectral emissivity curve shifted to the higher level after anodizing for 10 min, but little changed afterwards. The infrared radiant material with high level spectral emissivity curve can be achieved by making an oxide film thicker than about 15 {mu}m on the surface of aluminum. Thus, anodized aluminum is applicable for the infrared radiation heating. (orig.)

  17. HIGH ALUMINUM HLW GLASSES FOR HANFORD'S WTP

    International Nuclear Information System (INIS)

    Kruger, A.A.; Joseph, I.; Bowman, B.W.; Gan, H.; Kot, W.; Matlack, K.S.; Pegg, I.L

    2009-01-01

    The world's largest radioactive waste vitrification facility is now under construction at the United State Department of Energy's (DOE's) Hanford site. The Hanford Tank Waste Treatment and Immobilization Plant (WTP) is designed to treat nearly 53 million gallons of mixed hazardous and radioactive waste now residing in 177 underground storage tanks. This multi-decade processing campaign will be one of the most complex ever undertaken because of the wide chemical and physical variability of the waste compositions generated during the cold war era that are stored at Hanford. The DOE Office of River Protection (ORP) has initiated a program to improve the long-term operating efficiency of the WTP vitrification plants with the objective of reducing the overall cost of tank waste treatment and disposal and shortening the duration of plant operations. Due to the size, complexity and duration of the WTP mission, the lifecycle operating and waste disposal costs are substantial. As a result, gains in High Level Waste (HLW) and Low Activity Waste (LAW) waste loadings, as well as increases in glass production rate, which can reduce mission duration and glass volumes for disposal, can yield substantial overall cost savings. EnergySolutions and its long-term research partner, the Vitreous State Laboratory (VSL) of the Catholic University of America, have been involved in a multi-year ORP program directed at optimizing various aspects of the HLW and LAW vitrification flow sheets. A number of Hanford HLW streams contain high concentrations of aluminum, which is challenging with respect to both waste loading and processing rate. Therefore, a key focus area of the ORP vitrification process optimization program at EnergySolutions and VSL has been development of HLW glass compositions that can accommodate high Al 2 O 3 concentrations while maintaining high processing rates in the Joule Heated Ceramic Melters (JHCMs) used for waste vitrification at the WTP. This paper, reviews the

  18. Reduction of Oxidative Melt Loss of Aluminum and Its Alloys

    Energy Technology Data Exchange (ETDEWEB)

    Dr. Subodh K. Das; Shridas Ningileri

    2006-03-17

    identified as the primary factor that accelerates dross formation specifically in the transition from two phases to three phase growth. Limiting magnesium oxidation on the surface of molten aluminum therefore becomes the key to minimizing melt loss, and technology was developed to prevent magnesium oxidation on the aluminum surface. This resulted in a lot of the work being focused on the control of Mg oxidation. Two potential molten metal covering agents that could inhibit dross formation during melting and holding consisting of boric acid and boron nitride were identified. The latter was discounted by industry as it resulted in Boron pick up by the melt beyond that allowed by specifications during plant trials. The understanding of the kinetics of dross formation by the industry partners helped them understand how temperature, alloy chemistry and furnace atmosphere (burner controls--e.g. excess air) effected dross formation. This enables them to introduce in their plant process changes that reduced unnecessary holding at high temperatures, control burner configurations, reduce door openings to avoid ingress of air and optimize charge mixes to ensure rapid melting and avoid excess oxidation.

  19. New electrolytes for aluminum production: Ionic liquids

    Science.gov (United States)

    Zhang, Mingming; Kamavarum, Venkat; Reddy, Ramana G.

    2003-11-01

    In this article, the reduction, refining/recycling, and electroplating of aluminum from room-temperature molten salts are reviewed. In addition, the characteristics of several non-conventional organic solvents, electrolytes, and molten salts are evaluated, and the applicability of these melts for production of aluminum is discussed with special attention to ionic liquids. Also reviewed are electrochemical processes and conditions for electrodeposition of aluminum using ionic liquids at near room temperatures.

  20. PREPARATION OF ACTINIDE-ALUMINUM ALLOYS

    Science.gov (United States)

    Moore, R.H.

    1962-09-01

    BS>A process is given for preparing alloys of aluminum with plutonium, uranium, and/or thorium by chlorinating actinide oxide dissolved in molten alkali metal chloride with hydrochloric acid, chlorine, and/or phosgene, adding aluminum metal, and passing air and/or water vapor through the mass. Actinide metal is formed and alloyed with the aluminum. After cooling to solidification, the alloy is separated from the salt. (AEC)

  1. An all aluminum alloy UHV components

    International Nuclear Information System (INIS)

    Sugisaki, Kenzaburo

    1985-01-01

    An all aluminum components was developed for use with UHV system. Aluminum alloy whose advantage are little discharge gas, easy to bake out, light weight, little damage against radieactivity radiation is used. Therefore, as it is all aluminum alloy, baking is possible. Baking temperature is 150 deg C in case of not only ion pump, gate valve, angle valve but also aluminum components. Ion pump have to an ultrahigh vacuum of order 10 -9 torr can be obtained without baking, 10 -10 torr order can be obtained after 24 hour of baking. (author)

  2. Gut: An underestimated target organ for Aluminum.

    Science.gov (United States)

    Vignal, C; Desreumaux, P; Body-Malapel, M

    2016-06-01

    Since World War II, several factors such as an impressive industrial growth, an enhanced environmental bioavailability and intensified food consumption have contributed to a significant amplification of human exposure to aluminum. Aluminum is particularly present in food, beverages, some drugs and airbone dust. In our food, aluminum is superimposed via additives and cooking utensils. Therefore, the tolerable intake of aluminum is exceeded for a significant part of the world population, especially in children who are more vulnerable to toxic effects of pollutants than adults. Faced with this oral aluminum influx, intestinal tract is an essential barrier, especially as 38% of ingested aluminum accumulates at the intestinal mucosa. Although still poorly documented to date, the impact of oral exposure to aluminum in conditions relevant to real human exposure appears to be deleterious for gut homeostasis. Aluminum ingestion affects the regulation of the permeability, the microflora and the immune function of intestine. Nowadays, several arguments are consistent with an involvement of aluminum as an environmental risk factor for inflammatory bowel diseases. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  3. Investigating aluminum alloy reinforced by graphene nanoflakes

    Energy Technology Data Exchange (ETDEWEB)

    Yan, S.J., E-mail: shaojiuyan@126.com [Beijing Institute of Aeronautical Materials, Beijing 100095 (China); Dai, S.L.; Zhang, X.Y.; Yang, C.; Hong, Q.H.; Chen, J.Z. [Beijing Institute of Aeronautical Materials, Beijing 100095 (China); Lin, Z.M. [Aviation Industry Corporation of China, Beijing 100022 (China)

    2014-08-26

    As one of the most important engineering materials, aluminum alloys have been widely applied in many fields. However, the requirement of enhancing their mechanical properties without sacrificing the ductility is always a challenge in the development of aluminum alloys. Thanks to the excellent physical and mechanical properties, graphene nanoflakes (GNFs) have been applied as promising reinforcing elements in various engineering materials, including polymers and ceramics. However, the investigation of GNFs as reinforcement phase in metals or alloys, especially in aluminum alloys, is still very limited. In this study, the aluminum alloy reinforced by GNFs was successfully prepared via powder metallurgy approach. The GNFs were mixed with aluminum alloy powders through ball milling and followed by hot isostatic pressing. The green body was then hot extruded to obtain the final GNFs reinforced aluminum alloy nanocomposite. The scanning electron microscopy and transmission electron microscope analysis show that GNFs were well dispersed in the aluminum alloy matrix and no chemical reactions were observed at the interfaces between the GNFs and aluminum alloy matrix. The mechanical properties' testing results show that with increasing filling content of GNFs, both tensile and yield strengths were remarkably increased without losing the ductility performance. These results not only provided a pathway to achieve the goal of preparing high strength aluminum alloys with excellent ductilitybut they also shed light on the development of other metal alloys reinforced by GNFs.

  4. 40 CFR 180.1091 - Aluminum isopropoxide and aluminum secondary butoxide; exemption from the requirement of a...

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Aluminum isopropoxide and aluminum... PESTICIDE CHEMICAL RESIDUES IN FOOD Exemptions From Tolerances § 180.1091 Aluminum isopropoxide and aluminum secondary butoxide; exemption from the requirement of a tolerance. Aluminum isopropoxide (CAS Reg. No. 555...

  5. Hydrogen effects in aluminum alloys

    International Nuclear Information System (INIS)

    Louthan, M.R. Jr.; Caskey, G.R. Jr.; Dexter, A.H.

    1976-01-01

    The permeability of six commercial aluminum alloys to deuterium and tritium was determined by several techniques. Surface films inhibited permeation under most conditions; however, contact with lithium deuteride during the tests minimized the surface effects. Under these conditions phi/sub D 2 / = 1.9 x 10 -2 exp (--22,400/RT) cc (NTP)atm/sup -- 1 / 2 / s -1 cm -1 . The six alloys were also tested before, during, and after exposure to high pressure hydrogen, and no hydrogen-induced effects on the tensile properties were observed

  6. Effect of Silicon on Desulfurization of Aluminum-killed Steels

    Science.gov (United States)

    Roy, Debdutta

    Recent reports have suggested that silicon has a beneficial effect on the rate of desulfurization of Al-killed steel. This effect is difficult to understand looking at the overall desulfurization reaction which does not include silicon. However an explanation is proposed by taking into account the (SiO2)/[Si] equilibrium in which some Al reaching the slag-metal interface is used in reducing the SiO2 in the slag. This reaction can be suppressed to some extent if the silicon content of the metal is increased and in doing so, more Al will be available at the slag-metal interface for the desulfurization reaction and this would increase the rate of the desulfurization reaction. A model was developed, assuming the rates are controlled by mass transfer, taking into account the coupled reactions of the reduction of silica, and other unstable oxides, namely iron oxide and manganese oxide, in the slag and desulfurization reaction in the steel by aluminum. The model predicts that increasing silicon increases the rate and extent of desulfurization. Plant data was analyzed to obtain rough estimates of ladle desulfurization rates and also used to validate the model predictions. Experiments have been conducted on a kilogram scale of material in an induction furnace to test the hypothesis. The major conclusions of the study are as follows: The rate and extent of desulfurization improve with increasing initial silicon content in the steel; the effect diminishes at silicon contents higher than approximately 0.2% and with increasing slag basicity. This was confirmed with kilogram-scale laboratory experiments. The effects of the silicon content in the steel (and of initial FeO and MnO in the slag) largely arise from the dominant effects of these reactions on the equilibrium aluminum content of the steel: as far as aluminum consumption or pick-up is concerned, the Si/SiO2 reaction dominates, and desulfurization has only a minor effect on aluminum consumption. The rate is primarily

  7. Evaluation and Characterization of In-Line Annealed Continuous Cast Aluminum Sheet

    Energy Technology Data Exchange (ETDEWEB)

    Dr Subodh K. Das

    2006-01-17

    This R&D program will develop optimized, energy-efficient thermo-mechanical processing procedures for in-line annealing of continuously cast hot bands of two 5000 series aluminum alloys (5754 and 5052). The implementation of the R&D will result in the production of sheet with improved formability at high levels of productivity consistency and quality. The proposed R&D involves the following efforts: (1) Design and build continuous in-line annealing equipment for plant-scale trials; (2) Carry out plant-scale trials at Commonwealth Aluminum Corp.'s (CAC) plant in Carson; (3) Optimize the processing variables utilizing a metallurgical model for the kinetics of microstructure and texture evolution during thermo-mechanical processing; (4) Determine the effects of processing variables on the microstructure, texture, mechanical properties, and formability of aluminum sheet; (5) Develop design parameters for commercial implementation; and (6) Conduct techno-economic studies of the recommended process equipment to identify impacts on production costs. The research and development is appropriate for the domestic industry as it will result in improved aluminum processing capabilities and thus lead to greater application of aluminum in various industries including the automotive market. A teaming approach is critical to the success of this effort as no single company alone possesses the breadth of technical and financial resources for successfully carrying out the effort. This program will enable more energy efficient aluminum sheet production technology, produce consistent high quality product, and have The proposal addresses the needs of the aluminum industry as stated in the aluminum industry roadmap by developing new and improved aluminum processes utilizing energy efficient techniques. The effort is primarily related to the subsection on Rolling and Extrusion with the R&D to address energy and environmental efficiencies in aluminum manufacturing and will provide

  8. Aluminum access to the brain: A role for transferrin and its receptor

    International Nuclear Information System (INIS)

    Roskams, A.J.; Connor, J.R.

    1990-01-01

    The toxicity of aluminum in plant and animal cell biology is well established, although poorly understood. Several recent studies have identified aluminum as a potential, although highly controversial, contributory factor in the pathology of Alzheimer's disease, amyotrophic lateral sclerosis, and dialysis dementia. For example, aluminum has been found in high concentrations in senile plaques and neurofibrillary tangles, which occur in the brains of subjects with Alzheimer's disease. However, a mechanism for the entry of aluminum (Al 3+ ) into the cells of the central nervous system (CNS) has yet to be found. Here the authors describe a possible route of entry for aluminum into the cells of the CNS via the same high-affinity receptor-ligand system that has been postulated for iron (Fe 3 ) aluminum is able to gain access to the central nervous system under normal physiological conditions. Furthermore, these data suggest that the interaction between transferrin and its receptor may function as a general metal ion regulatory system in the CNS, extending beyond its postulated role in iron regulation

  9. Aluminum corrosion product release kinetics

    Energy Technology Data Exchange (ETDEWEB)

    Edwards, Matt, E-mail: Matthew.Edwards@cnl.ca; Semmler, Jaleh; Guzonas, Dave; Chen, Hui Qun; Toor, Arshad; Hoendermis, Seanna

    2015-07-15

    Highlights: • Release of Al corrosion product was measured in simulated post-LOCA sump solutions. • Increased boron was found to enhance Al release kinetics at similar pH. • Models of Al release as functions of time, temperature, and pH were developed. - Abstract: The kinetics of aluminum corrosion product release was examined in solutions representative of post-LOCA sump water for both pressurized water and pressurized heavy-water reactors. Coupons of AA 6061 T6 were exposed to solutions in the pH 7–11 range at 40, 60, 90 and 130 °C. Solution samples were analyzed by inductively coupled plasma atomic emission spectroscopy, and coupon samples were analyzed by secondary ion mass spectrometry. The results show a distinct “boron effect” on the release kinetics, expected to be caused by an increase in the solubility of the aluminum corrosion products. New models were developed to describe both sets of data as functions of temperature, time, and pH (where applicable)

  10. The use of aluminum oxychlorides to coagulate water having high content of organic impurities and low alkalinity

    Science.gov (United States)

    Evsyutin, A. V.; Boglovskii, A. V.

    2007-07-01

    Results from laboratory investigations and industrial tests of the coagulation of source water at the Pskov district power station are presented. It is shown that the source water may not be alkalified if it is treated with aluminum oxychlorides. As a result, the clarified water becomes less corrosive and a lower salt load is placed on water treatment plants as compared with the case when aluminum sulfate is used for coagulation.

  11. Overexpression of BdMATE Gene Improves Aluminum Tolerance in Setaria viridis

    Directory of Open Access Journals (Sweden)

    Ana P. Ribeiro

    2017-06-01

    Full Text Available Acidic soils are distributed worldwide, predominantly in tropical and subtropical areas, reaching around 50% of the arable soil. This type of soil strongly reduces crop production, mainly because of the presence of aluminum, which has its solubility increased at low pH levels. A well-known physiological mechanism used by plants to cope with Al stress involves activation of membrane transporters responsible for organic acid anions secretion from the root apex to the rhizosphere, which chelate Al, preventing its absorption by roots. In sorghum, a membrane transporter gene belonging to multidrug and toxic compound extrusion (MATE family was identified and characterized as an aluminum-activated citrate transporter gene responsible for Al tolerance in this crop. Setaria viridis is an emerging model for C4 species and it is an important model to validate some genes for further C4 crops transformation, such as sugarcane, maize, and wheat. In the present work, Setaria viridis was used as a model plant to overexpress a newly identified MATE gene from Brachypodium distachyon (BdMATE, closely related to SbMATE, for aluminum tolerance assays. Transgenic S. viridis plants overexpressing a BdMATE presented an improved Al tolerance phenotype, characterized by sustained root growth and exclusion of aluminum from the root apex in transgenic plants, as confirmed by hematoxylin assay. In addition, transgenic plants showed higher root citrate exudation into the rhizosphere, suggesting that Al tolerance improvement in these plants could be related to the chelation of the metal by the organic acid anion. These results suggest that BdMATE gene can be used to transform C4 crops of economic importance with improved aluminum tolerance.

  12. Aluminum alloy and associated anode and battery

    International Nuclear Information System (INIS)

    Tarcy, G.P.

    1990-01-01

    This patent describes an aluminum alloy. It comprises: eutectic amounts of at least two alloying elements selected from the group consisting of bismuth, cadmium, scandium, gallium, indium, lead, mercury, thallium, tin, and zinc with the balance being aluminum and the alloying elements being about 0.01 to 3.0 percent by weight of the alloy

  13. Assessment of secondary aluminum reserves of nations

    DEFF Research Database (Denmark)

    Maung, Kyaw Nyunt; Yoshida, Tomoharu; Liu, Gang

    2017-01-01

    aluminum resources are accumulated in landfill sites. Understanding the sizes of primary and secondary aluminum reserves enables us to extend knowledge of efficient raw material sourcing from a narrow perspective of primary reserves alone to a broader perspective of both primary and secondary reserves...

  14. 21 CFR 172.310 - Aluminum nicotinate.

    Science.gov (United States)

    2010-04-01

    ... and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) FOOD ADDITIVES PERMITTED FOR DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION Special Dietary and Nutritional Additives § 172.310 Aluminum nicotinate. Aluminum nicotinate may be safely...

  15. Scientific Background for Processing of Aluminum Waste

    Science.gov (United States)

    Kononchuk, Olga; Alekseev, Alexey; Zubkova, Olga; Udovitsky, Vladimir

    2017-11-01

    Changing the source of raw materials for producing aluminum and the emergence of a huge number of secondary alumina waste (foundry slag, sludge, spent catalysts, mineral parts of coal and others that are formed in various industrial enterprises) require the creation of scientific and theoretical foundations for their processing. In this paper, the aluminum alloys (GOST 4784-97) are used as an aluminum raw material component, containing the aluminum component produced as chips in the machine-building enterprises. The aluminum waste is a whole range of metallic aluminum alloys including elements: magnesium, copper, silica, zinc and iron. Analysis of the aluminum waste A1- Zn-Cu-Si-Fe shows that depending on the content of the metal the dissolution process of an aluminum alloy should be treated as the result of the chemical interaction of the metal with an alkaline solution. It is necessary to consider the behavior of the main components of alloys in an alkaline solution as applied to the system Na2O - Al2O3 - SiO2 - CO2 - H2O.

  16. Aluminum low temperature smelting cell metal collection

    Science.gov (United States)

    Beck, Theodore R.; Brown, Craig W.

    2002-07-16

    A method of producing aluminum in an electrolytic cell containing alumina dissolved in an electrolyte. The method comprises the steps of providing a molten salt electrolyte in an electrolytic cell having an anodic liner for containing the electrolyte, the liner having an anodic bottom and walls including at least one end wall extending upwardly from the anodic bottom, the anodic liner being substantially inert with respect to the molten electrolyte. A plurality of non-consumable anodes is provided and disposed vertically in the electrolyte. A plurality of cathodes is disposed vertically in the electrolyte in alternating relationship with the anodes. The anodes are electrically connected to the anodic liner. An electric current is passed through the anodic liner to the anodes, through the electrolyte to the cathodes, and aluminum is deposited on said cathodes. Oxygen bubbles are generated at the anodes and the anodic liner, the bubbles stirring the electrolyte. Molten aluminum is collected from the cathodes into a tubular member positioned underneath the cathodes. The tubular member is in liquid communication with each cathode to collect the molten aluminum therefrom while excluding electrolyte. Molten aluminum is delivered through the tubular member to a molten aluminum reservoir located substantially opposite the anodes and cathodes. The molten aluminum is collected from the cathodes and delivered to the reservoir while avoiding contact of the molten aluminum with the anodic bottom.

  17. Laboratory Powder Metallurgy Makes Tough Aluminum Sheet

    Science.gov (United States)

    Royster, D. M.; Thomas, J. R.; Singleton, O. R.

    1993-01-01

    Aluminum alloy sheet exhibits high tensile and Kahn tear strengths. Rapid solidification of aluminum alloys in powder form and subsequent consolidation and fabrication processes used to tailor parts made of these alloys to satisfy such specific aerospace design requirements as high strength and toughness.

  18. Aluminum extrusion with a deformable die

    NARCIS (Netherlands)

    Assaad, W.

    2010-01-01

    Aluminum extrusion process is one of metal forming processes. In aluminum extrusion, a work-piece (billet) is pressed through a die with an opening that closely resembles a desired shape of a profile. By this process, long profiles with an enormous variety of cross-sections can be produced to

  19. Effects of aluminum on root growth and absorption of nutrients by ...

    African Journals Online (AJOL)

    USER

    2010-06-28

    Jun 28, 2010 ... In Taiwan, pineapple (Ananas comosus (L.) Merr) is one of important fruits in sacrifice and daily consumption (Chang, 1995). Most of the pineapples were ..... culture. J. Plant Nutr. 17: 953-962. Nichol BE, Oliveira LA, Glass ADM, Siddiqi MY (1993). The effects of aluminum on the influx of calcium, potassium, ...

  20. Phosphate adsorption on aluminum-impregnated mesoporous silicates : surface structure and behavior of adsorbents

    Science.gov (United States)

    Eun Woo Shin; James S. Han; Min Jang; Soo-Hong Min; Jae Kwang Park; Roger M. Rowell

    2004-01-01

    Phosphorus from excess fertilizers and detergents ends up washing into lakes, creeks, and rivers. This overabundance of phosphorus causes excessive aquatic plant and algae growth and depletes the dissolved oxygen supply in the water. In this study, aluminum-impregnated mesoporous adsorbents were tested for their ability to remove phosphate from water. The surface...

  1. Aluminum inhibits phosphatidic acid formation by blocking the phospholipase C pathway

    NARCIS (Netherlands)

    Ramos-Díaz, A.; Brito-Argáez, L.; Munnik, T.; Hernández-Sotomayor, S.M.T.

    2007-01-01

    Aluminum (Al(3+)) has been recognized as a main toxic factor in crop production in acid lands. Phosphatidic acid (PA) is emerging as an important lipid signaling molecule and has been implicated in various stress-signaling pathways in plants. In this paper, we focus on how PA generation is affected

  2. Effects of aluminum on root growth and absorption of nutrients by ...

    African Journals Online (AJOL)

    Aluminum (Al) is a biotoxic which often influences the absorption of nutrients by plants in strongly acidic soils. In this experiment, the effect of Al on root growth, absorption of macronutrients; phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg) and micronutrients; iron (Fe), manganese (Mn), copper (Cu) and zinc ...

  3. Trends in the global aluminum fabrication industry

    Science.gov (United States)

    Das, Subodh; Yin, Weimin

    2007-02-01

    The aluminum fabrication industry has become more vital to the global economy as international aluminum consumption has grown steadily in the past decades. Using innovation, value, and sustainability, the aluminum industry is strengthening its position not only in traditional packaging and construction applications but also in the automotive and aerospace markets to become more competitive and to face challenges from other industries and higher industrial standards. The aluminum fabrication industry has experienced a significant geographical shift caused by rapid growth in emerging markets in countries such as Brazil, Russia, India, and China. Market growth and distribution will vary with different patterns of geography and social development; the aluminum industry must be part of the transformation and keep pace with market developments to benefit.

  4. Aluminum-based metal-air batteries

    Science.gov (United States)

    Friesen, Cody A.; Martinez, Jose Antonio Bautista

    2016-01-12

    Provided in one embodiment is an electrochemical cell, comprising: (i) a plurality of electrodes, comprising a fuel electrode that comprises aluminum and an air electrode that absorbs gaseous oxygen, the electrodes being operable in a discharge mode wherein the aluminum is oxidized at the fuel electrode and oxygen is reduced at the air electrode, and (ii) an ionically conductive medium, comprising an organic solvent; wherein during non-use of the cell, the organic solvent promotes formation of a protective interface between the aluminum of the fuel electrode and the ionically conductive medium, and wherein at an onset of the discharge mode, at least some of the protective interface is removed from the aluminum to thereafter permit oxidation of the aluminum during the discharge mode.

  5. Aluminum phosphate shows more adjuvanticity than Aluminum hydroxide in recombinant hepatitis –B vaccine formulation

    Directory of Open Access Journals (Sweden)

    2008-08-01

    Full Text Available Background: Although a number of investigation have been carried out to find alternative adjuvants to aluminum salts in vaccine formulations, they are still extensively used due to their good track record of safety, low cost and proper adjuvanticity with a variety of antigens. Adsorption of antigens onto aluminum compounds depends heavily on electrostatic forces between adjuvant and antigen. Commercial recombinant protein hepatitis B vaccines containing aluminum hydroxide as adjuvant is facing low induction of immunity in some sections of the vaccinated population. To follow the current global efforts in finding more potent hepatitis B vaccine formulation, adjuvanticity of aluminum phosphate has been compared to aluminum hydroxide. Materials and methods: The adjuvant properties of aluminum hydroxide and aluminum phosphate in a vaccine formulation containing a locally manufactured hepatitis B (HBs surface antigen was evaluated in Balb/C mice. The formulations were administered intra peritoneally (i.p. and the titers of antibody which was induced after 28 days were determined using ELISA technique. The geometric mean of antibody titer (GMT, seroconversion and seroprotection rates, ED50 and relative potency of different formulations were determined. Results: All the adjuvanicity markers obtained in aluminum phosphate formulation were significantly higher than aluminum hydroxide. The geometric mean of antibody titer of aluminum phosphate was approximately three folds more than aluminum hydroxide. Conclusion: Aluminum phosphate showed more adjuvanticity than aluminum hydroxide in hepatitis B vaccine. Therefore the use of aluminum phosphate as adjuvant in this vaccine may lead to higher immunity with longer duration of effects in vaccinated groups.

  6. Aluminum recovery as a product with high added value using aluminum hazardous waste

    International Nuclear Information System (INIS)

    David, E.; Kopac, J.

    2013-01-01

    Highlights: • Granular and compact aluminum dross were physically and chemically characterized. • A relationship between density, porosity and metal content from dross was established. • Chemical reactions involving aluminum in landfill and negative consequences are shown. • A processing method for aluminum recovering from aluminum dross was developed. • Aluminum was recovered as an value product with high grade purity such as alumina. -- Abstract: The samples of hazardous aluminum solid waste such as dross were physically and chemically characterized. A relationship between density, porosity and metal content of dross was established. The paper also examines the chemical reactions involving aluminum dross in landfill and the negative consequences. To avoid environmental problems and to recovery the aluminum, a processing method was developed and aluminum was recovered as an added value product such as alumina. This method refers to a process at low temperature, in more stages: acid leaching, purification, precipitation and calcination. At the end of this process aluminum was extracted, first as Al 3+ soluble ions and final as alumina product. The composition of the aluminum dross and alumina powder obtained were measured by applying the leaching tests, using atomic absorption spectrometry (AAS) and chemical analysis. The mineralogical composition of aluminum dross samples and alumina product were determined by X-ray diffraction (XRD) and the morphological characterization was performed by scanning electron microscopy (SEM). The method presented in this work allows the use of hazardous aluminum solid waste as raw material to recover an important fraction from soluble aluminum content as an added value product, alumina, with high grade purity (99.28%)

  7. Aluminum tolerance association mapping in triticale

    Directory of Open Access Journals (Sweden)

    Niedziela Agnieszka

    2012-02-01

    Full Text Available Abstract Background Crop production practices and industrialization processes result in increasing acidification of arable soils. At lower pH levels (below 5.0, aluminum (Al remains in a cationic form that is toxic to plants, reducing growth and yield. The effect of aluminum on agronomic performance is particularly important in cereals like wheat, which has promoted the development of programs directed towards selection of tolerant forms. Even in intermediately tolerant cereals (i.e., triticale, the decrease in yield may be significant. In triticale, Al tolerance seems to be influenced by both wheat and rye genomes. However, little is known about the precise chromosomal location of tolerance-related genes, and whether wheat or rye genomes are crucial for the expression of that trait in the hybrid. Results A mapping population consisting of 232 advanced breeding triticale forms was developed and phenotyped for Al tolerance using physiological tests. AFLP, SSR and DArT marker platforms were applied to obtain a sufficiently large set of molecular markers (over 3000. Associations between the markers and the trait were tested using General (GLM and Multiple (MLM Linear Models, as well as the Statistical Machine Learning (SML approach. The chromosomal locations of candidate markers were verified based on known assignments of SSRs and DArTs or by using genetic maps of rye and triticale. Two candidate markers on chromosome 3R and 9, 15 and 11 on chromosomes 4R, 6R and 7R, respectively, were identified. The r2 values were between 0.066 and 0.220 in most cases, indicating a good fit of the data, with better results obtained with the GML than the MLM approach. Several QTLs on rye chromosomes appeared to be involved in the phenotypic expression of the trait, suggesting that rye genome factors are predominantly responsible for Al tolerance in triticale. Conclusions The Diversity Arrays Technology was applied successfully to association mapping studies

  8. Emissions of naturally occurring radioactivity from aluminum and copper facilities. Report No. 6 (final)

    International Nuclear Information System (INIS)

    Andrews, V.E.

    1982-11-01

    This report summarizes five surveys which were conducted at a Bauxite mining operation, an alumina reduction plant, an aluminum reduction plant, an underground copper mine and mill, and an open pit copper mine and concentrator. Process components and controlled source releases were sampled for naturally occurring radioactivity. Particular emphasis was given to radon-222, lead-210, and polonium-210 emissions from crushing and drying processes

  9. Process for anodizing aluminum foil

    International Nuclear Information System (INIS)

    Ball, J.A.; Scott, J.W.

    1984-01-01

    In an integrated process for the anodization of aluminum foil for electrolytic capacitors including the formation of a hydrous oxide layer on the foil prior to anodization and stabilization of the foil in alkaline borax baths during anodization, the foil is electrochemically anodized in an aqueous solution of boric acid and 2 to 50 ppm phosphate having a pH of 4.0 to 6.0. The anodization is interrupted for stabilization by passing the foil through a bath containing the borax solution having a pH of 8.5 to 9.5 and a temperature above 80 0 C. and then reanodizing the foil. The process is useful in anodizing foil to a voltage of up to 760 V

  10. Oxidation dynamics of aluminum nanorods

    Energy Technology Data Exchange (ETDEWEB)

    Li, Ying [Argonne Leadership Computing Facility, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Kalia, Rajiv K.; Nakano, Aiichiro; Vashishta, Priya [Collaboratory for Advanced Computing and Simulations, Department of Physics and Astronomy, Department of Chemical Engineering and Materials Science, Department of Computer Science, University of Southern California, Los Angeles, California 90089-0242 (United States)

    2015-02-23

    Aluminum nanorods (Al-NRs) are promising fuels for pyrotechnics due to the high contact areas with oxidizers, but their oxidation mechanisms are largely unknown. Here, reactive molecular dynamics simulations are performed to study thermally initiated burning of oxide-coated Al-NRs with different diameters (D = 26, 36, and 46 nm) in oxygen environment. We found that thinner Al-NRs burn faster due to the larger surface-to-volume ratio. The reaction initiates with the dissolution of the alumina shell into the molten Al core to generate heat. This is followed by the incorporation of environmental oxygen atoms into the resulting Al-rich shell, thereby accelerating the heat release. These results reveal an unexpectedly active role of the alumina shell as a “nanoreactor” for oxidation.

  11. Lead exposure from aluminum cookware in Cameroon

    International Nuclear Information System (INIS)

    Weidenhamer, Jeffrey D.; Kobunski, Peter A.; Kuepouo, Gilbert; Corbin, Rebecca W.; Gottesfeld, Perry

    2014-01-01

    Blood lead levels have decreased following the removal of lead from gasoline in most of the world. However, numerous recent studies provide evidence that elevated blood lead levels persist in many low and middle-income countries around the world at much higher prevalence than in the more developed countries. One potential source of lead exposure that has not been widely investigated is the leaching of lead from artisanal aluminum cookware, which is commonly used in the developing world. Twenty-nine samples of aluminum cookware and utensils manufactured by local artisans in Cameroon were collected and analyzed for their potential to release lead during cooking. Source materials for this cookware included scrap metal such as engine parts, radiators, cans, and construction materials. The lead content of this cookware is relatively low (< 1000 ppm by X-ray fluorescence), however significant amounts of lead, as well as aluminum and cadmium were released from many of the samples using dilute acetic acid extractions at boiling and ambient temperatures. Potential exposures to lead per serving were estimated to be as high as 260 μg, indicating that such cookware can pose a serious health hazard. We conclude that lead, aluminum and cadmium can migrate from this aluminum cookware during cooking and enter food at levels exceeding recommended public health guidelines. Our results support the need to regulate lead content of materials used to manufacture these pots. Artisanal aluminum cookware may be a major contributor to lead poisoning throughout the developing world. Testing of aluminum cookware in other developing countries is warranted. - Highlights: • Cookware is manufactured in Cameroon from scrap aluminum including car parts. • Twenty-nine cookware samples were evaluated for their potential to leach lead. • Boiling extractions to simulate the effects of cooking released significant lead. • Potential lead exposures per serving are estimated as high as 260 μg.

  12. Lead exposure from aluminum cookware in Cameroon

    Energy Technology Data Exchange (ETDEWEB)

    Weidenhamer, Jeffrey D.; Kobunski, Peter A. [Department of Chemistry, Geology and Physics, 401 College Ave., Ashland University, Ashland, OH 44805 (United States); Kuepouo, Gilbert [Research and Education Centre for Development (CREPD), Yaounde (Cameroon); Corbin, Rebecca W. [Department of Chemistry, Geology and Physics, 401 College Ave., Ashland University, Ashland, OH 44805 (United States); Gottesfeld, Perry, E-mail: pgottesfeld@okinternational.org [Occupational Knowledge International, San Francisco, CA (United States)

    2014-10-15

    Blood lead levels have decreased following the removal of lead from gasoline in most of the world. However, numerous recent studies provide evidence that elevated blood lead levels persist in many low and middle-income countries around the world at much higher prevalence than in the more developed countries. One potential source of lead exposure that has not been widely investigated is the leaching of lead from artisanal aluminum cookware, which is commonly used in the developing world. Twenty-nine samples of aluminum cookware and utensils manufactured by local artisans in Cameroon were collected and analyzed for their potential to release lead during cooking. Source materials for this cookware included scrap metal such as engine parts, radiators, cans, and construction materials. The lead content of this cookware is relatively low (< 1000 ppm by X-ray fluorescence), however significant amounts of lead, as well as aluminum and cadmium were released from many of the samples using dilute acetic acid extractions at boiling and ambient temperatures. Potential exposures to lead per serving were estimated to be as high as 260 μg, indicating that such cookware can pose a serious health hazard. We conclude that lead, aluminum and cadmium can migrate from this aluminum cookware during cooking and enter food at levels exceeding recommended public health guidelines. Our results support the need to regulate lead content of materials used to manufacture these pots. Artisanal aluminum cookware may be a major contributor to lead poisoning throughout the developing world. Testing of aluminum cookware in other developing countries is warranted. - Highlights: • Cookware is manufactured in Cameroon from scrap aluminum including car parts. • Twenty-nine cookware samples were evaluated for their potential to leach lead. • Boiling extractions to simulate the effects of cooking released significant lead. • Potential lead exposures per serving are estimated as high as 260 μg.

  13. Fatigue analysis of aluminum drill pipes

    Directory of Open Access Journals (Sweden)

    João Carlos Ribeiro Plácido

    2005-12-01

    Full Text Available An experimental program was performed to investigate the fundamental fatigue mechanisms of aluminum drill pipes. Initially, the fatigue properties were determined through small-scale tests performed in an optic-mechanical fatigue apparatus. Additionally, full-scale fatigue tests were carried out with three aluminum drill pipe specimens under combined loading of cyclic bending and constant axial tension. Finally, a finite element model was developed to simulate the stress field along the aluminum drill pipe during the fatigue tests and to estimate the stress concentration factors inside the tool joints. By this way, it was possible to estimate the stress values in regions not monitored during the fatigue tests.

  14. Nanshan Aluminum Reached Strategic Cooperation with CSR Corporation Limited

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    As a key supplier of aluminum profiles and aluminum plate,sheet and trip products for CSR Corporation Limited,Nanshan Aluminum will join hands with CSR Corporation Limited to reach strategic cooperation.On January 5,Nanshan Aluminum signed strategic cooperation agreement with CSR Sifang Locomotive&Rolling; Stock Co.,Ltd,both

  15. 49 CFR 178.505 - Standards for aluminum drums.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Standards for aluminum drums. 178.505 Section 178... PACKAGINGS Non-bulk Performance-Oriented Packaging Standards § 178.505 Standards for aluminum drums. (a) The following are the identification codes for aluminum drums: (1) 1B1 for a non-removable head aluminum drum...

  16. Formulation and method for preparing gels comprising hydrous aluminum oxide

    Science.gov (United States)

    Collins, Jack L.

    2014-06-17

    Formulations useful for preparing hydrous aluminum oxide gels contain a metal salt including aluminum, an organic base, and a complexing agent. Methods for preparing gels containing hydrous aluminum oxide include heating a formulation to a temperature sufficient to induce gel formation, where the formulation contains a metal salt including aluminum, an organic base, and a complexing agent.

  17. 46 CFR 154.195 - Aluminum cargo tank: Steel enclosure.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Aluminum cargo tank: Steel enclosure. 154.195 Section... Equipment Hull Structure § 154.195 Aluminum cargo tank: Steel enclosure. (a) An aluminum cargo tank and its... the aluminum cargo tank must meet the steel structural standards of the American Bureau of Shipping...

  18. A simple aluminum gasket for use with both stainless steel and aluminum flanges

    Energy Technology Data Exchange (ETDEWEB)

    Langley, R.A.

    1991-01-01

    A technique has been developed for making aluminum wire seal gaskets of various sizes and shapes for use with both stainless steel and aluminum alloy flanges. The gasket material used is 0.9999 pure aluminum, drawn to a diameter of 3 mm. This material can be easily welded and formed into various shapes. A single gasket has been successfully used up to five times without baking. The largest gasket tested to date is 3.5 m long and was used in the shape of a parallelogram. Previous use of aluminum wire gaskets, including results for bakeout at temperatures from 20 to 660{degree}C, is reviewed. A search of the literature indicates that this is the first reported use of aluminum wire gaskets for aluminum alloy flanges. The technique is described in detail, and the results are summarized. 11 refs., 4 figs.

  19. Coordination Structure of Aluminum in Magnesium Aluminum Hydroxide Studied by 27Al NMR

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The coordination structure of aluminum in magnesium aluminum hydroxide was studiedby 27Al NMR. The result showed that tetrahedral aluminum (AlⅣ) existed in magnesiumaluminum hydroxide, and the contents of AlⅣ increased with the increase of the ratio of Al/Mg andwith the peptizing temperature. AlⅣ originated from the so-called Al13 polymer with the structureof one Al tetrahedron surrounded by twelve Al octahedrons.

  20. The Oxidation Products of Aluminum Hydride and Boron Aluminum Hydride Clusters

    Science.gov (United States)

    2016-01-04

    AFRL-AFOSR-VA-TR-2016-0075 The Oxidation Products of Aluminum Hydride and Boron Aluminum Hydride Clusters KIT BOWEN JOHNS HOPKINS UNIV BALTIMORE MD...2. REPORT TYPE Final Performance 3. DATES COVERED (From - To) 30-09-2014 to 29-09-2015 4. TITLE AND SUBTITLE The Oxidation Products of Aluminum ...Hydride and Boron Aluminum Hydride Clusters 5a.  CONTRACT NUMBER 5b.  GRANT NUMBER FA9550-14-1-0324 5c.  PROGRAM ELEMENT NUMBER 61102F 6. AUTHOR(S) KIT

  1. 40 CFR 63.5753 - How do I calculate the combined organic HAP content of aluminum wipedown solvents and aluminum...

    Science.gov (United States)

    2010-07-01

    ... HAP content of aluminum wipedown solvents and aluminum recreational boat surface coatings? 63.5753... Standards for Hazardous Air Pollutants for Boat Manufacturing Standards for Aluminum Recreational Boat Surface Coating Operations § 63.5753 How do I calculate the combined organic HAP content of aluminum...

  2. Electron-beam welding of aluminum alloys

    Energy Technology Data Exchange (ETDEWEB)

    Brillant, Marcel; de Bony, Yves

    1980-08-15

    The objective of this article is to describe the status of the application of electron-beam welding to aluminum alloys. These alloys are widely employed in the aeronautics, space and nuclear industries.

  3. Electrometallurgical treatment of aluminum-based fuels

    International Nuclear Information System (INIS)

    Willit, J. L.

    1998-01-01

    We have successfully demonstrated aluminum electrorefining from a U-Al-Si alloy that simulates spent aluminum-based reactor fuel. The aluminum product contains less than 200 ppm uranium. All the results obtained have been in agreement with predictions based on equilibrium thermodynamics. We have also demonstrated the need for adequate stirring to achieve a low-uranium product. Most of the other process steps have been demonstrated in other programs. These include uranium electrorefining, transuranic fission product scrubbing, fission product oxidation, and product consolidation by melting. Future work will focus on the extraction of active metal and rare earth fission products by a molten flux salt and scale-up of the aluminum electrorefining

  4. Masking of aluminum surface against anodizing

    Science.gov (United States)

    Crawford, G. B.; Thompson, R. E.

    1969-01-01

    Masking material and a thickening agent preserve limited unanodized areas when aluminum surfaces are anodized with chromic acid. For protection of large areas it combines well with a certain self-adhesive plastic tape.

  5. Aluminum titanate crucible for molten uranium

    International Nuclear Information System (INIS)

    Asbury, J.J.

    1975-01-01

    An improved crucible for molten uranium is described. The crucible or crucible liner is formed of aluminum titanate which essentially eliminates contamination of uranium and uranium alloys during molten states thereof. (U.S.)

  6. Interpretation of aluminum-alloy weld radiography

    Science.gov (United States)

    Duren, P. C.; Risch, E. R.

    1971-01-01

    Report proposes radiographic terminology standardization which allows scientific interpretation of radiographic films to replace dependence on individual judgement and experience. Report includes over 50 photographic pages where radiographs of aluminum welds with defects are compared with prepared weld sections photomacrographs.

  7. Recycling of aluminum to produce green energy

    Energy Technology Data Exchange (ETDEWEB)

    Martinez, Susana Silva; Lopez Benites, Wendy; Alvarez Gallegos, Alberto A. [Centro de Investigacion en Ingenieria y Ciencias Aplicadas, Av. Universidad 1001, Col. Chamilpa, Cuernavaca, Morelos C.P. 62210 (Mexico); Sebastian, P.J. [Centro de Investigacion en Energia-UNAM, 62580 Temixco, Morelos (Mexico)

    2005-07-15

    High-purity hydrogen gas was generated from the chemical reaction of aluminum with sodium hydroxide. Several molar relations of sodium hydroxide/aluminum were investigated in this study. The experimental results showed that hydrogen yields are acceptable and its purity was good enough to be used in a proton exchange membrane (PEM) fuel cell to produce electricity. An estimation of the amount of energy produced from the reaction of 100 aluminum cans with caustic soda showed that the hydrogen production is feasible to be scaled up to reach up to 5kWh in a few hours. This study is environmentally friendly and also shows that green energy can be produced from aluminum waste at a low cost.

  8. Aluminum alloy excellent in neutron absorbing performance

    International Nuclear Information System (INIS)

    Iida, Tetsuya; Tamamura, Tadao; Morimoto, Hiroyuki; Ouchi, Ken-ichiro.

    1987-01-01

    Purpose: To obtain structural materials made of aluminum alloys having favorable neutron absorbing performance and excellent in the performance as structural materials such as processability and strength. Constitution: Powder of Gd 2 O 3 as a gadolinium compound or metal gadolinium is uniformly mixed with the powder of aluminum or aluminum alloy. The amount of the gadolinium compound added is set to 0.1 - 30 % by weight. No sufficient neutron absorbing performance can be obtained if it is less than 0.1 % by weight, whereas the processability and mechanical property of the alloy are degraded if it exceeds 30 % by weight. Further, the grain size is set to less about 50 μm. Further, since the neutron absorbing performance varies greatly if the aluminum powder size exceeds 100 μm, the diameter is set to less than about 100 μm. These mixtures are molded in a hot press. This enables to obtain aimed structural materials. (Takahashi, M.)

  9. Seacoast stress corrosion cracking of aluminum alloys

    Science.gov (United States)

    Humphries, T. S.; Nelson, E. E.

    1981-01-01

    The stress corrosion cracking resistance of high strength, wrought aluminum alloys in a seacoast atmosphere was investigated and the results were compared with those obtained in laboratory tests. Round tensile specimens taken from the short transverse grain direction of aluminum plate and stressed up to 100 percent of their yield strengths were exposed to the seacoast and to alternate immersion in salt water and synthetic seawater. Maximum exposure periods of one year at the seacoast, 0.3 or 0.7 of a month for alternate immersion in salt water, and three months for synthetic seawater were indicated for aluminum alloys to avoid false indications of stress corrosion cracking failure resulting from pitting. Correlation of the results was very good among the three test media using the selected exposure periods. It is concluded that either of the laboratory test media is suitable for evaluating the stress corrosion cracking performance of aluminum alloys in seacoast atmosphere.

  10. Inhibition of aluminum corrosion using Opuntia extract

    International Nuclear Information System (INIS)

    El-Etre, A.Y.

    2003-01-01

    The inhibitive action of the mucilage extracted from the modified stems of prickly pears, toward acid corrosion of aluminum, is tested using weight loss, thermometry, hydrogen evolution and polarization techniques. It was found that the extract acts as a good corrosion inhibitor for aluminum corrosion in 2.0 M HCl solution. The inhibition action of the extract was discussed in view of Langmuir adsorption isotherm. It was found that the adsorption of the extract on aluminum surface is a spontaneous process. The inhibition efficiency (IE) increases as the extract concentration is increased. The effect of temperature on the IE was studied. It was found that the presence of extract increases the activation energy of the corrosion reaction. Moreover, the thermodynamic parameters of the adsorption process were calculated. It was found also that the Opuntia extract provides a good protection to aluminum against pitting corrosion in chloride ion containing solutions

  11. Corrosion of aluminum components and remedial measures

    International Nuclear Information System (INIS)

    Sheikh, S.T.; Khalique, A.; Malik, F.A.

    2006-01-01

    Aluminum has versatile physical properties, mechanical strength, corrosion resistance, and is used in special applications like aerospace, automobiles and other strategic industries. The outdoor exposed structural components of aluminum have very good corrosion resistance due to the thick oxide layer (0.2 -0.4 micro). This study involves the corrosion of aluminum based components, though aluminum is protected by an oxide layer but due to extreme weather and environmental conditions the oxide layer was damaged. The corroded product was removed, pits or cavities formed due to the material removal were filled with epoxy resins and acrylic-based compounds containing fibreglass as reinforcement. Optimum results were obtained with epoxy resins incorporated with 5% glass fibers. The inner surface of the components was provided further protection with a cellulose nitrate compound. (author)

  12. Beryllium-aluminum alloys for investment castings

    International Nuclear Information System (INIS)

    Nachtrab, W.T.; Levoy, N.

    1997-01-01

    Beryllium-aluminum alloys containing greater than 60 wt % beryllium are very favorable materials for applications requiring light weight and high stiffness. However, when produced by traditional powder metallurgical methods, these alloys are expensive and have limited applications. To reduce the cost of making beryllium-aluminum components, Nuclear Metals Inc. (NMI) and Lockheed Martin Electronics and Missiles have recently developed a family of patented beryllium-aluminum alloys that can be investment cast. Designated Beralcast, the alloys can achieve substantial weight savings because of their high specific strength and stiffness. In some cases, weight has been reduced by up to 50% over aluminum investment casting. Beralcast is now being used to make thin wall precision investment castings for several advanced aerospace applications, such as the RAH-66 Comanche helicopter and F-22 jet fighter. This article discusses alloy compositions, properties, casting method, and the effects of cobalt additions on strength

  13. Fast LIBS Identification of Aluminum Alloys

    Directory of Open Access Journals (Sweden)

    Tawfik W.

    2007-04-01

    Full Text Available Laser-induced breakdown spectroscopy (LIBS has been applied to analysis aluminum alloy targets. The plasma is generated by focusing a 300 mJ pulsed Nd: YAG laser on the target in air at atmospheric pressure. Such plasma emission spectrum was collected using a one-meter length wide band fused-silica optical fiber connected to a portable Echelle spectrometer with intensified CCD camera. Spectroscopic analysis of plasma evolution of laser produced plasmas has been characterized in terms of their spectra, electron density and electron temperature assuming the LTE and optically thin plasma conditions. The LIBS spectrum was optimized for high S/N ratio especially for trace elements. The electron temperature and density were determined using the emission intensity and stark broadening, respectively, of selected aluminum spectral lines. The values of these parameters were found to change with the aluminum alloy matrix, i.e. they could be used as a fingerprint character to distinguish between different aluminum alloy matrices using only one major element (aluminum without needing to analysis the rest of elements in the matrix. Moreover, It was found that the values of T e and N e decrease with increasing the trace elements concentrations in the aluminum alloy samples. The obtained results indicate that it is possible to improve the exploitation of LIBS in the remote on-line industrial monitoring application, by following up only the values of T e and N e for aluminum in aluminum alloys as a marker for the correct alloying using an optical fiber probe.

  14. Fast LIBS Identification of Aluminum Alloys

    Directory of Open Access Journals (Sweden)

    Tawfik W.

    2007-04-01

    Full Text Available Laser-induced breakdown spectroscopy (LIBS has been applied to analysis aluminum alloy targets. The plasma is generated by focusing a 300 mJ pulsed Nd: YAG laser on the target in air at atmospheric pressure. Such plasma emission spectrum was collected using a one-meter length wide band fused-silica optical fiber connected to a portable Echelle spectrometer with intensified CCD camera. Spectroscopic analysis of plasma evolution of laser produced plasmas has been characterized in terms of their spectra, electron density and electron temperature assuming the LTE and optically thin plasma conditions. The LIBS spectrum was optimized for high S/N ratio especially for trace elements. The electron temperature and density were determined using the emission intensity and stark broadening, respectively, of selected aluminum spectral lines. The values of these parameters were found to change with the aluminum alloy matrix, i.e. they could be used as a fingerprint character to distinguish between different aluminum alloy matrices using only one major element (aluminum without needing to analysis the rest of elements in the matrix. Moreover, It was found that the values of T(e and N(e decrease with increasing the trace elements concentrations in the aluminum alloy samples. The obtained results indicate that it is possible to improve the exploitation of LIBS in the remote on-line industrial monitoring application, by following up only the values of T(e and N(e for the aluminum in aluminum alloys using an optical fiber probe.

  15. Anodizing of aluminum with improved corrosion properties

    International Nuclear Information System (INIS)

    John, P.; Khan, I.U.

    2010-01-01

    Anodizing of aluminum was studied in sulphuric/oxalic/boric acid electroiyte system. The corrosion resistance of the anodic oxide coating of aluminum was determined by potentiodynamic polarization test and scanning electron microscope (SEM) was used to investigate the surface morphology before and after corrosion test. It was found that the oxide coating obtained by this method showed better corrosion resistance with no significant difference in surface morphology. (author)

  16. The effects of ultrasonic solidification on aluminum

    OpenAIRE

    Đorđević Slavko 1

    2003-01-01

    The effect of ultrasound on characteristics of solidified aluminum was shown. An ultrasonic head and ultrasonic system for modification was designed and applied to the crystallizing aluminum melt. The ultrasonic generator allows power of 50-500 W, amplitude of oscillations 10-100 um.m and the operating frequency of 25 kHz. Ultrasonic modification was done by ultrasound introduced from above into the melt. Microstructure photographs show decreasing of the grain size more than five times.

  17. The effects of ultrasonic solidification on aluminum

    Directory of Open Access Journals (Sweden)

    Đorđević Slavko 1

    2003-01-01

    Full Text Available The effect of ultrasound on characteristics of solidified aluminum was shown. An ultrasonic head and ultrasonic system for modification was designed and applied to the crystallizing aluminum melt. The ultrasonic generator allows power of 50-500 W, amplitude of oscillations 10-100 um.m and the operating frequency of 25 kHz. Ultrasonic modification was done by ultrasound introduced from above into the melt. Microstructure photographs show decreasing of the grain size more than five times.

  18. Scientific Background for Processing of Aluminum Waste

    Directory of Open Access Journals (Sweden)

    Kononchuk Olga

    2017-01-01

    of the aluminum waste A1- Zn-Cu-Si-Fe shows that depending on the content of the metal the dissolution process of an aluminum alloy should be treated as the result of the chemical interaction of the metal with an alkaline solution. It is necessary to consider the behavior of the main components of alloys in an alkaline solution as applied to the system Na2O - Al2O3 - SiO2 - CO2 - H2O.

  19. Advanced powder metallurgy aluminum alloys and composites

    Science.gov (United States)

    Lisagor, W. B.; Stein, B. A.

    1982-01-01

    The differences between powder and ingot metallurgy processing of aluminum alloys are outlined. The potential payoff in the use of advanced powder metallurgy (PM) aluminum alloys in future transport aircraft is indicated. The national program to bring this technology to commercial fruition and the NASA Langley Research Center role in this program are briefly outlined. Some initial results of research in 2000-series PM alloys and composites that highlight the property improvements possible are given.

  20. Research of plating aluminum and aluminum foil on internal surface of carbon fiber composite material centrifuge rotor drum

    International Nuclear Information System (INIS)

    Lu Xiuqi; Dong Jinping; Dai Xingjian

    2014-01-01

    In order to improve the corrosion resistance, thermal conductivity and sealability of the internal surface of carbon fiber/epoxy composite material centrifuge rotor drum, magnetron sputtering aluminum and pasting an aluminum foil on the inner wall of the drum are adopted to realize the aim. By means of XRD, SEM/EDS and OM, the surface topography of aluminum coated (thickness of 5 μm and 12 μm) and aluminum foil (12 μm) are observed and analyzed; the cohesion of between aluminum coated (or aluminum foil) and substrate material (CFRP) is measured by scratching experiment, direct drawing experiment, and shear test. Besides, the ultra-high-speed rotation experiment of CFRP ring is carried out to analyze stress and strain of coated aluminum (or aluminum foil) which is adhered on the ring. The results showed aluminum foil pasted on inner surface do better performance than magnetron sputtering aluminum on CFRP centrifuge rotor drum. (authors)

  1. Soil Quality of Restinga Forest: Organic Matter and Aluminum Saturation

    Science.gov (United States)

    Rodrigues Almeida Filho, Jasse; Casagrande, José Carlos; Martins Bonilha, Rodolfo; Soares, Marcio Roberto; Silva, Luiz Gabriel; Colato, Alexandre

    2013-04-01

    The restinga vegetation (sand coastal plain vegetation) consists of a mosaic of plant communities, which are defined by the characteristics of the substrates, resulting from the type and age of the depositional processes. This mosaic complex of vegetation types comprises restinga forest in advanced (high restinga) and medium regeneration stages (low restinga), each with particular differentiating vegetation characteristics. Of all ecosystems of the Atlantic Forest, restinga is the most fragile and susceptible to anthropic disturbances. The purpose of this study was evaluating the organic matter and aluminum saturation effects on soil quality index (SQI). Two locations were studied: State Park of the Serra do Mar, Picinguaba, in the city of Ubatuba (23°20' e 23°22' S / 44°48' e 44°52' W), and State Park of Cardoso Island in the city of Cananéia (25°03'05" e 25°18'18" S / 47°53'48" e 48° 05'42" W). The soil samples were collect at a depth of 0-10 cm, where concentrate 70% of vegetation root system. Was studied an additive model to evaluate soil quality index. The shallow root system development occurs due to low calcium levels, whose disability limits their development, but also can reflect on delay, restriction or even in the failure of the development vegetation. The organic matter is kept in the soil restinga ecosystem by high acidity, which reduces the decomposition of soil organic matter, which is very poor in nutrients. The base saturation, less than 10, was low due to low amounts of Na, K, Ca and Mg, indicating low nutritional reserve into the soil, due to very high rainfall and sandy texture, resulting in high saturation values for aluminum. Considering the critical threshold to 3% organic matter and for aluminum saturation to 40%, the IQS ranged from 0.95 to 0.1 as increased aluminum saturation and decreased the soil organic matter, indicating the main limitation to the growth of plants in this type of soil, when deforested.

  2. Studies of aluminum in rat brain

    Energy Technology Data Exchange (ETDEWEB)

    Lipman, J.J.; Brill, A.B.; Som, P.; Jones, K.W.; Colowick, S.; Cholewa, M.

    1985-01-01

    The effects of high aluminum concentrations in rat brains were studied using /sup 14/C autoradiography to measure the uptake of /sup 14/C 2-deoxy-D-glucose (/sup 14/C-2DG) and microbeam proton-induced x-ray emission (microPIXE) with a 20-..mu..m resolution to measure concentrations of magnesium, aluminum, potassium, and calcium. The aluminum was introduced intracisternally in the form of aluminum tartrate (Al-T) while control animals were given sodium tartrate (Na-T). The /sup 14/C was administered intravenously. The animals receiving Al-T developed seizure disorders and had pathological changes that included cerebral cortical atrophy. The results showed that there was a decreased uptake of /sup 14/C-2DG in cortical regions in which increased aluminum levels were measured, i.e., there is a correlation between the aluminum in the rat brain and decreased brain glucose metabolism. A minimum detection limit of about 16 ppM (mass fraction) or 3 x 10/sup 9/ Al atoms was obtained for Al under the conditions employed. 14 refs., 4 figs., 1 tab.

  3. Aluminum neurotoxicity in the rat brain

    Energy Technology Data Exchange (ETDEWEB)

    Yumoto, S [Tokyo Univ. (Japan). Faculty of Medicine; Ohashi, H; Nagai, H; Kakimi, S; Ogawa, Y; Iwata, Y; Ishii, K

    1993-12-31

    To investigate the etiology of Alzheimer`s disease, we administered aluminum to healthy rats and examined the aluminum uptake in the brain and isolated brain cell nuclei by particle-induced X-ray emission (PIXE) analysis. Ten days after the last injection, Al was detected in the rat brain and in isolated brain cell nuclei by PIXE analysis. Al was also demonstrated in the brain after 15 months of oral aluminum administration. Moreover, Al was detected in the brain and isolated brain cell nuclei from the patients with Alzheimer`s disease. Silver impregnation studies revealed that spines attached to the dendritic processes of cortical nerve cells decreased remarkably after aluminum administration. Electron microscopy revealed characteristic inclusion bodies in the hippocampal nerve cells 75 days after the injection. These morphological changes in the rat brain after the aluminum administration were similar to those reportedly observed in the brain of Alzheimer`s disease patients. Our results indicate that Alzheimer`s disease is caused by irreversible accumulation of aluminum in the brain, as well as in the nuclei of brain cells. (author).

  4. Aluminum neurotoxicity in the rat brain

    International Nuclear Information System (INIS)

    Yumoto, S.; Ohashi, H.; Nagai, H.; Kakimi, S.; Ogawa, Y.; Iwata, Y.; Ishii, K.

    1992-01-01

    To investigate the etiology of Alzheimer's disease, we administered aluminum to healthy rats and examined the aluminum uptake in the brain and isolated brain cell nuclei by particle-induced X-ray emission (PIXE) analysis. Ten days after the last injection, Al was detected in the rat brain and in isolated brain cell nuclei by PIXE analysis. Al was also demonstrated in the brain after 15 months of oral aluminum administration. Moreover, Al was detected in the brain and isolated brain cell nuclei from the patients with Alzheimer's disease. Silver impregnation studies revealed that spines attached to the dendritic processes of cortical nerve cells decreased remarkably after aluminum administration. Electron microscopy revealed characteristic inclusion bodies in the hippocampal nerve cells 75 days after the injection. These morphological changes in the rat brain after the aluminum administration were similar to those reportedly observed in the brain of Alzheimer's disease patients. Our results indicate that Alzheimer's disease is caused by irreversible accumulation of aluminum in the brain, as well as in the nuclei of brain cells. (author)

  5. Studies of aluminum in rat brain

    International Nuclear Information System (INIS)

    Lipman, J.J.; Brill, A.B.; Som, P.; Jones, K.W.; Colowick, S.; Cholewa, M.

    1985-01-01

    The effects of high aluminum concentrations in rat brains were studied using 14 C autoradiography to measure the uptake of 14 C 2-deoxy-D-glucose ( 14 C-2DG) and microbeam proton-induced x-ray emission (microPIXE) with a 20-μm resolution to measure concentrations of magnesium, aluminum, potassium, and calcium. The aluminum was introduced intracisternally in the form of aluminum tartrate (Al-T) while control animals were given sodium tartrate (Na-T). The 14 C was administered intravenously. The animals receiving Al-T developed seizure disorders and had pathological changes that included cerebral cortical atrophy. The results showed that there was a decreased uptake of 14 C-2DG in cortical regions in which increased aluminum levels were measured, i.e., there is a correlation between the aluminum in the rat brain and decreased brain glucose metabolism. A minimum detection limit of about 16 ppM (mass fraction) or 3 x 10 9 Al atoms was obtained for Al under the conditions employed. 14 refs., 4 figs., 1 tab

  6. Spray rolling aluminum alloy strip

    Energy Technology Data Exchange (ETDEWEB)

    McHugh, Kevin M.; Delplanque, J.-P.; Johnson, S.B.; Lavernia, E.J.; Zhou, Y.; Lin, Y

    2004-10-10

    Spray rolling combines spray forming with twin-roll casting to process metal flat products. It consists of atomizing molten metal with a high velocity inert gas, cooling the resultant droplets in flight and directing the spray between mill rolls. In-flight convection heat transfer from atomized droplets teams with conductive cooling at the rolls to rapidly remove the alloy's latent heat. Hot deformation of the semi-solid material in the rolls results in fully consolidated, rapidly solidified product. While similar in some ways to twin-roll casting, spray rolling has the advantage of being able to process alloys with broad freezing ranges at high production rates. This paper describes the process and summarizes microstructure and tensile properties of spray-rolled 2124 and 7050 aluminum alloy strips. A Lagrangian/Eulerian poly-dispersed spray flight and deposition model is described that provides some insight into the development of the spray rolling process. This spray model follows droplets during flight toward the rolls, through impact and spreading, and includes oxide film formation and breakup when relevant.

  7. Aluminum bioavailability from tea infusion.

    Science.gov (United States)

    Yokel, Robert A; Florence, Rebecca L

    2008-12-01

    The objective was to estimate oral Al bioavailability from tea infusion in the rat, using the tracer (26)Al. (26)Al citrate was injected into tea leaves. An infusion was prepared from the dried leaves and given intra-gastrically to rats which received concurrent intravenous (27)Al infusion. Oral Al bioavailability (F) was calculated from the area under the (26)Al, compared to (27)Al, serum concentration x time curves. Bioavailability from tea averaged 0.37%; not significantly different from water (F=0.3%), or basic sodium aluminum phosphate (SALP) in cheese (F=0.1-0.3%), but greater than acidic SALP in a biscuit (F=0.1%). Time to maximum serum (26)Al concentration was 1.25, 1.5, 8 and 4.8h, respectively. These results of oral Al bioavailability x daily consumption by the human suggest tea can provide a significant amount of the Al that reaches systemic circulation. This can allow distribution to its target organs of toxicity, the central nervous, skeletal and hematopoietic systems. Further testing of the hypothesis that Al contributes to Alzheimer's disease may be more warranted with studies focusing on total average daily food intake, including tea and other foods containing appreciable Al, than drinking water.

  8. Anodized aluminum on LDEF: A current status of measurements on chromic acid anodized aluminum

    International Nuclear Information System (INIS)

    Golden, J.L.

    1992-01-01

    Chromic acid anodize was used as the exterior coating for aluminum surfaces on LDEF to provide passive thermal control. Chromic acid anodized aluminum was also used as test specimens in thermal control coatings experiments. The following is a compilation and analysis of the data obtained thus far

  9. Anodized aluminum on LDEF: A current status of measurements on chromic acid anodized aluminum

    Science.gov (United States)

    Golden, Johnny L.

    1992-01-01

    Chromic acid anodize was used as the exterior coating for aluminum surfaces on LDEF to provide passive thermal control. Chromic acid anodized aluminum was also used as test specimens in thermal control coatings experiments. The following is a compilation and analysis of the data obtained thus far.

  10. Casting Characteristics of High Cerium Content Aluminum Alloys

    Energy Technology Data Exchange (ETDEWEB)

    Weiss, D; Rios, O R; Sims, Z C; McCall, S K; Ott, R T

    2017-09-05

    This paper compares the castability of the near eutectic aluminum-cerium alloy system to the aluminum-silicon and aluminum-copper systems. The alloys are compared based on die filling capability, feeding characteristics and tendency to hot tear in both sand cast and permanent mold applications. The castability ranking of the binary Al–Ce systems is as good as the aluminum-silicon system with some deterioration as additional alloying elements are added. In alloy systems that use cerium in combination with common aluminum alloying elements such as silicon, magnesium and/or copper, the casting characteristics are generally better than the aluminum-copper system. In general, production systems for melting, de-gassing and other processing of aluminum-silicon or aluminum-copper alloys can be used without modification for conventional casting of aluminum-cerium alloys.

  11. Problems in repair-welding of duplex-treated tool steels

    OpenAIRE

    T. Muhič; J. Tušek; M. Pleterski; D. Bombač

    2009-01-01

    The present paper addresses problems in laser welding of die-cast tools used for aluminum pressure die-castings and plastic moulds. To extend life cycle of tools various surface improvements are used. These surface improvements significantly reduce weldability of the material. This paper presents development of defects in repair welding of duplex-treated tool steel. The procedure is aimed at reduction of defects by the newly developed repair laser welding techniques. Effects of different repa...

  12. Problemi kod reparaturnog zavarivanja alatnog čelika sa duplex zaštitom

    OpenAIRE

    Muhič, T.; Tušek, J.; Pleterski, M.; Bombač, D.

    2009-01-01

    The present paper addresses problems in laser welding of die-cast tools used for aluminum pressure die-castings and plastic moulds. To extend life cycle of tools various surface improvements are used. These surface improvements significantly reduce weldability of the material. This paper presents development of defects in repair welding of duplex-treated tool steel. The procedure is aimed at reduction of defects by the newly developed repair laser welding techniques. Effects of different repa...

  13. Study of Shell Zone Formation in Lithographic and Anodizing Quality Aluminum Alloys: Experimental and Numerical Approach

    Science.gov (United States)

    Brochu, Christine; Larouche, André; Hark, Robert

    Shell thickness is an important quality factor for lithographic and anodizing quality aluminum alloys. Increasing pressure is placed on casting plants to produce a thinner shell zone for these alloys. This study, based on plant trials and mathematical modelling highlights the most significant parameters influencing shell zone formation. Results obtained show the importance of metal temperature and distribution and mould metal level on shell zone formation. As an answer to specific plant problems, this study led to the development of improved metal distribution systems for DC casting of litho and anodizing quality alloys.

  14. Experimental and numerical analysis of the combustor for a cogeneration system based on the aluminum/water reaction

    International Nuclear Information System (INIS)

    Milani, Massimo; Montorsi, Luca; Paltrinieri, Fabrizio; Stefani, Matteo

    2014-01-01

    Highlights: • Aluminum reaction with water is studied as a technology for hydrogen production. • A test rig is developed for the analysis of aluminum/water reaction. • The system is the core component of a cogeneration plant for hydrogen/power production. • The interaction of liquid aluminum jet and water steam stream is investigated. • The main capabilities of the injection system are assessed. - Abstract: The paper focuses on the design of the experimental apparatus aimed at analyzing the performance of the combustion chamber of a cogeneration system based on the reaction of liquid aluminum and water steam. The cogeneration system exploits the heat released by the oxidation of aluminum with water for super-heating the vapor of a steam cycle and simultaneously producing hydrogen. The only by-product is alumina, which in a closed loop can be recycled back and transformed again into aluminum. Therefore, aluminum is used as an energy carrier to transport the energy from the alumina reduction plant to the location of the proposed system. The water is also used in a closed loop since the amount of water produced employing the hydrogen obtained by the proposed system corresponds to the oxidizing water for the Al/H 2 O reaction. This study investigates the combustor where the liquid aluminum–steam reaction takes place. In particular, the design of the combustion chamber and the interaction between the liquid aluminum jet and the water steam flow are evaluated using a numerical and an experimental approach. The test rig is specifically designed for the analysis of the liquid aluminum injection in a slightly super-heated steam stream. The first experiments are carried out to verify the correct behavior of the test rig. Thermography is employed to qualitatively assess the steam entrainment of the liquid aluminum jet. Finally, the experimental measurements are compared with the multi-dimension multi-phase flow simulations in order to estimate the influence of

  15. Deposition behavior of residual aluminum in drinking water distribution system: Effect of aluminum speciation.

    Science.gov (United States)

    Zhang, Yue; Shi, Baoyou; Zhao, Yuanyuan; Yan, Mingquan; Lytle, Darren A; Wang, Dongsheng

    2016-04-01

    Finished drinking water usually contains some residual aluminum. The deposition of residual aluminum in distribution systems and potential release back to the drinking water could significantly influence the water quality at consumer taps. A preliminary analysis of aluminum content in cast iron pipe corrosion scales and loose deposits demonstrated that aluminum deposition on distribution pipe surfaces could be excessive for water treated by aluminum coagulants including polyaluminum chloride (PACl). In this work, the deposition features of different aluminum species in PACl were investigated by simulated coil-pipe test, batch reactor test and quartz crystal microbalance with dissipation monitoring. The deposition amount of non-polymeric aluminum species was the least, and its deposition layer was soft and hydrated, which indicated the possible formation of amorphous Al(OH)3. Al13 had the highest deposition tendency, and the deposition layer was rigid and much less hydrated, which indicated that the deposited aluminum might possess regular structure and self-aggregation of Al13 could be the main deposition mechanism. While for Al30, its deposition was relatively slower and deposited aluminum amount was relatively less compared with Al13. However, the total deposited mass of Al30 was much higher than that of Al13, which was attributed to the deposition of particulate aluminum matters with much higher hydration state. Compared with stationary condition, stirring could significantly enhance the deposition process, while the effect of pH on deposition was relatively weak in the near neutral range of 6.7 to 8.7. Copyright © 2015. Published by Elsevier B.V.

  16. Electrochemically replicated smooth aluminum foils for anodic alumina nanochannel arrays

    International Nuclear Information System (INIS)

    Biring, Sajal; Tsai, K-T; Sur, Ujjal Kumar; Wang, Y-L

    2008-01-01

    A fast electrochemical replication technique has been developed to fabricate large-scale ultra-smooth aluminum foils by exploiting readily available large-scale smooth silicon wafers as the masters. Since the adhesion of aluminum on silicon depends on the time of surface pretreatment in water, it is possible to either detach the replicated aluminum from the silicon master without damaging the replicated aluminum and master or integrate the aluminum film to the silicon substrate. Replicated ultra-smooth aluminum foils are used for the growth of both self-organized and lithographically guided long-range ordered arrays of anodic alumina nanochannels without any polishing pretreatment

  17. Precision forging technology for aluminum alloy

    Science.gov (United States)

    Deng, Lei; Wang, Xinyun; Jin, Junsong; Xia, Juchen

    2018-03-01

    Aluminum alloy is a preferred metal material for lightweight part manufacturing in aerospace, automobile, and weapon industries due to its good physical properties, such as low density, high specific strength, and good corrosion resistance. However, during forging processes, underfilling, folding, broken streamline, crack, coarse grain, and other macro- or microdefects are easily generated because of the deformation characteristics of aluminum alloys, including narrow forgeable temperature region, fast heat dissipation to dies, strong adhesion, high strain rate sensitivity, and large flow resistance. Thus, it is seriously restricted for the forged part to obtain precision shape and enhanced property. In this paper, progresses in precision forging technologies of aluminum alloy parts were reviewed. Several advanced precision forging technologies have been developed, including closed die forging, isothermal die forging, local loading forging, metal flow forging with relief cavity, auxiliary force or vibration loading, casting-forging hybrid forming, and stamping-forging hybrid forming. High-precision aluminum alloy parts can be realized by controlling the forging processes and parameters or combining precision forging technologies with other forming technologies. The development of these technologies is beneficial to promote the application of aluminum alloys in manufacturing of lightweight parts.

  18. Determination of aluminum by four analytical methods

    International Nuclear Information System (INIS)

    Hanson, T.J.; Smetana, K.M.

    1975-11-01

    Four procedures have been developed for determining the aluminum concentration in basic matrices. Atomic Absorption Spectroscopy (AAS) was the routine method of analysis. Citrate was required to complex the aluminum and eliminate matrix effects. AAS was the least accurate of the four methods studied and was adversely affected by high aluminum concentrations. The Fluoride Electrode Method was the most accurate and precise of the four methods. A Gran's Plot determination was used to determine the end point and average standard recovery was 100% +- 2%. The Thermometric Titration Method was the fastest method for determining aluminum and could also determine hydroxide concentration at the same time. Standard recoveries were 100% +- 5%. The pH Electrode Method also measures aluminum and hydroxide content simultaneously, but is less accurate and more time consuming that the thermal titration. Samples were analyzed using all four methods and results were compared to determine the strengths and weaknesses of each. On the basis of these comparisons, conclusions were drawn concerning the application of each method to our laboratory needs

  19. Growth and ABA responses of maple seedlings to aluminum

    Energy Technology Data Exchange (ETDEWEB)

    Bertrand, A.; Robitaille, G.; Boutin, R. [Canadian Forestry Service, Sainte Foy, PQ (Canada); Nadeau, P. [Agriculture and Agri-Food Canada Research Station, Sainte-Foy, PQ (Canada)

    1995-12-01

    The impacts of low pH and 2.0 mM aluminum (Al) on the growth of sugar maple seedlings was assessed over a 13-week period. The hypothesis was that low pH and high aluminum concentration would lower the vigor of sugar maple seedlings and were contributing factors to sugar maple stand decline. The effects of the stresses were measured in roots and shoots. The concentration of abscisis acid (ABA) in xylem sap in response to Al over time was measured to determine whether it could be used as an indicator of Al stress in sugar maple seedlings. At week 9, total leaf area of Al-treated seedlings was reduced by 27%, but by week 13 leaf area was similar for seedlings in all treatments. None of the other growth parameters examined were negatively affected by the treatments at either week 9 or week 13. ABA concentration in the xylem sap was not affected by any of the treatments. The duration of exposure to Al was found critical when assessing a threshold concentration for Al toxicity because plants can acclimate to an Al concentration previously considered toxic. 36 refs., 1 tab., 6 figs.

  20. Lithium-aluminum-magnesium electrode composition

    Science.gov (United States)

    Melendres, Carlos A.; Siegel, Stanley

    1978-01-01

    A negative electrode composition is presented for use in a secondary, high-temperature electrochemical cell. The cell also includes a molten salt electrolyte of alkali metal halides or alkaline earth metal halides and a positive electrode including a chalcogen or a metal chalcogenide as the active electrode material. The negative electrode composition includes up to 50 atom percent lithium as the active electrode constituent and a magnesium-aluminum alloy as a structural matrix. Various binary and ternary intermetallic phases of lithium, magnesium, and aluminum are formed but the electrode composition in both its charged and discharged state remains substantially free of the alpha lithium-aluminum phase and exhibits good structural integrity.

  1. Lithium-aluminum-iron electrode composition

    Science.gov (United States)

    Kaun, Thomas D.

    1979-01-01

    A negative electrode composition is presented for use in a secondary electrochemical cell. The cell also includes an electrolyte with lithium ions such as a molten salt of alkali metal halides or alkaline earth metal halides that can be used in high-temperature cells. The cell's positive electrode contains a a chalcogen or a metal chalcogenide as the active electrode material. The negative electrode composition includes up to 50 atom percent lithium as the active electrode constituent in an alloy of aluminum-iron. Various binary and ternary intermetallic phases of lithium, aluminum and iron are formed. The lithium within the intermetallic phase of Al.sub.5 Fe.sub.2 exhibits increased activity over that of lithium within a lithium-aluminum alloy to provide an increased cell potential of up to about 0.25 volt.

  2. Diffusionless bonding of aluminum to Zircaloy-2

    International Nuclear Information System (INIS)

    Watson, R.D.

    1965-04-01

    Aluminum can be bonded to zirconium without difficulty even when a thin layer of oxide is present on the surface of the zirconium . No detectable diffusion takes place during the bonding process. The bond layer can be stretched as much. as 8% without affecting the bond. The bond can be heated for 1000 hours at 260 o C (500 o F), and can be water quenched from 260 o C (500 o F) without any noticeable change in the bond strength. An extrusion technique has been devised for making transition sections of aluminum bonded to zirconium which can then be used to join these metals by conventional welding. Welding can be done close to the bond zone without seriously affecting the integrity of the bond. This method of bonding aluminum to Zircaloy-2 is covered by Canadian patent 702,438 January 26, 1965. (author)

  3. NASA-427: A New Aluminum Alloy

    Science.gov (United States)

    Nabors, Sammy A.

    2015-01-01

    NASA's Marshall Space Flight Center researchers have developed a new, stronger aluminum alloy, ideal for cast aluminum products that have powder or paint-baked thermal coatings. With advanced mechanical properties, the NASA-427 alloy shows greater tensile strength and increased ductility, providing substantial improvement in impact toughness. In addition, this alloy improves the thermal coating process by decreasing the time required for heat treatment. With improvements in both strength and processing time, use of the alloy provides reduced materials and production costs, lower product weight, and better product performance. The superior properties of NASA-427 can benefit many industries, including automotive, where it is particularly well-suited for use in aluminum wheels.

  4. Aluminum phosphate ceramics for waste storage

    Science.gov (United States)

    Wagh, Arun; Maloney, Martin D

    2014-06-03

    The present disclosure describes solid waste forms and methods of processing waste. In one particular implementation, the invention provides a method of processing waste that may be particularly suitable for processing hazardous waste. In this method, a waste component is combined with an aluminum oxide and an acidic phosphate component in a slurry. A molar ratio of aluminum to phosphorus in the slurry is greater than one. Water in the slurry may be evaporated while mixing the slurry at a temperature of about 140-200.degree. C. The mixed slurry may be allowed to cure into a solid waste form. This solid waste form includes an anhydrous aluminum phosphate with at least a residual portion of the waste component bound therein.

  5. Study of aluminum-doped silicon clusters

    International Nuclear Information System (INIS)

    Zhan Shichang; Li Baoxing; Yang Jiansong

    2007-01-01

    Using full-muffin-tin-orbital molecular-dynamics (FP-LMTO-MD) method, we have investigated the effect of aluminum heteroatoms on the geometric structures and bond characteristics of Si n (n=5-10) clusters in detail. It is found that the geometric framework of the ground state structures for Si n (n=5-10) clusters change to some extent upon the substitution of Al atoms in some Si atoms. The effect of aluminum doping on the silicon clusters depends on the geometric structures of Si n (n=5-10) clusters. In particular, the calculations suggest that the aluminum doping would improve the bond strength of some Si-Si bonds in the mixed Si n - m Al m clusters

  6. Study on Explosive Forming of Aluminum Alloy

    Directory of Open Access Journals (Sweden)

    H Iyama

    2016-09-01

    Full Text Available Now, the aluminum alloy is often used as auto parts, for example, body, engine. For example, there are the body, a cylinder block, a piston, a connecting rod, interior, exterior parts, etc. These are practical used the characteristic of a light and strong aluminum alloy efficiently. However, although an aluminum alloy is lighter than steel, the elongation is smaller than that. Therefore, in press forming, some problems often occur. We have proposed use of explosive forming, in order to solve this problem. In the explosive forming, since a blank is formed at high speed, a strain rate effect becomes large and it can be made the elongation is larger. Then, in order to clarify this feature, we carried out experimental research and numerical analysis. In this paper, these contents will be discussed.

  7. Air-Impregnated Nanoporous Anodic Aluminum Oxide Layers for Enhancing the Corrosion Resistance of Aluminum.

    Science.gov (United States)

    Jeong, Chanyoung; Lee, Junghoon; Sheppard, Keith; Choi, Chang-Hwan

    2015-10-13

    Nanoporous anodic aluminum oxide layers were fabricated on aluminum substrates with systematically varied pore diameters (20-80 nm) and oxide thicknesses (150-500 nm) by controlling the anodizing voltage and time and subsequent pore-widening process conditions. The porous nanostructures were then coated with a thin (only a couple of nanometers thick) Teflon film to make the surface hydrophobic and trap air in the pores. The corrosion resistance of the aluminum substrate was evaluated by a potentiodynamic polarization measurement in 3.5 wt % NaCl solution (saltwater). Results showed that the hydrophobic nanoporous anodic aluminum oxide layer significantly enhanced the corrosion resistance of the aluminum substrate compared to a hydrophilic oxide layer of the same nanostructures, to bare (nonanodized) aluminum with only a natural oxide layer on top, and to the latter coated with a thin Teflon film. The hydrophobic nanoporous anodic aluminum oxide layer with the largest pore diameter and the thickest oxide layer (i.e., the maximized air fraction) resulted in the best corrosion resistance with a corrosion inhibition efficiency of up to 99% for up to 7 days. The results demonstrate that the air impregnating the hydrophobic nanopores can effectively inhibit the penetration of corrosive media into the pores, leading to a significant improvement in corrosion resistance.

  8. Oxidation of nano-sized aluminum powders

    International Nuclear Information System (INIS)

    Vorozhtsov, A.B.; Lerner, M.; Rodkevich, N.; Nie, H.; Abraham, A.; Schoenitz, M.; Dreizin, E.L.

    2016-01-01

    Highlights: • Weight gain measured in TG oxidation experiments was split between particles of different sizes. • Reaction kinetics obtained by isoconversion explicitly accounting for the effect of size distribution. • Activation energy is obtained as a function of oxide thickness for growth of amorphous alumina. • Oxidation mechanism for nanopowders remains the same as for coarser aluminum powders. - Abstract: Oxidation of aluminum nanopowders obtained by electro-exploded wires is studied. Particle size distributions are obtained from transmission electron microscopy (TEM) images. Thermo-gravimetric (TG) experiments are complemented by TEM and XRD studies of partially oxidized particles. Qualitatively, oxidation follows the mechanism developed for coarser aluminum powder and resulting in formation of hollow oxide shells. Sintering of particles is also observed. The TG results are processed to account explicitly for the particle size distribution and spherical shapes, so that oxidation of particles of different sizes is characterized. The apparent activation energy is obtained as a function of the reaction progress using model-free isoconversion processing of experimental data. A complete phenomenological oxidation model is then proposed assuming a spherically symmetric geometry. The oxidation kinetics of aluminum powder is shown to be unaffected by particle sizes reduced down to tens of nm. The apparent activation energy describing growth of amorphous alumina is increasing at the very early stages of oxidation. The higher activation energy is likely associated with an increasing homogeneity in the growing amorphous oxide layer, initially containing multiple defects and imperfections. The trends describing changes in both activation energy and pre-exponent of the growing amorphous oxide are useful for predicting ignition delays of aluminum particles. The kinetic trends describing activation energies and pre-exponents in a broader range of the oxide

  9. Thermally sprayed coatings: Aluminum on lead

    International Nuclear Information System (INIS)

    Usmani, S.; Czajkowski, C.J.; Zatorski, R.

    1999-01-01

    An experimental program to determine the feasibility of thermally spraying aluminum on a lead substrate was initiated in support of the accelerator production of tritium (APT) Project for the US Department of Energy. The program consisted of two distinct parts: (1) the characterization of the thermally sprayed coatings, including microhardness testing, effects of heating, and microstructure and porosity determinations, and (2) effects of mercury doping and heat treatments on the thermally sprayed composite. The project determined that aluminum could successfully be thermally sprayed onto the lead. The coatings had a dense microstructure, with a Vicker's Pyramid Hardness (VPH) of about 60, and a maximum porosity (found in strips on the samples) of 12%

  10. Weld Development for Aluminum Fission Chamber

    Energy Technology Data Exchange (ETDEWEB)

    Cross, Carl Edward [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Martinez, Jesse Norris [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-05-16

    The Sigma welding team was approached to help fabricate a small fission chamber (roughly ½ inch dia. x ½ inch tall cylinder). These chambers are used as radiation sensors that contain small traces of radionuclides (Cf 252, U 235, and U 238) that serve to ionize gas atoms in addition to external radiation. When a voltage is applied within the chamber, the resulting ion flow can be calibrated and monitored. Aluminum has the advantage of not forming radioactive compounds when exposed to high external radiation (except from minor Na alloy content). Since aluminum has not been used before in this application, this presented an unexplored challenge.

  11. A 1-D Analytical Model for the Thermally Induced Stresses in the Mould Surface During Die Casting

    DEFF Research Database (Denmark)

    Hattel, Jesper; Hansen, Preben

    1994-01-01

    This paper presents an anlytically based method for predicting the normal stresses in a die mold surface exposed to a thermal load. A example of application of the method is the high-pressure di casting process where the surface stresses in critical cases lead to cracks. Expressions for the normal...... stresses as afunction of the thermal and mechanical properties have been developed for a casting both without and with a coating. Finally, the resulting relationships are derived and evaluated, with particular emphasis on the effect of the heat transfer coefficient between the casting and the mold....

  12. Assembly optimization realized by a die-cast magnesium construction; Montageverbesserungen verwirklicht durch eine Magnesium-Druckguss-Konstruktion

    Energy Technology Data Exchange (ETDEWEB)

    Tikal, F.; Vollmer, C.; Pippert, J.

    1996-11-01

    Vehicle development today cannot be envisaged without non-contact and slip free distance- and speed-measurement. As it is superior to contact methods in terms of reliability and accuracy, it has gained more and more acceptance in the past few years and now provides measurement results of the utmost precision. This is particularly necessary in the large application range of tyre and vehicle development to ensure high safety levels; moreover, it is required for future vehicle control systems, as they need precise speed information for ABS, ASC, or for navigation methods. In principle, optical acoustic and microwave sensors can be used for these applications. The microwave sensors can be used for these applications. The microwave-Doppler principle provides certain advantages over optical or ultrasound methods as it can be used under any weather conditions and provides a larger vertical operating range and a long lifespan. Datron-Messtechnik, market leader in the field of correlator optical speed sensors, has made use of this measurement principle and with its microwave sensor introduces a new development covering the great demands of speed measurement. (orig.) [Deutsch] Die Pkw-Tuer, ein Bestandteil der Karosserie, ist im Laufe der Automobilgeschichte nicht wesentlich veraendert worden. Jedoch mussten in den letzten Jahren Flankenschutz, Seitenairbag und andere neue Bauteile in die Tuer integriert werden. Diese Elemente der passiven Sicherheit sind vom Verbraucher gewuenschte Schutzmassnahmen. Mit dem gehobenen Sicherheitsimage bemuehen sich die Produzenten, den potentiellen Kaeufer zum Kauf ihres Produktes zu bewegen. Am Institut fuer Produktionstechnik und Logistik (IPL) der Universitaet Gesamthochschule Kassel (GhK) wurde eine Pkw-Tuer, basierend auf einem Magnesium-Druckgussrahmen, entwickelt. Zur Orientierung und Studienzwecken ist ein Holzmodell erstellt worden. Mit dem praxisnahen Modell konnte die Montage und der Einbau in das Automobil getestet werden. Das Gussverfahren ermoeglicht die hochintegrierte Bauweise. Der modulartige Aufbau und die Vorteile von Magnesium als Leichtbauwerkstoff erlauben neuartige Ansaetze im Vergleich zu konventionellen Konstruktionen. (orig.)

  13. Influence of surface liquid segregation on corrosion behavior of semi-solid metal high pressure die cast aluminium alloys

    CSIR Research Space (South Africa)

    Masuku, EP

    2010-09-01

    Full Text Available alloys 7075-T6 and 2024-T6. Potentiodynamic testing was performed in deaerated 3.5%NaCl solution. In separate tests, the open-circuit potential was monitored in aerated 3.5% NaCl for 30 minutes after immersion. The electrochemical tests show...

  14. Anodization process produces opaque, reflective coatings on aluminum

    Science.gov (United States)

    1965-01-01

    Opaque, reflective coatings are produced on aluminum articles by an anodizing process wherein the anodizing bath contains an aqueous dispersion of finely divided insoluble inorganic compounds. These particles appear as uniformly distributed occlusions in the anodic deposit on the aluminum.

  15. Evaluation of aluminum migration into foodstuffs from aluminium cookware

    Directory of Open Access Journals (Sweden)

    M Radi

    2014-05-01

    Full Text Available Nowadays, the existence of aluminum in human diet as a food contaminant has attracted the concerns of many researchers. It seems that the cooking pans are common sources of aluminum exposure through foodstuffs in Iran. The aim of this study was to evaluate the migration of aluminum from cooking containers into foodstuffs. For this purpose, solutions with different concentrations of citric acid, sodium chloride, fat, protein and sugar were prepared and migration of aluminum into these solutions was measured using atomic absorption spectrometry. Results showed that salt and citric acid concentrations could enhance aluminum migration; whereas, acid concentration was more effective than salt due to its corrosive effect. The intensity of heat processing and the duration of heat treatment had direct relation with aluminum migration. The aluminum content of cooked foods in aluminum cooking pans was also significantly more than control samples.

  16. Low Mass, Aluminum NOFBX Combustion Chamber Development, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Our team proposes to define a diffusion bonding process for aluminum as an enabling step to ultimately develop an innovative, lightweight, long life, aluminum...

  17. Exploration the extrudability of aluminum matrix composite (LM6/TIC ...

    African Journals Online (AJOL)

    Aluminum matrix composites (LM6/TiC) is a mix of excellent properties of aluminum ... ABAQUS/CAE software has been successfully employed for Modeling and ... Experimental results show that, many mechanical properties are improved and ...

  18. Effect of the aluminum flow pattern on the bonding of aluminum to oxidized Zircaloy-2

    International Nuclear Information System (INIS)

    Watson, R.D.; Lambert, J.P.

    1965-04-01

    The bonds produced when hot aluminum is allowed to flow smoothly from an extrusion die to the oxidized surface of a heated tube of Zircaloy-2 are consistently inferior to those produced with back-extruded flow. The difference is believed to be due to the reduction in, or elimination of, the oxide layer on the aluminum that comes in contact with the surface of the Zircaloy-2. This method of bonding aluminum to Zircaloy-2 is covered by Canadian patent 702,438 January 1965. (author)

  19. Enthalpy of formation of vanadates of iron, chromium, and aluminum

    Energy Technology Data Exchange (ETDEWEB)

    Kesler, Y.A.; Cheshnitskii, S.M.; Fotiev, A.A.; Tret' yakov, Y.D.

    1985-09-01

    The study of vanadates of iron, aluminum and chromium is of importance for the analysis of the functioning of catalysts of organic synthesis reactions and for the study of vanadium corrosion of structural materials. Of principal interest, however, are the processes in the treatment of vanadium-containing metallurgical slags and waste from thermal power plants, in which these compounds play a major role. At the same time, the thermochemical properties of these substances, which are necessary for creating the physicochemical foundations of industrially important processes, have not been investigated sufficiently. The authors therefore undertake here a study of the compounds FeVO/sub 4/, AIVO/sub 4/, CrVO/sub 4/ and FeCr(VO/sub 4/)/sub 2/, to determine their enthalpies of formation.

  20. Transition of hydrated oxide layer for aluminum electrolytic capacitors

    International Nuclear Information System (INIS)

    Chi, Choong-Soo; Jeong, Yongsoo; Ahn, Hong-Joo; Lee, Jong-Ho; Kim, Jung-Gu; Lee, Jun-Hee; Jang, Kyung-Wook; Oh, Han-Jun

    2007-01-01

    A hydrous oxide film for the application as dielectric film is synthesized by immersion of pure aluminum in hot water. From a Rutherford backscattering analysis, the ratio of aluminum to oxygen atoms was found to be 3:2 in the anodized aluminum oxide film, and 2:1 in the hydrous oxide layer. Anodization of the hydrous oxide layer was more effective for the transition of amorphous anodic oxides to the crystalline aluminum oxides

  1. Defect reduction in seeded aluminum nitride crystal growth

    Science.gov (United States)

    Bondokov, Robert T.; Schowalter, Leo J.; Morgan, Kenneth; Slack, Glen A; Rao, Shailaja P.; Gibb, Shawn Robert

    2017-09-26

    Bulk single crystal of aluminum nitride (AlN) having an areal planar defect density.ltoreq.100 cm.sup.-2. Methods for growing single crystal aluminum nitride include melting an aluminum foil to uniformly wet a foundation with a layer of aluminum, the foundation forming a portion of an AlN seed holder, for an AlN seed to be used for the AlN growth. The holder may consist essentially of a substantially impervious backing plate.

  2. Membrane Purification Cell for Aluminum Recycling

    Energy Technology Data Exchange (ETDEWEB)

    David DeYoung; James Wiswall; Cong Wang

    2011-11-29

    Recycling mixed aluminum scrap usually requires adding primary aluminum to the scrap stream as a diluent to reduce the concentration of non-aluminum constituents used in aluminum alloys. Since primary aluminum production requires approximately 10 times more energy than melting scrap, the bulk of the energy and carbon dioxide emissions for recycling are associated with using primary aluminum as a diluent. Eliminating the need for using primary aluminum as a diluent would dramatically reduce energy requirements, decrease carbon dioxide emissions, and increase scrap utilization in recycling. Electrorefining can be used to extract pure aluminum from mixed scrap. Some example applications include producing primary grade aluminum from specific scrap streams such as consumer packaging and mixed alloy saw chips, and recycling multi-alloy products such as brazing sheet. Electrorefining can also be used to extract valuable alloying elements such as Li from Al-Li mixed scrap. This project was aimed at developing an electrorefining process for purifying aluminum to reduce energy consumption and emissions by 75% compared to conventional technology. An electrolytic molten aluminum purification process, utilizing a horizontal membrane cell anode, was designed, constructed, operated and validated. The electrorefining technology could also be used to produce ultra-high purity aluminum for advanced materials applications. The technical objectives for this project were to: - Validate the membrane cell concept with a lab-scale electrorefining cell; - Determine if previously identified voltage increase issue for chloride electrolytes holds for a fluoride-based electrolyte system; - Assess the probability that voltage change issues can be solved; and - Conduct a market and economic analysis to assess commercial feasibility. The process was tested using three different binary alloy compositions (Al-2.0 wt.% Cu, Al-4.7 wt.% Si, Al-0.6 wt.% Fe) and a brazing sheet scrap composition (Al-2

  3. Use of low-cost aluminum in electric energy production

    Science.gov (United States)

    Zhuk, Andrey Z.; Sheindlin, Alexander E.; Kleymenov, Boris V.; Shkolnikov, Eugene I.; Lopatin, Marat Yu.

    Suppression of the parasitic corrosion while maintaining the electrochemical activity of the anode metal is one of the serious problems that affects the energy efficiency of aluminum-air batteries. The need to use high-purity aluminum or special aluminum-based alloys results in a significant increase in the cost of the anode, and thus an increase in the total cost of energy generated by the aluminum-air battery, which narrows the range of possible applications for this type of power source. This study considers the process of parasitic corrosion as a method for hydrogen production. Hydrogen produced in an aluminum-air battery by this way may be further employed in a hydrogen-air fuel cell (Hy-air FC) or in a heat engine, or it may be burnt to generate heat. Therefore, anode materials may be provided by commercially pure aluminum, commercially produced aluminum alloys, and secondary aluminum. These materials are much cheaper and more readily available than special anode alloys of aluminum and high-purity aluminum. The aim of present study is to obtain experimental data for comparison of energy and cost parameters of some commercially produced aluminum alloys, of high-purity aluminum, and of a special Al-ln anode alloy in the context of using these materials as anodes for an Al-air battery and for combined production of electrical power and hydrogen.

  4. 21 CFR 582.2122 - Aluminum calcium silicate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Aluminum calcium silicate. 582.2122 Section 582.2122 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED....2122 Aluminum calcium silicate. (a) Product. Aluminum calcium silicate. (b) Tolerance. 2 percent. (c...

  5. 21 CFR 182.2122 - Aluminum calcium silicate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Aluminum calcium silicate. 182.2122 Section 182.2122 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED....2122 Aluminum calcium silicate. (a) Product. Aluminum calcium silicate. (b) Tolerance. 2 percent. (c...

  6. Activated aluminum hydride hydrogen storage compositions and uses thereof

    Science.gov (United States)

    Sandrock, Gary; Reilly, James; Graetz, Jason; Wegrzyn, James E.

    2010-11-23

    In one aspect, the invention relates to activated aluminum hydride hydrogen storage compositions containing aluminum hydride in the presence of, or absence of, hydrogen desorption stimulants. The invention particularly relates to such compositions having one or more hydrogen desorption stimulants selected from metal hydrides and metal aluminum hydrides. In another aspect, the invention relates to methods for generating hydrogen from such hydrogen storage compositions.

  7. Passivation of aluminum with alkyl phosphonic acids for biochip applications

    Science.gov (United States)

    Attavar, Sachin; Diwekar, Mohit; Linford, Matthew R.; Davis, Mark A.; Blair, Steve

    2010-09-01

    Self-assembly of decylphosphonic acid (DPA) and octadecylphosphonic acid (ODPA) was studied on aluminum films using XPS, ToF-SIMS and surface wettability. Modified aluminum films were tested for passivation against silanization and subsequent oligonucleotide attachment. Passivation ratios of at least 450:1 compared to unprotected aluminum were obtained, as quantified by attachment of radio-labeled oligos.

  8. 21 CFR 73.1010 - Alumina (dried aluminum hydroxide).

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Alumina (dried aluminum hydroxide). 73.1010... GENERAL LISTING OF COLOR ADDITIVES EXEMPT FROM CERTIFICATION Drugs § 73.1010 Alumina (dried aluminum hydroxide). (a) Identity. (1) The color additive alumina (dried aluminum hydroxide) is a white, odorless...

  9. 21 CFR 582.1781 - Sodium aluminum phosphate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Sodium aluminum phosphate. 582.1781 Section 582.1781 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... Additives § 582.1781 Sodium aluminum phosphate. (a) Product. Sodium aluminum phosphate. (b) Conditions of...

  10. 21 CFR 73.1015 - Chromium-cobalt-aluminum oxide.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Chromium-cobalt-aluminum oxide. 73.1015 Section 73... LISTING OF COLOR ADDITIVES EXEMPT FROM CERTIFICATION Drugs § 73.1015 Chromium-cobalt-aluminum oxide. (a) Identity. The color additive chromium-cobalt-aluminum oxide is a blue-green pigment obtained by calcining a...

  11. 21 CFR 182.1781 - Sodium aluminum phosphate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Sodium aluminum phosphate. 182.1781 Section 182.1781 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... Food Substances § 182.1781 Sodium aluminum phosphate. (a) Product. Sodium aluminum phosphate. (b...

  12. Bearing capacity check of aluminum profiles

    Directory of Open Access Journals (Sweden)

    Cristian Grigoraşenco

    2013-06-01

    Full Text Available Because of suspended ceiling options to be customizable they are the choice for implementation in spaces like offices buildings, schools, hospitals and commercial premises. Recent problems with suspended gypsum ceilings falling in some commercial premises led to verification by tensile test and flexural bearing capacity of 5 types of aluminum elements used to suspend the ceilings.

  13. Absorptive coating for aluminum solar panels

    Science.gov (United States)

    Desmet, D.; Jason, A.; Parr, A.

    1979-01-01

    Method for coating forming coating of copper oxide from copper component of sheet aluminum/copper alloy provides strong durable solar heat collector panels. Copper oxide coating has solar absorption characteristics similar to black chrome and is much simpler and less costly to produce.

  14. Aluminum Solubility in Complex Electrolytes - 13011

    Energy Technology Data Exchange (ETDEWEB)

    Agnew, S.F. [Columbia Energy and Environmental Services, Inc., 1806 Terminal Dr., Richland, WA 99354 (United States); Johnston, C.T. [Dept. of Crop, Soil, and Environmental Sciences, Purdue University, West Lafayette, IN 47907 (United States)

    2013-07-01

    Predicting aluminum solubility for Hanford and Savannah River waste liquids is very important for their disposition. It is a key mission goal at each Site to leach as much aluminum as practical from sludges in order to minimize the amount of vitrified high level waste. And it is correspondingly important to assure that any soluble aluminum does not precipitate during subsequent decontamination of the liquid leachates with ion exchange. This report shows a very simple and yet thermodynamic model for aluminum solubility that is consistent with a wide range of Al liquors, from simple mixtures of hydroxide and aluminate to over 300 Hanford concentrates and to a set of 19 Bayer liquors for temperatures from 20-100 deg. C. This dimer-dS{sub mix} (DDS) model incorporates an ideal entropy of mixing along with previous reports for the Al dimer, water activities, gibbsite, and bayerite thermodynamics. We expect this model will have broad application for nuclear wastes as well as the Bayer gibbsite process industry. (authors)

  15. Chemical Reduction Synthesis of Iron Aluminum Powders

    Science.gov (United States)

    Zurita-Méndez, N. N.; la Torre, G. Carbajal-De; Ballesteros-Almanza, L.; Villagómez-Galindo, M.; Sánchez-Castillo, A.; Espinosa-Medina, M. A.

    In this study, a chemical reduction synthesis method of iron aluminum (FeAl) nano-dimensional intermetallic powders is described. The process has two stages: a salt reduction and solvent evaporation by a heat treatment at 1100°C. The precursors of the synthesis are ferric chloride, aluminum foil chips, a mix of Toluene/THF in a 75/25 volume relationship, and concentrated hydrochloric acid as initiator of the reaction. The reaction time was 20 days, the product obtained was dried at 60 °C for 2 h and calcined at 400, 800, and 1100 °C for 4 h each. To characterize and confirm the obtained synthesis products, X-Ray Diffraction (XRD), and Scanning Electron Microscopy (SEM) techniques were used. The results of morphology and chemical characterization of nano-dimensional powders obtained showed a formation of agglomerated particles of a size range of approximately 150 nm to 1.0 μm. Composition of powders was identified as corundum (Al2O3), iron aluminide (FeAl3), and iron-aluminum oxides (Fe0. 53Al0. 47)2O3 phases. The oxide phases formation were associated with the reaction of atmospheric concentration-free oxygen during synthesis and sintering steps, reducing the concentration of the iron aluminum phase.

  16. Corrosion of Graphite Aluminum Metal Matrix Composites

    Science.gov (United States)

    1991-02-01

    cathodic protection of G/AI MMCs resulted in overprotection 13. Overprotection resulted from a local increase in pH near cathodic sites during...34Cathodic Overprotection of SiC/6061-T6 and G/6061- T6 Aluminum Alloy Metal Matrix Composites," Scripta Metallurgica, 22 (1988) 413-418. 14. R

  17. Electrometallurgical treatment of aluminum-matrix fuels

    International Nuclear Information System (INIS)

    Willit, J.L.; Gay, E.C.; Miller, W.E.; McPheeters, C.C.; Laidler, J.J.

    1996-01-01

    The electrometallurgical treatment process described in this paper builds on our experience in treating spent fuel from the Experimental Breeder Reactor (EBR-II). The work is also to some degree, a spin-off from applying electrometallurgical treatment to spent fuel from the Hanford single pass reactors (SPRs) and fuel and flush salt from the Molten Salt Reactor Experiment (MSRE) in treating EBR-II fuel, we recover the actinides from a uranium-zirconium fuel by electrorefining the uranium out of the chopped fuel. With SPR fuel, uranium is electrorefined out of the aluminum cladding. Both of these processes are conducted in a LiCl-KCl molten-salt electrolyte. In the case of the MSRE, which used a fluoride salt-based fuel, uranium in this salt is recovered through a series of electrochemical reductions. Recovering high-purity uranium from an aluminum-matrix fuel is more challenging than treating SPR or EBR-II fuel because the aluminum- matrix fuel is typically -90% (volume basis) aluminum

  18. Strong, corrosion-resistant aluminum tubing

    Science.gov (United States)

    Reed, M. W.; Adams, F. F.

    1980-01-01

    When aluminum tubing having good corrosion resistance and postweld strength is needed, type 5083 alloy should be considered. Chemical composition is carefully controlled and can be drawn into thin-wall tubing with excellent mechanical properties. Uses of tubing are in aircraft, boats, docks, and process equipment.

  19. Explosion hazards of aluminum finishing operations

    NARCIS (Netherlands)

    Taveau, J.R.; Hochgreb, Simone; Lemkowitz, S.M.; Roekaerts, D.J.E.M.

    2018-01-01

    Metal dust deflagrations have become increasingly common in recent years. They are also more devastating than deflagrations involving organic materials, owing to metals' higher heat of combustion, rate of pressure rise, explosion pressure and flame temperature. Aluminum finishing operations offer

  20. Explosion hazards of aluminum finishing operations

    NARCIS (Netherlands)

    Taveau, J.; Hochgreb, S.; Lemkowitz, S.M.; Roekaerts, D.J.E.M.

    2018-01-01

    Metal dust deflagrations have become increasingly common in recent years. They are also more devastating than deflagrations involving organic materials, owing to metals' higher heat of combustion, rate of pressure rise, explosion pressure and flame temperature. Aluminum finishing operations offer a

  1. The use of aluminum dome tank roofs

    International Nuclear Information System (INIS)

    Morovich, G.L.

    1992-01-01

    Since the late 1970's the aluminum dome tank roof has gained wide usage for both new and retrofit applications. The increased application for the structure results from a need for maintenance reduction, environmental considerations, concern for product quality and economics. The American Petroleum Institute (API) has approved Standard API 650, Appendix G - Structurally Supported Aluminum Dome Roofs for publication. The aluminum dome was originally used as weather cover for retrofiting external floating roof tanks. The roof was considered for the reduction of maintenance related to draining water from the external floating roofs and problems resulting from freezing of drain lines and snow accumulation. This paper reports that environmental concerns have expanded the value of aluminum dome roofs. Rainwater bypassing the seals of an external floating roof became classified as a hazardous material requiring special and expensive disposal procedures. The marketing terminal facilities typically do not have the capacity for proper treatment of contaminated bottom water. With new fuel additives being water soluble, water contamination not only created a hazardous waste disposal problem, but resulted in reduced product quality

  2. Molybdate Coatings for Protecting Aluminum Against Corrosion

    Science.gov (United States)

    Calle, Luz Marina; MacDowell, Louis G.

    2005-01-01

    Conversion coatings that comprise mixtures of molybdates and several additives have been subjected to a variety of tests to evaluate their effectiveness in protecting aluminum and alloys of aluminum against corrosion. Molybdate conversion coatings are under consideration as replacements for chromate conversion coatings, which have been used for more than 70 years. The chromate coatings are highly effective in protecting aluminum and its alloys against corrosion but are also toxic and carcinogenic. Hexavalent molybdenum and, hence, molybdates containing hexavalent molybdenum, have received attention recently as replacements for chromates because molybdates mimic chromates in a variety of applications but exhibit significantly lower toxicity. The tests were performed on six proprietary formulations of molybdate conversion coatings, denoted formulations A through F, on panels of aluminum alloy 2024-T3. A bare alloy panel was also included in the tests. The tests included electrochemical impedance spectroscopy (EIS), measurements of corrosion potentials, scanning electron microscopy (SEM) with energy-dispersive spectroscopy (EDS), and x-ray photoelectron spectroscopy (XPS).

  3. Radiation corrosion in aluminum alloy bellows

    International Nuclear Information System (INIS)

    Konno, Osamu

    1987-01-01

    Testing was carried out in which materials for vacuum devices (Al, Ti, Cu, SUS) are exposed to electron beams (50 MeV, average current 80 μA) to determine the changes in the quantity, partial pressure and composition of the gases released from the materials. The test appratus used are made of Al alloys alone. During the test, vacuum leak is found in the Al alloy bellows used in the drive device. The leak is found to result from corrosion caused by water. The surface structure is analyzed by SEM, EPMA, ESCA and IMA. It is confirmed that the Al alloy used as material for the bellows if highly resistant to corrosion. It is concluded that it is necessary to use high purity cooling water to prevent the cooling water from causing corrosion. It has been reported that high purity aluminum is very high in resistance to corrosion. Based on these measurements and considerations, it is suggested that when aluminum is to be used as material for vacuum devices in an accelerator, it is required to provide protection film on its surface to prevent corrosion or to use cooling water pipes cladded with pure aluminum and an aluminum alloy. In addition, the temperature of the cooling water should be set after adequately considering the environmental conditions in the room. (Nogami, K.)

  4. Stress Corrosion Cracking of Certain Aluminum Alloys

    Science.gov (United States)

    Hasse, K. R.; Dorward, R. C.

    1983-01-01

    SC resistance of new high-strength alloys tested. Research report describes progress in continuing investigation of stress corrosion (SC) cracking of some aluminum alloys. Objective of program is comparing SC behavior of newer high-strength alloys with established SC-resistant alloy.

  5. Reinforcement of Aluminum Castings with Dissimilar Metals

    Energy Technology Data Exchange (ETDEWEB)

    Han, Q

    2004-01-07

    The project ''Reinforcement of Aluminum Casting with Dissimilar Metal'' was a Cooperative Research and Development Agreements (CRADAs) between Oak Ridge National Laboratory (ORNL) and Cummins Inc. This project, technologies have been developed to reinforce aluminum castings with steel insert. Defect-free bond between the steel insert and the aluminum casting has been consistently obtained. The push-out experiment indicated that the bond strength is higher than that of the Al-Fin method. Two patents have been granted to the project team that is comprised of Cummins Inc. and ORNL. This report contains four sections: the coating of the steel pins, the cast-in method, microstructure characterization, and the bond strength. The section of the coating of the steel pins contains coating material selection, electro-plating technique for plating Cu and Ni on steel, and diffusion bonding of the coatings to the steel. The section of cast-in method deals with factors that affecting the quality of the metallurgical bond between the coated steel and the aluminum castings. The results of microstructure characteristics of the bonding are presented in the microstructure characterization section. A push-out experiment and the results obtained using this method is described in the section of bond strength/mechanical property.

  6. Preparation of aluminum nitride-silicon carbide nanocomposite powder by the nitridation of aluminum silicon carbide

    NARCIS (Netherlands)

    Itatani, K.; Tsukamoto, R.; Delsing, A.C.A.; Hintzen, H.T.J.M.; Okada, I.

    2002-01-01

    Aluminum nitride (AlN)-silicon carbide (SiC) nanocomposite powders were prepared by the nitridation of aluminum-silicon carbide (Al4SiC4) with the specific surface area of 15.5 m2·g-1. The powders nitrided at and above 1400°C for 3 h contained the 2H-phases which consisted of AlN-rich and SiC-rich

  7. Investigation of Methods for Selectively Reinforcing Aluminum and Aluminum-Lithium Materials

    Science.gov (United States)

    Bird, R. Keith; Alexa, Joel A.; Messick, Peter L.; Domack, Marcia S.; Wagner, John A.

    2013-01-01

    Several studies have indicated that selective reinforcement offers the potential to significantly improve the performance of metallic structures for aerospace applications. Applying high-strength, high-stiffness fibers to the high-stress regions of aluminum-based structures can increase the structural load-carrying capability and inhibit fatigue crack initiation and growth. This paper discusses an investigation into potential methods for applying reinforcing fibers onto the surface of aluminum and aluminum-lithium plate. Commercially-available alumina-fiber reinforced aluminum alloy tapes were used as the reinforcing material. Vacuum hot pressing was used to bond the reinforcing tape to aluminum alloy 2219 and aluminum-lithium alloy 2195 base plates. Static and cyclic three-point bend testing and metallurgical analysis were used to evaluate the enhancement of mechanical performance and the integrity of the bond between the tape and the base plate. The tests demonstrated an increase in specific bending stiffness. In addition, no issues with debonding of the reinforcing tape from the base plate during bend testing were observed. The increase in specific stiffness indicates that selectively-reinforced structures could be designed with the same performance capabilities as a conventional unreinforced structure but with lower mass.

  8. Method of melting and decontaminating radioactive contaminated aluminum material

    International Nuclear Information System (INIS)

    Uda, Tatsuhiko; Miura, Noboru; Kawasaki, Katsuo; Iba, Hajime.

    1986-01-01

    Purpose: To improve the decontaminating efficiency upon melting decontamination of radioactive-contaminated aluminum materials. Method: This invention concerns an improvement for the method of melting decontamination by adding slug agent composed of organic compound to contaminated aluminum material and extracting the radioactive materials into the slug thereby decontaminating the aluminum material. Specifically metals effective for reducing the active amount of aluminum are added such that the content is greater than a predetermined value in the heat melting process. The metal comprises Mg, Cu or a mixture thereof and the content is more than 4 % including those previously contained in the aluminum material. (Ikeda, J.)

  9. FLOWSHEET FOR ALUMINUM REMOVAL FROM SLUDGE BATCH 6

    International Nuclear Information System (INIS)

    Pike, J.; Gillam, J.

    2008-01-01

    Samples of Tank 12 sludge slurry show a substantially larger fraction of aluminum than originally identified in sludge batch planning. The Liquid Waste Organization (LWO) plans to formulate Sludge Batch 6 (SB6) with about one half of the sludge slurry in Tank 12 and one half of the sludge slurry in Tank 4. LWO identified aluminum dissolution as a method to mitigate the effect of having about 50% more solids in High Level Waste (HLW) sludge than previously planned. Previous aluminum dissolution performed in a HLW tank in 1982 was performed at approximately 85 C for 5 days and dissolved nearly 80% of the aluminum in the sludge slurry. In 2008, LWO successfully dissolved 64% of the aluminum at approximately 60 C in 46 days with minimal tank modifications and using only slurry pumps as a heat source. This report establishes the technical basis and flowsheet for performing an aluminum removal process in Tank 51 for SB6 that incorporates the lessons learned from previous aluminum dissolution evolutions. For SB6, aluminum dissolution process temperature will be held at a minimum of 65 C for at least 24 days, but as long as practical or until as much as 80% of the aluminum is dissolved. As planned, an aluminum removal process can reduce the aluminum in SB6 from about 84,500 kg to as little as 17,900 kg with a corresponding reduction of total insoluble solids in the batch from 246,000 kg to 131,000 kg. The extent of the reduction may be limited by the time available to maintain Tank 51 at dissolution temperature. The range of dissolution in four weeks based on the known variability in dissolution kinetics can range from 44 to more than 80%. At 44% of the aluminum dissolved, the mass reduction is approximately 1/2 of the mass noted above, i.e., 33,300 kg of aluminum instead of 66,600 kg. Planning to reach 80% of the aluminum dissolved should allow a maximum of 81 days for dissolution and reduce the allowance if test data shows faster kinetics. 47,800 kg of the dissolved

  10. BoALMT1, an Al-Induced Malate Transporter in Cabbage, Enhances Aluminum Tolerance in Arabidopsis thaliana

    OpenAIRE

    Zhang, Lei; Wu, Xin-Xin; Wang, Jinfang; Qi, Chuandong; Wang, Xiaoyun; Wang, Gongle; Li, Mingyue; Li, Xingsheng; Guo, Yang-Dong

    2018-01-01

    Aluminum (Al) is present in approximately 50% of the arable land worldwide and is regarded as the main limiting factor of crop yield on acidic soil. Al-induced root malate efflux plays an important role in the Al tolerance of plants. Here, the aluminum induced malate transporter BoALMT1 (KF322104) was cloned from cabbage (Brassica oleracea). BoALMT1 showed higher expression in roots than in shoots. The expression of BoALMT1 was specifically induced by Al treatment, but not the trivalent catio...

  11. Wheat genotypes differing in aluminum tolerance differ in their growth response to CO2 enrichment in acid soils

    OpenAIRE

    Tian, Qiuying; Zhang, Xinxin; Gao, Yan; Bai, Wenming; Ge, Feng; Ma, Yibing; Zhang, Wen-Hao

    2013-01-01

    Aluminum (Al) toxicity is a major factor limiting plant growth in acid soils. Elevated atmospheric CO2 [CO2] enhances plant growth. However, there is no report on the effect of elevated [CO2] on growth of plant genotypes differing in Al tolerance grown in acid soils. We investigated the effect of short-term elevated [CO2] on growth of Al-tolerant (ET8) and Al-sensitive (ES8) wheat plants and malate exudation from root apices by growing them in acid soils under ambient [CO2] and elevated [CO2]...

  12. Aluminum as anode for energy storage and conversion: a review

    Science.gov (United States)

    Li, Qingfeng; Bjerrum, Niels J.

    Aluminum has long attracted attention as a potential battery anode because of its high theoretical voltage and specific energy. The protective oxide layer on the aluminum surface is however detrimental to the battery performance, contributing to failure to achieve the reversible potential and causing the delayed activation of the anode. By developing aluminum alloys as anodes and solution additives to electrolytes, a variety of aluminum batteries have been extensively investigated for various applications. From molten salt and other non-aqueous electrolytes, aluminum can be electrodeposited and therefore be suitable for developing rechargable batteries. Considerable efforts have been made to develop secondary aluminum batteries of high power density. In the present paper, these research activities are reviewed, including aqueous electrolyte primary batteries, aluminum-air batteries and molten salt secondary batteries.

  13. Carbon contaminant in the ion processing of aluminum oxide film

    International Nuclear Information System (INIS)

    Chaug, Y.; Roy, N.

    1989-01-01

    Ion processing can induce contamination on the bombarded surface. However, this process is essential for the microelectronics device fabrication. Auger electron spectroscopy has been used to study the simultaneous deposition of carbon impurity during ion bombardment of magnetron rf-sputtering deposited aluminum oxide film. Ion bombardment on aluminum oxide results in a preferential removal of surface oxygen and a formation of a metastable state of aluminum suboxide. Cosputtered implanted carbon contaminant appears to have formed a new state of stoichiometry on the surface of the ion bombarded aluminum oxide and existed as an aluminum carbide. This phase has formed due to the interaction of the implanted carbon and the aluminum suboxide. The Ar + ion sputter etching rate is reduced for the carbon contaminated oxide. The electrical resistance of the aluminum oxide between two gold strips has been measured. It is found that the electrical resistance is also reduced due to the formation of the new stoichiometry on the surface

  14. Aluminum Target Dissolution in Support of the Pu-238 Program

    Energy Technology Data Exchange (ETDEWEB)

    McFarlane, Joanna [ORNL; Benker, Dennis [ORNL; DePaoli, David W [ORNL; Felker, Leslie Kevin [ORNL; Mattus, Catherine H [ORNL

    2014-09-01

    Selection of an aluminum alloy for target cladding affects post-irradiation target dissolution and separations. Recent tests with aluminum alloy 6061 yielded greater than expected precipitation in the caustic dissolution step, forming up to 10 wt.% solids of aluminum hydroxides and aluminosilicates. We present a study to maximize dissolution of aluminum metal alloy, along with silicon, magnesium, and copper impurities, through control of temperature, the rate of reagent addition, and incubation time. Aluminum phase transformations have been identified as a function of time and temperature, using X-ray diffraction. Solutions have been analyzed using wet chemical methods and X-ray fluorescence. These data have been compared with published calculations of aluminum phase diagrams. Temperature logging during the transients has been investigated as a means to generate kinetic and mass transport data on the dissolution process. Approaches are given to enhance the dissolution of aluminum and aluminosilicate phases in caustic solution.

  15. Vapor corrosion of aluminum cladding alloys and aluminum-uranium fuel materials in storage environments

    International Nuclear Information System (INIS)

    Lam, P.; Sindelar, R.L.; Peacock, H.B. Jr.

    1997-04-01

    An experimental investigation of the effects of vapor environments on the corrosion of aluminum spent nuclear fuel (A1 SNF) has been performed. Aluminum cladding alloys and aluminum-uranium fuel alloys have been exposed to environments of air/water vapor/ionizing radiation and characterized for applications to degradation mode analysis for interim dry and repository storage systems. Models have been developed to allow predictions of the corrosion response under conditions of unlimited corrodant species. Threshold levels of water vapor under which corrosion does not occur have been identified through tests under conditions of limited corrodant species. Coupons of aluminum 1100, 5052, and 6061, the US equivalent of cladding alloys used to manufacture foreign research reactor fuels, and several aluminum-uranium alloys (aluminum-10, 18, and 33 wt% uranium) were exposed to various controlled vapor environments in air within the following ranges of conditions: Temperature -- 80 to 200 C; Relative Humidity -- 0 to 100% using atmospheric condensate water and using added nitric acid to simulate radiolysis effects; and Gamma Radiation -- none and 1.8 x 10 6 R/hr. The results of this work are part of the body of information needed for understanding the degradation of the A1 SNF waste form in a direct disposal system in the federal repository. It will provide the basis for data input to the ongoing performance assessment and criticality safety analyses. Additional testing of uranium-aluminum fuel materials at uranium contents typical of high enriched and low enriched fuels is being initiated to provide the data needed for the development of empirical models

  16. First-principles surface interaction studies of aluminum-copper and aluminum-copper-magnesium secondary phases in aluminum alloys

    Science.gov (United States)

    da Silva, Thiago H.; Nelson, Eric B.; Williamson, Izaak; Efaw, Corey M.; Sapper, Erik; Hurley, Michael F.; Li, Lan

    2018-05-01

    First-principles density functional theory-based calculations were performed to study θ-phase Al2Cu, S-phase Al2CuMg surface stability, as well as their interactions with water molecules and chloride (Cl-) ions. These secondary phases are commonly found in aluminum-based alloys and are initiation points for localized corrosion. Density functional theory (DFT)-based simulations provide insight into the origins of localized (pitting) corrosion processes of aluminum-based alloys. For both phases studied, Cl- ions cause atomic distortions on the surface layers. The nature of the distortions could be a factor to weaken the interlayer bonds in the Al2Cu and Al2CuMg secondary phases, facilitating the corrosion process. Electronic structure calculations revealed not only electron charge transfer from Cl- ions to alloy surface but also electron sharing, suggesting ionic and covalent bonding features, respectively. The S-phase Al2CuMg structure has a more active surface than the θ-phase Al2Cu. We also found a higher tendency of formation of new species, such as Al3+, Al(OH)2+, HCl, AlCl2+, Al(OH)Cl+, and Cl2 on the S-phase Al2CuMg surface. Surface chemical reactions and resultant species present contribute to establishment of local surface chemistry that influences the corrosion behavior of aluminum alloys.

  17. An experimental study on the aluminum nitride flux detector

    International Nuclear Information System (INIS)

    Moon, Byung Soo; Hwang, In Koo; Chung, Chong Eun; Kwon, Kee Choon

    2004-06-01

    The result of a study on the 'development of a solid state flux monitor' performed as a part of the I-NERI project 'development of enhanced reactor operation through improved sensing and control at nuclear power pants' is described in this report. Dozens of aluminum nitride based flux sensors have been fabricated with different sizes 3mm x 3mm x 0.635mm and 3mm x 3mm x 0.381mm by ORNL and were packaged with MGO insulation by KAERI for a feasibility study to use them as the in-core flux monitor in the nuclear power plants. In chapter 1, we describe the basic properties of the aluminum nitride and the geometric shape of the fabricated detectors with the signal cables attached. In chapter 2, we describe the calculation results based on the EGS4 and MCNP4B code to determine the neutron sensitivity of the aluminum nitride and the optimal thickness for the gamma rejection for the case of the detectors being used in the pulse mode operation. In chapter 3, we describe the results of measurements for the insulation resistance and of the experiments to determine the optimum operating voltage of the sensors after the packaging with long cables attached. In chapter 4, we describe the results of experiments to measure the high gamma flux from the 187Ci Co60, 77,000Ci Co60, and the 200,000Ci Co60 at the high level irradiation facility at KAERI at various distances and compared the results with the EGS4 based calculation results. In chapter 5, we describe the results of pulse counts at the IR beam port of the Hanaro reactor, the low flux measurements in the current mode at the Pohang accelerator, and the high flux measurements in the current mode inside the cold neutron source hole of the Hanaro reacter. Finally, in chapter 6, we analyze the results of the above experiments and describe the necessary future work

  18. An experimental study on the aluminum nitride flux detector

    Energy Technology Data Exchange (ETDEWEB)

    Moon, Byung Soo; Hwang, In Koo; Chung, Chong Eun; Kwon, Kee Choon

    2004-06-01

    The result of a study on the 'development of a solid state flux monitor' performed as a part of the I-NERI project 'development of enhanced reactor operation through improved sensing and control at nuclear power pants' is described in this report. Dozens of aluminum nitride based flux sensors have been fabricated with different sizes 3mm x 3mm x 0.635mm and 3mm x 3mm x 0.381mm by ORNL and were packaged with MGO insulation by KAERI for a feasibility study to use them as the in-core flux monitor in the nuclear power plants. In chapter 1, we describe the basic properties of the aluminum nitride and the geometric shape of the fabricated detectors with the signal cables attached. In chapter 2, we describe the calculation results based on the EGS4 and MCNP4B code to determine the neutron sensitivity of the aluminum nitride and the optimal thickness for the gamma rejection for the case of the detectors being used in the pulse mode operation. In chapter 3, we describe the results of measurements for the insulation resistance and of the experiments to determine the optimum operating voltage of the sensors after the packaging with long cables attached. In chapter 4, we describe the results of experiments to measure the high gamma flux from the 187Ci Co60, 77,000Ci Co60, and the 200,000Ci Co60 at the high level irradiation facility at KAERI at various distances and compared the results with the EGS4 based calculation results. In chapter 5, we describe the results of pulse counts at the IR beam port of the Hanaro reactor, the low flux measurements in the current mode at the Pohang accelerator, and the high flux measurements in the current mode inside the cold neutron source hole of the Hanaro reacter. Finally, in chapter 6, we analyze the results of the above experiments and describe the necessary future work.

  19. Phases in lanthanum-nickel-aluminum alloys

    International Nuclear Information System (INIS)

    Mosley, W.C.

    1992-01-01

    Lanthanum-nickel-aluminum (LANA) alloys will be used to pump, store and separate hydrogen isotopes in the Replacement Tritium Facility (RTF). The aluminum content (y) of the primary LaNi 5 -phase is controlled to produce the desired pressure-temperature behavior for adsorption and desorption of hydrogen. However, secondary phases cause decreased capacity and some may cause undesirable retention of tritium. Twenty-three alloys purchased from Ergenics, Inc. for development of RTF processes have been characterized by scanning electron microscopy (SEM) and by electron microprobe analysis (EMPA) to determine the distributions and compositions of constituent phases. This memorandum reports the results of these characterization studies. Knowledge of the structural characteristics of these alloys is a useful first step in selecting materials for specific process development tests and in interpreting results of those tests. Once this information is coupled with data on hydrogen plateau pressures, retention and capacity, secondary phase limits for RTF alloys can be specified

  20. Etching Behavior of Aluminum Alloy Extrusions

    Science.gov (United States)

    Zhu, Hanliang

    2014-11-01

    The etching treatment is an important process step in influencing the surface quality of anodized aluminum alloy extrusions. The aim of etching is to produce a homogeneously matte surface. However, in the etching process, further surface imperfections can be generated on the extrusion surface due to uneven materials loss from different microstructural components. These surface imperfections formed prior to anodizing can significantly influence the surface quality of the final anodized extrusion products. In this article, various factors that influence the materials loss during alkaline etching of aluminum alloy extrusions are investigated. The influencing variables considered include etching process parameters, Fe-rich particles, Mg-Si precipitates, and extrusion profiles. This study provides a basis for improving the surface quality in industrial extrusion products by optimizing various process parameters.

  1. Aluminum recycling—An integrated, industrywide approach

    Science.gov (United States)

    Das, Subodh K.; Green, John A. S.; Kaufman, J. Gilbert; Emadi, Daryoush; Mahfoud, M.

    2010-02-01

    The aluminum industry is a leading proponent of global sustainability and strongly advocates the use of recycled metal. As the North American primary aluminum industry continues to move offshore to other geographic areas such as Iceland and the Middle East, where energy is more readily available at lower cost, the importance of the secondary (i.e., recycled metal) market in the U.S. will continue to increase. The purpose of this paper is to take an integrated, industry-wide look at the recovery of material from demolished buildings, shredded automobiles, and aging aircraft, as well as from traditional cans and other rigid containers. Attempts will be made to assess how the different alloys used in these separate markets can be recycled in the most energy-efficient manner.

  2. Generation and structural characterization of aluminum cyanoacetylide

    Energy Technology Data Exchange (ETDEWEB)

    Cabezas, Carlos; Peña, Isabel; Alonso, José L., E-mail: alargo@qf.uva.es, E-mail: jlalonso@qf.uva.es [Grupo de Espectroscopia Molecular (GEM), Edificio Quifima, Laboratorios de Espectroscopia y Bioespectroscopia, Unidad Asociada CSIC, Parque Científico Uva, Universidad de Valladolid, Paseo de Belén 5, 47011 Valladolid (Spain); Barrientos, Carmen; Largo, Antonio, E-mail: alargo@qf.uva.es, E-mail: jlalonso@qf.uva.es [Departamento de Química Física y Química Inorgánica, Facultad de Ciencias, Universidad de Valladolid, Campus Miguel Delibes, Paseo de Belén 7, 47011 Valladolid (Spain); Guillemin, Jean-Claude [Institut des Sciences Chimiques de Rennes, École Nationale Supérieure de Chimie de Rennes, CNRS, UMR 6226, 11 Allée de Beaulieu, CS 50837, 35708 Rennes Cedex 7 (France); Cernicharo, José [Group of Molecular Astrophysics, ICMM C/Sor Juana Ines de la Cruz N3 Cantoblanco, 28049 Madrid (Spain)

    2014-09-14

    Combined spectroscopy measurements and theoretical calculations bring to light a first investigation of a metallic cyanoacetylide, AlC{sub 3}N, using laser ablation molecular beam Fourier transform microwave spectroscopy. This molecule was synthesized in a supersonic expansion by the reaction of aluminum vapour with C{sub 3}N, produced from solid aluminum rods and BrCCCN in a newly constructed ablation-heating nozzle device. A set of accurate rotational and {sup 27}Al and {sup 14}N nuclear quadrupole coupling constants have been determined from the analysis of the rotational spectrum and compared with those predicted in a high-level ab initio study, conducting to the assignment of the observed species to linear AlCCCN. We have searched for this species towards the carbon-rich evolved star IRC + 10216 but only an upper limit to its abundance has been obtained.

  3. Cratering Equations for Zinc Orthotitanate Coated Aluminum

    Science.gov (United States)

    Hyde, James; Christiansen, Eric; Liou, Jer-Chyi; Ryan, Shannon

    2009-01-01

    The final STS-125 servicing mission (SM4) to the Hubble Space Telescope (HST) in May of 2009 saw the return of the 2nd Wide Field Planetary Camera (WFPC2) aboard the shuttle Discovery. This hardware had been in service on HST since it was installed during the SM1 mission in December of 1993 yielding one of the longest low Earth orbit exposure times (15.4 years) of any returned space hardware. The WFPC2 is equipped with a 0.8 x 2.2 m radiator for thermal control of the camera electronics (Figure 1). The space facing surface of the 4.1 mm thick aluminum radiator is coated with Z93 zinc orthotitanate thermal control paint with a nominal thickness of 0.1 0.2 mm. Post flight inspections of the radiator panel revealed hundreds of micrometeoroid/orbital debris (MMOD) impact craters ranging in size from less than 300 to nearly 1000 microns in diameter. The Z93 paint exhibited large spall areas around the larger impact sites (Figure 2) and the craters observed in the 6061-T651 aluminum had a different shape than those observed in uncoated aluminum. Typical hypervelocity impact craters in aluminum have raised lips around the impact site. The craters in the HST radiator panel had suppressed crater lips, and in some cases multiple craters were present instead of a single individual crater. Humes and Kinard observed similar behavior after the WFPC1 post flight inspection and assumed the Z93 coating was acting like a bumper in a Whipple shield. Similar paint behavior (spall) was also observed by Bland2 during post flight inspection of the International Space Station (ISS) S-Band Antenna Structural Assembly (SASA) in 2008. The SASA, with similar Z93 coated aluminum, was inspected after nearly 4 years of exposure on the ISS. The multi-crater phenomena could be a function of the density, composition, or impact obliquity angle of the impacting particle. For instance, a micrometeoroid particle consisting of loosely bound grains of material could be responsible for creating the

  4. Aluminum matrix composites reinforced with alumina nanoparticles

    CERN Document Server

    Casati, Riccardo

    2016-01-01

    This book describes the latest efforts to develop aluminum nanocomposites with enhanced damping and mechanical properties and good workability. The nanocomposites exhibited high strength, improved damping behavior and good ductility, making them suitable for use as wires. Since the production of metal matrix nanocomposites by conventional melting processes is considered extremely problematic (because of the poor wettability of the nanoparticles), different powder metallurgy routes were investigated, including high-energy ball milling and unconventional compaction methods. Special attention was paid to the structural characterization at the micro- and nanoscale, as uniform nanoparticle dispersion in metal matrix is of prime importance. The aluminum nanocomposites displayed an ultrafine microstructure reinforced with alumina nanoparticles produced in situ or added ex situ. The physical, mechanical and functional characteristics of the materials produced were evaluated using different mechanical tests and micros...

  5. [Analysis of tartrazine aluminum lake and sunset yellow aluminum lake in foods by capillary zone electrophoresis].

    Science.gov (United States)

    Zhang, Yiding; Chang, Cuilan; Guo, Qilei; Cao, Hong; Bai, Yu; Liu, Huwei

    2014-04-01

    A novel analytical method for tartrazine aluminum lake and sunset yellow aluminum lake using capillary zone electrophoresis (CZE) was studied. The pigments contained in the color lakes were successfully separated from the aluminum matrix in the pre-treatment process, which included the following steps: dissolve the color lakes in 0.1 mol/L H2SO4, adjust the pH of the solution to 5.0, then mix it with the solution of EDTA x 2Na and heat it in a water bath, then use polyamide powder as the stationary phase of solid phase extraction to separate the pigments from the solution, and finally elute the pigments with 0.1 mol/L NaOH. The CZE conditions systematically optimized for tartrazine aluminum lake were: 48.50 cm of a fused silica capillary with 40.00 cm effective length and 50 microm i. d., the temperature controlled at 20.0 degrees C, 29.0 kV applied, HPO4(2-)-PO4(3-) (0.015 mol/L, pH 11.45) solution as running buffer, detection at 263 nm. The conditions for sunset yellow aluminum lake were: the same capillary and temperature, 25.0 kV applied, HPO4(2-)-PO4(3-) (0.025 mol/L, pH 11.45) solution as running buffer, detection at 240 nm. The limits of detection were 0.26 mg/L and 0.27 mg/L, and the linear ranges were 0.53-1.3 x 10(2) mg/L and 0.54-1.4 x 10(2) mg/L for tartrazine aluminum lake and sunset yellow aluminum lake, respectively. The RSDs were 4.3% and 5.7% (run to run, n = 6), 5.6% and 6.0% (day to day, n = 6) for tartrazine aluminum lake and sunset yellow aluminum lake, respectively. Further developments for this method could make it a routinely used method analyzing color lakes in foods.

  6. Deformation behaviors of aluminum alloys for automobile parts studied by neutron diffraction

    International Nuclear Information System (INIS)

    Katayanagi, Kazue; Morita, Kensuke; Tomota, Yo; Kamiyama, Takashi; Terakado, Katsuyoshi

    2008-01-01

    In situ time of flight neutron diffraction measurements during tension test were performed for three Al-Si alloys with different microstructures including hot-forged (AHS 2), T 6 heat-treated (AHS 2-T 6) and die-cast (ACD 12) specimens. Strength and work-hardening behaviors of these specimens are investigated by evaluating phase stresses, i.e., stress partitioning between Si and the Al matrix as well as intergranular stresses of [hkl] oriented family grains in the component phases. It is revealed that Si particles embedded in the Al matrix play a role of the hard second phase. The size and shape of the Si particles affect work hardening and fracture of the alloys. (author)

  7. Evaluating the Tensile Properties of Aluminum Foundry Alloys through Reference Castings-A Review.

    Science.gov (United States)

    Anilchandra, A R; Arnberg, Lars; Bonollo, Franco; Fiorese, Elena; Timelli, Giulio

    2017-08-30

    The tensile properties of an alloy can be exploited if detrimental defects and imperfections of the casting are minimized and the microstructural characteristics are optimized through several strategies that involve die design, process management and metal treatments. This paper presents an analysis and comparison of the salient characteristics of the reference dies proposed in the literature, both in the field of pressure and gravity die-casting. The specimens produced with these reference dies, called separately poured specimens, are effective tools for the evaluation and comparison of the tensile and physical behaviors of Al-Si casting alloys. Some of the findings of the present paper have been recently developed in the frame of the European StaCast project whose results are complemented here with some more recent outcomes and a comprehensive analysis and discussion.

  8. Evaluating the Tensile Properties of Aluminum Foundry Alloys through Reference Castings—A Review

    Science.gov (United States)

    Anilchandra, A.R.; Arnberg, Lars; Bonollo, Franco; Fiorese, Elena

    2017-01-01

    The tensile properties of an alloy can be exploited if detrimental defects and imperfections of the casting are minimized and the microstructural characteristics are optimized through several strategies that involve die design, process management and metal treatments. This paper presents an analysis and comparison of the salient characteristics of the reference dies proposed in the literature, both in the field of pressure and gravity die-casting. The specimens produced with these reference dies, called separately poured specimens, are effective tools for the evaluation and comparison of the tensile and physical behaviors of Al-Si casting alloys. Some of the findings of the present paper have been recently developed in the frame of the European StaCast project whose results are complemented here with some more recent outcomes and a comprehensive analysis and discussion. PMID:28867796

  9. Ignition of Aluminum Particles and Clouds

    Energy Technology Data Exchange (ETDEWEB)

    Kuhl, A L; Boiko, V M

    2010-04-07

    Here we review experimental data and models of the ignition of aluminum (Al) particles and clouds in explosion fields. The review considers: (i) ignition temperatures measured for single Al particles in torch experiments; (ii) thermal explosion models of the ignition of single Al particles; and (iii) the unsteady ignition Al particles clouds in reflected shock environments. These are used to develop an empirical ignition model appropriate for numerical simulations of Al particle combustion in shock dispersed fuel explosions.

  10. Anodizing And Sealing Aluminum In Nonchromated Solutions

    Science.gov (United States)

    Emmons, John R.; Kallenborn, Kelli J.

    1995-01-01

    Improved process for anodizing and sealing aluminum involves use of 5 volume percent sulfuric acid in water as anodizing solution, and 1.5 to 2.0 volume percent nickel acetate in water as sealing solution. Replaces process in which sulfuric acid used at concentrations of 10 to 20 percent. Improved process yields thinner coats offering resistance to corrosion, fatigue life, and alloy-to-alloy consistency equal to or superior to those of anodized coats produced with chromated solutions.

  11. Preparation and characterization of aluminum stearate

    Directory of Open Access Journals (Sweden)

    Lončar Eva S.

    2003-01-01

    Full Text Available Preparation of aluminum stearate by the precipitation method was examined under various conditions of stearic acid saponification with sodium hydroxide. It was proved that the most favorable ratio of acid/alkali was 1:1.5 and that the obtained soap was very similar to the commercial product. Endothermic effects determined by differential scanning calorimetry and also the other parameters showed that the soaps consisted mono-, di-, tristearates and non-reacted substances, where distearate was the dominant form.

  12. Thermoelectric charge imbalance in superconducting aluminum

    International Nuclear Information System (INIS)

    Heidel, D.F.; Garland, J.C.

    1981-01-01

    The charge imbalance voltage produced in superconducting aluminum by the presence of a temperature gradient and an electric current has been studied over the temperature range 0.5-1.2 K. Measurements were obtained of the magnitude and temperature dependence of the charge imbalance voltage of seven samples, two of which contained magnetic impurities. The data are compared with recent theoretical models of the effect

  13. Testing conformal mapping with kitchen aluminum foil

    OpenAIRE

    Haas, S.; Cooke, D. A.; Crivelli, P.

    2016-01-01

    We report an experimental verification of conformal mapping with kitchen aluminum foil. This experiment can be reproduced in any laboratory by undergraduate students and it is therefore an ideal experiment to introduce the concept of conformal mapping. The original problem was the distribution of the electric potential in a very long plate. The correct theoretical prediction was recently derived by A. Czarnecki (Can. J. Phys. 92, 1297 (2014)).

  14. Ultrasonic maps of porosity in aluminum castings

    International Nuclear Information System (INIS)

    Ghaffari, Bita; Potter, Timothy J.; Mozurkewich, George

    2002-01-01

    The use of cast aluminum in the automotive industry has grown dramatically in recent years, leading to increased need for quantitative characterization of microporosity. As previously reported in the literature, the attenuation of ultrasound can be used to measure the porosity volume fraction and the mean pore size. An immersion ultrasound system has been built utilizing this technique to scan castings with high spatial resolution. Maps of attenuation are shown to locate areas of varying porosity readily and reliably

  15. Internal Heterogeneous Processes in Aluminum Combustion

    Science.gov (United States)

    Dreizin, E. L.

    1999-01-01

    This paper discusses the aluminum particle combustion mechanism which has been expanded by inclusion of gas dissolution processes and ensuing internal phase transformations. This mechanism is proposed based on recent normal and microgravity experiments with particles formed and ignited in a pulsed micro-arc. Recent experimental findings on the three stages observed in Al particle combustion in air and shows the burning particle radiation, trajectory (streak), smoke cloud shapes, and quenched particle interiors are summarized. During stage I, the radiation trace is smooth and the particle flame is spherically symmetric. The temperature measured using a three-color pyrometer is close to 3000 K. Because it exceeds the aluminum boiling point (2730 K), this temperature most likely characterizes the vapor phase flame zone rather than the aluminum surface. The dissolved oxygen content within particles quenched during stage I was below the detection sensitivity (about 1 atomic %) for Wavelength Dispersive Spectroscopy (WDS). After an increase in the radiation intensity (and simultaneous decrease in the measured color temperature from about 3000 to 2800 K) indicative of the transition to stage II combustion, the internal compositions of the quenched particles change. Both oxygen-rich (approx. 10 atomic %) and oxygen-lean (combustion behavior and the evolution of its internal composition, the change from the spherically symmetric to asymmetric flame shape occurring upon the transition from stage I to stage II combustion could not be understood based only on the fact that dissolved oxygen is detected in the particles. The connection between the two phenomena appeared even less significant because in earlier aluminum combustion studies carried in O2/Ar mixtures, flame asymmetry was not observed as opposed to experiments in air or O2/CO mixtures. It has been proposed that the presence of other gases, i.e., hydrogen, or nitrogen causes the change in the combustion regime.

  16. Concept Development of an Aluminum Pedestrian Bridge

    OpenAIRE

    Brekke, Christian Arne Raknes

    2017-01-01

    As part of new initiatives from Norwegian Public Road Administration (NPRA) and Nye Veier AS towards reduced cost of road construction and maintenance, alternative materials for bridges are being considered. For the construction phase, quick installation and utilization of prefabricated units are being requested. For the operational phase, solutions not requiring periodical maintenance are favorized. In total, these new requirements are well suited for the use of aluminum. Especially for pede...

  17. Aluminum-Activated Malate Transporters Can Facilitate GABA Transport.

    Science.gov (United States)

    Ramesh, Sunita A; Kamran, Muhammad; Sullivan, Wendy; Chirkova, Larissa; Okamoto, Mamoru; Degryse, Fien; McLaughlin, Michael; Gilliham, Matthew; Tyerman, Stephen D

    2018-05-01

    Plant aluminum-activated malate transporters (ALMTs) are currently classified as anion channels; they are also known to be regulated by diverse signals, leading to a range of physiological responses. Gamma-aminobutyric acid (GABA) regulation of anion flux through ALMT proteins requires a specific amino acid motif in ALMTs that shares similarity with a GABA binding site in mammalian GABA A receptors. Here, we explore why TaALMT1 activation leads to a negative correlation between malate efflux and endogenous GABA concentrations ([GABA] i ) in both wheat ( Triticum aestivum ) root tips and in heterologous expression systems. We show that TaALMT1 activation reduces [GABA] i because TaALMT1 facilitates GABA efflux but GABA does not complex Al 3+ TaALMT1 also leads to GABA transport into cells, demonstrated by a yeast complementation assay and via 14 C-GABA uptake into TaALMT1 -expressing Xenopus laevis oocytes; this was found to be a general feature of all ALMTs we examined. Mutation of the GABA motif (TaALMT1 F213C ) prevented both GABA influx and efflux, and resulted in no correlation between malate efflux and [GABA] i We conclude that ALMTs are likely to act as both GABA and anion transporters in planta. GABA and malate appear to interact with ALMTs in a complex manner to regulate each other's transport, suggestive of a role for ALMTs in communicating metabolic status. © 2018 American Society of Plant Biologists. All rights reserved.

  18. Recycling production designs: the value of coordination and flexibility in aluminum recycling operations

    Science.gov (United States)

    Brommer, Tracey H.

    The growing motivation for aluminum recycling has prompted interest in recycling alternative and more challenging secondary materials. The nature of these alternative secondary materials necessitates the development of an intermediate recycling facility that can reprocess the secondary materials into a liquid product Two downstream aluminum remelters will incorporate the liquid products into their aluminum alloy production schedules. Energy and environmental benefits result from delivering the products as liquid but coordination challenges persist because of the energy cost to maintain the liquid. Further coordination challenges result from the necessity to establish a long term recycling production plan in the presence of long term downstream aluminum remelter production uncertainty and inherent variation in the daily order schedule of the downstream aluminum remelters. In this context a fundamental question arises, considering the metallurgical complexities of dross reprocessing, what is the value of operating a coordinated set of by-product reprocessing plants and remelting cast houses? A methodology is presented to calculate the optimal recycling center production parameters including 1) the number of recycled products, 2) the volume of recycled products, 3) allocation of recycled materials across recycled products, 4) allocation of recycled products across finished alloys, 4) the level of flexibility for the recycling center to operate. The methods implemented include, 1) an optimization model to describe the long term operations of the recycling center, 2) an uncertainty simulation tool, 3) a simulation optimization method, 4) a dynamic simulation tool with four embedded daily production optimization models of varying degrees of flexibility. This methodology is used to quantify the performance of several recycling center production designs of varying levels of coordination and flexibility. This analysis allowed the identification of the optimal recycling

  19. Reshock and release response of aluminum single crystal

    International Nuclear Information System (INIS)

    Huang, H.; Asay, J. R.

    2007-01-01

    Reshock and release experiments were performed on single crystal aluminum along three orientations and on polycrystalline 1050 aluminum with 50 μm grain size at shock stresses of 13 and 21 GPa to investigate the mechanisms for previously observed quasielastic recompression behavior. Particle velocity profiles obtained during reshocking both single crystals and polycrystalline aluminum from initial shock stresses of 13-21 GPa show similar quasielastic recompression behavior. Quasielastic release response is also observed in all single crystals, but the magnitude of the effect is crystal orientation dependent, with [111] and [110] exhibiting more ideal elastic-plastic release for unloading from the shocked state than for the [100] orientation and polycrystalline aluminum. The quasielastic response of 1050 aluminum is intermediate to that of the [100] and [111] orientations. Comparison of the wave profiles obtained for both unloading and reloading of single crystals and polycrystalline 1050 aluminum from shocked states suggests that the observed quasielastic response of polycrystalline aluminum results from the averaging response of single crystals for shock propagation along different orientations, and that the response of 1050 aluminum with large grain boundaries is not significantly different from the results obtained on single crystal aluminum. The yield strength of the single crystals and 1050 aluminum is found to increase with shock stress, which is consistent with previous results [H. Huang and I. R. Asay, J. Appl. Phys. 98, 033524 (2005)

  20. Low Velocity Impact Properties of Aluminum Foam Sandwich Structural Composite

    Directory of Open Access Journals (Sweden)

    ZHAO Jin-hua

    2018-01-01

    Full Text Available Sandwich structural composites were prepared by aluminum foam as core materials with basalt fiber(BF and ultra-high molecular weight polyethylene(UHMWPE fiber composite as faceplate. The effect of factors of different fiber type faceplates, fabric layer design and the thickness of the corematerials on the impact properties and damage mode of aluminum foam sandwich structure was studied. The impact properties were also analyzed to compare with aluminum honeycomb sandwich structure. The results show that BF/aluminum foam sandwich structural composites has bigger impact damage load than UHMWPE/aluminum foam sandwich structure, but less impact displacement and energy absorption. The inter-layer hybrid fabric design of BF and UHMWPE has higher impact load and energy absorption than the overlay hybrid fabric design faceplate sandwich structure. With the increase of the thickness of aluminum foam,the impact load of the sandwich structure decreases, but the energy absorption increases. Aluminum foam sandwich structure has higher impact load than the aluminum honeycomb sandwich structure, but smaller damage energy absorption; the damage mode of aluminum foam core material is mainly the fracture at the impact area, while aluminum honeycomb core has obvious overall compression failure.

  1. Experimental research on the poly-aluminum chloride for treating the Pi River water in winter and summer

    Science.gov (United States)

    Jia, Rusheng; Bai, Yulin; Yang, Jie

    2018-02-01

    In the beaker experiments that the disposal of low turbidity water, we observed the influence of some factors, such as the dosage of poly-aluminum chloride coagulant, the pH value of raw water, in disposing the high natural organic matters of low turbidity water in winter and summer. we discussed the removal of residual aluminum and UV254 in summer. The experimental results show that when the turbidity is less than 10 NTU, the optimum dosage are 14.4 mg.L-1 and 8.2 mg.L-1 respectively in winter and summer. No matter in winter or summer, the effect of pH value on coagulation treatment is very significant, the best pH value is about 8.1. In summer, with the increase of dosage of poly-aluminum chloride, residual aluminum increased slowly after decrease, turbidity and UV254 after precipitation is similar removal trend. Finally, according to the current market price of poly-aluminum chloride economic analysis, daily differences in pharmaceutical costs about 1600 yuan in summer and winter in the second water plant in Lu’an.

  2. Chromic acid anodizing of aluminum foil

    Science.gov (United States)

    Dursch, H.

    1988-01-01

    The success of the Space Station graphite/epoxy truss structure depends on its ability to endure long-term exposure to the LEO environment, primarily the effects of atomic oxygen and the temperture cycling resulting from the 94 minute orbit. This report describes the development and evaluation of chromic acid anodized (CAA) aluminum foil as protective coatings for these composite tubes. Included are: development of solar absorptance and thermal emittance properties required of Al foil and development of CAA parameters to achieve these optical properties; developing techniques to CAA 25 ft lengths of Al foil; developing bonding processes for wrapping the Al foil to graphite/epoxy tubes; and atomic oxygen testing of the CAA Al foil. Two specifications were developed and are included in the report: Chromic Acid Anodizing of Aluminum Foil Process Specification and Bonding of Anodized Aluminum Foil to Graphite/Epoxy Tubes. Results show that CAA Al foil provides and excellent protective and thermal control coating for the Space Station truss structure.

  3. Nitrogen bonding in aluminum oxynitride films

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Paul W., E-mail: pwang@bradley.edu [Department of Physics, Bradley University, 1501 W. Bradley Ave., Peoria, IL 61625 (United States); Hsu, Jin-Cherng [Department of Physics, Fu Jen Catholic University, Hsinchuang, Taipei Hsien 24205, Taiwan (China); Lin, Yung-Hsin; Chen, Huang-Lu [Graduate Institute of Applied Science and Engineering, Fu Jen Catholic University, Hsinchuang, Taipei Hsien 24205, Taiwan (China)

    2010-04-15

    Assignment of oxidation states of N{sub 1s} in XPS spectra of aluminum oxynitride by curve fitting is difficult. The XPS curve fitting was previously discussed in the paper published in J. Non-Cryst. Solids, 224 (1998) 31, in which O{sub 1s} photoelectrons from GeO{sub 2} glass were used to illustrate how to fit the XPS spectra. Three different ways were pointed out to eliminate the ambiguity caused by curve fitting such as comparing the data to data from standard samples, investigating the continuous surface modifications caused by slowly sputtering the surface, and monitoring the continuous surface modifications due to gradual increases in surface species under heating, cooling, or irradiation. Our recent work in aluminum oxynitride films provides another example of how to fit the XPS spectra of N{sub 1s} by three different oxidation states of N{sup +}, N{sup 2+}, and N{sup 3+}, by comparison of the measured data to data from previously published results, and by the gradual changes of spectra as functions of the oxygen contents in the films. Three oxidation states in different nitrogen bonding in the aluminum oxynitride, AlO{sub 2}N, Al{sub 2}O{sub 5}N{sub 2}, and AlO{sub 3}N, were clearly deduced.

  4. Yttrium aluminum garnet coating on glass substrate

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, Camila M.A.; Freiria, Gabriela S.; Faria, Emerson H. de; Rocha, Lucas A.; Ciuffi, Katia J.; Nassar, Eduardo J., E-mail: eduardo.nassar@unifran.edu.br

    2016-02-15

    Thin luminescent films have seen great technological advances and are applicable in the production of a variety of materials such as sensors, solar cells, photovoltaic devices, optical magnetic readers, waveguides, lasers, and recorders. Systems that contain yttrium aluminum oxide are important hosts for lanthanide ions and serve as light emission devices. This work deals with the deposition of yttrium aluminum garnet (YAG) film doped with Eu{sup 3+} onto a glass substrate obtained by the sol–gel methodology. Spray pyrolysis furnished the yttrium aluminum oxide powder. Dip-coating at a withdrawal speed of 10 mm min{sup −1} and evaporation led to deposition of different numbers of layers of the YAG:Eu{sup 3+} film onto the glass substrate from a YAG:Eu{sup 3+} powder suspension containing ethanol, water, and tetraethylorthosilicate. Photoluminescence, X-ray diffraction, scanning electron microscopy, and transparency measurements aided film characterization. The emission spectra revealed that the number of layers influenced film properties. - Highlights: • The spray pyrolysis was used to obtain luminescent YAG:Eu{sup 3+}. • The matrix was deposited as transparent films. • The YAG:Eu{sup 3+} was deposited by sol–gel process onto glass substrate.

  5. Yttrium aluminum garnet coating on glass substrate

    International Nuclear Information System (INIS)

    Ferreira, Camila M.A.; Freiria, Gabriela S.; Faria, Emerson H. de; Rocha, Lucas A.; Ciuffi, Katia J.; Nassar, Eduardo J.

    2016-01-01

    Thin luminescent films have seen great technological advances and are applicable in the production of a variety of materials such as sensors, solar cells, photovoltaic devices, optical magnetic readers, waveguides, lasers, and recorders. Systems that contain yttrium aluminum oxide are important hosts for lanthanide ions and serve as light emission devices. This work deals with the deposition of yttrium aluminum garnet (YAG) film doped with Eu 3+ onto a glass substrate obtained by the sol–gel methodology. Spray pyrolysis furnished the yttrium aluminum oxide powder. Dip-coating at a withdrawal speed of 10 mm min −1 and evaporation led to deposition of different numbers of layers of the YAG:Eu 3+ film onto the glass substrate from a YAG:Eu 3+ powder suspension containing ethanol, water, and tetraethylorthosilicate. Photoluminescence, X-ray diffraction, scanning electron microscopy, and transparency measurements aided film characterization. The emission spectra revealed that the number of layers influenced film properties. - Highlights: • The spray pyrolysis was used to obtain luminescent YAG:Eu 3+ . • The matrix was deposited as transparent films. • The YAG:Eu 3+ was deposited by sol–gel process onto glass substrate.

  6. Hydrolysis of aluminum dross material to achieve zero hazardous waste

    International Nuclear Information System (INIS)

    David, E.; Kopac, J.

    2012-01-01

    Highlights: ► The hydrolysis of aluminum dross in tap water generates pure hydrogen. ► Aluminum particles from dross are activated by mechanically milling technique. ► The process is completely greenhouse gases free and is cleanly to environment. ► Hydrolysis process leads to recycling of waste aluminum by hydrogen production. - Abstract: A simple method with high efficiency for generating high pure hydrogen by hydrolysis in tap water of highly activated aluminum dross is established. Aluminum dross is activated by mechanically milling to particles of about 45 μm. This leads to removal of surface layer of the aluminum particles and creation of a fresh chemically active metal surface. In contact with water the hydrolysis reaction takes place and hydrogen is released. In this process a Zero Waste concept is achieved because the other product of reaction is aluminum oxide hydroxide (AlOOH), which is nature-friendly and can be used to make high quality refractory or calcium aluminate cement. For comparison we also used pure aluminum powder and alkaline tap water solution (NaOH, KOH) at a ratio similar to that of aluminum dross content. The rates of hydrogen generated in hydrolysis reaction of pure aluminum and aluminum dross have been found to be similar. As a result of the experimental setup, a hydrogen generator was designed and assembled. Hydrogen volume generated by hydrolysis reaction was measured. The experimental results obtained reveal that aluminum dross could be economically recycled by hydrolysis process with achieving zero hazardous aluminum dross waste and hydrogen generation.

  7. Electrical transport through single-wall carbon nanotube-anodic aluminum oxide-aluminum heterostructures

    International Nuclear Information System (INIS)

    Kukkola, Jarmo; Rautio, Aatto; Sala, Giovanni; Pino, Flavio; Toth, Geza; Leino, Anne-Riikka; Maeklin, Jani; Jantunen, Heli; Uusimaeki, Antti; Kordas, Krisztian; Gracia, Eduardo; Terrones, Mauricio; Shchukarev, Andrey; Mikkola, Jyri-Pekka

    2010-01-01

    Aluminum foils were anodized in sulfuric acid solution to form thick porous anodic aluminum oxide (AAO) films of thickness ∼6 μm. Electrodes of carboxyl-functionalized single-wall carbon nanotube (SWCNT) thin films were inkjet printed on the anodic oxide layer and the electrical characteristics of the as-obtained SWCNT-AAO-Al structures were studied. Nonlinear current-voltage transport and strong temperature dependence of conduction through the structure was measured. The microstructure and chemical composition of the anodic oxide layer was analyzed using transmission and scanning electron microscopy as well as x-ray photoelectron spectroscopy. Schottky emission at the SWCNT-AAO and AAO-Al interfaces allowed by impurity states in the anodic aluminum oxide film together with ionic surface conduction on the pore walls of AAO gives a reasonable explanation for the measured electrical conduction. Calcined AAO is proposed as a dielectric material for SWCNT-field effect transistors.

  8. Effect of aluminum on metabolism of organic acids and chemical forms of aluminum in root tips of Eucalyptus camaldulensis Dehnh.

    Science.gov (United States)

    Ikka, Takashi; Ogawa, Tsuyoshi; Li, Donghua; Hiradate, Syuntaro; Morita, Akio

    2013-10-01

    Eucalyptus (Eucalyptus camaldulensis) has relatively high resistance to aluminum (Al) toxicity than the various herbaceous plants and model plant species. To investigate Al-tolerance mechanism, the metabolism of organic acids and the chemical forms of Al in the target site (root tips) in Eucalyptus was investigated. To do this, 2-year old rooted cuttings of E. camaldulensis were cultivated in half-strength Hoagland solution (pH 4.0) containing Al (0, 0.25, 0.5, 1.0, 2.5 and 5.0mM) salts for 5weeks; growth was not affected at concentrations up to 2.5mM even with Al concentration reaching 6000μgg(-1) DW. In roots, the citrate content also increased with increasing Al application. Concurrently, the activities of aconitase and NADP(+)-isocitrate dehydrogenase, which catalyze the decomposition of citrate, decreased. On the other hand, the activity of citrate synthase was not affected at concentrations up to 2.5mM Al. (27)Al-NMR spectroscopic analyses were carried out where it was found that Al-citrate complexes were a major chemical form present in cell sap of root tips. These findings suggested that E. camaldulensis detoxifies Al by forming Al-citrate complexes, and that this is achieved through Al-induced citrate accumulation in root tips via suppression of the citrate decomposition pathway. Copyright © 2013 Elsevier Ltd. All rights reserved.

  9. Multitrophic effects of calcium availability on invasive alien plants, birds, and bird prey items

    Science.gov (United States)

    Vince D' Amico; Greg Shriver; Jake Bowman; Meg Ballard; Whitney Wiest; Liz Tymkiw; Melissa. Miller

    2011-01-01

    Acid rain alters forest soil calcium concentrations in two ways: (1) hydrogen ions displace exchangeable calcium adsorbed to soil surfaces, and (2) aluminum is released to soil water by acid rain and displaces adsorbed calcium. This increases the absorption of aluminum by plant roots, and decreases the absorption of calcium, causing calcium to be more readily leached...

  10. 75 FR 20387 - Contech Castings, LLC, Including Workers Whose Unemployment Insurance (UI) Wages Are Reported...

    Science.gov (United States)

    2010-04-19

    ... Apply for Worker Adjustment Assistance In accordance with Section 223 of the Trade Act of 1974, as... aluminum and magnesium die casted component parts for automobiles. New information shows that the assets of... workers of the subject firm who were adversely affected by increased imports of aluminum and magnesium die...

  11. Low-temperature resistance of cyclically strained aluminum

    International Nuclear Information System (INIS)

    Segal, H.R.; Richard, T.G.

    1977-01-01

    An experimental study of the resistance changes in high-purity, reinforced aluminum due to cyclic straining is presently underway. The purpose of this work is to determine the optimum purity of aluminum to be used as a stabilizing material for superconducting magnets used for energy storage. Since pure aluminum has a low yield strength, it is not capable of supporting the stress levels in an energized magnet. Therefore, it has been bonded to a high-strength material--in this case, 6061 aluminum alloy. This bonding permits pure aluminum to be strained cyclically beyond its elastic limit with recovery of large plastic strains upon release of the load. The resistance change in this composite material is less than that of pure, unreinforced aluminum

  12. Chemical effects in the Corrosion of Aluminum and Aluminum Alloys. A Bibliography

    Science.gov (United States)

    1976-10-01

    tances.II. Effect Of Pomegranate Juice And The Aqueous Extract Of Pomegranate Fruits And Tea leaves On The Corrosion Of Aluminum" The effect of the juices...T7651 tempers to exfoliation and stress- corrosion cracking . 1968-8 D.P. Doyle and H.P. Godard ,a) Tr. Mezhdunar. Kongr. Korroz. Metal, 4, 439-48, (1968...Tapper Brit. Corros. J., 3, 285-87, (1968) "Corrosion Of Aluminum" Summary of the literature of Al corrosion which includes stress- corrosion cracking

  13. Preparation of Aluminum Nanomesh Thin Films from an Anodic Aluminum Oxide Template as Transparent Conductive Electrodes

    Science.gov (United States)

    Li, Yiwen; Chen, Yulong; Qiu, Mingxia; Yu, Hongyu; Zhang, Xinhai; Sun, Xiao Wei; Chen, Rui

    2016-02-01

    We have employed anodic aluminum oxide as a template to prepare ultrathin, transparent, and conducting Al films with a unique nanomesh structure for transparent conductive electrodes. The anodic aluminum oxide template is obtained through direct anodization of a sputtered Al layer on a glass substrate, and subsequent wet etching creates the nanomesh metallic film. The optical and conductive properties are greatly influenced by experimental conditions. By tuning the anodizing time, transparent electrodes with appropriate optical transmittance and sheet resistance have been obtained. The results demonstrate that our proposed strategy can serve as a potential method to fabricate low-cost TCEs to replace conventional indium tin oxide materials.

  14. Morpho-physiological analysis of tolerance to aluminum toxicity in rice varieties of North East India.

    Science.gov (United States)

    Awasthi, Jay Prakash; Saha, Bedabrata; Regon, Preetom; Sahoo, Smita; Chowra, Umakanta; Pradhan, Amit; Roy, Anupam; Panda, Sanjib Kumar

    2017-01-01

    Aluminum (Al) is the third most abundant metal in earth crust, whose chemical form is mainly dependent on soil pH. The most toxic form of Al with respect to plants is Al3+, which exists in soil pH Eastern India 80% soil are acidic). Al3+ toxicity in plants ensues root growth inhibition leading to less nutrient and water uptake impacting crop productivity as a whole. Rice is one of the chief grains which constitutes the staple food of two-third of the world population including India and is not untouched by Al3+ toxicity. Al contamination is a critical constraint to plant production in agricultural soils of North East India. 24 indigenous Indica rice varieties (including Badshahbhog as tolerant check and Mashuri as sensitive check) were screened for Al stress tolerance in hydroponic plant growth system. Results show marked difference in growth parameters (relative growth rate, Root tolerance index, fresh and dry weight of root) of rice seedlings due to Al (100 μM) toxicity. Al3+ uptake and lipid peroxidation level also increased concomitantly under Al treatment. Histochemical assay were also performed to elucidate uptake of aluminum, loss of membrane integrity and lipid peroxidation, which were found to be more in sensitive genotypes at higher Al concentration. This study revealed that aluminum toxicity is a serious harmful problem for rice crop productivity in acid soil. Based on various parameters studied it's concluded that Disang is a comparatively tolerant variety whereas Joymati a sensitive variety. Western blot hybridization further strengthened the claim, as it demonstrated more accumulation of Glutathione reductase (GR) protein in Disang rice variety than Joymati under stressed condition. This study also observed that the emergence of lethal toxic symptoms occurs only after 48h irrespective of the dose used in the study.

  15. Morpho-physiological analysis of tolerance to aluminum toxicity in rice varieties of North East India.

    Directory of Open Access Journals (Sweden)

    Jay Prakash Awasthi

    Full Text Available Aluminum (Al is the third most abundant metal in earth crust, whose chemical form is mainly dependent on soil pH. The most toxic form of Al with respect to plants is Al3+, which exists in soil pH <5. Acidic soil significantly limits crop production mainly due to Al3+ toxicity worldwide, impacting approximately 50% of the world's arable land (in North-Eastern India 80% soil are acidic. Al3+ toxicity in plants ensues root growth inhibition leading to less nutrient and water uptake impacting crop productivity as a whole. Rice is one of the chief grains which constitutes the staple food of two-third of the world population including India and is not untouched by Al3+ toxicity. Al contamination is a critical constraint to plant production in agricultural soils of North East India. 24 indigenous Indica rice varieties (including Badshahbhog as tolerant check and Mashuri as sensitive check were screened for Al stress tolerance in hydroponic plant growth system. Results show marked difference in growth parameters (relative growth rate, Root tolerance index, fresh and dry weight of root of rice seedlings due to Al (100 μM toxicity. Al3+ uptake and lipid peroxidation level also increased concomitantly under Al treatment. Histochemical assay were also performed to elucidate uptake of aluminum, loss of membrane integrity and lipid peroxidation, which were found to be more in sensitive genotypes at higher Al concentration. This study revealed that aluminum toxicity is a serious harmful problem for rice crop productivity in acid soil. Based on various parameters studied it's concluded that Disang is a comparatively tolerant variety whereas Joymati a sensitive variety. Western blot hybridization further strengthened the claim, as it demonstrated more accumulation of Glutathione reductase (GR protein in Disang rice variety than Joymati under stressed condition. This study also observed that the emergence of lethal toxic symptoms occurs only after 48h

  16. Molecular regulation of aluminum resistance and sulfur nutrition during root growth.

    Science.gov (United States)

    Alarcón-Poblete, Edith; Inostroza-Blancheteau, Claudio; Alberdi, Miren; Rengel, Zed; Reyes-Díaz, Marjorie

    2018-01-01

    Aluminum toxicity and sulfate deprivation both regulate microRNA395 expression, repressing its low-affinity sulfate transporter ( SULTR2;1 ) target. Sulfate deprivation also induces the high-affinity sulfate transporter gene ( SULTR12 ), allowing enhanced sulfate uptake. Few studies about the relationships between sulfate, a plant nutrient, and aluminum, a toxic ion, are available; hence, the molecular and physiological processes underpinning this interaction are poorly understood. The Al-sulfate interaction occurs in acidic soils, whereby relatively high concentrations of trivalent toxic aluminum (Al 3+ ) may hamper root growth, limiting uptake of nutrients, including sulfur (S). On the other side, Al 3+ may be detoxified by complexation with sulfate in the acid soil solution as well as in the root-cell vacuoles. In this review, we focus on recent insights into the mechanisms governing plant responses to Al toxicity and its relationship with sulfur nutrition, emphasizing the role of phytohormones, microRNAs, and ion transporters in higher plants. It is known that Al 3+ disturbs gene expression and enzymes involved in biosynthesis of S-containing cysteine in root cells. On the other hand, Al 3+ may induce ethylene biosynthesis, enhance reactive oxygen species production, alter phytohormone transport, trigger root growth inhibition and promote sulfate uptake under S deficiency. MicroRNA395, regulated by both Al toxicity and sulfate deprivation, represses its low-affinity Sulfate Transporter 2;1 (SULTR2;1) target. In addition, sulfate deprivation induces High Affinity Sulfate Transporters (HAST; SULTR1;2), improving sulfate uptake from low-sulfate soil solutions. Identification of new microRNAs and cloning of their target genes are necessary for a better understanding of the role of molecular regulation of plant resistance to Al stress and sulfate deprivation.

  17. 49 CFR 178.512 - Standards for steel or aluminum boxes.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Standards for steel or aluminum boxes. 178.512... aluminum boxes. (a) The following are identification codes for steel or aluminum boxes: (1) 4A for a steel box; and (2) 4B for an aluminum box. (b) Construction requirements for steel or aluminum boxes are as...

  18. Physical and Electrical Characterization of Polymer Aluminum Capacitors

    Science.gov (United States)

    Liu, David; Sampson, Michael J.

    2010-01-01

    Polymer aluminum capacitors from several manufacturers with various combinations of capacitance, rated voltage, and ESR values were physically examined and electrically characterized. The physical construction analysis of the capacitors revealed three different capacitor structures, i.e., traditional wound, stacked, and laminated. Electrical characterization results of polymer aluminum capacitors are reported for frequency-domain dielectric response at various temperatures, surge breakdown voltage, and other dielectric properties. The structure-property relations in polymer aluminum capacitors are discussed.

  19. A Study on the Anodic Dissolution of Aluminum(II)

    International Nuclear Information System (INIS)

    Nam, C. W.; Park, C. S.; Park, C. S.

    1978-01-01

    In many cases oxide films formed on metals in atmosphere or aqueous solution are chemically inactive, especially it is the case with aluminum. In this study, anodic dissolution of aluminum was done using various electrolyte and cathode, mechanism of which was examined. As a consequence, oxide film on aluminum surface was dissolved together with the dissolution reaction of metal by the anodic current. It was shown that the dissolution reaction due to the contact between electrolyte and metal happened in the same time

  20. Sensitization of Naturally Aged Aluminum 5083 Armor Plate

    Science.gov (United States)

    2015-07-29

    5 - 1 - SENSITIZATION OF NATURALLY AGED ALUMINUM 5083 ARMOR PLATE INTRODUCTION Aluminum -magnesium alloys are important for both ship...boundaries [3,4]. The magnesium-rich phase (normally β-Al3Mg2) is highly anodic with respect to the surrounding aluminum phase, thus is susceptible... alloys , and with varying amounts of debris scattered about the surface consistent with corrosion product, Figure 2b, that often forms over time within

  1. Physical and Electrical Characterization of Aluminum Polymer Capacitors

    Science.gov (United States)

    Liu, David; Sampson, Michael J.

    2010-01-01

    Polymer aluminum capacitors from several manufacturers with various combinations of capacitance, rated voltage, and ESR values were physically examined and electrically characterized. The physical construction analysis of the capacitors revealed three different capacitor structures, i.e., traditional wound, stacked, and laminated. Electrical characterization results of polymer aluminum capacitors are reported for frequency-domain dielectric response at various temperatures, surge breakdown voltage, and other dielectric properties. The structure-property relations in polymer aluminum capacitors are discussed.

  2. Improved Density Functional Tight Binding Potentials for Metalloid Aluminum Clusters

    Science.gov (United States)

    2016-06-01

    unlimited IMPROVED DENSITY-FUNCTIONAL TIGHT BINDING POTENTIALS FOR METALLOID ALUMINUM CLUSTERS by Joon H. Kim June 2016 Thesis Advisor...DATES COVERED Master’s thesis 4. TITLE AND SUBTITLE IMPROVED DENSITY-FUNCTIONAL TIGHT BINDING POTENTIALS FOR METALLOID ALUMINUM CLUSTERS 5. FUNDING...repulsive potentials for use in density-functional tight binding (DFTB) simulations of low-valence aluminum metalloid clusters . These systems are under

  3. Monolithic Approach to Oxide Dispersion Strengthened Aluminum, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Nassau Stern Company is investigating an approach for manufacturing oxide dispersion strengthened (ODS) aluminum in bulk rather than powder form. The approach...

  4. Manufacturing of aluminum composite material using stir casting process

    International Nuclear Information System (INIS)

    Jokhio, M.H.; Panhwar, M.I.; Unar, M.A.

    2011-01-01

    Manufacturing of aluminum alloy based casting composite materials via stir casting is one of the prominent and economical route for development and processing of metal matrix composites materials. Properties of these materials depend upon many processing parameters and selection of matrix and reinforcements. Literature reveals that most of the researchers are using 2, 6 and 7 xxx aluminum matrix reinforced with SiC particles for high strength properties whereas, insufficient information is available on reinforcement of 'AI/sub 2/O/sub 3/' particles in 7 xxx aluminum matrix. The 7 xxx series aluminum matrix usually contains Cu-Zn-Mg; Therefore, the present research was conducted to investigate the effect of elemental metal such as Cu-Zn-Mg in aluminum matrix on mechanical properties of stir casting of aluminum composite materials reinforced with alpha 'AI/sub 2/O/sub 3/' particles using simple foundry melting alloying and casting route. The age hardening treatments were also applied to study the aging response of the aluminum matrix on strength, ductility and hardness. The experimental results indicate that aluminum matrix cast composite can be manufactured via conventional foundry method giving very good responses to the strength and ductility up to 10% 'AI/sub 2/O/sub 3/' particles reinforced in aluminum matrix. (author)

  5. The aluminum chemistry and corrosion in alkaline solutions

    International Nuclear Information System (INIS)

    Zhang Jinsuo; Klasky, Marc; Letellier, Bruce C.

    2009-01-01

    Aluminum-alkaline solution systems are very common in engineering applications including nuclear engineering. Consequently, a thorough knowledge of the chemistry of aluminum and susceptibility to corrosion in alkaline solutions is reviewed. The aluminum corrosion mechanism and corrosion rate are examined based on current experimental data. A review of the phase transitions with aging time and change of environment is also performed. Particular attention is given to effect of organic and inorganic ions. As an example, the effect of boron is examined in detail because of the application in nuclear reactor power systems. Methods on how to reduce the corrosion rate of aluminum in alkaline solutions are also highlighted

  6. Dissolution mechanism of aluminum hydroxides in acid media

    Science.gov (United States)

    Lainer, Yu. A.; Gorichev, I. G.; Tuzhilin, A. S.; Gololobova, E. G.

    2008-08-01

    The effects of the concentration, temperature, and potential at the hydroxide/electrolyte interface on the aluminum hydroxide dissolution in sulfuric, hydrochloric, and perchloric acids are studied. The limiting stage of the aluminum hydroxide dissolution in the acids is found to be the transition of the complexes that form on the aluminum hydroxide surface from the solid phase into the solution. The results of the calculation of the acid-base equilibrium constants at the oxide (hydroxide)/solution interface using the experimental data on the potentiometric titration of Al2O3 and AlOOH suspensions are analyzed. A mechanism is proposed for the dissolution of aluminum hydroxides in acid media.

  7. Improving pitting corrosion resistance of aluminum by anodizing process

    International Nuclear Information System (INIS)

    John, P.; Khan, I.U.

    2013-01-01

    Summary: Anodizing of aluminum was studied in sulphuric/citric/boric acid electrolyte system to improve pitting corrosion resistance. Maximum oxide film thickness was obtained using 5% sulphuric acid, 3% citric acid and 0.5% boric acid electrolyte composition. The corrosion resistance of aluminum sample was determined to find the effectiveness of oxide coating by potentiodynamic polarization test. The surface morphology of aluminum samples was investigated using scanning electron microscope (SEM) before and after corrosion test. It was found that the coated aluminum sample obtained by anodizing in sulphuric/citric/boric acid electrolyte system exhibited better pitting corrosion resistance with no significant difference in surface morphology. (author)

  8. Technological, Economic, and Environmental Optimization of Aluminum Recycling

    Science.gov (United States)

    Ioana, Adrian; Semenescu, Augustin

    2013-08-01

    The four strategic directions (referring to the entire life cycle of aluminum) are as follows: production, primary use, recycling, and reuse. Thus, in this work, the following are analyzed and optimized: reducing greenhouse gas emissions from aluminum production, increasing energy efficiency in aluminum production, maximizing used-product collection, recycling, and reusing. According to the energetic balance at the gaseous environment level, the conductive transfer model is also analyzed through the finished elements method. Several principles of modeling and optimization are presented and analyzed: the principle of analogy, the principle of concepts, and the principle of hierarchization. Based on these principles, an original diagram model is designed together with the corresponding logic diagram. This article also presents and analyzes the main benefits of aluminum recycling and reuse. Recycling and reuse of aluminum have the main advantage that it requires only about 5% of energy consumed to produce it from bauxite. The aluminum recycling and production process causes the emission of pollutants such as dioxides and furans, hydrogen chloride, and particulate matter. To control these emissions, aluminum recyclers are required to comply with the National Emission Standards for Hazardous Air Pollutants for Secondary Aluminum Production. The results of technological, economic, and ecological optimization of aluminum recycling are based on the criteria function's evaluation in the modeling system.

  9. A liquid aluminum corrosion resistance surface on steel substrate

    International Nuclear Information System (INIS)

    Wang Deqing; Shi Ziyuan; Zou Longjiang

    2003-01-01

    The process of hot dipping pure aluminum on a steel substrate followed by oxidation was studied to form a surface layer of aluminum oxide resistant to the corrosion of aluminum melt. The thickness of the pure aluminum layer on the steel substrate is reduced with the increase in temperature and time in initial aluminizing, and the thickness of the aluminum layer does not increase with time at given temperature when identical temperature and complete wetting occur between liquid aluminum and the substrate surface. The thickness of the Fe-Al intermetallic layer on the steel base is increased with increasing bath temperature and time. Based on the experimental data and the mathematics model developed by the study, a maximum exists in the thickness of the Fe-Al intermetallic at certain dipping temperature. X-ray diffraction (XRD) and energy dispersive X-ray (EDX) analysis reveals that the top portion of the steel substrate is composed of a thin layer of α-Al 2 O 3 , followed by a thinner layer of FeAl 3 , and then a much thicker one of Fe 2 Al 5 on the steel base side. In addition, there is a carbon enrichment zone in diffusion front. The aluminum oxide surface formed on the steel substrate is in perfect condition after corrosion test in liquid aluminum at 750 deg. C for 240 h, showing extremely good resistance to aluminum melt corrosion

  10. Joining of parts via magnetic heating of metal aluminum powders

    Science.gov (United States)

    Baker, Ian

    2013-05-21

    A method of joining at least two parts includes steps of dispersing a joining material comprising a multi-phase magnetic metal-aluminum powder at an interface between the at least two parts to be joined and applying an alternating magnetic field (AMF). The AMF has a magnetic field strength and frequency suitable for inducing magnetic hysteresis losses in the metal-aluminum powder and is applied for a period that raises temperature of the metal-aluminum powder to an exothermic transformation temperature. At the exothermic transformation temperature, the metal-aluminum powder melts and resolidifies as a metal aluminide solid having a non-magnetic configuration.

  11. Analysis of Material Flow in Screw Extrusion of Aluminum

    International Nuclear Information System (INIS)

    Haugen, Bjoern; Oernskar, Magnus; Welo, Torgeir; Wideroee, Fredrik

    2010-01-01

    Screw extrusion of aluminum is a new process for production of aluminum profiles. The commercial potential could be large. Little experimental and numerical work has been done with respect to this process.The material flow of hot aluminum in a screw extruder has been analyzed using finite element formulations for the non-Newtonian Navier-Stokes equations. Aluminum material properties are modeled using the Zener-Holloman material model. Effects of stick-slip conditions are investigated with respect to pressure build up and mixing quality of the extrusion process.The numerical results are compared with physical experiments using an experimental screw extruder.

  12. Reactive ion assisted deposition of aluminum oxynitride thin films

    International Nuclear Information System (INIS)

    Hwangbo, C.K.; Lingg, L.J.; Lehan, J.P.; Macleod, H.A.; Suits, F.

    1989-01-01

    Optical properties, stoichiometry, chemical bonding states, and crystal structure of aluminum oxynitride (AlO/sub x/N/sub y/) thin films prepared by reactive ion assisted deposition were investigated. The results show that by controlling the amount of reactive gases the refractive index of aluminum oxynitride films at 550 nm is able to be varied from 1.65 to 1.83 with a very small extinction coefficient. Variations of optical constants and chemical bonding states of aluminum oxynitride films are related to the stoichiometry. From an x-ray photoelectron spectroscopy analysis it is observed that our aluminum oxynitride film is not simply a mixture of aluminum oxide and aluminum nitride but a continuously variable compound. The aluminum oxynitride films are amorphous from an x-ray diffraction analysis. A rugate filter using a step index profile of aluminum oxynitride films was fabricated by nitrogen ion beam bombardment of a growing Al film with backfill oxygen pressure as the sole variation. This filter shows a high resistivity to atmospheric moisture adsorption, suggesting that the packing density of aluminum oxynitride films is close to unity and the energetic ion bombardment densifies the film as well as forming the compound

  13. Secondary Aluminum Production: National Emission Standards for Hazardous Air Pollutants

    Science.gov (United States)

    National emission standards for hazardous air pollutants (NESHAP) for new and existing sources at secondary aluminum production facilities. Includes rule history, summary, federal register citations and implementation information.

  14. Investigation of magnetism in aluminum-doped silicon carbide nanotubes

    Science.gov (United States)

    Behzad, Somayeh; Chegel, Raad

    2013-11-01

    The effect of aluminum doping on the structural, electronic and magnetic properties of (8,0) silicon carbide nanotube (SiCNT) is investigated using spin-polarized density functional theory. It is found from the calculation of the formation energies that aluminum substitution for silicon atom is preferred. Our results show that the magnetization depends on the substitutional site, aluminum substitution at silicon site does not introduce any spin-polarization, whereas the aluminum substitution for carbon atom yields a spin polarized, almost dispersionless π band within the original band gap.

  15. Manufacturing of Aluminum Composite Material Using Stir Casting Process

    Directory of Open Access Journals (Sweden)

    Muhammad Hayat Jokhio

    2011-01-01

    Full Text Available Manufacturing of aluminum alloy based casting composite materials via stir casting is one of the prominent and economical route for development and processing of metal matrix composites materials. Properties of these materials depend upon many processing parameters and selection of matrix and reinforcements. Literature reveals that most of the researchers are using 2, 6 and 7xxx aluminum matrix reinforced with SiC particles for high strength properties whereas, insufficient information is available on reinforcement of \\"Al2O3\\" particles in 7xxx aluminum matrix. The 7xxx series aluminum matrix usually contains Cu-Zn-Mg. Therefore, the present research was conducted to investigate the effect of elemental metal such as Cu-Zn-Mg in aluminum matrix on mechanical properties of stir casting of aluminum composite materials reinforced with alpha \\"Al2O3\\" particles using simple foundry melting alloying and casting route. The age hardening treatments were also applied to study the aging response of the aluminum matrix on strength, ductility and hardness. The experimental results indicate that aluminum matrix cast composite can be manufactured via conventional foundry method giving very good responses to the strength and ductility up to 10% \\"Al2O3\\" particles reinforced in aluminum matrix.

  16. Accelerating Thick Aluminum Liners Using Pulsed Power

    International Nuclear Information System (INIS)

    Kyrala, G.A.; Hammerburg, J.E.; Bowers, D.; Stokes, J.; Morgan, D.V.; Anderson, W.E.; Cochrane, J.C.

    1999-01-01

    The authors have investigated the acceleration of very thick cylindrical aluminum liners using the Pegasus II capacitory bank. These accelerated solid liners will be used to impact other objects at velocities below 1.5 km/sec, allowing one to generate and sustain shocks of a few 100 kilobar for a few microseconds. A cylindrical shell of 1100 series aluminum with an initial inner radius of 23.61 mm, an initial thickness of 3.0 mm, and a height of 20 mm, was accelerated using a current pulse of 7.15 MA peak current and a 7.4 microsecond quarter cycle time. The aluminum shell was imploded within confining copper glide planes with decreasing separation with an inward slope of 8 degrees. At impact with a cylindrical target of diameter 3-cm, the liner was moving at 1.4 km/sec and its thickness increased to 4.5 mm. Radial X-ray radiograms of the liner showed both the liner and the glide plane interface. The curvature of the inner surface of the liner was measured before impact with the 15-mm radius target. The radiograms also showed that the copper glide planes distorted as the liner radius decreased and that some axial stress is induced in the liner. The axial stresses did not affect the inner curvature significantly. Post-shot calculations of the liner behavior indicated that the thickness of the glide plane played a significant role in the distortion of the interface between the liner and the glide plane

  17. Phonon optimized interatomic potential for aluminum

    Directory of Open Access Journals (Sweden)

    Murali Gopal Muraleedharan

    2017-12-01

    Full Text Available We address the problem of generating a phonon optimized interatomic potential (POP for aluminum. The POP methodology, which has already been shown to work for semiconductors such as silicon and germanium, uses an evolutionary strategy based on a genetic algorithm (GA to optimize the free parameters in an empirical interatomic potential (EIP. For aluminum, we used the Vashishta functional form. The training data set was generated ab initio, consisting of forces, energy vs. volume, stresses, and harmonic and cubic force constants obtained from density functional theory (DFT calculations. Existing potentials for aluminum, such as the embedded atom method (EAM and charge-optimized many-body (COMB3 potential, show larger errors when the EIP forces are compared with those predicted by DFT, and thus they are not particularly well suited for reproducing phonon properties. Using a comprehensive Vashishta functional form, which involves short and long-ranged interactions, as well as three-body terms, we were able to better capture interactions that reproduce phonon properties accurately. Furthermore, the Vashishta potential is flexible enough to be extended to Al2O3 and the interface between Al-Al2O3, which is technologically important for combustion of solid Al nano powders. The POP developed here is tested for accuracy by comparing phonon thermal conductivity accumulation plots, density of states, and dispersion relations with DFT results. It is shown to perform well in molecular dynamics (MD simulations as well, where the phonon thermal conductivity is calculated via the Green-Kubo relation. The results are within 10% of the values obtained by solving the Boltzmann transport equation (BTE, employing Fermi’s Golden Rule to predict the phonon-phonon relaxation times.

  18. Oxidation of zirconium-aluminum alloys

    International Nuclear Information System (INIS)

    Cox, B.

    1967-10-01

    Examination of the processes occurring during the oxidation of Zr-1% A1, Zr-3% A1, and Zr-1.5% A1-0.5% Mo alloys has shown that in steam rapid oxidation occurs predominantly around the Zr 3 A1 particles, which at low temperatures appear to be relatively unattacked. The unoxidised particles become incorporated in the oxide, and become fully oxidised as the film thickens. This rapid localised oxidation is preceded by a short period of uniform film growth, during which the oxide film thickness does not exceed ∼200A-o. Thus the high oxidation rates can probably be ascribed to aluminum in solution in the zirconium matrix, although its precise mode of operation has not been determined. Once the solubility limit of aluminum is exceeded, the size, distribution and number of intermetallic particles affects the oxidation rate merely by altering the distribution of regions of metal giving high oxidation rates. The controlling process during the early stages of oxidation is electron transport and not ionic transport. Thus, the aluminum in the oxide film is presumably increasing the ionic conductivity more than the electronic. The oxidation rates in atmospheric pressure steam are very high and their irregular temperature dependence suggests that the oxidation rate will be pressure dependent. This was confirmed, in part, by a comparison with oxidation in moist air. It was found that the rate of development of white oxide around intermetallic particles was considerably reduced by the decrease in the partial pressure of H 2 O; the incubation period was not much different, however. (author)

  19. Phonon optimized interatomic potential for aluminum

    Science.gov (United States)

    Muraleedharan, Murali Gopal; Rohskopf, Andrew; Yang, Vigor; Henry, Asegun

    2017-12-01

    We address the problem of generating a phonon optimized interatomic potential (POP) for aluminum. The POP methodology, which has already been shown to work for semiconductors such as silicon and germanium, uses an evolutionary strategy based on a genetic algorithm (GA) to optimize the free parameters in an empirical interatomic potential (EIP). For aluminum, we used the Vashishta functional form. The training data set was generated ab initio, consisting of forces, energy vs. volume, stresses, and harmonic and cubic force constants obtained from density functional theory (DFT) calculations. Existing potentials for aluminum, such as the embedded atom method (EAM) and charge-optimized many-body (COMB3) potential, show larger errors when the EIP forces are compared with those predicted by DFT, and thus they are not particularly well suited for reproducing phonon properties. Using a comprehensive Vashishta functional form, which involves short and long-ranged interactions, as well as three-body terms, we were able to better capture interactions that reproduce phonon properties accurately. Furthermore, the Vashishta potential is flexible enough to be extended to Al2O3 and the interface between Al-Al2O3, which is technologically important for combustion of solid Al nano powders. The POP developed here is tested for accuracy by comparing phonon thermal conductivity accumulation plots, density of states, and dispersion relations with DFT results. It is shown to perform well in molecular dynamics (MD) simulations as well, where the phonon thermal conductivity is calculated via the Green-Kubo relation. The results are within 10% of the values obtained by solving the Boltzmann transport equation (BTE), employing Fermi's Golden Rule to predict the phonon-phonon relaxation times.

  20. Hydrolysis-precipitation studies of aluminum (III) solutions. I. Titration of acidified aluminum nitrate solutions

    NARCIS (Netherlands)

    Vermeulen, A.C.; Geus, John W.; Stol, R.J.; Bruyn, P.L. de

    Acidified aluminum nitrate solutions were titrated with alkali (NaOH or KOH) over a temperature range of 24°C to 90°C. A homogeneous distribution of added base was achieved by: (i) in situ decomposition of urea (90°C); and (ii) a novel method involving injection through a capillary submerged in the

  1. pH dependent dissolution of sediment aluminum in six Danish lakes treated with aluminum

    DEFF Research Database (Denmark)

    Reitzel, Kasper; Jensen, Henning S.; Egemose, Sara

    2013-01-01

    The possible pH dependent dissolution of aluminum hydroxides (Al(OH)(3)) from lake sediments was studied in six lakes previously treated with Al to bind excess phosphorus (P). Surface sediment was suspended for 2 h in lake water of pH 7.5, 8.5, or 9.5 with resulting stepwise increments in dissolved...

  2. Polarization properties of real aluminum mirrors; I. Influence of the aluminum oxide layer

    NARCIS (Netherlands)

    van Harten, G.; Snik, F.; Keller, C.U.

    2009-01-01

    In polarimetry, it is important to characterize the polarization properties of the instrument itself to disentangle real astrophysical signals from instrumental effects. This article deals with the accurate measurement and modeling of the polarization properties of real aluminum mirrors, as used in

  3. Modeling aluminum-lithium alloy welding characteristics

    Science.gov (United States)

    Bernstein, Edward L.

    1996-01-01

    The purpose of this project was to develop a finite element model of the heat-affected zone in the vicinity of a weld line on a plate in order to determine an accurate plastic strain history. The resulting plastic strain increments calculated by the finite element program were then to be used to calculate the measure of damage D. It was hoped to determine the effects of varying welding parameters, such as beam power, efficiency, and weld speed, and the effect of different material properties on the occurrence of microfissuring. The results were to be compared first to the previous analysis of Inconel 718, and then extended to aluminum 2195.

  4. Cleaning of aluminum after machining with coolants

    International Nuclear Information System (INIS)

    Roop, B.

    1992-01-01

    An x-ray photoemission spectroscopic study was undertaken to compare the cleaning of the Advanced Photon Source (APS) aluminum extrusion storage ring vacuum chambers after machining with and without water soluble coolants. While there was significant contamination left by the coolants, the cleaning process was capable of removing the residue. The variation of the surface and near surface composition of samples machined either dry or with coolants was negligible after cleaning. The use of such coolants in the machining process is therefore recommended

  5. Alloyed Aluminum Contacts for Silicon Solar Cells

    International Nuclear Information System (INIS)

    Tin Tin Aye

    2010-12-01

    Aluminium is usually deposited and alloyed at the back of p-p silicon solar cell for making a good ohmic contact and establishing a back electric field which avoids carrier recombination of the back surface. It was the deposition of aluminum on multicrystalline silicon (mc-Si) substrate at various annealing temperature. Physical and elemental analysis was carried out by using scanning electron microscopy (SEM) and X-rays diffraction (XRD). The electrical (I-V) characteristic of the photovoltaic cell was also measured.

  6. Proposal of 99.99%-aluminum/7N01-Aluminum clad beam tube for high energy booster of Superconducting Super Collider

    International Nuclear Information System (INIS)

    Ishimaru, Hajime

    1994-01-01

    Proposal of 99.99% pure aluminum/7N01 aluminum alloy clad beam tube for high energy booster in Superconducting Super Collider is described. This aluminum clad beam tube has many good performances, but a eddy current effect is large in superconducting magnet quench collapse. The quench test result for aluminum clad beam tube is basically no problem against magnet quench collapse. (author)

  7. 75 FR 51243 - Aluminum Extrusions from the People's Republic of China: Postponement of Preliminary...

    Science.gov (United States)

    2010-08-19

    ... DEPARTMENT OF COMMERCE International Trade Administration [A-570-967] Aluminum Extrusions from the... Department of Commerce (``the Department'') initiated an antidumping duty investigation on Aluminum... Aluminum Extrusions from the People's Republic of China: Initiation of Antidumping Duty Investigation, 75...

  8. Simulation of uranium aluminide dissolution in a continuous aluminum dissolver system

    International Nuclear Information System (INIS)

    Evans, D.R.; Farman, R.F.; Christian, J.D.

    1990-01-01

    This paper reports on the Idaho Chemical Processing Plant (ICPP) which recovers highly-enriched uranium (uranium that contains at least 20 atom percent 235 U) from spent nuclear reactor fuel by dissolution of the fuel elements and extraction of the uranium from the aqueous dissolver product. Because the uranium is highly-enriched, consideration must be given to whether a critical mass can form at any stage of the process. In particular, suspended 235 U-containing particles are of special concern, due to their high density (6.8 g/cm 3 ) and due to the fact that they can settle into geometrically unfavorable configurations when not adequately mixed. A portion of the spent fuel is aluminum-alloy-clad uranium aluminide (UAl 3 ) particles, which dissolve more slowly than the cladding. As the aluminum alloy cladding dissolves in mercury-catalyzed nitric acid, UAl 3 is released. Under standard operating conditions, the UAl 3 dissolves rapidly enough to preclude the possibility of forming a critical mass anywhere in the system. However, postulated worst-case abnormal operating conditions retard uranium aluminide dissolution, and thus require evaluation. To establish safety limits for operating parameters, a computerized simulation model of uranium aluminide dissolution in the aluminum fuel dissolver system was developed

  9. Modification of Sr on 4004 Aluminum Alloy

    Science.gov (United States)

    Guo, Erjun; Cao, Guojian; Feng, Yicheng; Wang, Liping; Wang, Guojun; Lv, Xinyu

    2013-05-01

    As a brazing foil, 4004 Al alloy has good welding performance. However, the high Si content decreases the plasticity of the alloy. To improve the plasticity of 4004 Al alloy and subsequently improve the productivity of 4004 Al foil or 434 composite foil, 4004 Al alloy was modified by Al-10%Sr master alloy. Modification effects of an additional amount of Sr, modification temperature, and holding time on 4004 aluminum alloy were studied by orthogonal design. The results showed that the greatest impact parameter of 4004 aluminum alloy modification was the additional amount of Sr, followed by holding time and modification temperature. The optimum modification parameters obtained by orthogonal design were as follows: Sr addition of 0.04%, holding time of 60 min, and modification temperature of 760°C. The effect of Sr addition on modification was analyzed in detail based on orthogonal results. With increasing of Sr addition, elongation of 4004 alloy increased at first, and decreased after reaching the maximum value.

  10. Aluminum limiter experiment in ST tokamak

    International Nuclear Information System (INIS)

    Meservey, E.B.; Bretz, N.; Dimock, D.L.; Hinnov, E.

    1976-01-01

    In order to investigate the effects of a light-element limiter on plasma parameters, aluminum rail limiters interchangeable with Mo rails were installed top, bottom, and outside directions in the ST tokamak. The inside limiter remained a fixed Mo rail. Compared with discharges produced immediately before and after with the usual Mo limiters, the ''aluminum'' discharges showed an increase of T/sub e/ (by factors of 1.4-2 near the center) and of energy confinement (by factors of 2 to 3 in el. energy/power input, depending on time of observation). H 2 and He discharges showed practically identical effects. In plasma composition, the Mo concentration dropped significantly, but Fe only slightly if at all; the Al concentration was about 3-5 percent (i.e., large compared to the heavier metals), whereas oxygen, about 4 to 8 percent to start with, dropped to insignificance, probably as a result of Al evaporation. The z/sub eff/ from resistivity increased 20-30 percent although the resistance dropped because of the higher T/sub e/. The improved T/sub e/ and energy confinement are thought to be the result of cumulative effects of more favorable radial current and power input distributions rather than direct energy losses by radiation

  11. The Anisotropy of Replicated Aluminum Foams

    Directory of Open Access Journals (Sweden)

    Eugeny L. Furman

    2014-01-01

    Full Text Available The replication casting process gives the open-cell aluminum foams that can be used in many industrial applications as well as in filtering technology. The essential requirement for filters is the uniformity of filtering degree which is defined by the minimal pore size. However the structure of replication castings is often inhomogeneous and the minimal pore radius is decreasing in the direction of melt infiltration. The objective of this investigation is to study the dynamics of melt impregnation of the porous medium by vacuum suction to identify the possibility of reducing the anisotropy. Theoretical data illustrate the processes at the boundary between melt and gas medium. The experiments were carried out using the replication aluminum samples produced according to commercial technology. It was found that the permeability coefficient varies throughout the height of castings. A method for estimation of pressure on the line of melt movement was proposed. The resistance of NaCl layer and circular vents of the mold causes the inhomogeneity of castings. Finally the ways of minimizing the anisotropy were offered.

  12. Solid Aluminum Borohydrides for Prospective Hydrogen Storage.

    Science.gov (United States)

    Dovgaliuk, Iurii; Safin, Damir A; Tumanov, Nikolay A; Morelle, Fabrice; Moulai, Adel; Černý, Radovan; Łodziana, Zbigniew; Devillers, Michel; Filinchuk, Yaroslav

    2017-12-08

    Metal borohydrides are intensively researched as high-capacity hydrogen storage materials. Aluminum is a cheap, light, and abundant element and Al 3+ can serve as a template for reversible dehydrogenation. However, Al(BH 4 ) 3 , containing 16.9 wt % of hydrogen, has a low boiling point, is explosive on air and has poor storage stability. A new family of mixed-cation borohydrides M[Al(BH 4 ) 4 ], which are all solid under ambient conditions, show diverse thermal decomposition behaviors: Al(BH 4 ) 3 is released for M=Li + or Na + , whereas heavier derivatives evolve hydrogen and diborane. NH 4 [Al(BH 4 ) 4 ], containing both protic and hydridic hydrogen, has the lowest decomposition temperature of 35 °C and yields Al(BH 4 ) 3 ⋅NHBH and hydrogen. The decomposition temperatures, correlated with the cations' ionic potential, show that M[Al(BH 4 ) 4 ] species are in the most practical stability window. This family of solids, with convenient and versatile properties, puts aluminum borohydride chemistry in the mainstream of hydrogen storage research, for example, for the development of reactive hydride composites with increased hydrogen content. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Spray Forming Aluminum - Final Report (Phase II)

    Energy Technology Data Exchange (ETDEWEB)

    D. D. Leon

    1999-07-08

    The U.S. Department of Energy - Office of Industrial Technology (DOE) has an objective to increase energy efficient and enhance competitiveness of American metals industries. To support this objective, ALCOA Inc. entered into a cooperative program to develop spray forming technology for aluminum. This Phase II of the DOE Spray Forming Program would translate bench scale spray forming technology into a cost effective world class process for commercialization. Developments under DOE Cooperative Agreement No. DE-FC07-94ID13238 occurred during two time periods due to budgetary constraints; April 1994 through September 1996 and October 1997 and December 1998. During these periods, ALCOA Inc developed a linear spray forming nozzle and specific support processes capable of scale-up for commercial production of aluminum sheet alloy products. Emphasis was given to alloys 3003 and 6111, both being commercially significant alloys used in the automotive industry. The report reviews research performed in the following areas: Nozzel Development, Fabrication, Deposition, Metal Characterization, Computer Simulation and Economics. With the formation of a Holding Company, all intellectual property developed in Phases I and II of the Project have been documented under separate cover for licensing to domestic producers.

  14. Excited state electron affinity calculations for aluminum

    Science.gov (United States)

    Hussein, Adnan Yousif

    2017-08-01

    Excited states of negative aluminum ion are reviewed, and calculations of electron affinities of the states (3s^23p^2)^1D and (3s3p^3){^5}{S}° relative to the (3s^23p)^2P° and (3s3p^2)^4P respectively of the neutral aluminum atom are reported in the framework of nonrelativistic configuration interaction (CI) method. A priori selected CI (SCI) with truncation energy error (Bunge in J Chem Phys 125:014107, 2006) and CI by parts (Bunge and Carbó-Dorca in J Chem Phys 125:014108, 2006) are used to approximate the valence nonrelativistic energy. Systematic studies of convergence of electron affinity with respect to the CI excitation level are reported. The calculated value of the electron affinity for ^1D state is 78.675(3) meV. Detailed Calculations on the ^5S°c state reveals that is 1216.8166(3) meV below the ^4P state.

  15. Molten aluminum alloy fuel fragmentation experiments

    International Nuclear Information System (INIS)

    Gabor, J.D.; Purviance, R.T.; Cassulo, J.C.; Spencer, B.W.

    1992-01-01

    Experiments were conducted in which molten aluminum alloys were injected into a 1.2 m deep pool of water. The parameters varied were (i) injectant material (8001 aluminum alloy and 12.3 wt% U-87.7 wt% Al), (ii) melt superheat (O to 50 K), (iii) water temperature (313, 343 and 373 K) and (iv) size and geometry of the pour stream (5, 10 and 20 mm diameter circular and 57 mm annular). The pour stream fragmentation was dominated by surface tension with large particles (∼30 mm) being formed from varicose wave breakup of the 10-mm circular pours and from the annular flow off a 57 mm diameter tube. The fragments produced by the 5 mm circular et were smaller (∼ mm), and the 20 mm jet which underwent sinuous wave breakup produced ∼100 mm fragments. The fragments froze to form solid particles in 313 K water, and when the water was ≥343 K, the melt fragments did not freeze during their transit through 1.2 m of water

  16. Structural changes in leaves and roots are anatomical markers of aluminum sensitivity in sunflower

    Directory of Open Access Journals (Sweden)

    Daniel da Silva de Jesus

    2016-12-01

    Full Text Available Aluminum (Al toxicity in plants evidences the importance of genotype evaluation to the identification of tolerance markers. This study aimed at evaluating the effects of aluminum stress on the relative water content, membrane damages and anatomical changes, in Al-tolerant and Al-sensitive sunflower cultivars. Sunflower plants [Catissol (Al-tolerant and IAC-Uruguai (Al-sensitive] were grown in nutrient solution (control or nutrient solution containing 0.15 mM of AlCl3 (Al-stress treatment, in a greenhouse. The experimental design was completely randomized, in a factorial arrangement consisting of four harvest times x two sunflower cultivars x two Al levels, with four replications. The results showed that Al negatively affected the absolute integrity percentage and relative water content only for the IAC-Uruguay cultivar. These results in the stressed leaves of the Al-sensitive cultivar may be due to damage in the xylem structure. In addition, the increase in leaf blade thickness and parenchyma layers, as well as lignification of root tissues, are important traits of IAC-Uruguay plants and may be used as anatomical markers of Al sensitivity in sunflower.

  17. Photosynthesis and photoprotective systems of plants in response to ...

    African Journals Online (AJOL)

    Aluminum (Al) toxicity is the major factor limiting plant growth in acidic soils, which comprise up to 70% of the world's potentially arable lands. Although, Al toxicity and tolerance in plant roots have been extensively studied during the past decades because inhibition of root growth is one of the earliest symptoms of Al injury ...

  18. High strength corrosion-resistant zirconium aluminum alloys

    International Nuclear Information System (INIS)

    Schulson, E.M.; Cameron, D.J.

    1976-01-01

    A zirconium-aluminum alloy is described possessing superior corrosion resistance and mechanical properties. This alloy, preferably 7.5-9.5 wt% aluminum, is cast, worked in the Zr(Al)-Zr 2 Al region, and annealed to a substantially continuous matrix of Zr 3 Al. (E.C.B.)

  19. Selenium Adsorption To Aluminum-Based Water Treatment Residuals

    Science.gov (United States)

    Aluminum-based water treatment residuals (WTR) can adsorb water-and soil-borne P, As(V), As(III), and perchlorate, and may be able to adsorb excess environmental selenium. WTR, clay minerals, and amorphous aluminum hydroxide were shaken for 24 hours in selenate or selenite solut...

  20. Evaluation of microstructure of A356 aluminum alloy casting ...

    Indian Academy of Sciences (India)

    The objective of this investigation was to evaluate the effect of vibrations (during solidification) on the metallurgical properties of A356 aluminum casting. Mechanical vibrations were applied to A356 aluminum alloy through set up. A356 melt has been subjected to mechanical vibration with the frequency range from 0 to 400 ...