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Sample records for cast aluminum alloy

  1. Casting Characteristics of Aluminum Die Casting Alloys

    Energy Technology Data Exchange (ETDEWEB)

    Makhlouf M. Makhlouf; Diran Apelian

    2002-02-05

    The research program investigates the casting characteristics of selected aluminum die casting alloys. Specifically, the alloys' tendencies towards die soldering and sludge formation, and the alloys' fluidity and machinability are evaluated. It was found that: When the Fe and Mn contents of the alloy are low; caution has to be taken against possible die soldering. When the alloy has a high sludge factor, particularly a high level of Fe, measures must be taken to prevent the formation of large hardspots. For this kind of alloy, the Fe content should be kept at its lowest allowable level and the Mn content should be at its highest possible level. If there are problems in die filling, measures other than changing the alloy chemistry need to be considered first. In terms of alloy chemistry, the elements that form high temperature compounds must be kept at their lowest allowable levels. The alloys should not have machining problems when appropriate machining techniques and machining parameters are used.

  2. 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.

  3. Technique of Aluminum Alloy Composite by Inversion Casting

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The influence of the temperature of liquid aluminum alloy, the dipping time in liquid alloy and the thickness of base strips on the solidified layer was studied during the process of producing aluminum alloy composite strips used in automobile radiator with inversion casting. It is concluded that there is welding as well as diffusion of alloying elements between the base strip and the coating. Experiments proved that the interface has a good bonding.

  4. China’s Aluminum Alloy Die Castings Industry has Promising Prospects

    Institute of Scientific and Technical Information of China (English)

    2013-01-01

    <正>Engine aluminum alloy engine block die casting experienced rapid development in recent years. Domestic enterprises introduced large die casting machine automatic production lines, and developed large aluminum alloy die cast-

  5. The Role of Particles in Fatigue Crack Propagation of Aluminum Matrix Composites and Casting Aluminum Alloys

    Institute of Scientific and Technical Information of China (English)

    Zhenzhong CHEN; Ping HE; Liqing CHEN

    2007-01-01

    Fatigue crack propagation (FCP) behaviors were studied to understand the role of SiC particles in 10 wt pct SiCp/A2024 composites and Si particles in casting aluminum alloy A356. The results show that a few particles appeared on the fracture surfaces in SiCp/Al composites even at high AK region, which indicates that cracks propagated predominantly within the matrix avoiding SiC particles due to the high strength of the particles and the strong particle/matrix interface. In casting aluminum alloy, Si particle debonding was more prominent.Compared with SiCp/Al composite, the casting aluminum alloy exhibited lower FCP rates, but had a slight steeper slope in the Paris region. Crack deflection and branching were found to be more remarkable in the casting aluminum alloy than that in the SiCp/Al composites, which may be contributed to higher FCP resistance in casting aluminum alloy.

  6. 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.

  7. Texture evolution of continuous cast and direct chill cast AA 3003 aluminum alloys during cold rolling

    International Nuclear Information System (INIS)

    The texture evolution of continuous cast (CC) and direct chill cast (DC) AA 3003 aluminum alloys during cold rolling was investigated by X-ray diffraction. The relationship between texture volume fractions and rolling true strain was described quantitatively by mathematical formulae. The effect of processing method (CC vs. DC) on texture evolution was determined

  8. Optimization of Squeeze Casting for Aluminum Alloy Parts

    Energy Technology Data Exchange (ETDEWEB)

    David Schwam; John F. Wallace; Qingming Chang; Yulong Zhu

    2002-07-30

    This study was initiated with the installation of a new production size UBE 350 Ton VSC Squeeze Casting system in the Metal Casting Laboratory at Case Western University. A Lindberg 75k W electrical melting furnace was installed alongside. The challenge of installation and operation of such industrial-size equipment in an academic environment was met successfully. Subsequently, a Sterling oil die heater and a Visi-Track shot monitoring system were added. A significant number of inserts were designed and fabricated over the span of the project, primarily for squeeze casting different configurations of test bars and plates. A spiral ''ribbon insert'' for evaluation of molten metal fluidity was also fabricated. These inserts were used to generate a broad range of processing conditions and determine their effect on the quality of the squeeze cast parts. This investigation has studied the influence of the various casting variables on the quality of indirect squeeze castings primarily of aluminum alloys. The variables studied include gating design, fill time and fill patter, metal pressure and die temperature variations. The quality of the die casting was assessed by an analysis of both their surface condition and internal soundness. The primary metal tested was an aluminum 356 alloy. In addition to determining the effect of these casting variables on casting quality as measured by a flat plate die of various thickness, a number of test bar inserts with different gating designs have been inserted in the squeeze casting machine. The mechanical properties of these test bars produced under different squeeze casting conditions were measured and reported. The investigation of the resulting properties also included an analysis of the microstructure of the squeeze castings and the effect of the various structural constituents on the resulting properties. The main conclusions from this investigation are as follows: The ingate size and shape are very important

  9. TESTING OF ALUMINUM-SILICON ALLOYS MECHANICAL PROPERTIES ON SEPARATELY CASTED SPECIMENS

    OpenAIRE

    Krushenko, G.

    2010-01-01

    The mechanical properties of aluminum alloys before casting into moulds were determined on separately casted control specimens casted in horizontal or vertical forms. A comparison of the mechanical properties (tensile strength t, elongation 8, hardness HB) of 12-mm-diameter individually casted of AK7ch alloy control specimens and its density in the solid state (p) showed that it is necessary to use specimens casted in a horizontal mold for evaluation of castings quality. It was estimated that...

  10. Rheological behavior of continuous roll casting process of aluminum alloy

    Institute of Scientific and Technical Information of China (English)

    ZHAN Li-hua; ZHONG Jue; LI Xiao-qian; HUANG Ming-hui

    2005-01-01

    The rheological behavior of aluminum alloy and its influencing factors in physical simulation of continuous roll casting process were studied by using a Gleeble-1500 thermal-mechanical simulation tester with a set of special clamp system. The relationships between the flow stress and the strain rate in the deformation process of simulating roll casting experiment were obtained. The results show that four different characteristic stages exist in the temperature range of the whole rheological process. The first occurs when the temperature is higher than 600℃, which belongs to the creep deformation stage; the second occurs when the temperature lies in the range of 500-600℃, and it can be regarded as the high temperature and low stress level deformation stage; the third occurs when the temperature decreases to the range of 300-500℃, it is considered to be the middle stress level deformation stage; the last occurs when the temperature is less than 300℃ and the strain rate is less than 1.00 s -1, it belongs to middle stress level deformation stage. But when the strain rate is larger than 1.00 s -1, it belongs to the high stress level deformation stage. And the relative constitutive models suitable for the four different stages of continuous roll casting process were established through multivariate linear regression analysis of the experimental data.

  11. Aluminum Alloy Semisolid Strip Casting Using an Unequal Diameter Twin Roll Caster

    OpenAIRE

    Haga, T.; Sakaguchi, H; H. Inui; H. Watari; S. Kumai

    2005-01-01

    Purpose: A Purpose of the present study was to break through the disadvantage of the twin roll caster for aluminum alloy. They were slow casting speed and limitation of alloy. For example, the casting speed was slower than 5 m/min, and casting of hypereutectic Al-Si alloy was difficult. In order to break through the disadvantages, semisolid casting using an unequal diameter twin roll caster was tested its ability.Design/methodology/approach: The specification of the unequal diameter twin roll...

  12. Technical parameters in electromagnetic continuous casting of aluminum alloy

    Institute of Scientific and Technical Information of China (English)

    李玉梅; 张兴国; 贾非; 姚山; 金俊泽

    2003-01-01

    The temperature field of aluminum ingot during electromagnetic continuous casting was calculated by the numerical method, and the effects of cooling water strength, position of the cooling water holes and pouring temperature as well as induction heat on casting speed, were studied. The results show that among the technical parameters the distance from the position of the cooling water holes to the bottom of the mold is the most important factor, whose change from 20mm to 15mm and from 15mm to 10mm causes the setting rate increasing respectively by 0.14mm/s and 0.3mm/s.The calculated results also agree with the experiment well. The simulation program can be used to determine technical parameters of electromagnetic casting of aluminum ingot effectively.

  13. Influences on Burr Size During Face-Milling of Aluminum Alloys and Cast Iron

    OpenAIRE

    Shefelbine, Wendy; Dornfeld, David

    2004-01-01

    The Exit Order Sequence (EOS) theory discussed by previous LMA students predicts the size of burrs formed during face milling. Other influences are tool geometry, coolant use, and material properties in aluminum silicon alloys and cast iron. Used, worn tools also increase the size of the burr. The effect of speed and feed are also discussed, particularly with regards to cast iron.

  14. Effect of Electromagnetic Frequency on Microstructures of Continuous Casting Aluminum Alloys

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The relationship between electromagnetic frequency and microstructures of continuous casting aluminum alloyswas studied. 7075 aluminum alloy ingot of 100 mm in diameter was produced by electromagnetic continuouscasting process, the microstructures of as-cast ingot was examined by scanning electron microscopy (SEM) equippedwith energy dispersive spectrometer (EDS). The results showed that electromagnetic frequency greatly influencedsegregation and microstructures of as-cast ingot, and product quality can be guaranteed by the application of aproper frequency. Electromagnetic frequency plays a significant role in solute redistribution; Iow frequency is moreefficient for promoting solution of alloying elements.

  15. Strengthening technology and mechanism for semi-solid die casting of aluminum alloy

    Institute of Scientific and Technical Information of China (English)

    张恒华; 许珞萍; 邵光杰; 余忠土

    2003-01-01

    Combined with theoretical evaluation,an optimized strengthening process for the semi-solid die castings of A356 aluminum alloy was obtained by studying the mechanical properties of castings solution treated and aged under different conditions in detail,then,the semi-solid die castings and liquid die castings were heat treated with the optimized process.The results show that the mechanical properties of semi-solid die castings of aluminum alloy are superior to those of the liquid die castings,especially the strengthening degree of heat treated semi-solid die castings is much greater than that of liquid die castings with the tensile strength more than 330 Mpa and the elongation more than 10%,and this is mainly contributed to the non-dendritic and more compact microstructure of semi-solid die castings.The strengthening mechanism of heat treatment for the semi-solid die castings of A356 aluminum alloy is due to the dispersive precipitation of the second phase(Mg2 Si)and formation of GP Zone.

  16. Adhesion enhancement of titanium nitride coating on aluminum casting alloy by intrinsic microstructures

    Science.gov (United States)

    Nguyen, Chuong L.; Preston, Andrew; Tran, Anh T. T.; Dickinson, Michelle; Metson, James B.

    2016-07-01

    Aluminum casting alloys have excellent castability, high strength and good corrosion resistance. However, the presence of silicon in these alloys prevents surface finishing with conventional methods such as anodizing. Hard coating with titanium nitride can provide wear and corrosion resistances, as well as the aesthetic finish. A critical factor for a durable hard coating is its bonding with the underlying substrate. In this study, a titanium nitride layer was coated on LM25 casting alloy and a reference high purity aluminum substrate using Ion Assisted Deposition. Characterization of the coating and the critical interface was carried out by a range of complementing techniques, including SIMS, XPS, TEM, SEM/EDS and nano-indentation. It was observed that the coating on the aluminum alloy is stronger compared to that on the pure aluminum counterpart. Silicon particles in the alloy offers the reinforcement though mechanical interlocking at microscopic level, even with nano-scale height difference. This reinforcement overcomes the adverse effect caused by surface segregation of magnesium in aluminum casting alloys.

  17. As-cast structure of DC casting 7075 aluminum alloy obtained under dual-frequency electromagnetic field

    Institute of Scientific and Technical Information of China (English)

    Zhi-hao Zhao; Zhen Xu; Gao-song Wang; Qing-feng Zhu; Jian-zhong Cui

    2014-01-01

    We have experimentally determined the as-cast structures of semi-continuous casting 7075 aluminum alloy obtained in the pres-ence of dual-frequency electromagnetic field. Results suggest that the use of dual-frequency electromagnetic field during the semi-continuous casting process of 7075 aluminum alloy ingots reduces the thickness of the surface segregation layer, increases the height of the melt menis-cus, enhances the surface quality of the ingot, and changes the surface morphology of the melt pool. Moreover, low-frequency electromag-netic field was found to show the most obvious influence on improving the as-cast structure because of its high permeability in conductors.

  18. Cold cracking in DC-cast high strength aluminum alloy ingots: An intrinsic problem intensified by casting process parameters

    NARCIS (Netherlands)

    Lalpoor, M.; Eskin, D.G.; Ruvalcaba, D.; Fjaer, H.G.; Ten Cate, A.; Ontijt, N.; Katgerman, L.

    2011-01-01

    For almost half a century the catastrophic failure of direct chill (DC) cast high strength aluminum alloys has been challenging the production of sound ingots. To overcome this problem, a criterion is required that can assist the researchers in predicting the critical conditions which facilitate the

  19. Development of Deformation-Semisolid-Casting (D-SSC) Process and Applications to Some Aluminum Alloys

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Recent advances in the semisolid casting technologies are introduced for aluminum alloys. The advantages of the rheocast and thixocast methods to fabricate alloys with refined spheroidized α-Al particles are described.The deformation-semisolid-casting (D-SSC) process developed by the author's group is presented. The D-SSC process is extremely effective to produce microstructures of refined intermetallic compound particles as well as the spheroidized α-Al particles in the Al-Si based alloys containing highly concentrated Fe. In the D-SSC processed Al-Si-Cu alloy high elongation of about 20% was achieved even contained concentrated impurity of Fe. The D-SSC process is also useful to produce wrought aluminum alloys with microstructures of refined α-Al particles.

  20. Recrystallization microstructures and textures in AA 5052 continuous cast and direct chill cast aluminum alloy

    International Nuclear Information System (INIS)

    Commercially produced hot bands of AA 5052 continuous cast (CC) and direct chill (DC) cast aluminum alloys were cold rolled to (thickness) reductions of 70%, 80%, and 90% followed by annealing at different conditions. The recrystallization kinetics are found equivalent for both the CC and DC materials. Recrystallization microstructures are different between the CC and DC materials. Evolution of recrystallization texture in the CC and DC materials were investigated by using three-dimensional orientation distribution functions (ODFs) that were determined by X-ray diffraction. The recrystallization texture was correlated with cold rolling reduction (prior to annealing), annealing temperature, and annealing time. Results showed that the R {124} and cube {001} are dominant recrystallization texture components in both CC and DC materials. During annealing, the intensity and volume fraction of the cube component strongly depend on the prior cold rolling history. In contrast, the intensity and volume fraction of the R component remains almost constant regardless of the different cold rolling reductions prior to annealing. After complete recrystallization, the intensity and volume fraction of both R and cube components appear to be independent of the annealing temperature and annealing time

  1. Comparison of recrystallization texture in cold-rolled continuous cast AA5083 and 5182 aluminum alloys

    International Nuclear Information System (INIS)

    The recrystallization microstructure and texture of cold-rolled continuous cast AA 5083 and 5182 aluminum alloys with and without prior heat treatment were investigated by optical microscopy, X-ray diffraction and TEM. The results obtained were discussed with regard to the effect of Zener-particle pinning

  2. Comparison of recrystallization texture in cold-rolled continuous cast AA5083 and 5182 aluminum alloys

    Energy Technology Data Exchange (ETDEWEB)

    Li, J. [Department of Civil and Environmental Engineering, Beijing Jiaotong University (China); Liu, W.C. [Department of Chemical and Materials Engineering, University of Kentucky, 177 Anderson Hall, Lexington, KY 40506 (United States); Zhai, T. [Department of Chemical and Materials Engineering, University of Kentucky, 177 Anderson Hall, Lexington, KY 40506 (United States)]. E-mail: tzhai@engr.uky.edu; Kenik, E.A. [Metals and Ceramics Division, Oak Ridge National Laboratory, 100 Bethel Valley Road, Building 4515, MS-6064, P.O. Box 2008, Oak Ridge, TN 37831-6064 (United States)

    2005-02-15

    The recrystallization microstructure and texture of cold-rolled continuous cast AA 5083 and 5182 aluminum alloys with and without prior heat treatment were investigated by optical microscopy, X-ray diffraction and TEM. The results obtained were discussed with regard to the effect of Zener-particle pinning.

  3. THE INVESTIGATION ON THE RHEOLOGICAL BEHAVIOR OF SEMI-SOLID ALUMINUM ALLOY DURING DIE CASTING

    Institute of Scientific and Technical Information of China (English)

    X.J. Yang; J. Lin

    2002-01-01

    Under the condition of die casting and reheating temperature of 570-580° C, the Rhe-ological behavior of semi-solid aluminum alloy (A356) is pseudoplasticity at the shearrate of 2×10s-1×104 s-1, and also shows dilatancy at the rate over 106s-1.

  4. Aluminum Alloy Semisolid Strip Casting Using an Unequal Diameter Twin Roll Caster

    Directory of Open Access Journals (Sweden)

    T. Haga

    2005-12-01

    Full Text Available Purpose: A Purpose of the present study was to break through the disadvantage of the twin roll caster for aluminum alloy. They were slow casting speed and limitation of alloy. For example, the casting speed was slower than 5 m/min, and casting of hypereutectic Al-Si alloy was difficult. In order to break through the disadvantages, semisolid casting using an unequal diameter twin roll caster was tested its ability.Design/methodology/approach: The specification of the unequal diameter twin roll caster is as below. The diameter of the upper roll was 250 mm, and that of the lower roll was 1000 mm. The width of the roll was 100 mm. The semisolid slurry was made by a cooling slope.Findings: The microstructure of the strip became very fine. Especially, primary and eutectic Si became very fine. This was the effect of rapid solidification. As the result, the ductility of Al-16%Si was improved.Research limitations/implications: 6111 aluminum alloy strip was cast at speeds of 5, 10 and 20 m/min. This caster could cast the strip at the speeds higher than the conventional twin roll caster. Start of casting was very easy. The hypereutectic Al-16%Si alloy, which has wide freezing zone, could be cast in to the strip by the unequal diameter twin roll caster. This was the effect of the cooling of the strip on the lower roll.Originality/value: The roll cast Al-16mass%Si strip had good ductility, and could be cold rolled. Annealed 0.5 mm thick Al-16mass%Si could be bent at radius of 0.75mm.

  5. Machining studies of die cast aluminum alloy-silicon carbide composites

    Science.gov (United States)

    Sornakumar, Thambu; Kathiresan, Marimuthu

    2010-10-01

    Metal matrix composites (MMCs) with high specific stiffness, high strength, improved wear resistance, and thermal properties are being increasingly used in advanced structural, aerospace, automotive, electronics, and wear applications. Aluminum alloy-silicon carbide composites were developed using a new combination of the vortex method and the pressure die-casting technique in the present work. Machining studies were conducted on the aluminum alloy-silicon carbide (SiC) composite work pieces using high speed steel (HSS) end-mill tools in a milling machine at different speeds and feeds. The quantitative studies on the machined work piece show that the surface finish is better for higher speeds and lower feeds. The surface roughness of the plain aluminum alloy is better than that of the aluminum alloy-silicon carbide composites. The studies on tool wear show that flank wear increases with speed and feed. The end-mill tool wear is higher on machining the aluminum alloy-silicon carbide composites than on machining the plain aluminum alloy.

  6. Processing map of as-cast 7075 aluminum alloy for hot working

    Institute of Scientific and Technical Information of China (English)

    Guo Lianggang a; Yang Shuang a; Yang He a; Zhang Jun b

    2015-01-01

    The true stress–strain curves of as-cast 7075 aluminum alloy have been obtained by isothermal compression tests at temperatures of 300–500 ?C and strain rates of 0.01–10 s?1. The plastic flow instability map is established based on Gegel B and Murthy instability criteria because the deformed compression samples suggest that the combination of the above two instability criteria has more comprehensive crack prediction ability. And the processing map based on Dynamic Mate-rial Model (DMM) of as-cast 7075 aluminum alloy has been developed through a superposition of the established instability map and power dissipation map. In terms of microstructure of the deformed samples and whether plastic flow is stable or not, the processing map can be divided into five areas: stable area with as-cast grain, stable area with homogeneous grain resulting from dynamic recovery, instability area with as-cast grain, instability area with the second phase and instability area with mixed grains. In consideration of microstructure characteristics in the above five areas of the processing map, the stable area with homogeneous grain resulting from dynamic recovery, namely the temperatures at 425–465 ?C and the strain rates at 0.01–1 s?1, is suggested to be suitable processing window for the as-cast 7075 aluminum alloy.

  7. Processing map of as-cast 7075 aluminum alloy for hot working

    Directory of Open Access Journals (Sweden)

    Guo Lianggang

    2015-12-01

    Full Text Available The true stress–strain curves of as-cast 7075 aluminum alloy have been obtained by isothermal compression tests at temperatures of 300–500 °C and strain rates of 0.01–10 s−1. The plastic flow instability map is established based on Gegel B and Murthy instability criteria because the deformed compression samples suggest that the combination of the above two instability criteria has more comprehensive crack prediction ability. And the processing map based on Dynamic Material Model (DMM of as-cast 7075 aluminum alloy has been developed through a superposition of the established instability map and power dissipation map. In terms of microstructure of the deformed samples and whether plastic flow is stable or not, the processing map can be divided into five areas: stable area with as-cast grain, stable area with homogeneous grain resulting from dynamic recovery, instability area with as-cast grain, instability area with the second phase and instability area with mixed grains. In consideration of microstructure characteristics in the above five areas of the processing map, the stable area with homogeneous grain resulting from dynamic recovery, namely the temperatures at 425–465 °C and the strain rates at 0.01–1 s−1, is suggested to be suitable processing window for the as-cast 7075 aluminum alloy.

  8. Effect of Low Frequency Electromagnetic Field on Macrosegregation of Horizontal Direct Chill Casting Aluminum Alloys

    Institute of Scientific and Technical Information of China (English)

    Zhihao ZHAO; Jianzhong CUI; Jie DONG; Beijiang ZHANG

    2005-01-01

    The horizontal direct chill (HDC) casting process is a well-established production route for aluminum alloy ingot but the ingot may suffer from macrosegregation sometimes. In order to control the defect, a low frequency electromagnetic field has been applied in HDC casting process and the relevant influence has been studied. The results show that application of low frequency electromagnetic field can reduce macrosegregation in HDC casting process; and two main parameters of electromagnetic field density and frequency, have great influences on the solution distribution along the diameter of ingot. Moreover, the mechanisms of reduction of macrosegregation by electromagnetic field have been discussed.

  9. Process for Producing a Cast Article from a Hypereutectic Aluminum-Silicon Alloy

    Science.gov (United States)

    Lee, Jonathan A. (Inventor); Chen, Po-Shou (Inventor)

    2003-01-01

    A process for making a cast article from an aluminum alloy includes first casting an article from an alloy having the following composition, in weight percent: Silicon (Si) 14.0-25.0, Copper (CU) 5.5-8.0, Iron (Fe) 0-0.8, Magnesium (Mg) 0.5-1.5, Nickel (Ni) 0.05-1.2, Manganese (Mn) 0-1.0, Titanium (Ti) 0.05-1.2, Zirconium (Zr) 0.12-1.2, Vanadium (V) 0.05-1.2, Zinc (Zn) 0-0.9, Phosphorus (P) 0.001-0.1, Aluminum, balance. In this alloy the ration of Si:Mg is 15-35, and the ratio of Cu:Mg is 4-15. After an article is cast from the alloy, the cast article is aged at a temperature within the range of 400 F to 500 F for a time period within the range of four to 16 hours. It has been found especially advantageous if the cast article is first exposed to a solutionizing step prior to the aging step. This solutionizing step is carried out by exposing the cast article to a temperature within the range of 875 F to 1025 F for a time period of fifteen minutes to four hours. It has also been found to be especially advantageous if the solutionizing step is followed directly with a quenching step, wherein the cast article is quenched in a quenching medium such as water at a temperature within the range of 120 F to 300 F. The resulting cast article is highly suitable in a number of high temperature applications, such as heavy-duty pistons for internal combustion engines.

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

    Directory of Open Access Journals (Sweden)

    M. Górny

    2009-01-01

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

  11. Rapid air film continuous casting of aluminum alloy using static magnetic field

    Institute of Scientific and Technical Information of China (English)

    Fu QU; Huixue JIANG; Gaosong WANG; Qingfeng ZHU; Xiangjie WANG; Jianzhong CUI

    2009-01-01

    The influences of the cooling style and static magnetic field on the air film casting process were investigated. Ingots of 6063 aluminum alloy were produced by AIRSOL VEIL casting with double-layer cooling water and static magnetic field. Surface segregation, hot crack and variation of solute content along the radius direction of ingot were examined. The results showed that double-layer cooling water can improve the surface quality and avoid of hot crack, which created conditions to increase the casting speed. The electromagnetic casting process can effectively improve the surface quality in high speed casting process, and static magnetic field has a great influence on solute distribution along the radius direction of ingot.

  12. Development of a New Ferrous Aluminosilicate Refractory Material for Investment Casting of Aluminum Alloys

    Science.gov (United States)

    Yuan, Chen; Jones, Sam; Blackburn, Stuart

    2012-12-01

    Investment casting is a time-consuming, labour intensive process, which produces complex, high value-added components for a variety of specialised industries. Current environmental and economic pressures have resulted in a need for the industry to improve current casting quality, reduce manufacturing costs and explore new markets for the process. Alumino-silicate based refractories are commonly used as both filler and stucco materials for ceramic shell production. A new ceramic material, norite, is now being produced based on ferrous aluminosilicate chemistry, having many potential advantages when used for the production of shell molds for casting aluminum alloy. This paper details the results of a direct comparison made between the properties of a ceramic shell system produced with norite refractories and a typical standard refractory shell system commonly used in casting industry. A range of mechanical and physical properties of the systems was measured, and a full-scale industrial casting trial was also carried out. The unique properties of the norite shell system make it a promising alternative for casting aluminum based alloys in the investment foundry.

  13. PARTING COATINGS FOR ALUMINUM-ALLOY PRESSURE-DIE CASTING MOULDS

    Directory of Open Access Journals (Sweden)

    A. M. Michalzov

    2011-01-01

    Full Text Available The paper reveals how to obtain a parting coating with high sedimentation resistance. The parting coating is used for  oiling aluminum-alloy pressure-die casting moulds and obtained on the basis of high-molecular silicon polymers (polymethylsilicone fluid PMS300 with  addition of light vegetable oil soap stocks as an emulsion the weighing material and the stabilizing agent of an emulsion filling an stabilizing agent. 

  14. EFFECT OF CASTING MOULD ON MECHANICAL PROPERTIES OF 6063 ALUMINUM ALLOY

    Directory of Open Access Journals (Sweden)

    WASIU AJIBOLA AYOOLA

    2012-02-01

    Full Text Available Modern production methods for casting articles include the use of sand- mould, metal-mould, die, and centrifugal castings. Castings produced using sand mould is known to have peculiar microstructures depending on average size, distribution and shape of the moulding sand grains and the chemical composition of the alloy. These affect the surface finish, permeability and refractoriness of all the castings. In this paper, the effect of using CO2 process, metal mould, cement-bonded sand mould and naturally-bonded sand mould on the hardness, tensile and impact strengths of as-cast 6063 Aluminum alloy is presented. The results show that there is significant increase in hardness(33.7 HB of the alloy when naturally-bonded sand mould is used for its production over that of metal, CO2 and cement moulds. The stress-strain curves behaviour of the samples also indicated that sample from naturally bonded sand has highest tensile strength with superior ductility. The alloy shows highest impact strength when metal mould is used for sample preparation in comparison with other moulds.

  15. Preparation of casting alloy ZL101 with coarse aluminum-silicon alloy

    Institute of Scientific and Technical Information of China (English)

    YOU Jing; WANG Yao-wu; FENG Nai-xiang; YANG Ming-sheng

    2008-01-01

    The coarse Al-Si alloy produced by carbothermal reduction of aluminous ore contains 55% Al, 25% Si and some impurities. The main impurities are slag and iron. The process of manufacturing casting Al-Si alloy ZL101 with the coarse Al-Si alloy was studied. The phase constitution and microstructure of the coarse Al-Si alloy, slag and ZL101 were examined by X-ray diffractometry and scanning electron microscopy. The results show that the content of silicon and iron in the casting alloy reduces with the increase of the dosage of purificant and manganese, but increases with the rise of filtering temperature. It is found that casting Al-Si alloy conforming to industrial standard can be produced after refining by using purificant, and removing iron by using manganese and added magnesium.

  16. 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

  17. Stress ratio effects in fatigue of lost foam cast aluminum alloy 356

    Science.gov (United States)

    Palmer, David E.

    Lost foam casting is a highly versatile metalcasting process that offers significant benefits in terms of design flexibility, energy consumption, and environmental impact. In the present work, the fatigue behavior of lost foam cast aluminum alloy 356, in conditions T6 and T7, was investigated, under both zero and non-zero mean stress conditions, with either as-cast or machined surface finish. Scanning electron microscopy was used to identify and measure the defect from which fatigue fracture initiated. Based on the results, the applicability of nine different fatigue mean stress equations was compared. The widely-used Goodman equation was found to be highly non-conservative, while the Stulen, Topper-Sandor, and Walker equations performed reasonably well. Each of these three equations includes a material-dependent term for stress ratio sensitivity. The stress ratio sensitivity was found to be affected by heat treatment, with the T6 condition having greater sensitivity than the T7 condition. The surface condition (as-cast vs. machined) did not significantly affect the stress ratio sensitivity. The fatigue life of as-cast specimens was found to be approximately 60--70% lower than that of machined specimens at the same equivalent stress. This reduction could not be attributed to pore size alone, and is suspected to be due to the greater concentration of pyrolysis products at the as-cast surface. Directions for future work, including improved testing methods and some possible methods of improving the properties of lost foam castings, are discussed.

  18. Non-dendritic structural 7075 aluminum alloy byliquidus cast and its semi-solid compression behavior

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Fine, equiaxed, non-dendritic structure needed by semi-solid processing was obtained by liquidus cast, i.e.7075 wrought aluminum alloy cast from liquidus temperature. The microstructures after heat treatment at different tem-peratures and time in the semi-solid range were observed, and the compression deformation behavior at different tempera-tures (490 ~ 600 C) and strain rates (5 × 10-3 ~ 5s-1) was investigated by means of Gleeble-1500 thermal-mechenicalsimulator. Thc results show that the deformation resistance of the non-dendritic structure attained by liquidus cast in semi-solid is remarkably lower than that of conventional dendritic structure. The formability of non-dendritic structure is betterthan that of dendritic structure

  19. The Influence of Silicon Content on Recrystallization of Twin-Roll Cast Aluminum Alloys for Heat Exchangers

    OpenAIRE

    Poková, Michaela; Cieslar, Miroslav; Lacaze, Jacques

    2012-01-01

    International audience Thin foils of aluminum alloys are commonly used in automotive industry for manufacturing heat exchangers. Use of twin-roll casting instead of direct-chill casting requires modifications in the manufacturing process and use of improved materials. In the present study, the evolution in microstructure and mechanical properties during isochronal annealing of two AW3003-based alloys differing in silicon content was monitored. The silicon influenced both the microhardness ...

  20. The influence of the parameters of lost foam process on the quality of aluminum alloys castings

    Directory of Open Access Journals (Sweden)

    Aćimović-Pavlović Zagorka

    2010-01-01

    Full Text Available This paper presents the research results of application of Lost foam process for aluminum alloys castings of a simple geometry. The process characteristic is that patterns and gating of moulds, made of polymers, stay in the mould till the liquid metal inflow. In contact with the liquid metal, pattern intensely and in relatively short time decomposes and evaporates, which is accompanied by casting crystallization. As a consequence of polymer pattern decomposition and evaporation a great quantity of liquid and gaseous products are produced, which is often the cause of different types of casting errors. This paper presents the results of a research with a special consideration given to detecting and analyzing the errors of castings. In most cases the cause of these errors are defects of polymer materials used for evaporable patterns production, as well as defects of materials for refractory coatings production for polymer patterns. The researches have shown that different types of coatings determine properties of the obtained castings. Also, the critical processing parameters (polymer pattern density, casting temperature, permeability of refractory coating and sand, construction of patterns and gating of moulds significantly affect on castings quality. During the research a special consideration was given to control and optimization of these parameters with the goal of achieving applicable castings properties. The study of surface and internal error of castings was performed systematically in order to carry out preventive measures to avoid errors and minimize production costs. In order to achieve qualitative and profitable castings production by the method of Lost foam it is necessary to reach the balance in the system: evaporable polymer pattern - liquid metal - refractory coating - sandy cast in the phase of metal inflow, decomposition and evaporation of polymer pattern, formation and solidification of castings. By optimizing the processing

  1. Evaluation of the Characteristics of the Aluminum Alloy Casting Material by Heat Treatment

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Syung Yul; Park, Dong Hyun; Won, Jong Pil; Kim, Yun Hae; Lee, Myung Hoon; Moon, Kyung Man; Jeong, Jae Hyun [Korea Maritime Univ., Busan (Korea, Republic of)

    2012-06-15

    Aluminum is on active metal, but it is well known that its oxide film plays a role as protective barrier which is comparatively stable in air and neutral aqueous solution. Thus, aluminum alloys have been widely applied in architectural trim, cold and hot-water storage vessels and piping etc., furthermore, the aluminum alloy of AC8A have been widely used in mold casting material of engine piston because of its properties of temperature and wear resistance. In recent years, the oil price is getting higher and higher, thus the using of low quality oil has been significantly increased in engines of ship and vehicle. Therefore it is considered that evaluation of corrosion resistance as well as wear resistance of AC8A material is also important to improve its property and prolong its lifetime. In this study, the effect of solution and tempering heat treatment to corrosion and wear resistance is investigated with electrochemical method and measurement of hardness. The hardness decreased with solution heat treatment compared to mold casting condition, but its value increased with tempering heat treatment and exhibited the highest value of hardness with tempering heat treatment temperature at 190 .deg. C for 24hrs. Furthermore, corrosion resistance increased with decreasing of the hardness, and decreased with increasing of the hardness reversely. As a result, it is suggested that the optimum heat treatment to improve both corrosion and wear resistance is tempering heat treatment temperature at 190 .deg. C for 16hrs.

  2. Cerium-Based, Intermetallic-Strengthened Aluminum Casting Alloy: High-Volume Co-product Development

    Science.gov (United States)

    Sims, Zachary C.; Weiss, D.; McCall, S. K.; McGuire, M. A.; Ott, R. T.; Geer, Tom; Rios, Orlando; Turchi, P. A. E.

    2016-07-01

    Several rare earth elements are considered by-products to rare earth mining efforts. By using one of these by-product elements in a high-volume application such as aluminum casting alloys, the supply of more valuable rare earths can be globally stabilized. Stabilizing the global rare earth market will decrease the long-term criticality of other rare earth elements. The low demand for Ce, the most abundant rare earth, contributes to the instability of rare earth extraction. In this article, we discuss a series of intermetallic-strengthened Al alloys that exhibit the potential for new high-volume use of Ce. The castability, structure, and mechanical properties of binary, ternary, and quaternary Al-Ce based alloys are discussed. We have determined Al-Ce based alloys to be highly castable across a broad range of compositions. Nanoscale intermetallics dominate the microstructure and are the theorized source of the high ductility. In addition, room-temperature physical properties appear to be competitive with existing aluminum alloys with extended high-temperature stability of the nanostructured intermetallic.

  3. Processing map of as-cast 7075 aluminum alloy for hot working

    OpenAIRE

    Guo Lianggang; Yang Shuang; Yang He; Zhang Jun

    2015-01-01

    The true stress–strain curves of as-cast 7075 aluminum alloy have been obtained by isothermal compression tests at temperatures of 300–500 °C and strain rates of 0.01–10 s−1. The plastic flow instability map is established based on Gegel B and Murthy instability criteria because the deformed compression samples suggest that the combination of the above two instability criteria has more comprehensive crack prediction ability. And the processing map based on Dynamic Material Model (DMM) of as-c...

  4. Numerical simulation of continuous roll-casting process of aluminum alloy

    Institute of Scientific and Technical Information of China (English)

    XIE Shui-sheng; YANG Hao-qiang; HUANG Guo-jie

    2006-01-01

    In order to improve the strip quality of continuous roll-casting process (CRP) of aluminum alloy, the investigations of the flow behavior within the metal pool, the heat transfer condition between roll and strip, the pouring temperature of molten alloy, the roll-casting speed and the control of the position of solidification final point are important. The finite volume method was applied to the analysis of the continuous roll-casting process. A two-dimensional incompressible non-Newtonian fluid flow with heat transfer was considered, which was described by the continuity equation, the Navier-Stokes equation and the energy equation. With this mathematical model, the flow patterns, temperature fields and solid fraction distributions in the metal pool between two rolls were simulated. From the calculated results, the effects of technical parameters to the position of solidification final point are obtained.The simulated results show that the roll-casting speed and pouring temperature have an enormous effect on the temperature distribution and the position of solidification final point.

  5. Characterization of Phases in an As-cast Copper-Manganese-Aluminum Alloy

    Institute of Scientific and Technical Information of China (English)

    J.Iqbal, F.Hasan; F.Ahmad

    2006-01-01

    Copper-manganese-aluminum (CMA) alloys, containing small additions of Fe, Ni, and Si, exhibit good strength and remarkable corrosion resistance against sea water. The alloys are used in as-cast condition, and their microstructure can show wide variations. The morphology, crystallography and composition of the phases presented in an as-cast (CMA) alloy of nominal composition Cu-14%Mn-8%Al-3%Fe-2%Ni were investigated using optical, electron optical, and microprobe analytical techniques. The as-cast microstructure consisted of the grains of fcc α and bcc β-phases alongwith intermetallic precipitates of various morphologies. The dendritic-shaped particles and the cuboid-shaped precipitates, which were rich in Fe and Mn and had an fcc DO3 structure. These four different morphologies of intermetallic precipitates exhibited discrete orientationrelationships with the α-matrix. The β-grains only contained very small cuboid shaped precipitates, which could only be resolved through transmission electron microscopy. These precipitates were found to be based on Fe3Al and had the DO3 structure.

  6. Gating system optimization of low pressure casting A356 aluminum alloy intake manifold based on numerical simulation

    Directory of Open Access Journals (Sweden)

    Jiang Wenming

    2014-03-01

    Full Text Available To eliminate the shrinkage porosity in low pressure casting of an A356 aluminum alloy intake manifold casting, numerical simulation on filling and solidification processes of the casting was carried out using the ProCAST software. The gating system of the casting is optimized according to the simulation results. Results show that when the gating system consists of only one sprue, the filling of the molten metal is not stable; and the casting does not follow the sequence solidification, and many shrinkage porosities are observed through the casting. After the gating system is improved by adding one runner and two in-gates, the filling time is prolonged from 4.0 s to 4.5 s, the filling of molten metal becomes stable, but this casting does not follow the sequence solidification either. Some shrinkage porosity is also observed in the hot spots of the casting. When the gating system was further improved by adding risers and chill to the hot spots of the casting, the shrinkage porosity defects were eliminated completely. Finally, by using the optimized gating system the A356 aluminum alloy intake manifold casting with integrated shape and smooth surface as well as dense microstructure was successfully produced.

  7. Application of a criterion for cold cracking to casting high strength aluminum alloys

    NARCIS (Netherlands)

    Lalpoor, M.; Eskin, D.G.; Fjaer, H.G.; Ten Cate, A.; Ontijt, N.; Katgerman, L.

    2010-01-01

    Direct chill (DC) casting of high strength 7xxx series aluminium alloys is difficult mainly due to solidification cracking (hot cracks) and solid state cracking (cold cracks). Poor thermal properties along with extreme brittleness in the as-cast condition make DC-casting of such alloys a challenging

  8. High strength aluminum cast alloy: A Sc modification of a standard Al–Si–Mg cast alloy

    Energy Technology Data Exchange (ETDEWEB)

    Muhammad, Arfan, E-mail: engr.arfan@gmail.com [Key Laboratory of Aerospace Advanced Materials and Performance of Ministry of Education, School of Material Science and Engineering, Beihang University, Beijing 100191 (China); Xu, Cong; Xuejiao, Wang [Key Laboratory of Aerospace Advanced Materials and Performance of Ministry of Education, School of Material Science and Engineering, Beihang University, Beijing 100191 (China); Hanada, Shuji [Institute for Materials Research, Tohoku University, Sendai 980-8577 (Japan); Yamagata, Hiroshi [Center for Advanced Die Engineering and Technology, Gifu University, 1-1 Yanagido, Gifu City, Gifu 501-1193 (Japan); Hao, LiRong [Hebei Sitong New Metal Material Co., Ltd., Baoding 071105 (China); Chaoli, Ma [Key Laboratory of Aerospace Advanced Materials and Performance of Ministry of Education, School of Material Science and Engineering, Beihang University, Beijing 100191 (China)

    2014-05-01

    A standard Aluminum–Silicon–Magnesium cast alloy (A357 foundry alloy without Beryllium) modified with different weight percentages of Scandium (Sc), has been studied to evaluate the effects of Sc contents on microstructure and strength. Study has been conducted under optimized parameters of melting, casting and heat treatment. Characterization techniques like optical microscopy, SEM, TEM and tensile testing were employed to analyze the microstructure and mechanical properties. Results obtained in this research indicate that with the increase of Sc contents up to 0.4 wt%, grain size is decreased by 80% while ultimate tensile strength and hardness are increased by 28% and 19% respectively. Moreover along with the increase in strength, elongation to failure is also increased up to 165%. This is quite interesting behavior because usually strength and ductility have inverse relationship.

  9. High strength aluminum cast alloy: A Sc modification of a standard Al–Si–Mg cast alloy

    International Nuclear Information System (INIS)

    A standard Aluminum–Silicon–Magnesium cast alloy (A357 foundry alloy without Beryllium) modified with different weight percentages of Scandium (Sc), has been studied to evaluate the effects of Sc contents on microstructure and strength. Study has been conducted under optimized parameters of melting, casting and heat treatment. Characterization techniques like optical microscopy, SEM, TEM and tensile testing were employed to analyze the microstructure and mechanical properties. Results obtained in this research indicate that with the increase of Sc contents up to 0.4 wt%, grain size is decreased by 80% while ultimate tensile strength and hardness are increased by 28% and 19% respectively. Moreover along with the increase in strength, elongation to failure is also increased up to 165%. This is quite interesting behavior because usually strength and ductility have inverse relationship

  10. Physico-chemical characteristic of aluminum alloy castings manufactured with cores containing fly ash as a base material

    OpenAIRE

    A. Baliński

    2008-01-01

    Castings were poured from PA9 aluminum alloy. Cores in the form of standard cylindrical specimens were made from the core mixture based on fly ash of the identified chemical and granular composition. The binder for the fly ash-based core mixture was chemically modified, hydrated sodium silicate. From the ready test castings, specimens were cut out for metallographic examinations and evaluation of morphology in the examined microregions. The structure was examined under a NEOPHOT 32 metallogra...

  11. Prediction of as-cast grain size of inoculated aluminum alloys melt solidified under non-isothermal conditions

    Science.gov (United States)

    Du, Qiang; Li, Yanjun

    2015-06-01

    In this paper, a multi-scale as-cast grain size prediction model is proposed to predict as-cast grain size of inoculated aluminum alloys melt solidified under non-isothermal condition, i.e., the existence of temperature gradient. Given melt composition, inoculation and heat extraction boundary conditions, the model is able to predict maximum nucleation undercooling, cooling curve, primary phase solidification path and final as-cast grain size of binary alloys. The proposed model has been applied to two Al-Mg alloys, and comparison with laboratory and industrial solidification experimental results have been carried out. The preliminary conclusion is that the proposed model is a promising suitable microscopic model used within the multi-scale casting simulation modelling framework.

  12. Microstructure and mechanical properties of low frequency electromagnetic casting 7075 aluminum alloy

    Institute of Scientific and Technical Information of China (English)

    Gaosong WANG; Zhihao ZHAO; Jianzhong CUI; Qiang GUO

    2012-01-01

    This work explores the microstructure of low frequency electromagnetic casting (LFEC) 7075 aluminum alloys and investigates the effect of heat treatment process on its mechanical properties via the mechanical properties test,X-ray diffraction and transmission electron microscopy.It was found that the grains of LFEC ingot were finer and more evenly distributed than that of the conventional direct chill cast (DC) ingots.The microstructure of LFEC ingot extruded kept their original as-cast structure with small and fine grains.With the same extrusion ratio,the average grain diameters of LFEC and conventional DC extruded were about 10 and 20 μm,respectively.LFEC extruded also had a better aging property,since the regime of T6 treatment peak value aging was at 120 ℃ for 24 h,the tensile strength and hardness (HV) of the LFEC extruded were 673.50 MPa and 194.62,respectively,which were all higher than those of the conventional DC extruded,indicating that the process regime can be applied in the industrial production.

  13. Application of a criterion for cold cracking to casting high strength aluminum alloys

    OpenAIRE

    Lalpoor, M; Eskin, D G; Fjaer, H.G.; Ten Cate, A.; Ontijt, N.; Katgerman, L.

    2010-01-01

    Direct chill (DC) casting of high strength 7xxx series aluminium alloys is difficult mainly due to solidification cracking (hot cracks) and solid state cracking (cold cracks). Poor thermal properties along with extreme brittleness in the as-cast condition make DC-casting of such alloys a challenging process. Therefore, a criterion that can predict the catastrophic failure and cold cracking of the ingots would be highly beneficial to the aluminium industry. The already established criteria are...

  14. Centerline Depletion in Direct-Chill Cast Aluminum Alloys: The Avalanche Effect and Its Consequence for Turbulent Jet Casting

    Science.gov (United States)

    Wagstaff, Samuel R.; Allanore, Antoine

    2016-07-01

    Avalanche dynamics of sedimenting grains in direct-chill casting of aluminum ingots is investigated as a primary driving force for centerline segregation. An analytical model predicting the importance of avalanche events as a function of casting parameters is proposed and validated with prior art results. New experimental results investigating the transient and steady-state centerline segregation of DC casting with a turbulent jet are reported.

  15. Density and solidiifcation feeding model of vacuum counter-pressure cast aluminum alloy under grade-pressuring conditions

    Institute of Scientific and Technical Information of China (English)

    Qing-song Yan; Huan Yu; Gang Lu; Bo-wen Xiong; Suai Xu

    2016-01-01

    The density of vacuum counter-pressure cast aluminum alloy samples under grade-pressuring condition was studied. The effect of grade pressure difference and time on the density of aluminum aloys was discussed, and the solidiifcation feeding model under grade-pressuring condition was established. The results indicate the grade-pressured solidiifcation feeding ability of vacuum counter-pressure casting mainly depends on grade pressure difference and time. With the increase of grade pressure difference, the density of al the aluminum aloy samples increases, and the trend of change in density from the pouring gate to the top location is first decreasing gradually and then increasing. In addition, in obtaining the maximum density, the optimal grade-pressuring time is different for samples with different wal thicknesses, and the solidiifcation time when the solid volume fraction of aluminum aloy reaches about 0.65 appears to be the optimal beginning time for grade-pressuring.

  16. Effect of low-frequency electromagnetic field on the as-cast microstructure of a new super high strength aluminum alloy by horizontal continuous casting

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    The super high strength aluminum alloy ingots with 100 mm in diameter were cast by the process of low-frequency electromagnetic horizontal continuous casting (LFEHC) and the effect of electromagnetic field on the as-cast microstructure was studied. Results show that microstructure of the sample prepared by the LFEHC process was greatly refined. Microstructures at the border and the center of the ingots were fine, uniform and rosette-shaped.Electromagnetic frequency plays a key role in microstructure refining. Fine and uniform microstructures can be obtained with optimal electromagnetic frequency. In this experiment, under a frequency of 30 Hz the microstructure was the finest and the most uniform.

  17. Effects of casting speed on microstructure and segregation of electromagnetically stirred Aluminum alloy in continuous casting process

    Institute of Scientific and Technical Information of China (English)

    LEE Dock-Young; KANG Suk-Won; CHO Duck-Ho; KIM Ki-Bae

    2006-01-01

    Recently, a semi-solid metal processing has been acknowledged as a cost-effective technique to be able to manufacture high quality product for the transportation industry.In this study a hypo-eutectic Al alloy was fabricated by means of an electromagnetic stirrer in continuous casting process and the microstructural change during solidification due to a fluid flow by electromagnetic stirring was examined.Due to the forced fluid flow during solidification a dendritic phase of primary α phase of Al alloy was turned into a globular phase, which can make the Al alloy get a thixotropic behavior in the semi-solid region.In order to establish the quantitative relationship between microstructure and the process parameters, the morphology shape, a silicon distribution and a size of primary α phase were observed according to casting speed in continuous casting machine.The primary α phase was turned into the degenerate dendrites approaching a spherical configuration with increasing casting speed.The fine-grained and equiaxed microstructure appeared at higher casting speed.A segregation behavior of Si element was declined with increasing casting speed and a very uniform distribution of Si element was observed on the billet at a casting speed of 600 mm·min-1.A thickness of the solidifying shell of the billet was shortened with increasing the casting speed.

  18. DEFINITION OF THE CASTING MECHANISMS OF ALUMINUM-SILICON ALLOYS WITH SUPERFINE AND INVERTED MICROSTRUCTURE

    Directory of Open Access Journals (Sweden)

    V. Yu. Stetsenko

    2013-01-01

    Full Text Available The basic mechanisms of Al-Si alloysmodifying are determined. Fast solidification and inheritance modification are major in casting of alloys with a highly dispersed and inverted microstructure.

  19. Casting of aluminum-copper based alloy by controlled diffusion solidification

    Directory of Open Access Journals (Sweden)

    Li Fan

    2015-03-01

    Full Text Available A quaternary alloy (Al-5.0Cu-0.35Mn-0.25Ti, wt.%, having a similar chemical component with ZL205A, was prepared using a controlled diffusion solidification (CDS process and a conventional casting process. The effect of the casting process on microstructure and hardness was investigated. The grain morphology and casting defects of the alloy prepared via the conventional casting and CDS were observed and compared at various pouring temperatures. Results show that the CDS process can alleviate the hot tearing defects and reduce the density of porosity, while getting rid of the riser that is generally used for feeding during conventional casting. Structure observations show that the grain morphology of the conventional cast alloy is mainly dendritic, and the grain size decreases when the pouring temperature is decreased, while the CDS cast alloy consists of a large number of spherical grains, which can decrease the thermal cracking tendency and segregation defect, and enhance the hardness of the alloy.

  20. Effect of hot and cold deformation on the recrystallization texture of continuous cast AA 5052 aluminum alloy

    International Nuclear Information System (INIS)

    The effect of different relative amounts of hot and cold deformation on the recrystallization texture of a continuous cast AA 5052 aluminum alloy was investigated by X-ray diffraction. The results show that hot deformation promotes the cube and Goss components at the expense of the r-cube and remainder components. The formation of the R component does not appear to be affected by hot and cold deformation

  1. Effect of hot and cold deformation on the recrystallization texture of continuous cast AA 5052 aluminum alloy

    Energy Technology Data Exchange (ETDEWEB)

    Liu, W.C. [Department of Chemical and Materials Engineering, University of Kentucky, 177 Anderson Hall, Lexington, KY 40506 (United States)]. E-mail: wcliu@engr.uky.edu; Man, C.-S. [Department of Mathematics, University of Kentucky, 715 Patterson Office Tower, Lexington, KY 40506 (United States); Raabe, D. [Max-Planck-Institut fuer Eisenforschung, Microstructure Physics, Max-Planck-Str. 1, 40237, Duesseldorf (Germany); Morris, J.G. [Department of Chemical and Materials Engineering, University of Kentucky, 177 Anderson Hall, Lexington, KY 40506 (United States)

    2005-12-15

    The effect of different relative amounts of hot and cold deformation on the recrystallization texture of a continuous cast AA 5052 aluminum alloy was investigated by X-ray diffraction. The results show that hot deformation promotes the cube and Goss components at the expense of the r-cube and remainder components. The formation of the R component does not appear to be affected by hot and cold deformation.

  2. Microstructure and Mechanical Properties of MWCNTs Reinforced A356 Aluminum Alloys Cast Nanocomposites Fabricated by Using a Combination of Rheocasting and Squeeze Casting Techniques

    Directory of Open Access Journals (Sweden)

    Abou Bakr Elshalakany

    2014-01-01

    Full Text Available A356 hypoeutectic aluminum-silicon alloys matrix composites reinforced by different contents of multiwalled carbon nanotubes (MWCNTs were fabricated using a combination of rheocasting and squeeze casting techniques. A novel approach by adding MWCNTs into A356 aluminum alloy matrix with CNTs has been performed. This method is significant in debundling and preventing flotation of the CNTs within the molten alloy. The microstructures of nanocomposites and the interface between the aluminum alloy matrix and the MWCNTs were examined by using an optical microscopy (OM and scanning electron microscopy (SEM equipped with an energy dispersive X-ray analysis (EDX. This method remarkably facilitated a uniform dispersion of nanotubes within A356 aluminum alloy matrix as well as a refinement of grain size. In addition, the effects of weight fraction (0.5, 1.0, 1.5, 2.0, and 2.5 wt% of the CNT-blended matrix on mechanical properties were evaluated. The results have indicated that a significant improvement in ultimate tensile strength and elongation percentage of nanocomposite occurred at the optimal amount of 1.5 wt% MWCNTs which represents an increase in their values by a ratio of about 50% and 280%, respectively, compared to their corresponding values of monolithic alloy. Hardness of the samples was also significantly increased by the addition of CNTs.

  3. Semi-solid thixo casting structure of aluminum alloy and relevant assistant analysis with the help of computer simulation

    Institute of Scientific and Technical Information of China (English)

    Yi-tao YANG; Jian-fu WANG; Meng CHEN; Heng-hua ZHANG; Guang-jie SHAO

    2008-01-01

    The relationship between structure morphology of semi-solid aluminum alloy die-casting sample and filling condition was studied. By systematical structure analysis and computer simulation of the filling process, the quant-itative relationship between microscopic morphology (such as solid fraction, grain size and shape) and formation state was studied. The results showed that the billet microstruc-ture must have fine and round grains for the die-casting of complex shapes. It is necessary to optimize injection speeds to escape the non-uniform distribution of the solid fraction in complex and changeable mold cavity.

  4. Rotary bending fatigue behavior of A356 –T6 aluminum alloys by vacuum pressurizing casting

    Directory of Open Access Journals (Sweden)

    Yong-qin Liu

    2015-09-01

    Full Text Available Vacuum pressurizing casting technique, providing better mould filling and inter-dendritic feeding, can reduce the porosity greatly in cast aluminum alloys, and improve the fatigue properties. The rotary bending fatigue properties of A356-T6 alloys prepared by vacuum pressurizing casting were investigated. The S-N curve and limit strength 90 MPa under fatigue life of 107 cycles were obtained. The analyses on the fatigue fractography and microstructure of specimens showed that the fatigue fracture mainly occurs at the positions with casting defects in the subsurface, especially at porosities regions, which attributed to the crack propagation during the fatigue fracture process. Using the empirical crack propagation law of Pairs-Erdogon, the quantitative relationship among the initial crack size, fatigue life and applied stress was established. The fatigue life decreases with an increase in initial crack size. Two constants in the Pairs-Erdogon equation of aluminum alloy A356-T6 were calculated using the experimental data.

  5. Instability of the Liquid Metal-Pattern Interface in the Lost Foam Casting of Aluminum Alloys

    Science.gov (United States)

    Griffiths, W. D.; Ainsworth, M. J.

    2016-06-01

    The nature of the liquid metal-pattern interface during mold filling in the Lost Foam casting of aluminum alloys was investigated using real-time X-ray radiography for both normal expanded polystyrene, and brominated polystyrene foam patterns. Filling the pattern under the action of gravity from above or below had little effect on properties, both cases resulting in a large scatter of tensile strength values, (quantified by their Weibull Modulus). Countergravity filling at different velocities demonstrated that the least scatter of tensile strength values (highest Weibull Modulus) was associated with the slowest filling, when a planar liquid metal-pattern interface occurred. Real-time X-ray radiography showed that the advancing liquid metal front became unstable above a certain critical velocity, leading to the entrainment of the degrading pattern material and associated defects. It has been suggested that the transition of the advancing liquid metal-pattern interface into an unstable regime may be a result of Saffman-Taylor Instability.

  6. The Effect of Applied Pressure During Feeding of Critical Cast Aluminum Alloy Components With Particular Reference to Fatigue Resistance

    Energy Technology Data Exchange (ETDEWEB)

    J.T. Berry; R. Luck; B. Zhang; R.P. Taylor

    2003-06-30

    the medium to long freezing range alloys of aluminum such as A356, A357, A206, 319 for example are known to exhibit dispersed porosity, which is recognized as a factor affecting ductility, fracture toughness, and fatigue resistance of light alloy castings. The local thermal environment, for example, temperature gradient and freezing from velocity, affect the mode of solidification which, along with alloy composition, heat treatment, oxide film occlusion, hydrogen content, and the extent to which the alloy contracts on solidification, combine to exert strong effects on the porosity formation in such alloys. In addition to such factors, the availability of liquid metal and its ability to flow through the partially solidified casting, which will be affect by the pressure in the liquid metal, must also be considered. The supply of molten metal will thus be controlled by the volume of the riser available for feeding the particular casting location, its solidification time, and its location together with any external pressure that might be applied at the riser.

  7. 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.

  8. Physico-chemical characteristic of aluminum alloy castings manufactured with cores containing fly ash as a base material

    Directory of Open Access Journals (Sweden)

    A. Baliński

    2008-07-01

    Full Text Available Castings were poured from PA9 aluminum alloy. Cores in the form of standard cylindrical specimens were made from the core mixture based on fly ash of the identified chemical and granular composition. The binder for the fly ash-based core mixture was chemically modified, hydrated sodium silicate. From the ready test castings, specimens were cut out for metallographic examinations and evaluation of morphology in the examined microregions. The structure was examined under a NEOPHOT 32 metallographic microscope using metallographic polished sections etched and unetched. For the specimen surface morphology evaluation a STEREOSCAN 420 scanning electron microscope and SE1 detector were used. The X-ray microanalysis was made on an EDS LINK ISIS 300 microanalyser. The fly ash was observed to have no major effect on the structure and chemical composition of castings.

  9. Experimental Observation and Analytical Modeling of Melting and Solidification during Aluminum Alloy Repair by Turbulence Flow Casting

    Directory of Open Access Journals (Sweden)

    Muki Satya Permana

    2015-10-01

    Full Text Available This paper presents an overview on the state of the art of applicable casting technology for applications in the field of repairing aluminum alloy components. Repair process on the Al alloy sample using similar metal has been carried out to investigate the micro-structural effect. Joining occurs as a result of convection heat transfer of molten flow into the sand mold which melts the existing base metal inside the mold and subsequent solidification. The analytical model has been developed to describe aluminum alloy component repair by turbulence flow casting. The model is designed based on heat transfer principle that can handle the phenomena of heat flow. The experimental result and analytical model analyses pointed out that joint quality are greatly affected by parameters of preheating temperature and duration of molten metal flow in the mold. To obtain a desired metallurgical sound at the joint, the optimum temperature and time were adjusted in order to obtain a similarity of microstructure between filler and base metal. This model is aimed to predict the use of the process parameter ranges in order to have the optimum parameters when it is applied to the experiment. The fixed parameters are flow rate, sand ratio, and pouring temperature. The process parameters are preheating temperature and pouring time. It is concluded that analytical modeling has good agreement with the experimental result.

  10. Optimization of Manganese and Magnesium Contents in As-cast Aluminum-Zinc-Indium Alloy as Sacrificial Anode

    Institute of Scientific and Technical Information of China (English)

    Mohammed R. Saeri; Ahmad Keywni

    2011-01-01

    In this study, effects of manganese and magnesium content on the electrochemical properties of Al-Zn-ln sacrificial anode were studied in 0.5 mol/L NaCl solution (pH=5). The aluminum base alloy with different amounts of Mn and Mg were melted at 750℃, then casted at molds at 25℃. Corrosion experiments were mounted to determine the optimal effect of Mn and Mg on the efficiencies of the aluminum alloy anodes. The corroded and unexposed sample surfaces were subjected to microstructure characterization by optical and scanning electron microscopy. AI-Zn-ln alloy doped with 0%, 0.01%, 0.05%.0.2% and 0.3% by weights of Mn and 0%, 0.5%, 1.0%, 1.5%, 2.0%, 2.5% and 3.0% by weights of Mg were prepared to determine the effect of Mn and Mg on anode efficiency in the environment. The different microstructures of the evolved AI- Zn-ln-Mg-Mn alloy were correlated with the anode efficiencies. The Al-5.0%Zn-2.0%Mg-0.15%Mn-0.02%ln gave the best anode efficiency (about 83%). The microstructures of the corroded surface of the optimized alloy revealed decreased distribution of the pockets of localized attacks which are characteristics of pitting (or crevice) corrosion.

  11. A computational study of low-head direct chill slab casting of aluminum alloy AA2024

    Science.gov (United States)

    Hasan, Mainul; Begum, Latifa

    2016-04-01

    The steady state casting of an industrial-sized AA2024 slab has been modeled for a vertical low-head direct chill caster. The previously verified 3-D CFD code is used to investigate the solidification phenomena of the said long-range alloy by varying the pouring temperature, casting speed and the metal-mold contact heat transfer coefficient from 654 to 702 °C, 60-180 mm/min, and 1.0-4.0 kW/(m2 K), respectively. The important predicted results are presented and thoroughly discussed.

  12. Crystallization characteristics of cast aluminum alloys during a unidirectional solidification process

    Energy Technology Data Exchange (ETDEWEB)

    Okayasu, Mitsuhiro, E-mail: mitsuhiro.okayasu@utoronto.ca; Takeuchi, Shuhei

    2015-05-01

    The crystal orientation characteristics of cast Al–Si, Al–Cu and Al–Mg alloys produced by a unidirectional solidification process are examined. Two distinct crystal orientation patterns are observed: uniform and random formation. A uniform crystal orientation is created by columnar growth of α-Al dendrites in the alloys with low proportions of alloying element, e.g., the Al–Si alloy (with Si <12.6%) and the Al–Cu and Al–Mg alloys (with Cu and Mg <2%). A uniformly organized crystal orientation with [100] direction is created by columnar growth of α-Al dendrites. With increasing proportion of alloying element (>2% Cu or Mg), the uniform crystal orientations collapse in the Al–Cu and Al–Mg alloys, owing to interruption of the columnar α-Al dendrite growth as a result of different dynamics of the alloying atoms and the creation of a core for the eutectic phases. For the hypo-eutectic Al–Si alloys, a uniform crystal orientation is obtained. In contrast, a random orientation can be detected in the hyper-eutectic Al–Si alloy (15% Si), which results from interruption of the growth of the α-Al dendrites due to precipitation of primary Si particles. There is no clear effect of crystal formation on ultimate tensile strength (UTS), whereas crystal orientation does influence the material ductility, with the alloys with a uniform crystal orientation being elongated beyond their UTS points and with necking occurring in the test specimens. In contrast, the alloys with a nonuniform crystal orientation are not elongated beyond their UTS points.

  13. 铝合金铸造副车架开发%Development of Aluminum Alloy Casting Sub-frame

    Institute of Scientific and Technical Information of China (English)

    陈磊; 程稳正; 孙珏; 王仕伟; 陈志刚; 侯杰

    2015-01-01

    以铝合金材料代替传统钢材是乘用车底盘结构件轻量化设计的有效方式之一,尤其在高端乘用车上应用更为广泛。介绍了铝合金副车架的设计开发过程。开发实践表明,采用铝合金材料及挤压铸造工艺,通过合理的结构设计及系统的工艺开发,可达到底盘系统对于结构件强度及耐久性的严格要求,提高整车的轻量化水平。%The substitution of traditional steel with aluminum alloy is an effective approach of lightweight design of passenger car chassis structural parts, especially in high-end passenger car. This article introduces the development process of aluminum alloy sub-frame. The development practice shows that, with the application of aluminum alloy and extrusion casting technology, with the aid of rational design of structure and systemic development of technology, the strict requirements on strength and durability of chassis structural component can be satisfied, and the lightweight level of vehicle is improved.

  14. Effect of non uniform void size and shape distributions on deformation failure in cast aluminum alloy

    Energy Technology Data Exchange (ETDEWEB)

    Song, Jun Su; Kang, Dong Hwan; Kim, Tae Won; Bae, Dae Sung [Hanyang Univ., Seoul (Korea, Republic of); Yoon, Hyung Sop [Hyundai Kia Motors R and D Division, Hwaseong (Korea, Republic of)

    2012-07-15

    Tensile tests were conducted on several cast aluminum specimens with different degrees of porosity. The effects of non uniform void size and shape distributions, including spherical and non spherical types, on stress-strain behavior resulting from different initiation mechanisms were investigated. A micro mechanics based statistical approach was employed, and the heterogeneous microstructures could therefore be modeled during the deformation process. The predicted changes of the distributions of void size and void shape generally agreed with experimental results. Void spatial variation was also quantified, and its effects on the level of failure were analyzed. The void spatial variation facilitated development of inhomogeneous deformation, which results in failure.

  15. Rheologic behaviors of A356 aluminum alloy billet produced by semisolid continuous casting process

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    The experiments for rheologic behaviors of semisolid continuous casting billets of A356 alloy in semisolid state had been carried out with a rnultifunctional rheometer. The results show that the deformation rate increases with loading time, the maximum strain reaches to 120 % ( which is one time larger than that of traditional mold casting billet) and the strain can be rapidly elirninated to 10% after unloading. Moreover, there is a critic stress for billet deformation even in semisolid state, which is named as critic shear stress. This stress increases with the decreasing of heating time. The rheologic behaviors can be expressed by five elements mechanical model (H2 - [N1 | H2] - [N2|S] ) and can be modified with the increasing of heating time.

  16. Application of a Pore Fraction Hot Tearing Model to Directionally Solidified and Direct Chill Cast Aluminum Alloys

    Science.gov (United States)

    Dou, Ruifeng; Phillion, A. B.

    2016-08-01

    Hot tearing susceptibility is commonly assessed using a pressure drop equation in the mushy zone that includes the effects of both tensile deformation perpendicular to the thermal gradient as well as shrinkage feeding. In this study, a Pore Fraction hot tearing model, recently developed by Monroe and Beckermann (JOM 66:1439-1445, 2014), is extended to additionally include the effect of strain rate parallel to the thermal gradient. The deformation and shrinkage pore fractions are obtained on the basis of the dimensionless Niyama criterion and a scaling variable method. First, the model is applied to the binary Al-Cu system under conditions of directional solidification. It is shown that for the same Niyama criterion, a decrease in the cooling rate increases both the deformation and shrinkage pore fractions because of an increase in the time spent in the brittle temperature region. Second, the model is applied to the industrial aluminum alloy AA5182 as part of a finite element simulation of the Direct Chill (DC) casting process. It is shown that an increase in the casting speed during DC casting increases the deformation and shrinkage pore fractions, causing the maximum point of pore fraction to move towards the base of the casting. These results demonstrate that including the strain rate parallel to the thermal gradient significantly improves the predictive quality of hot tearing criteria based on the pressure drop equation.

  17. Solidification, growth mechanisms, and associated properties of aluminum-silicon and magnesium lightweight casting alloys

    Science.gov (United States)

    Hosch, Timothy Al

    Continually rising energy prices have inspired increased interest in weight reduction in the automotive and aerospace industries, opening the door for the widespread use and development of lightweight structural materials. Chief among these materials are cast Al-Si and magnesium-based alloys. Utilization of Al-Si alloys depends on obtaining a modified fibrous microstructure in lieu of the intrinsic flake structure, a process which is incompletely understood. The local solidification conditions, mechanisms, and tensile properties associated with the flake to fiber growth mode transition in Al-Si eutectic alloys are investigated here using bridgman type gradient-zone directional solidification. Resulting microstructures are examined through quantitative image analysis of two-dimensional sections and observation of deep-etched sections showing three-dimensional microstructural features. The transition was found to occur in two stages: an initial stage dominated by in-plane plate breakup and rod formation within the plane of the plate, and a second stage where the onset of out-of-plane silicon rod growth leads to the formation of an irregular fibrous structure. Several microstructural parameters were investigated in an attempt to quantify this transition, and it was found that the particle aspect ratio is effective in objectively identifying the onset and completion velocity of the flake to fiber transition. The appearance of intricate out-of-plane silicon instability formations was investigated by adapting a perturbed-interface stability analysis to the Al-Si system. Measurements of silicon equilibrium shape particles provided an estimate of the anisotropy of the solid Si/liquid Al-Si system and incorporation of this silicon anisotropy into the model was found to improve prediction of the instability length scale. Magnesium alloys share many of the benefits of Al-Si alloys, with the added benefit of a 1/3 lower density and increased machinability. Magnesium castings

  18. Energy-Saving Melting and Revert Reduction Technology (E-SMARRT): Lost Foam Thin Wall - Feasibility of Producing Lost Foam Castings in Aluminum and Magnesium Based Alloys

    Energy Technology Data Exchange (ETDEWEB)

    Fasoyinu, Yemi [CanmetMATERIALS; Griffin, John A. [University of Alabama - Birmingham

    2014-03-31

    With the increased emphasis on vehicle weight reduction, production of near-net shape components by lost foam casting will make significant inroad into the next-generation of engineering component designs. The lost foam casting process is a cost effective method for producing complex castings using an expandable polystyrene pattern and un-bonded sand. The use of un-bonded molding media in the lost foam process will impose less constraint on the solidifying casting, making hot tearing less prevalent. This is especially true in Al-Mg and Al-Cu alloy systems that are prone to hot tearing when poured in rigid molds partially due to their long freezing range. Some of the unique advantages of using the lost foam casting process are closer dimensional tolerance, higher casting yield, and the elimination of sand cores and binders. Most of the aluminum alloys poured using the lost foam process are based on the Al-Si system. Very limited research work has been performed with Al-Mg and Al-Cu type alloys. With the increased emphasis on vehicle weight reduction, and given the high-strength-to-weight-ratio of magnesium, significant weight savings can be achieved by casting thin-wall (≤ 3 mm) engineering components from both aluminum- and magnesium-base alloys.

  19. The Comparison of the Microstructure and Corrosion Resistance of Sand Cast Aluminum Alloys

    Directory of Open Access Journals (Sweden)

    Dobkowska A.

    2016-03-01

    Full Text Available The influence of different types of precipitation on the corrosion behavior was investigated in three aluminum-siliconmagnesium alloys. The microstructures of the alloys were studied through optical (OM and scanning electron microscopy (SEM. The structures consisted of an α-Al solid solution matrix, Si eutectic crystals, secondary phases AlFeSi and AlMgFeSi (Chinese script, as well as Mg2Si. The corrosion behavior was examined with the use of a potentiodynamic polarization test followed by a SEM surface analysis. The results indicate that all the analyzed samples were in the passive state and AlSi10Mg was less reactive in the corrosive environment.

  20. 铝合金V法铸造工艺探索与实践%Investigation of V-EPC Casting Aluminum Alloy Castings

    Institute of Scientific and Technical Information of China (English)

    颜铉; 徐奇; 叶升平

    2012-01-01

    Some problems in effects of coatings spraying on environment and efficiency as well as long-term operation of vacuum system in practical production restricted the development of V-EPC technology. V-EPC casting aluminum alloy castings were conducted. The principle of V-EPC with coating-free was presented, and EVA film change for aluminum alloy was analyzed. Based on the analysis of principle, V-EPC with coating-free was conducted, and the proper parameters were investigated. In addition, to decrease the energy consumption of vacuum equipment, compound casting of V-EPC with green sand was presented.%在实际生产中发现,涂料喷涂对生产环境造成污染,并降低了生产效率;而真空系统的长期工作造成的巨大能耗制约了V法工艺的发展.采用V法工艺铸造铝合金铸件,并进行3个方面的探索:①提出无涂料V法工艺理论并在铝合金铸件条件下对EVA薄膜变化进行分析;②基于上述工艺理论基础,进行无涂料工艺试验,并分析该工艺适用于生产的条件;③为降低真空设备的持续工作能耗,尝试V法铸造与潮模砂铸造的复合工艺.

  1. EFFECT OF LOW-FREQUENCY ELECTROMAGNETIC FIELD ON THE AS-CASTING MICROSTRUCTURES AND MECHANICAL PROPERTIES OF HDC 2024 ALUMINUM ALLOY

    Institute of Scientific and Technical Information of China (English)

    Q.F.Zhu; Z.H.Zhao; J.Z.Cui; Y.B.Zuo; F.Qu

    2008-01-01

    The influences of the low frequency electromagnetic field on the horizontal direct chill casting process were investigated experimentally. Ingots of 2024 aluminum alloy with a cross size of 40 mm×200 mm were produced by the conventional horizontal chill casting process and low frequency electromagnetic horizontal chill casting processrespectively. The as-cast structures and the mechanical property of the ingots were examined. The results showed that the low frequency electromagnetic field could substantially refine the microstructures and pronouncedly reduce the macrosegregation in the horizontal direct chill casting process. Moreover, the surface quality of the ingot was prominently improved by the low frequency electromagnetic field. The fracture strength and elongation percentage of the ingot was increased with the low frequency electromagnetic field.

  2. CHIP MORPHOLOGY AND HOLE SURFACE TEXTURE IN THE DRILLING OF CAST ALUMINUM ALLOYS. (R825370C057)

    Science.gov (United States)

    The effects of cutting fluid and other process variables on chip morphology when drilling cast aluminium alloys are investigated. The effects of workpiece material, speed, feed, hole depth, cutting-fluid presence and percentage oil concentration, workpiece temperature, drill t...

  3. Effect of hot and cold deformation on the P {0 1 1} recrystallization texture in a continuous cast Al-Mn-Mg aluminum alloy

    International Nuclear Information System (INIS)

    The effect of different relative amounts of hot and cold deformation on the P {0 1 1} recrystallization texture in a continuous cast Al-Mn-Mg aluminum alloy was investigated by X-ray diffraction. The results show that at a given total rolling strain the sheet with a high hot rolling strain exhibits a significantly stronger P texture than the sheet with a low hot rolling strain. Hot deformation strongly promotes the formation of the P texture during recrystallization annealing

  4. Study on the Mechanical Properties of Cast 6063 Al Alloy Using a Mixture of Aluminum Dross and Green Sand as Mold

    Science.gov (United States)

    Adeosun, S. O.; Sekunowo, O. I.; Balogun, S. A.; Obembe, O. O.

    2012-08-01

    The mechanical characteristics of 6063 aluminum alloy cast in a mixture of aluminum dross and silica sand as mold have been examined. The amount of dross in the green silica sand was varied in the range of 0-80% with bentonite as binder. In all, 40 samples were cast, and 8 of these were left in the as-cast condition for control while 32 were first homogenized at 470°C for 6 h and then rolled in a two-high mill at ambient temperature to 10% reduction in one pass. The rolled samples were solution heat treated at 515°C for 8 h followed by normalizing, annealing, and quench tempering, respectively. The samples were then simulated and tensile behavior coupled with the evaluation of microhardness and microstructures developed. The results obtained demonstrate significant improvement in mechanical properties from 50% to 80% dross in the mold. Tensile strength increased to 177 MPa and 15% elongation compared with conventional 6063-T5 aluminum alloy with 145 MPa tensile strength and 8% elongation. The improvement in mechanical properties by the quench-tempered samples can be attributed to the inducement of fine and coherent Mg2Si crystals within the matrix. Furthermore, the overall analysis of the proportion of dross to the size of cast show that about 64% of dross generated can be utilized as mold material.

  5. Monotonic and cyclic deformation behavior of MIG-CMT welded and heat-treated joints of aluminum cast and wrought alloys

    Energy Technology Data Exchange (ETDEWEB)

    Kantehm, Matthias; Soeker, Marcus; Krupp, Ulrich; Michels, Wilhelm [Faculty of Engineering and Computer Science, Institute of Materials Design and Structural Integrity, University of Applied Sciences Osnabrueck, 49009 Osnabrueck (Germany)

    2012-10-15

    While the fatigue behavior of die cast aluminum as well as welded aluminum wrought alloys have been subject of several studies, no systematic work has been carried out on hybrid structures made as a combination of welded sand castings and wrought alloys. Aim of the present study is to correlate the monotonic and cyclic deformation behavior of thin sheet welded joints with the microstructure in the heat affected zone of the material combination sand cast EN AC-Al Si7Mg0.3 and wrought alloy EN AW-Al Si1MgMn (EN AW-6082). The metal sheets were welded using a metal inert gas cold metal transfer process under variation of the welding gap, the heat treatment parameters, as well as the surface finishes. It was demonstrated by Woehler diagrams based on bending fatigue tests that the fatigue life could be increased for the welded and heat treated specimens as compared to the as-received cast specimens. By means of optical microscopy this effect was attributed to microstructural changes due to the optimized welding and heat treatment process. A detailed analysis of the mechanical tests was possible by the application of an optical 3D strain analysis. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  6. Melting and casting of FeAl-based cast alloy

    Energy Technology Data Exchange (ETDEWEB)

    Sikka, V.K. [Oak Ridge National Lab., TN (United States); Wilkening, D. [Columbia Falls Aluminum Co., Columbia Falls, MT (United States); Liebetrau, J.; Mackey, B. [AFFCO, L.L.C., Anaconda, MT (United States)

    1998-11-01

    The FeAl-based intermetallic alloys are of great interest because of their low density, low raw material cost, and excellent resistance to high-temperature oxidation, sulfidation, carburization, and molten salts. The applications based on these unique properties of FeAl require methods to melt and cast these alloys into complex-shaped castings and centrifugal cast tubes. This paper addresses the melting-related issues and the effect of chemistry on the microstructure and hardness of castings. It is concluded that the use of the Exo-Melt{trademark} process for melting and the proper selection of the aluminum melt stock can result in porosity-free castings. The FeAl alloys can be melted and cast from the virgin and revert stock. A large variation in carbon content of the alloys is possible before the precipitation of graphite flakes occurs. Titanium is a very potent addition to refine the grain size of castings. A range of complex sand castings and two different sizes of centrifugal cast tubes of the alloy have already been cast.

  7. Melting and casting of FeAl-based cast alloy

    Energy Technology Data Exchange (ETDEWEB)

    Sikka, V.K. [Oak Ridge National Lab., TN (United States). Metals and Ceramics Div.; Wilkening, D. [Columbia Falls Aluminum Co., 2000 Aluminum Dr., Columbia Falls, MT 59912 (United States); Liebetrau, J.; Mackey, B. [AFFCO, L.L.C., P.O. Box 1071, Anaconda, MT 59711 (United States)

    1998-12-31

    The FeAl-based intermetallic alloys are of great interest because of their low density, low raw material cost, and excellent resistance to high-temperature oxidation, sulfidation, carburization, and molten salts. The applications based on these unique properties of FeAl require methods to melt and cast these alloys into complex-shaped castings and centrifugal cast tubes. This paper addresses the melting-related issues and the effect of chemistry on the microstructure and hardness of castings. It is concluded that the use of the Exo-Melt{sup TM} process for melting and the proper selection of the aluminum melt stock can result in porosity-free castings. The FeAl alloys can be melted and cast from the virgin and revert stock. A large variation in carbon content of the alloys is possible before the precipitation of graphite flakes occurs. Titanium is a very potent addition to refine the grain size of castings. A range of complex sand castings and two different sizes of centrifugal cast tubes of the alloy have already been cast. (orig.) 18 refs.

  8. Low-aluminum content iron-aluminum alloys

    Energy Technology Data Exchange (ETDEWEB)

    Sikka, V.K.; Goodwin, G.M.; Alexander, D.J. [and others

    1995-06-01

    The low-aluminum-content iron-aluminum program deals with the development of a Fe-Al alloy with aluminum content such as a produce the minimum environmental effect at room temperature. The FAPY is an Fe-16 at. % Al-based alloy developed at the Oak Ridge National Laboratory as the highest aluminum-containing alloy with essentially no environmental effect. The chemical composition for FAPY in weight percent is: aluminum = 8.46, chromium = 5.50, zirconium = 0.20, carbon = 0.03, molybdenum = 2.00, yttrium = 0.10 and iron = 83.71. The ignots of the alloy can be hot worked by extrusion, forging, and rolling processes. The hot-worked cast structure can be cold worked with intermediate anneals at 800{degrees}C. Typical room-temperature ductility of the fine-grained wrought structure is 20 to 25% for this alloy. In contrast to the wrought structure, the cast ductility at room temperature is approximately 1% with a transition temperature of approximately 100 to 150{degrees}C, above which ductility values exceed 20%. The alloy has been melted and processed into bar, sheet, and foil. The alloy has also been cast into slabs, step-blocks of varying thicknesses, and shapes. The purpose of this section is to describe the welding response of cast slabs of three different thicknesses of FAPY alloy. Tensile, creep, and Charpy-impact data of the welded plates are also presented.

  9. Numerical simulation for mold-filling of thin-walled aluminum alloy castings in traveling magnetic field

    OpenAIRE

    Wu, Shiping; Bangsheng LI; Guo, Jingjie

    2004-01-01

    The numeical simulation for mold-filling of thin-walled aluminum alloy castins in horizontal traveling magnetic field is performed. A force model of Al alloy melt in the traveling magnetic field is founded by analyzing traveling magnetic field carefully. Numerical model of Al alloy mold-filling is founded based on N-S equation, which was suitable for traveling magnetic field. By using acryl glass mold with indium as alloy melt, the experiment testiied the filling state of alloy in traveling m...

  10. Filler metal alloy for welding cast nickel aluminide alloys

    Science.gov (United States)

    Santella, M.L.; Sikka, V.K.

    1998-03-10

    A filler metal alloy used as a filler for welding cast nickel aluminide alloys contains from about 15 to about 17 wt. % chromium, from about 4 to about 5 wt. % aluminum, equal to or less than about 1.5 wt. % molybdenum, from about 1 to about 4.5 wt. % zirconium, equal to or less than about 0.01 wt. % yttrium, equal to or less than about 0.01 wt. % boron and the balance nickel. The filler metal alloy is made by melting and casting techniques such as are melting the components of the filler metal alloy and cast in copper chill molds. 3 figs.

  11. Aluminum-zinc alloy squeeze casting technological parameters optimization based on PSO and ANN

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    This paper presents a kind of ZA27 squeeze casting process parameter optimization method using artificial neural network (ANN) combined with the particle swarm optimizer (PSO). Regarding the test data as samples and using neural network create ZA27 squeeze casting process parameters and mechanical properties of nonlinear mapping model. Using PSO optimize the model and obtain the optimum value of the process parameters. Make full use of the non-neural network mapping capabilities and PSO global optimization capability. The network uses the radial direction primary function neural network, using the clustering and gradient method to make use of network learning, in order to enhance the generalization ability of the network. PSO takes dynamic changing inertia weights to accelerate the convergence speed and avoid a local minimum.

  12. Plunger Kinematic Parameters Affecting Quality of High-Pressure Die-Cast Aluminum Alloys

    Science.gov (United States)

    Fiorese, Elena; Bonollo, Franco

    2016-07-01

    The selection of the optimal process parameters in high-pressure die casting has been long recognized as a complex problem due to the involvement of a large number of interconnected variables. Among these variables, the effect of the plunger motion has been proved to play a prominent role, even if a thorough and exhaustive study is still missing in the literature. To overcome this gap, this work aims at identifying the most relevant plunger kinematic parameters and estimates their correlation with the casting quality, by means of a statistically significant sample manufactured with different plunger motion profiles. In particular, slow and fast shot velocities and switching position between two stages have been varied randomly in accordance with design of experiment methodology. The quality has been assessed through the static mechanical properties and porosity percentage. As a further proof, the percentage of oxides has been estimated on the fracture surfaces. These measurements have been correlated to novel parameters, representing the mechanical energy and the inertial force related to the plunger motion, that have been extracted from the time-history of the displacement curves. The application of statistical methods demonstrates that these novel parameters accurately explain and predict the overall quality of castings.

  13. 铝合金薄壁件真空吸铸充型能力的研究%Research on Filling Capacity of Vacuum Suction Casting for Thin-Walled Aluminum Alloy Castings

    Institute of Scientific and Technical Information of China (English)

    李剑; 郝启堂; 李新雷; 陈云龙

    2012-01-01

    Filling capacity is an important factor affecting the forming of vacuum suction casting thin-walled castings. The filling capacity of vacuum suction casting was compared with the low-pressure casting by pouring sheet casting of aluminum alloys. Furthermore, the effects of vacuum level, filling speed and wall thickness on filling capacity in vacuum suction casting were researched. Due to the lower counter pressure in mold, the filling capacity of vacuum suction casting is the best among the investigated casting methods. In addition, the increase of vacuum and filling speed is helpful to increase the filling capacity of antigravity aluminum alloy casting, and the increase range is closely related to the wall thickness.%充型能力是影响真空吸铸薄壁铸件成形生产的重要因素.本研究通过铝合金薄板件的浇注试验,对比了真空吸铸和低压铸造的充型能力差异,研究了真空吸铸条件下真空度大小、充型速度及壁厚对充型能力的影响规律.结果表明:真空吸铸具有优良的充型能力,较低的型内反压是充型能力提高的主要原因;此外,真空度和充型速度的增大有助于提高反重力浇注铝合金薄壁件的充型能力,提高幅度与壁厚有密切关系.

  14. As-Cast Acicular Ductile Aluminum Cast Iron

    Institute of Scientific and Technical Information of China (English)

    S M Mostafavi Kashani; S M A Boutorabi

    2009-01-01

    The effects of nickel (2.2%)and molybdenum (0.6%)additions on the kinetics, microstructure, and me-chanical properties of ductile aluminum cast iron were studied under the as-cast and tempered conditions. Test bars machined from cast to size samples were used for mechanical and metallurgical studies. The results showed that adding nickel and molybdenum to the base iron produced an upper bainitic structure, resulting in an increase in strength and hardness. The same trend was shown when the test bars were tempered at 300 ℃ in the range of 300℃ to 400 ℃. The elongation increased with increasing the temperature from 300 ℃ to 400 ℃. The carbon content of the retained austenite also increased with increasing the temperature. The results also showed that the kinetics, mi-crostructure, and mechanical properties of this iron were similar to those of Ni-Mo alloyed silicon ductile iron.

  15. Filler metal alloy for welding cast nickel aluminide alloys

    Energy Technology Data Exchange (ETDEWEB)

    Santella, Michael L. (Knoxville, TN); Sikka, Vinod K. (Oak Ridge, TN)

    1998-01-01

    A filler metal alloy used as a filler for welding east nickel aluminide alloys contains from about 15 to about 17 wt. % chromium, from about 4 to about 5 wt. % aluminum, equal to or less than about 1.5 wt. % molybdenum, from about 1 to about 4.5 wt. % zirconium, equal to or less than about 0.01 wt. % yttrium, equal to or less than about 0.01 wt. % boron and the balance nickel. The filler metal alloy is made by melting and casting techniques such as are melting the components of the filler metal alloy and east in copper chill molds.

  16. Gating of Permanent Molds for ALuminum Casting

    Energy Technology Data Exchange (ETDEWEB)

    David Schwam; John F. Wallace; Tom Engle; Qingming Chang

    2004-03-30

    This report summarizes a two-year project, DE-FC07-01ID13983 that concerns the gating of aluminum castings in permanent molds. The main goal of the project is to improve the quality of aluminum castings produced in permanent molds. The approach taken was determine how the vertical type gating systems used for permanent mold castings can be designed to fill the mold cavity with a minimum of damage to the quality of the resulting casting. It is evident that somewhat different systems are preferred for different shapes and sizes of aluminum castings. The main problems caused by improper gating are entrained aluminum oxide films and entrapped gas. The project highlights the characteristic features of gating systems used in permanent mold aluminum foundries and recommends gating procedures designed to avoid common defects. The study also provides direct evidence on the filling pattern and heat flow behavior in permanent mold castings.

  17. Effects of deformation temperature and rate on compressive deformation behaviour of Y 112 die cast aluminum alloy in semi-solid state

    Institute of Scientific and Technical Information of China (English)

    YANG Ming-bo; HU Hong-jun; TANG Li-wen; DAI Bing

    2006-01-01

    The semi-solid compression deformation behaviour of Y112 die casting aluminum alloy with nondendritic structure obtained under the semi-solid isothermal treatment condition of 570 ℃ and 120 min, was investigated by means of Gleeble-1500 thermal-mechanical simulator. The results show that, when the strain is lower than 0.8, along with the compression strain increasing,the compression stress firstly increases rapidly, then decreases gradually. Under the condition of different deformation temperatures and deformation rates, the maximium compression stress is obtained simultaneously when the strain is 0.07 approximately.Furthermore, when the deformation rate keeps a constant, the compression stress decreases along with the deformation temperature increasing, and when the deformation temperature keeps a constant, the compression stress increases along with the deformation rate increasing.

  18. Mechanical properties and constitutive behaviors of as-cast 7050 aluminum alloy from room temperature to above the solidus temperature

    Science.gov (United States)

    Bai, Qing-ling; Li, Hong-xiang; Du, Qiang; Zhang, Ji-shan; Zhuang, Lin-zhong

    2016-08-01

    The mechanical properties and constitutive behaviors of as-cast AA7050 in both the solid and semi-solid states were determined using the on-cooling and in situ solidification approaches, respectively. The results show that the strength in the solid state tends to increase with decreasing temperature. The strain rate plays an important role in the stress-strain behaviors at higher temperatures, whereas the influence becomes less pronounced and irregular when the temperature is less than 250°C. The experimental data were fitted to the extended Ludwik equation, which is suitable to describe the mechanical behavior of the materials in the as-cast state. In the semi-solid state, both the strength and ductility of the alloy are high near the solidus temperature and decrease drastically with decreasing solid fraction. As the solid fraction is less than 0.97, the maximum strength only slightly decreases, whereas the post-peak ductility begins to increase. The experimental data were fitted to the modified creep law, which is used to describe the mechanical behavior of semi-solid materials, to determine the equivalent parameter f GBWL, i.e., the fraction of grain boundaries covered by liquid phase.

  19. 铝合金砂型低压铸造浇注系统的选择与设计%Choice and Design of Gating System of Sand Mold Low-pressure Casting for Aluminum Alloy

    Institute of Scientific and Technical Information of China (English)

    佘瑞平; 赵拴勃; 千斌; 段昭; 曲媛

    2013-01-01

    低压铸造是目前获得优质铝合金铸件的有力手段之一.本文立足于低压铸造生产实践经验,结合低压铸造原理,对不同结构、材质(糊状凝固或顺序凝固模式)类型的铝合金铸件砂型低压铸造浇注系统的选择与设计进行了系统的归纳和总结.实践证明,所归纳总结的结果对铝合金低压铸造工艺设计具有一定参考作用.%The low-pressure foundry is one of the emollient means for acquiring a high-quality aluminum alloy castings currently. Based on fulfillment experience of casting production at die low pressure and combining low pressure casting principle. The choice and design of the aluminum alloy castings with different structures, and different material (paste form solidify or in proper order solidify mode) structure and sand type for the low-pressure foundry system were summaried. The research results have singificant effects on the design of aluminum alloy low-pressure casting process

  20. 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.

  1. Defects Morphology Characteristics of EPC Aluminum Alloy Castings%消失模Al合金铸件缺陷的形貌特征

    Institute of Scientific and Technical Information of China (English)

    刘伟明; 高成勋

    2013-01-01

    介绍了消失模铸造工艺以及消失模生产Al合金铸件的几种常见缺陷,包括:表面针孔和渣孔,气孔,夹渣,夹砂,粘砂,结瘤,缩孔、缩松,溃型,冷隔和重皮,以及浇不足等.分析了各种缺陷的产生原因,并介绍相应的解决措施.最后指出不同结构特点的铸件往往有不同的工艺要求,要采用不同的措施才能确保它们的质量.与此同时,采用合适、合格的生产设备和检测设备也是防止各种缺陷的先决条件.%The EPC casting process and the common defects of EPC process -produced aluminum alloy castings were introduced including: surface pinhole and slag hole,blowhole,slag inclusion,scab;burning-on,raised nubble,shrinkage cavity and porosity, mold collapse, cold shut and double skin and misrun. The reasons causing various defects were analyzed and the relevant solving measures were introduced. It was pointed out in the end that since the castings with different configuration characteristics often have different requirements in their casting method and process design and maybe also have different defects and therefore it necessary to adopt different measures to ensure their quality. At the samtime, using proper and qualified productive equipment and inspective equipment also is the precondition to prevent various defects.

  2. Comparatively Analysis of Characteristics of Aluminum or Magnesium Alloy Air Intake Manifold by Tilted Casting%铝、镁合金进气歧管倾转铸造的特点

    Institute of Scientific and Technical Information of China (English)

    陈红兵; 罗书强; 赵建华

    2011-01-01

    Flow behavior and heat release of aluminum alloy or magnesium alloy air intake manifolds during permanent mold tilting casting process were simulated by the Anycasting software. The results show that both magnesium alloy and aluminum alloy melt fully exhibit laminar flow during filling process. Cooling curves exhibit similar change shape for aluminum alloy and magnesium alloy manifold, however, solidification time of magnesium alloy melt is longer than that of aluminum alloy melt.%采用AnyCasting铸造模拟软件,分别模拟了金属型倾转铸造铝合金和镁合金进气歧管工艺,并对其流动模式和释放热量进行了比较.镁合金熔液在整个充型过程中完全属于层流流动,铝合金熔液也属于层流流动.模拟结果显示铝合金与镁合金进气歧管的冷却曲线变化趋势基本一致,但镁合金熔液比铝合金熔液冷却时间更长.

  3. Aluminum alloy impact sparkling

    Directory of Open Access Journals (Sweden)

    M. Dudyk

    2008-08-01

    Full Text Available The cast machine parts are widely used in many branches of industry. A very important issue is gaining the appropriate knowledge relating to the application of castings in places of explosion risks including but not limited to mining, chemical industry and rescue works. A possibility of explosion risks occurrence following the impact sparkling of the cast metal parts is still not solved problem in scientific research. In relation to this issue, in this article, the results of the study are presented, and relating to the tendency to impact sparkling of the aluminium alloys used in machine building. On the grounds of the results obtained, it was demonstrated that the registered impact sparkles bunches of feathers from the analyzed alloys: AlSi7Mg, (AK7; AlSi9Mg, (AK9; AlSi6Cu4, (AK64 and AlSi11, (AK11 show significant differences between each other. The quantitative analysis of the temperature distribution and nuclei surface area performed on the example of the alloy AK9 (subjected to defined period of corrosion allows for the statement that they are dangerous in conditions of explosion risk. Following this fact, designers and users of machine parts made from these materials should not use them in conditions where the explosive mixtures occur.

  4. Heat transport and solidification in the electromagnetic casting of aluminum alloys: Part II. Development of a mathematical model and comparison with experimental results

    Science.gov (United States)

    Prasso, D. C.; Evans, J. W.; Wilson, I. J.

    1995-02-01

    In this second article of a two-part series, a mathematical model for heat transport and solidification of aluminum in electromagnetic casting is developed. The model is a three-dimensional one but involves a simplified treatment of convective heat transport in the liquid metal pool. Heat conduction in the solid was thought to play a dominant role in heat transport, and the thermal properties of the two alloys used in measurements reported in Part I (AA 5182 and 3104) were measured independently for input to the model. Heat transfer into the water sprays impacting the sides of the ingot was approximated using a heat-transfer coefficient from direct chill casting; because this heat-transfer step appears not to be rate determining for solidification and cooling of most of the ingot, there is little inaccuracy involved in this approximation. Joule heating was incorporated into some of the computations, which were carried out using the finite element software FIDAP. There was good agreement between the computed results and extensive thermocouple measurements (reported in Part I) made on a pilot-scale caster at Reynolds Metals Company (Richmond, VA).

  5. Study on the Kinetics of Hydrogen Evolution in Aluminum Alloy Casting%铝合金铸造过程中析氢动力学研究

    Institute of Scientific and Technical Information of China (English)

    周迪生; 龙伟; 张恒华

    2012-01-01

    There always exists the phenomenon of hydrogen absorption in aluminum alloy melt. When melt temperature dropped, the solubility of hydrogen in melt decreased and the hydrogen precipitated from melt, which resulted in the blowhole and porosity in cast ingots or workpieces. Different mould preheating temperatures and decompression solidification were used in casting, the effect of mold preheating temperature on the diffusion rate and diffusion distance of hydrogen, the solidification pressure on the critical nucleation radius and growth of hydrogen bubble were analyzed. The results show that hydrogen diffusion and precipitation was inhibited at low mold preheating temperature, high solidification pressure produced large critical nucleation radius of hydrogen bubble and restrained the nucleation and growth of gas bubble. Hydrogen was dissolved in aluminum alloy melt and the comparability of the structure was improved in low mould preheating temperature and high solidification pressure.%铝及其合金在熔炼过程中,往往存在吸氢现象.当熔体温度下降时,氢在熔体中的溶解度下降,会从熔体中析出,导致铸锭或工件产生气孔、疏松等缺陷.采用不同模具预热温度浇注和减压凝固,分析了模具预热温度对熔体中氢扩散速度及扩散距离的影响,凝固压强对氢气泡临界形核半径和长大的影响.结果表明,低的模具预热温度抑制熔体中氢的扩散和析出;凝固压力大时氢气泡的临界形核半径较大,抑制气泡的形核和长大.所以低的模具预热温度和高的凝固压强可使氢固溶在铝合金中,从而提高其组织的致密性.

  6. Effects of low-frequency magnetic field on grain boundary segregation in horizontal direct chill casting of 2024 aluminum alloy

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Effects of low frequency electromagnetic field on grain boundary segregation in horizontal direct chill (HDC)casting process was investigated experimentally. The grain boundary segregation and microstructures of the ingots,which manufactured by conventional HDC casting and low frequency electromagnetic HDC casting were compared.Results show that low frequency electromagnetic field significantly refines the microstructures and reduces grain boundary segregation. Decreasing electromagnetic frequency or increasing electromagnetic intensity has great effects in reducing grain boundary segregation. Meanwhile, the governing mechanisms were discussed.

  7. Effect of low frequency electromagnetic field on microstructures and macrosegregation of horizontal direct chill casting aluminum alloy

    Institute of Scientific and Technical Information of China (English)

    赵志浩; 崔建忠; 董杰; 张海涛; 张北江

    2004-01-01

    The influences of low frequency electromagnetic field on cast surface, microstructures and macrosegregation in horizontal direct chill(HDC) casting process were investigated experimentally. The cast surfaces, microstructures and macrosegregation of the ingots manufactured by conventional HDC and low frequency electromagnetic HDC casting were compared. The results show that low frequency electromagnetic field significantly improves the surface quality, refines the microstructures and reduces macrosegregation. Further more, increasing electromagnetic intensity or decreasing frequency is beneficial to the improvement. In the range of ampere-turns and frequency employed in the experiments, the optimum ampere-turns is found to be 10 000 A · turn and the frequency to be 30 Hz.

  8. Standard digital reference images for inspection of aluminum castings

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2005-01-01

    1.1 These digital reference images illustrate the types and degrees of discontinuities that may be found in aluminum-alloy castings. The castings illustrated are in thicknesses of 1/ 4 in. [6.35 mm] and 3/4 in. [19.1mm]. 1.2 All areas of this standard may be open to agreement between the cognizant engineering organization and the supplier, or specific direction from the cognizant engineering organization. These items should be addressed in the purchase order or the contract. 1.3 The values stated in inch-pound units are to be regarded as standard. 1.4 These digital reference images are not intended to illustrate the types and degrees of discontinuities found in aluminum-alloy castings when performing film radiography. If performing film radiography of aluminum-alloy castings, refer to Reference Radiographs E 155. This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and he...

  9. Analysis of chemical composition of cast aluminum alloy by spark source atomic emission spectrometry%火花源原子发射光谱法分析铸铝合金的化学成分

    Institute of Scientific and Technical Information of China (English)

    刘博涛; 谢宝强; 于洋

    2009-01-01

    The chemical composition of ZAL cast-aluminum alloy was comprehensively analyzed by spark source atomic emission spectrometry.The working conditions of instrument such as the precombustion time, integration time and cleaning time of electrode were optimized.The appropriate two-spot standardized samples were used to find the calibration method for the simultaneous determination of chemical composition in ZAL cast-aluminum alloy.The proposed method was applied to the determination of Cu, Mn, Zn, Pb, Mg, Sn, Fe, Cr, Ni, Ti and Si in cast-aluminum alloy.The results were in good agreement with the certified values.%用火花源原子发射光谱仪对ZAL铸铝合金的化学成分进行全分析.通过实验确定了予燃时间、积分时间、对电极清理时间等最佳的仪器工作条件,并在最佳工作条件下,选取了适宜的两点标准化试样,给出了适合ZAL铸铝合金中化学成分同时测定的校准方案.所建立的方法应用于铸铝合金中Cu,Mn,Zn,Pb,Mg,Sn,Fe,Cr,Ni,Ti,Si等元素的测定,测得结果与认定值一致.

  10. Numerical Simulation for 7050 Aluminum Alloy Cast with Ultrasonic Treatment%7050铝合金施加超声铸造的数值模拟

    Institute of Scientific and Technical Information of China (English)

    张立华; 朱彪

    2013-01-01

    Using the mixture model and the cavitation model of Fluent,the ultrasonic cavitation effect and cast microstructure at different ultrasonic powers for 7050 aluminum alloy melt was simulated, and then was analysed through casting experiment with ultrasonic treatment (UST). The results show that the cavitation region in melt expanded gradually with the increase of the ultrasonic treatment time, and concentrated on the center of horn surface gradually. The higher the ultrasonic power and cavitation strength were, the refiner the microstructure was. The simulated results matched the experimental results.%利用流体力学软件Fluent及动网格技术,以多相流模型中的混合物模型(Mixture)为基础,并耦合空化模型,对不同功率超声作用下7050铝合金熔体所产生的空化效应及铸造组织进行了数值模拟,并通过超声铸造试验进行了验证.结果表明:随着超声时间的延长,熔体中的空化区域逐渐扩大,并逐步向变幅杆端面中心集中;超声功率越大,空化强度越高,对铸态组织的细化效果越明显;模拟结果与试验结果基本吻合.

  11. Control of Casting Crack on 7050Aluminum Alloy Slab%7050合金扁锭铸造裂纹控制

    Institute of Scientific and Technical Information of China (English)

    张芯华; 向曙光

    2016-01-01

    Melting & casting characteristics and casting difficulty of 7050 alloy were introduced. Casting difficulties of 7050 alloy slab have been overcome by aid of computer simulation technology, water fender technology, efficient melt purification technology and automation casting technology, slabs with(400~520)×(1320~1600)mm have been obtained successfully.%介绍了7050合金熔铸特点和扁锭的铸造难点,通过采取计算机模拟技术、挡水板技术、高效的熔体净化技术以及自动化熔铸技术等有效措施,攻克了该合金扁锭熔铸难题,成功铸造出了(400~520)mm×(1320~1600)mm规格扁锭。

  12. 高压开关设备中铝合金铸造工艺发展综述%General Description of the Technological Development of Aluminum Alloy Casting in High-voltage Switchgear

    Institute of Scientific and Technical Information of China (English)

    张猛; 陈丽芬

    2011-01-01

    笔者通过高压开关设备产品中铸造工艺几十年的发展过程,叙述了中国高压开关行业的铸造专业发展史,体现了中国的改革开放给企业及技术人员带来的挑战及机遇,并使铸造专业技术人员有了对高压开关设备产品中铸造铝合金零件的铸造工艺设计开始了从无到有、逐步发展、壮大的一种探索过程.总结了铸造铝硅合金不同类型零件的铸造工艺设计要点、发展应用过程,同时指出了其以后的发展方向.%Through the several decades of development of casting technology in high-voltage switchgear, this paper narrated the developing history of casting industry of Chinese high-voltage switchgear field, indicated the challenge and opportunities China's reform had brought to Chinese enterprises and technicians. Furthermore, it made the casting professional technicians starting the exploration for the casting technology of casting aluminum alloy components in high-voltage switchgear industry from preliminary stage to mature stage. Moreover, it summarized the key points of the casting technological design and developing application process of different types of components of casting aluminum silicon alloy, and also pointed out the future development trends.

  13. Effect of Ablation Casting on Microstructure and Casting Properties of A356 Aluminium Casting Alloy

    Institute of Scientific and Technical Information of China (English)

    V.Bohlooli; M.Shabani Mahalli; S.M.A.Boutorabi

    2013-01-01

    Recently the Ablation Casting Technology was invented as a new casting process to improve foundry products quality.In this study,the effects of processing variables on the porosity content,microstructure and feedability of A356 casting alloy were investigated.Secondary dendrite arm spacing (SDAS) and eutectic silicon morphologies were studied to evaluate the influence of Ablation Casting on the microstructure.Casting density was measured in order to identify porosity content and feedability of ablated and non-ablated specimens.In addition,solidification behavior of the samples was investigated by using thermal analysis technique.The cooling curves and the first derivative curves were plotted and compared with each other.Results showed the ablation process could increase solidification rate significantly.In addition,the microstructural evidences revealed that Ablation Casting process results in more fine and homogeneous structure compared to the nonablated casting.The feedability improved,SDAS reduced to 35% and porosity content decreased to 3.84 vol.% by implementing this process.It concluded the Ablation Casting is an effective process to gain higher quality in aluminum foundry.

  14. Mensuration and simulation of mold filling process in semi-solid die-cast of aluminum alloy

    Institute of Scientific and Technical Information of China (English)

    YANG Yi-tao; WANG Jian-fu; ZHANG Heng-hua; SHAO Guang-jie

    2006-01-01

    To understand the flow trace of semi-solid slurry in mold cavity, some thermocouples were inserted in mold cavity, and the reaction timing of thermocouples showed the arrival of fluid. The filling time and rate were estimated by comparison between the experiment and calculation. The introduction of computer simulation technique based on ADSTEFAN was to predict injectionforming process and to prevent defects during trial manufacture of various parts. By comparing the formed appearance of parts in experiment and in simulation, and observing the relationship between internal defects inspected by X-ray or microscope and the flow field obtained in simulation, it was indicated that both have quite good agreement in simulation and experiment. Right predictions for cast defects resulted from mold filling can be carried out and proper direction was also proposed. The realization of numerical visualization for filling process during semi-solid die-cast process will play an important role in optimizing technology plan.

  15. A study on the effect of coating's sorption capacity on the porosity in lost foam aluminum alloy casting

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    Effects of coating constituent, coating density, coating layer thickness and temperature on coating sorption capacity for polystyrene decomposition products have been studied systematically. It has been found that the effect of attapulgite clay on sorption capacity is the largest among coating constituents. The sorption capacity of the coating with 2 %attapulgite clay is elevated by 81%. The relationship between casting porosity and coating sorption capacity has been studied. It has been pointed out that higher coating sorption capacity for polystyrene decomposition products is helpful to decrease the casting porosity. Results also show that the sorption capacity of self- developed HW- 1 coating for polystyrene decomposition products is as good as that of Ashland coating from America.

  16. 铸造铝合金前副车架焊接技术研究%Research on Welding Process of Casting Aluminum Alloy Front Auxiliary Cradle

    Institute of Scientific and Technical Information of China (English)

    顾勇; 李芳; 徐佳利; 李涛; 蔡艳; 华学明

    2016-01-01

    针对某型号A356铸铝前副车架,采用直流脉冲焊方法,以ER5554焊丝作为填充材料进行了焊接工艺试验研究并实现了局部1∶1模拟接头的连接.针对局部1∶1模拟接头设计了相应的焊接试验方案,研究了焊接电流、焊接速度、拼接间隙等工艺参数对焊接质量的影响规律,在此基础上针对局部1∶1模拟接头测试了相关的力学性能.结果表明,焊接电流、焊接速度与拼接间隙对焊缝熔宽、余高与根部侧壁熔合有显著影响;间隙对焊缝根部侧壁熔合影响最大,过小的间隙容易造成焊缝根部未熔合,极大地降低接头抗拉强度.研究结果为实现铸铝副车架替代钢制副车架提供了连接技术方面理论指导,有较好的工业应用价值.%Aiming at A356 casting aluminum alloy front auxiliary gradle,using GMAW-P welding technology,taking ER5554 welding wire as filling material,the welding for A356 was carried out.Then,the connection of part 1 ∶ 1 simulation welded joint was realized.The related welding experimental scheme of part 1∶1 simulation weleded joint was designed.The effects of welding current,welding speed and gap on the welding quality were discussed.The rehted mechanical properties of part 1∶1 simulation welded joint were tested.The results show that the effects of welding current,welding speed and matching gap on the weld width,excess weld metal and fusion of root sidewall are obvious.The influence of gap on the fusion of root sidewall of weld seam is most the largest.Too small gap can easily cause incomplete fusion of weld root sidewall,and the the tensile strength of the welded joint greatly reduces.The results could provide some technology guidance for realizing casting aluminum alloy auxiliary cradle replacing steel auxiliary cradle.Then,the results have better industrial application value.

  17. Effects of silicon contents on formation of abnormal structures of aluminum alloy die castings; Aruminiumu gokin daikasuto no ijo soshiki keisei ni oyobosu keisoryo no eikyo

    Energy Technology Data Exchange (ETDEWEB)

    Komazaki, T.; Maruyama, Y.; Nishi, N. [Ryobi Ltd., Hiroshima (Japan)

    1995-04-25

    In this study, Al-5-11mass%Si binary alloys and commercial alloys with equivalent amount of silicon contents (AC2A, ADC10, ADC12) were fabricated into die castings with changed shot-time-lag, and effects of alloy structures on formation of abnormal structures were investigated. The results show the following discoveries. With the increasing of silicon contents in Al-Si binary alloys from 5 mass% to 11 mass%, the abnormal structures caused by the cooling and solidification of the molten metal in the injection sleeve will change from mainly coarse {alpha} phase to mainly breaking chill crystals as the solidification state is changing form porridge state to solid surface forming state. The abnormal structure of the commercial alloy AC2A mainly consists of coarse {alpha} phases and that of ADC12 mainly consists of breaking chill crystals. The ADC10 alloy is an intermediate alloy between them. The amount of dispersion for values of tensile strength of ADC12 alloy is larger than that of AC2A and ADC10 alloys because ADC12 alloy contains many breaking chill crystals. 12 refs., 11 figs., 4 tabs.

  18. [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. PMID:18669265

  19. RESEARCH OF GAS-FORMING ABILITY OF THE MATERIALS USED AT DEVELOPMENT OF DIVIDING COVERINGS FOR THE MOLDS OF CASTING OF ALUMINUM ALLOYS UNDER PRESSURE

    Directory of Open Access Journals (Sweden)

    A. M. Mihaltsov

    2012-01-01

    Full Text Available The methods of carrying out of experiments by determination of gas creating ability of different materials which are of interest from the point of view of molding of aluminum alloys under pressure are given and described, and the results of research are presented as well.

  20. Effect of metallurgical parameters on the hardness and microstructural characterization of as-cast and heat-treated 356 and 319 aluminum alloys

    Energy Technology Data Exchange (ETDEWEB)

    Tash, M. [Universite du Quebec a Chicoutimi, Chicoutimi, Quebec (Canada); Cairo University, Giza (Egypt); Samuel, F.H. [Universite du Quebec a Chicoutimi, Chicoutimi, Quebec (Canada)]. E-mail: fhsamuel@uqac.ca; Mucciardi, F. [McGill University, Montreal, Quebec (Canada); Doty, H.W. [General Motors Powertrain Group, Metal Casting Technology, Inc., Milford, NH (United States)

    2007-01-15

    The present study was undertaken to investigate the effect of metallurgical parameters on the hardness and microstructural characterization of as-cast and heat-treated 356 and 319 alloys, with the aim of adjusting these parameters to produce castings of suitable hardness and Fe-intermetallic volume fractions for subsequent use in studies relating to the machinability of these alloys. By measuring the amount of Fe- and Cu-intermetallics formed and the changes in the eutectic Si particle characteristics resulting from alloying additions (Fe, Mn, Mg), Sr-modification, and heat treatment of the 356 and 319 alloys, and the corresponding hardness values, it was possible to determine which conditions or metallurgical parameters yielded the required Fe-intermetallic volume fractions of 2 and 5% and hardness levels of 85 and 115 BHN. These levels conform to the most common levels observed in the commercial application of these alloys. The 356 and 319 alloys were examined in the as-cast and heat-treated conditions, using different combinations of grain refining, Sr-modification, and alloying additions. Aging treatments were carried out at 155, 180, 200, and 220 deg. C for 4 h, followed by air cooling, as well as at 180 and 220 deg. C for 2, 4, 6, and 8 h to determine conditions under which the specified hardness levels of 85 and 115 HBN could be obtained. Hardness measurements were carried out using a Brinell hardness tester. Peak hardness was observed in the 356 and 319 alloys at different aging conditions, depending upon the Fe-intermetallic type present in the alloy and whether the alloy was modified or not. Aging at 220 deg. C revealed a hardness peak at 2 h aging time in both 356 and 319 alloys. Addition of Mg to 319 alloys produced a remarkable increase in hardness at all aging temperatures. This may be explained on the basis of the combined effect of Cu- and Mg-intermetallics in the 319 alloys, where hardening during aging occurs by the cooperative precipitation of Al

  1. Effect of metallurgical parameters on the hardness and microstructural characterization of as-cast and heat-treated 356 and 319 aluminum alloys

    International Nuclear Information System (INIS)

    The present study was undertaken to investigate the effect of metallurgical parameters on the hardness and microstructural characterization of as-cast and heat-treated 356 and 319 alloys, with the aim of adjusting these parameters to produce castings of suitable hardness and Fe-intermetallic volume fractions for subsequent use in studies relating to the machinability of these alloys. By measuring the amount of Fe- and Cu-intermetallics formed and the changes in the eutectic Si particle characteristics resulting from alloying additions (Fe, Mn, Mg), Sr-modification, and heat treatment of the 356 and 319 alloys, and the corresponding hardness values, it was possible to determine which conditions or metallurgical parameters yielded the required Fe-intermetallic volume fractions of 2 and 5% and hardness levels of 85 and 115 BHN. These levels conform to the most common levels observed in the commercial application of these alloys. The 356 and 319 alloys were examined in the as-cast and heat-treated conditions, using different combinations of grain refining, Sr-modification, and alloying additions. Aging treatments were carried out at 155, 180, 200, and 220 deg. C for 4 h, followed by air cooling, as well as at 180 and 220 deg. C for 2, 4, 6, and 8 h to determine conditions under which the specified hardness levels of 85 and 115 HBN could be obtained. Hardness measurements were carried out using a Brinell hardness tester. Peak hardness was observed in the 356 and 319 alloys at different aging conditions, depending upon the Fe-intermetallic type present in the alloy and whether the alloy was modified or not. Aging at 220 deg. C revealed a hardness peak at 2 h aging time in both 356 and 319 alloys. Addition of Mg to 319 alloys produced a remarkable increase in hardness at all aging temperatures. This may be explained on the basis of the combined effect of Cu- and Mg-intermetallics in the 319 alloys, where hardening during aging occurs by the cooperative precipitation of Al

  2. 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

    Soldering of cast alloys to the dies has been a continuing source of die surface damage in the aluminum die-casting industry. To reduce the repair and maintenance costs, an approach to modeling the damage and predicting the die lifetime is required. The aim of the present study is the estimation...

  3. Modeling of Alternative Compositions of Recycled Wrought Aluminum Alloys

    Science.gov (United States)

    Kevorkijan, Varužan

    2013-08-01

    Nowadays, a significant part of postconsumed wrought aluminum scrap is still used for the production of comparatively cheaper cast alloys, in that way losing an important part of the potential added value. The share of postconsumed scrap in wrought aluminum alloys could be increased either by sorting to fractions with the required chemical composition and/or by broadening the standard compositional tolerance limits of alloying elements. The first solution requires hand or automatic sorting of postconsumed scrap as alloys or groups of alloys to the degree of separation sufficient to enable the blending of standard compositions of wrought alloys; the second solution is much more radical, predicting changes in the existing standards for wrought aluminum alloys toward nonstandard alloys but yet having properties acceptable for customers. In this case, the degree of separation of incoming postconsumed scrap required is much less demanding. The model presented in this work enables the design of optimal (standard and nonstandard recycling-friendly) compositions and properties of wrought aluminum alloys with significantly increased amounts of postconsumed scrap. The following two routes were modeled in detail: (I) the blending of standard and nonstandard compositions of wrought aluminum alloys starting from postconsumed aluminum scrap sorted to various degrees simulated by the model and (II) changing the initial standard composition of wrought aluminum alloys to nonstandard "recycling-friendly" ones, with broader concentration tolerance limits of alloying elements and without influencing the selected alloy properties, specified in advance. The applied algorithms were found to be very useful in the industrial design of both procedures: (I) the computation of the required chemical composition of the scrap streams obtained by sorting (or, in other words, the postconsumed scrap sorting level), necessary for achieving the standard wrought alloy composition and (II) the

  4. Impact Toughness and Heat Treatment for Cast Aluminum

    Science.gov (United States)

    Lee, Jonathan A (Inventor)

    2016-01-01

    A method for transforming a cast component made of modified aluminum alloy by increasing the impact toughness coefficient using minimal heat and energy. The aluminum alloy is modified to contain 0.55%-0.60% magnesium, 0.10%-0.15% titanium or zirconium, less than 0.07% iron, a silicon-tomagnesium product ratio of 4.0, and less than 0.15% total impurities. The shortened heat treatment requires an initial heating at 1,000deg F. for up to I hour followed by a water quench and a second heating at 350deg F. to 390deg F. for up to I hour. An optional short bake paint cycle or powder coating process further increase.

  5. Aluminum-Based Cast In Situ Composites: A Review

    Science.gov (United States)

    Pramod, S. L.; Bakshi, Srinivasa R.; Murty, B. S.

    2015-06-01

    In situ composites are a class of composite materials in which the reinforcement is formed within the matrix by reaction during the processing. In situ method of composite synthesis has been widely followed by researchers because of several advantages over conventional stir casting such as fine particle size, clean interface, and good wettability of the reinforcement with the matrix and homogeneous distribution of the reinforcement compared to other processes. Besides this, in situ processing of composites by casting route is also economical and amenable for large scale production as compared to other methods such as powder metallurgy and spray forming. Commonly used reinforcements for Al and its alloys which can be produced in situ are Al2O3, AlN, TiB2, TiC, ZrB2, and Mg2Si. The aim of this paper is to review the current research and development in aluminum-based in situ composites by casting route.

  6. Effect of hot and cold deformation on the P {l_brace}0 1 1{r_brace}<4 5 5> recrystallization texture in a continuous cast Al-Mn-Mg aluminum alloy

    Energy Technology Data Exchange (ETDEWEB)

    Liu, W.C. [Department of Chemical and Materials Engineering, University of Kentucky, 177 Anderson Hall, Lexington, KY 40506 (United States)]. E-mail: wcliu@engr.uky.edu; Morris, J.G. [Department of Chemical and Materials Engineering, University of Kentucky, 177 Anderson Hall, Lexington, KY 40506 (United States)

    2006-06-15

    The effect of different relative amounts of hot and cold deformation on the P {l_brace}0 1 1{r_brace}<4 5 5> recrystallization texture in a continuous cast Al-Mn-Mg aluminum alloy was investigated by X-ray diffraction. The results show that at a given total rolling strain the sheet with a high hot rolling strain exhibits a significantly stronger P texture than sheet with a low hot rolling strain. Hot deformation strongly promotes the formation of the P texture during recrystallization annealing.

  7. Prediction of ALLOY SHRINKAGE FACTORS FOR THE INVESTMENT CASTING PROCESS

    Energy Technology Data Exchange (ETDEWEB)

    Sabau, Adrian S [ORNL

    2006-01-01

    This study deals with the experimental measurements and numerical predictions of alloy shrinkage factors (SFs) related to the investment casting process. The dimensions of the A356 aluminum alloy casting were determined from the numerical simulation results of solidification, heat transfer, fluid dynamics, and deformation phenomena. The investment casting process was carried out using wax patterns of unfilled wax and shell molds that were made of fused silica with a zircon prime coat. The dimensions of the die tooling, wax pattern, and casting were measured, in order to determine the actual tooling allowances. Several numerical simulations were carried out, to assess the level of accuracy for the casting shrinkage. The solid fraction threshold, at which the transition from the fluid dynamics to the solid dynamics occurs, was found to be important in predicting shrinkage factors (SFs). It was found that accurate predictions were obtained for all measued dimensions when the shell mold was considered a deformable material.

  8. Thin-Wall Aluminum Die-Casting Technology for Development of Notebook Computer Housing

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Silicon-based aluminum casting alloys are known to be one of the most widely used alloy systems mainly due to their superior casting characteristics and unique combination of mechanical and physical properties.However, manufacturing of thin-walled aluminum die-casting components, less than 1.0 mm in thickness, is generally known to be very difficult task to achieve aluminum casting alloys with high fluidity. Therefore, in this study, the optimal die-casting conditions for producing 297 mm×210 mm×0.7 mm thin-walled aluminum component was examined experimentally by using 2 different gating systems, tangential and split type, and vent design. Furthermore, computational solidification simulation was also conducted. The results showed that split type gating system was preferable gating design than tangential type gating system at the point of view of soundness of casting and distortion generated after solidification. It was also found that proper vent design was one of the most important factors for producing thin-wall casting components because it was important for the fulfillment of the thin-wall cavity and the minimization of the casting distortion.

  9. Die Casting Mold Design of the Thin-walled Aluminum Case by Computational Solidification Simulation

    Institute of Scientific and Technical Information of China (English)

    Young-Chan Kim; Chang-Seog Kang; Jae-Ik Cho; Chang-Yeol Jeong; Se-Weon Choi; Sung-Kil Hong

    2008-01-01

    Recently, demand for the lightweight alloy in electric/electronic housings has been greatly increased. However, among the lightweight alloys, aluminum alloy thin-walled die casting is problematic because it is quite difficult to achieve sufficient fluidity and feedability to fill the thin cavity as the wall thickness becomes less than 1 mm. Therefore, in this study, thin-walled die casting of aluminum (Al-Si-Cu alloy: ALDC 12) in size of notebook computer housing and thickness of 0.8 mm was investigated by solidification simulation (MAGMA soft) and actual casting experiment (Buhler Evolution B 53D). Three different types of gating design, finger, tangential and split type with 6 vertical runners, were simulated and the results showed that sound thin-walled die casting was possible with tangential and split type gating design because those gates allowed aluminum melt to flow into the thin cavity uniformly and split type gating system was preferable gating design comparing to tangential type gating system at the point of view of soundness of casting and distortion generated after solidification. Also, the solidification simulation agreed well with the actual die-casting and the casting showed no casting defects and distortion.

  10. Low Cost Al-Si Casting Alloy As In-Situ Composite for High Temperature Applications

    Science.gov (United States)

    Lee, Jonathan A.

    2000-01-01

    A new aluminum-silicon (Al-Si) alloy has been successfully developed at NASA- Marshall Space Flight Center (MSFC) that has significant improvement in tensile and fatigue strength at elevated temperatures (500 F-700 F). The alloy offers a number of benefits such as light weight, high hardness, low thermal expansion and high surface wear resistance. In hypereutectic form, this alloy is considered as an in-situ Al-Si composite with tensile strength of about 90% higher than the auto industry 390 alloy at 600 F. This composite is very economically produced by using either conventional permanent steel molds or die casting. The projected material cost is less than $0.90 per pound, and automotive components such as pistons can be cast for high production rate using conventional casting techniques with a low and fully accounted cost. Key Words: Metal matrix composites, In-situ composite, aluminum-silicon alloy, hypereutectic alloy, permanent mold casting, die casting.

  11. Challenges for research and development of new aluminum alloys

    Directory of Open Access Journals (Sweden)

    D. Vojtĕch

    2010-07-01

    Full Text Available Modern trends in research and development of new aluminum alloys are characterized in the present work. Although conventional wrought and casting Al-based alloys show good specific strength, as compared to steels or Ti-based alloys, there is still a potential for significant improvement of their performance. It consists in application of new alloying elements, mainly transition metals, and uncommon processing routes, for example powder metallurgy. By this way, qualitatively new materials with ultra high strength and excellent thermal stability can be developed. However, there are many questions to be answered before new alloys can be competitive to conventional Al-based materials.

  12. Comparison of recrystallization and recrystallization textures in cold-rolled DC and CC AA 5182 aluminum alloys

    International Nuclear Information System (INIS)

    The recrystallization and recrystallization textures in cold-rolled direct chill cast (DC) and continuous cast (CC) AA 5182 aluminum alloys were investigated. The recrystallization behavior of cold-rolled DC and CC AA 5182 aluminum alloys was evaluated by tensile properties. The evolution of recrystallization textures in cold-rolled DC and CC AA 5182 aluminum alloys was determined by X-ray diffraction. The results showed that the recrystallization temperature of cold-rolled DC AA 5182 aluminum alloy was somewhat lower than that of cold-rolled CC AA 5182 aluminum alloy. The resulting recrystallization textures of cold-rolled AA 5182 aluminum alloy were characterized by the strong R orientation and the cube orientation with strong scattering about the rolling direction towards the Goss orientation. CC AA 5182 aluminum alloy showed slightly weaker recrystallization textures than DC AA 5182 aluminum alloy

  13. Combining Aluminum Heat Treat with Hot Isostatic Pressing:A Comparison of Structure, Properties, and Processing Routes for a Cast Al-Si-Mg Alloy

    Institute of Scientific and Technical Information of China (English)

    Stephen J. Mashl

    2004-01-01

    Bodycote researchers have successfully demonstrated that a T6 heat treatment can be integrated with Densal(R), a proprietary, aluminum specific, hot isostatic pressing (HIP) process. In this combined operation, at least a portion of the solution heat treatment is conducted at elevated pressure. During development, two issues, adiabatic cooling during depressurization and a possible variation in the kinetics of homogenization resulting from conducting the solution heat treat at elevated pressure were perceived as factors which could alter the heat treat response fiom that seen in conventional processing.This paper reviews the results of experiments performed to A1-Si-Mg (A356.0) castings subjected to both combined and conventional processing routes. Results indicate that the combined HIP and heat treat process is an efficient means of achieving a microstructure characteristic of a conventionally T6 processed material while eliminating porosity within the casting. Further, the fatigue life of an A356.0 casting processed using the combined cycle can be improved by more than an order of magnitude over the as-cast and T6 treated component.

  14. Welding and mechanical properties of cast FAPY (Fe-16 at. % Al-based) alloy slabs

    Energy Technology Data Exchange (ETDEWEB)

    Sikka, V.K.; Goodwin, G.M.; Alexander, D.J.; Howell, C.R.

    1995-08-01

    The low-aluminum-content iron-aluminum program deals with the development of a Fe-Al alloy with aluminum content such as a produce the minimum environmental effect at room temperature. The FAPY is an Fe-16 at. % Al-based alloy developed at the Oak Ridge National Laboratory as the highest aluminum-containing alloy with essentially no environmental effect. The chemical composition for FAPY in weight percent is: aluminum = 8.46, chromium = 5.50, zirconium = 0.20, carbon = 0.03, molybdenum = 2.00, yttrium = 0.10, and iron = 83.71. The cast ingots of the alloy can be hot worked by extrusion, forging, and rolling processes. The hot- worked cast structure can be cold worked with intermediate anneals at 800{degrees}C. Typical room-temperature ductility of the fine-grained wrought structure is 20 to 25% for this alloy. In contrast to the wrought structure, the cast ductility at room temperature is approximately 1% with a transition temperature of approximately 100 to 150{degrees}C, above which ductility values exceed 20%. The alloy has been melted and processed into bar, sheet, and foil. The alloy has also been cast into slabs, step-blocks of varying thicknesses, and shapes. The purpose of this section is to describe the welding response of cast slabs of three different thicknesses of FAPY alloy. Tensile, creep, and Charpy-impact data of the welded plates are also presented.

  15. Advanced metrology of surface defects measurement for aluminum die casting

    Directory of Open Access Journals (Sweden)

    D. Myszka

    2011-07-01

    Full Text Available The scientific objective of the research is to develop a strategy to build computer based vision systems for inspection of surface defects inproducts, especially discontinuities which appear in castings after machining. In addition to the proposed vision inspection method theauthors demonstrates the development of the advanced computer techniques based on the methods of scanning to measure topography ofsurface defect in offline process control. This method allow to identify a mechanism responsible for the formation of casting defects. Also,the method allow investigating if the, developed vision inspection system for identification of surface defects have been correctlyimplemented for an online inspection. Finally, in order to make casting samples with gas and shrinkage porosity defects type, the LGT gas meter was used . For this task a special camera for a semi-quantitative assessment of the gas content in aluminum alloy melts, using a Straube-Pfeiffer method was used. The results demonstrate that applied solution is excellent tool in preparing for various aluminum alloysthe reference porosity samples, identified next by the computer inspection system.

  16. A New Method for Evaluating Fatigue Property of A713 Cast Aluminum Alloy%评价铸造A713铝合金疲劳性能的新方法

    Institute of Scientific and Technical Information of China (English)

    张元彬; 罗辉; 霍玉双; 刘鹏; 翟同广

    2012-01-01

    在材料试验机上对铸造A713铝合金进行四点弯曲疲劳试验,并通过一种评价疲劳性能的新方法获得了该合金的疲劳弱点密度和强度曲线。结果表明:试验获得的铸造A713铝合金的疲劳强度为94.5MPa;该合金的疲劳弱点密度符合Weibull分布方程,疲劳弱点强度在应力水平为65%时最大;与气孔尺寸分布相比,疲劳弱点密度和强度的分布更适合作为材料疲劳性能的评价指标。%The four points bending fatigue test was applied to A713 cast aluminum alloy by a material tester,and the curves of the density and strength of fatigue weakest link of the alloy were obtained by a new method of evaluating fatigue property.The results show that the fatigue strength of A713 cast aluminum alloy obtained by this method was 94.5 MPa.The fatigue weakest link density corresponded with Weibull distribution equation,and the fatigue weakest link strength was maximum when the stress level was 65%.Compared with pore size distribution,the distribution of density and strength of fatigue weakest link was more suitable to be used as the evaluation index of fatigue property of materials.

  17. Gating of Permanent Molds for Aluminum Casting

    Energy Technology Data Exchange (ETDEWEB)

    David Schwam; John F. Wallace; Tom Engle; Qingming Chang

    2004-01-01

    This report summarizes a two-year project, DE-FC07-011D13983 that concerns the gating of aluminum castings in permanent molds. The main goal of the project is to improve the quality of aluminum castings produced in permanent molds. The approach taken was to determine how the vertical type gating systems used for permanent mold castings can be designed to fill the mold cavity with a minimum of damage to the quality of the resulting casting. It is evident that somewhat different systems are preferred for different shapes and sizes of aluminum castings. The main problems caused by improper gating are entrained aluminum oxide films and entrapped gas. The project highlights the characteristic features of gating systems used in permanent mold aluminum foundries and recommends gating procedures designed to avoid common defects. The study also provides direct evidence on the filling pattern and heat flow behavior in permanent mold castings. Equipment and procedure for real time X-Ray radiography of molten aluminum flow into permanent molds have been developed. Other studies have been conducted using water flow and behavior of liquid aluminum in sand mold using real time photography. This investigation utilizes graphite molds transparent to X-Rays making it possible to observe the flow pattern through a number of vertically oriented grating systems. These have included systems that are choked at the base of a rounded vertical sprue and vertical gating systems with a variety of different ingates into the bottom of a mold cavity. These systems have also been changed to include gating systems with vertical and horizontal gate configurations. Several conclusions can be derived from this study. A sprue-well, as designed in these experiments, does not eliminate the vena contracta. Because of the swirling at the sprue-base, the circulating metal begins to push the entering metal stream toward the open runner mitigating the intended effect of the sprue-well. Improved designs of

  18. Hydrogen effects in aluminum alloys

    International Nuclear Information System (INIS)

    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 D2/ = 1.9 x 10-2 exp (--22,400/RT) cc (NTP)atm/sup --1/2/ s-1cm-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

  19. Microstructure and interface reaction of investment casting TiAl alloys

    Institute of Scientific and Technical Information of China (English)

    CHEN Yu-yong; XIAO Shu-long; KONG Fan-tao; WANG Xue

    2006-01-01

    In order to research the microstructure of TiAl alloy and TiAl-mould reaction between TiAl and ceramic mould shells prepared with the low cost binder in investment casting, the ceramic mould shells were prepared with low cost binder and refractory materials. Using two kinds of casting methods (gravity casting and centrifugal casting), the titanium aluminum alloys with rare earth element (Ti-47.5Al-2Cr-2Nb-0.3Y and Ti-45Al-5Nb-0.3Y) were cast into the mould shells. The microstructures of investment casting titanium aluminum alloys were observed by optical microscope (OM). The distributions of elements of topping investment on the surfaces of titanium aluminum alloys castings were analyzed by the means of electron probe micro-analysis (EPMA), and the mechanical properties were studied. The results show that the microstructures of two kinds of titanium aluminum alloys are both lamella shape, and lamella is thin. The thickness of reaction and diffusing layer of Ti-47.5Al-2Cr-2Nb-0.3Y alloy is about 80 μm, and that of Ti-45Al-5Nb-0.3Y is less than 30 μm.

  20. Evaluation of Cracking Causes of AlSi5Cu3 Alloy Castings

    Directory of Open Access Journals (Sweden)

    Eperješi Š.

    2014-10-01

    Full Text Available Recently, the castings made from aluminum-silicon alloys by pressure die casting are increasingly used in the automotive industry. In practice, on these castings are high demands, mainly demands on quality of their structure, operating life and safety ensuring of their utilization. The AlSi5Cu3 alloy castings are widely used for production of car components. After the prescribed tests, the cracks and low mechanical properties have been identified for several castings of this alloy, which were produced by low pressure casting into a metal mould and subsequent they were heat treated. Therefore, analyses of the castings were realized to determine the causes of these defects. Evaluation of structure of the AlSi5Cu3 alloy and causes of failure were the subjects of investigation presented in this article.

  1. 激光熔铸修理航空铝合金LY12CZ组织与疲劳性能%Microstructure and fatigue properties of aviation aluminum alloy LY12CZ repaired by laser melt casting

    Institute of Scientific and Technical Information of China (English)

    卢长亮; 胡芳友; 黄旭仁; 崔爱勇; 胡滨; 付鹏飞

    2011-01-01

    Corrosion damaged aluminum alloy (LY12CZ) was repaired by laser melt casting with Al based rare-earth alloy powder. The microstructure of melt casting zone was investigated, and comparison test of fatigue life was carried out between repaired specimens and no-damage specimens. It is found that fine equiaxed crystals distribute in the casting layer and the crystal size is about 3-4 pjn. The columnar crystals, axial direction size of which reaches 30-40 μm, exist near the substrate with its crystallographic axis perpendicular to the interface. The fatigue life of specimens repaired by laser melt casting is much shorter than that of no-damage specimens, due to the origin of crack resulting from flaws in the casting layer; the columnar grains in the bottom of casting zone are easy to crack under the tensile stress; the residual stress after melt casting accelerates the initiation and growth of crack.%为修复腐蚀损伤的飞机铝合金构件,使用铝基稀土合金粉末,对预置模拟腐蚀损伤的铝合金(LY12CZ)试样进行激光熔铸修复,分析试样修复后熔铸层的显微组织结构,并对熔铸修理试样和无损试样进行疲劳对比试验.结果表明:熔铸层内为尺寸较小的等轴晶粒,尺寸为3~4 μm;靠近熔铸界面处为具有定向凝固特征的柱状枝晶,晶轴垂直于界面,轴向尺寸可达30~40 μm;激光熔铸修复的试样疲劳性能较完好试样大幅下降,主要原因为熔铸层内的熔铸加工缺陷形成了裂纹源,熔铸层底部的柱状枝晶具有较强的应力开裂倾向,熔铸残余拉应力加速裂纹的萌生与扩展.

  2. Development and application of titanium alloy casting technology in China

    Institute of Scientific and Technical Information of China (English)

    NAN Hai; XIE Cheng-mu; ZHAO Jia-qi

    2005-01-01

    The development and research of titanium cast alloy and its casting technology, especially its application inaeronautical industry in China are presented. The technology of molding, melting and casting of titanium alloy, casting quality control are introduced. The existing problems and development trend in titanium alloy casting technology are also discussed.

  3. 刷镀工艺在铝合金压铸件磨损后修复中的应用研究%Application of brush plating in repair of abraded aluminum alloy die-castings

    Institute of Scientific and Technical Information of China (English)

    张玉峰; 李云彪

    2001-01-01

    In view of the defects in brush plating of aluminum alloy such as poor adhesion, easily cracked or peeled, a new brush plating proces for aluminum and its alloys was advanced. Formula and operating conditions of the procedures were described, high-packed alkaline copper deposit was adopted to act as interlayer and fast nickel brush deposit as working layer. Adhesion and wear resistance of the brush deposits were tested according to GB2933-86. Results show that the process improves the adhesion and wear resistance of brush deposits, and extends the service life of brush plated articles, which is applicable to the repair of abraded aluminum alloy die castings.%鉴于铝合金刷镀层结合力差,易产生裂纹及剥落现象。本文提出了一种新的铝及其合金刷镀工艺。阐述了各工艺步骤的配方及操作条件。过渡层采用高堆积碱铜,工作层为快速刷镀镍。根据GB2933-86测试镀层结合力及耐磨性。结果表明:该工艺可提高刷镀层的结合力和耐磨性,延长零件使用寿命。适用于铝合金压铸件磨损后的修复。

  4. Microbial corrosion of aluminum alloy.

    Science.gov (United States)

    Yang, S S; Chen, C Y; Wei, C B; Lin, Y T

    1996-11-01

    Several microbes were isolated from the contaminated fuel-oil in Taiwan and the microbial corrosion of aluminum alloy A356-T6 was tested by MIL-STD-810E test method. Penicillium sp. AM-F5 and Cladosporium resinac ATCC 22712 had significant adsorption and pitting on the surface of aluminum alloy, Pseudomonas acruginosa AM-B5 had weak adsorption and some precipitation in the bottom, and Candida sp. AM-Y1 had the less adsorption and few cavities formation on the surface. pH of the aqueous phase decreased 0.3 to 0.7 unit for 4 months of incubation. The corrosion of aluminum alloy was very significant in the cultures of Penicillium sp. AM-F2, Penicillium sp. AM-F5 and C. resinac ATCC 22712. The major metabolites in the aqueous phase with the inoculation of C. resinac were citric acid and oxalic acid, while succinic acid and fumaric acid were the minors. PMID:10592801

  5. Microstructural features of intergranular brittle fracture and cold cracking in high strength aluminum alloys

    NARCIS (Netherlands)

    Lalpoor, M.; Eskin, D. G.; ten Brink, Gert; Katgerman, L.

    2010-01-01

    Intergranular brittle fracture has been mainly observed and reported in steel alloys and precipitation hardened At-alloys where intergranular precipitates cover a major fraction of the grain boundary area. 7xxx series aluminum alloys suffer from this problem in the as-cast condition when brittle int

  6. Bimetallic layered castings alloy steel – carbon cast steel

    Directory of Open Access Journals (Sweden)

    T. Wróbel

    2011-01-01

    Full Text Available In paper is presented technology of bimetallic layered castings based on founding method of layer coating directly in cast processso-called method of mould cavity preparation. Prepared castings consist two fundamental parts i.e. bearing part and working part (layer. The bearing part of bimetallic layered casting is typical foundry material i.e. ferritic-pearlitic carbon cast steel, whereas working part (layer is plate of austenitic alloy steel sort X10CrNi 18-8. The ratio of thickness between bearing and working part is 8:1. The quality of the bimetallic layered castings was evaluated on the basis of ultrasonic NDT (non-destructive testing, structure and macro- and microhardness researches.

  7. Microstructure of AM50 die casting magnesium alloy

    Directory of Open Access Journals (Sweden)

    A. Kiełbus

    2006-08-01

    Full Text Available Purpose: AM50 magnesium alloy allows high-energy absorption and elongation at high strength and has goodcastability. It contains aluminum and manganese. Typically, it is used in automotive industry for steering wheels,dashboards and seat frames. The aim of this paper is to present the results of investigations on the microstructureof the AM50 magnesium alloy in an ingot condition and after hot chamber die casting.Design/methodology/approach: Die casting was carried out on 280 tone locking force hot-chamber die castingmachine. For the microstructure observation, a Olympus GX+70 metallographic microscope and a HITACHIS-3400N scanning electron microscope with a Thermo Noran EDS spectrometer equipped with SYSTEM SIXwere used.Findings: Based on the investigation carried out it was found that the AM50 magnesium alloy in as ingotcondition is characterized by a solid solution structure a with partially divorced eutectic (a + Mg17Al12 andprecipitates of Mn5Al8 phase. After hot chamber die casting is characterized by a solid solution structure awith fully divorced eutectic a + Mg17Al12. Moreover, the occurrence of Mn5Al8 phase and some shrinkageporosity has been proved.Research limitations/implications: Future researches should contain investigations of the influence of the diecasting process parameters on the microstructure and mechanical properties of AM50 magnesium.Practical implications: AM50 magnesium alloy can be cast with cold- and hot-chamber die casting machine.Results of investigation may be useful for preparing die casting technology of this alloy.Originality/value: The results of the researches make up a basis for the investigations of new magnesium alloysfor hot chamber die casting with addition of RE elements designed to exploitation in temperature to 175°C.

  8. Effect of electromagnetic field on macrosegregation of continuous casting 7075 alloy

    Institute of Scientific and Technical Information of China (English)

    张北江; 崔建忠; 路贵民; 张勤; 班春燕

    2003-01-01

    The effect of electromagnetic field on macrosegregation of continuous casting aluminum alloy was stud-ied. 7075 aluminum alloy ingot with diameter of 200 mm was produced by electromagnetic casting. Magnitude of coilcurrent was varied from 100 A to 600 A, and frequency from 10 Hz to 100 Hz. Variation of element content along theradius of ingot was examined by means of chemical analysis. The results show that electromagnetic casting processcan effectively reduce the macrosegregation, and electromagnetic frequency has a great influence on element distribu-tion along the radius of ingot. When frequency is 30 Hz, macrosegregation is eliminated completely.

  9. Casting of Titanium and its Alloys

    OpenAIRE

    R. L. Saha; K. T. Jacob

    1986-01-01

    Titaniuni and its alloys have many applications in aerospace, marine and other engineering industries. Titanium requires special melting techniques because of its high reactivity at elevated temperatures and needs special mould materials and methods for castings. This paper reviews the development of titanium casting technology.

  10. Casting of Titanium and its Alloys

    Directory of Open Access Journals (Sweden)

    R. L. Saha

    1986-04-01

    Full Text Available Titaniuni and its alloys have many applications in aerospace, marine and other engineering industries. Titanium requires special melting techniques because of its high reactivity at elevated temperatures and needs special mould materials and methods for castings. This paper reviews the development of titanium casting technology.

  11. 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.

  12. Alloying and Casting Furnace for Shape Memory Alloys Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The concept in the proposed project is to create a melting, alloying and casting furnace for the processing titanium based SMA using cold crucible techniques. The...

  13. 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.

  14. Rheo-diecasting Process for Semi-solid Aluminum Alloys

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A novel one-step semisolid processing technique, the rheo-diecasting (RDC) process, was developed, which adapts in situ creation of semisolid metal slurry with fine and spherical solid particles followed by direct shaping of the slurry into a near-net shape component using the existing cold chamber diecasting process. The RDC process was applied to process A356 and A380 aluminum alloys. The resulting microstructures and mechanical properties of RDC products under as-cast and various heat treatment conditions were analyzed. The experimental results show that the RDC samples have an extremely low porosity, a fine and uniform microstructure throughout entire casting, and consequently much improved strength and ductility in the as-cast condition. The strength of RDC A356 alloy can be substantially improved under T5 and T6 heat treatments without loss of ductility.

  15. Laser surface treatment of cast magnesium alloys

    Directory of Open Access Journals (Sweden)

    L.A. Dobrzański

    2009-02-01

    Full Text Available Purpose: The goal of this work was to investigate influence of laser treatment on structure and properties MCMgAl3Zn1, MCMgAl6Zn1, MCMgAl9Zn1 and MCMgAl12Zn1 cast magnesium alloys.Design/methodology/approach: Tests were made on the experimental MCMgAl3Zn1 MCMgAl6Zn1 MCMgAl9Zn1 and MCMgAl12Zn1 casting magnesium alloys. Laser treatment was made using the Rofin DL020 HPDL high power diode laser in the argon shield gas cover with the technique of the continuous powder supply to the remelted pool area.Findings: Investigations of the surface layers carried out confirm that laser treatment of the surface layer of the Mg-Al-Zn casting magnesium alloys is feasible using the HPDL high power diode laser ensuring better properties compared to alloys properties after the regular heat treatment after employing the relevant process parameters. Occurrences were found based on the metallographic examinations of the remelted zone (RZ and the heat affected zone (HAZ in alloyed surface layer of the investigated casting magnesium alloy.Research limitations/implications: This investigation presents different laser power and in this research was used two powders, namely tungsten-, and titanium carbide.Practical implications: Reinforcing the surface of cast magnesium alloys by adding TiC and WC particles is such a possible way to achieve the possibilities of the laser melt injection process, which is a potential technique to produce a Metal-Matrix Composite (MMC layer in the top layer of a metal workpiece.Originality/value: The originality of this work is applying of High Power Diode Laser for alloying of magnesium alloy using hard particles like tungsten- and titanium carbide.

  16. Structure analysis of Al cast alloy

    Directory of Open Access Journals (Sweden)

    L.A. Dobrzański

    2008-03-01

    Full Text Available Purpose: The developed design methodologies both the material and technological ones will make it possible to improve shortly the quality of materials from the light alloys in the technological process, and the automatic process flow correction will make the production cost reduction possible, and - first of all - to reduce the amount of the waste products.Design/methodology/approach: Castings were analysed in the paper of car engine blocks and heads from the Al-Si-Cu alloys of the AC-AlSi7Cu3Mg type fabricated with the “Cosworth” technological process. In this work the AC-AlSi7Cu3Mg alloy structure was investigated, of this alloy samples were cut of for structure analysis of the cylinder part as well of crankshaft of a fuel engine. The investigation show a difference in the (phase structure morphology as a result of cast cooling rate.Findings: On the quality of casting has influence the walls thickness of car engine elements’.Practical implications: In the metal casting industry, an improvement of component quality depends mainly on better control over the production parameters.Originality/value: The value of the applied methodology was to correct identify the casting effects that occurred during the casting process.

  17. ''Heat Transfer at the Mold-Metal Interface in Permanent Mold Casting of Aluminum Alloys'' Final Project Report

    Energy Technology Data Exchange (ETDEWEB)

    Professor R. D. Pehlke, Principal Investigator, Dr. John M. Cookson, Dr. Shouwei Hao, Dr. Prasad Krishna, Kevin T. Bilkey

    2001-12-14

    This project on heat transfer coefficients in metal permanent mold casting has been conducted in three areas. They are the theoretical study at the University of Michigan, the experimental investigation of squeeze casting at CMI-Tech Center (Now Hayes-Lemmerz Technical Center) and the experimental investigation of low pressure permanent mold casting at Amcast Automotive.

  18. 大型复杂铝合金汽车动力部件的压铸技术开发%Development of Aluminum Alloy Large Complicated Vehicle Power Parts by Die Casting

    Institute of Scientific and Technical Information of China (English)

    张百在; 陈亮; 万里; 黄志垣; 涂云松; 常移迁; 徐飞跃; 黄明军; 张孝水; 廖伟平

    2009-01-01

    Aiming at a die casting large complicated aluminum alloy power parts, some technological ways including improving flow types and optimizing vacuum exhausting structure are employed to significantly reduce the gas-entrapment defects in the parts on the basis of understanding flow and filling process of liquid aluminum alloy by numerical simulation and physical examination. Meanwhile, shrinkage porosity (hole) in the parts is eliminated by adopting movable insert, local pressurization and exact control for die temperature. Through above technological ways, both the appearance and quality of the parts can meet the designing requirements, realizing volumetric-production in a short time.%针对某大型复杂铝合金动力部件的压铸成形,应用数值模拟和物理模拟方法,在准确把握铝合金液体流动充型状态的基础上,提出了改善铝液流动形态,优化真空排气结构的技术措施,大大减少了铸件内部的卷气缺陷.同时还采用活块、局部加压、模温精确控制等技术手段消除了内部缩孔/缩松缺陷,使铸件外观及内部品质均达到了设计要求,在短期内即实现了批量生产.

  19. Analysis and Preventive Measures of Causes of Cracks of 5A06 Aluminum Alloy Casting Ingot%5A06 铝合金铸锭裂纹原因分析及预防措施

    Institute of Scientific and Technical Information of China (English)

    高新宇; 王海彬; 孙婧彧; 谭树栋

    2015-01-01

    The reasons of 5A06 aluminum alloy casting ingot crack were analyzed through optical mi-croscope, SEM and EA.Through analyses of the casting crack, cracks are intergranular fracture that is belonging to hot cracking, and many micro -cracks were found in the crack region, and these cracks is associated with second phase.The large intragranular dispersion gathered near the cracks. The cracks were found in the end of the ingot solidification.The causes of crack of the 5A06 were an-alyzed based on formation mechanism, and the solutions are proposed in the respect of casting process.%通过显微组织、扫描电镜观察及能谱分析等手段,分析了5 A06铝合金铸锭裂纹的产生原因. 通过组织分析,该裂纹为沿晶断裂,属于热裂纹,在主裂纹区域发现很多微裂纹,并且裂纹与第二相伴生,存在大量晶内弥散相聚集于裂纹附近,裂纹发生时间为铸锭凝固末端. 并从形成机理上对5A06铝合金铸锭裂纹的成因进行了分析,从铸造工艺等方面提出了解决措施.

  20. Overheating temperature of 7B04 high strength aluminum alloy

    Institute of Scientific and Technical Information of China (English)

    GAO Feng-hua; LI Nian-kui; TIAN Ni; SUN Qiang; LIU Xian-dong; ZHAO Gang

    2008-01-01

    The microstructure and overheating characteristics of the direct chill semicontinuous casting ingot of 7B04 high strength aluminum alloy, and those after industrial homogenization treatment and multi-stage homogenization treatments, were studied by differential scanning calorimetry(DSC), optical microscopy(OM) and scanning electron microscopy with energy dispersive X-ray spectroscopy(SEM-EDX). The results show that the microstructure of direct chill semicontinuous casting ingot of the 7B04 alloy contains a large number of constituents in the form of dendritic networks that consist of nonequilibrium eutectic and Fe-containing phases. The nonequilibrium eutectic contains Al, Zn, Mg and Cu, and the Fe-containing phases include two kinds of phases, one containing Al, Fe, Mn and Cu, and the other having Al, Fe, Mn, Cr, Si and Cu. The melting point of the nonequilibrium eutectic is 478 ℃ for the casting ingot of the 7B04 alloy which is usually considered as its overheating temperature. During industrial homogenization treatment processing at 470 ℃, the nonequilibrium eutectic dissolves into the matrix of this alloy partly, and the remainder transforms into Al2CuMg phase that cannot be dissolved into the matrix at that temperature completely. The melting point of the Al2CuMg phase which can dissolve into the matrix completely by slow heating is about 490 ℃. The overheating temperature of this high strength aluminum alloy can rise to 500-520 ℃. By means of special multi-stage homogenization, the temperature of the homogenization treatment of the ingot of the 7B04 high strength aluminum alloy can reach 500 ℃ without overheating.

  1. Numerical determination of heat distribution and castability simulations of as cast Mg-Al alloys

    Energy Technology Data Exchange (ETDEWEB)

    Khan, Shehzad Saleem; Hort, Norbert [Institute for Materials Research, GKSS Forschungszentrum GmbH, Geesthacht (Germany); Eiken, Janin; Steinbach, Ingo [RWTH Aachen, ACCESS e.V., Aachen (Germany); Schmauder, Siegfried [Institut fuer Materialpruefung, Werkstoffkunde und Festigkeitslehre (IMWF), University Stuttgart (Germany)

    2009-03-15

    Magnesium alloys offer a large potential as lightweight structures especially in the automotive industry. Research and development of magnesium alloys depend largely on the metallurgist's understanding and ability to control the microstructure of the as cast part. This research work comprises the determination of experimental parameters to simulate fluidity and microstructure of magnesium/aluminum binary alloys. (Abstract Copyright [2009], Wiley Periodicals, Inc.)

  2. Energy-Saving Melting and Revert Reduction Technology (E-SMARRT): Development of Elevated Temperature Aluminum Metal Matrix Composite (MMC) Alloy and Its Processing Technology

    Energy Technology Data Exchange (ETDEWEB)

    Weiss, David C. [Eck Industreis, Inc.; Gegal, Gerald A.

    2014-04-15

    The objective of this project was to provide a production capable cast aluminum metal matrix composite (MMC) alloy with an operating temperature capability of 250-300°C. Important industrial sectors as well as the military now seek lightweight aluminum alloy castings that can operate in temperature ranges of 250-300°C. Current needs in this temperature range are being satisfied by the use of titanium alloy castings. These have the desired strength properties but the end components are heavier and significantly more costly. Also, the energy requirements for production of titanium alloy castings are significantly higher than those required for production of aluminum alloys and aluminum alloy castings.

  3. 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

  4. Analysis of influence of chemical composition of Al-Si-Cu casting alloy on formation of casting defects

    Directory of Open Access Journals (Sweden)

    R. Maniara

    2007-04-01

    Full Text Available Purpose: A methodology of the computer-aided determining relationship between chemical composition of aluminum alloy and castings quality was presented in the paper.Design/methodology/approach: To resolve the problem artificial neural networks were used. Classification problems were evaluated by the consideration mainly the values of mistakes and correct answers of networks for test data. On the basis of data analyzed by the neural network, which has the best quality classification of chemical composition of tested material, the concentration of alloying elements range, which have an effect on formation casting defects, were developed to eliminate them in the future.Findings: Combining of all methods making use of chemical composition of aluminium alloy and neural networks will make it possible to achieve a better casting quality.Research limitations/implications: The presented issues may be use, among others, for manufacturers of car subassemblies from light alloys, where meeting the stringent quality requirements ensures the demanded service life of the manufactured products.Originality/value: The correctly specified number of chemical composition of aluminum alloy enables such technological process control where the number of castings defects can be reduced by means of the proper correction of the process.

  5. Materials data handbook: Aluminum alloy 2219

    Science.gov (United States)

    Muraca, R. F.; Whittick, J. S.

    1972-01-01

    A summary of the materials property information for aluminum 2219 alloy is presented. The scope of the information includes physical and mechanical properties at cryogenic, ambient, and elevated temperatures. Information on material procurement, metallurgy of the alloy, corrosion, environmental effects, fabrication, and joining techniques is developed.

  6. Friction Stir Welding of Aluminum Alloys

    Institute of Scientific and Technical Information of China (English)

    FU Zhi-hong; HE Di-qiu; WANG Hong

    2004-01-01

    Friction stir welding(FSW), a new solid-state welding technology invited in the early 1990s,enables us weld aluminum alloys and titanium alloys etc. The processing of FSW, the microstructure in FSW alloysand the factors influencing weld quality are introduced. The complex factors affecting the properties are researched.

  7. Standard Specification for Copper-Aluminum-Silicon-Cobalt Alloy, Copper-Nickel-Silicon-Magnesium Alloy, Copper-Nickel-Silicon Alloy, Copper-Nickel-Aluminum-Magnesium Alloy, and Copper-Nickel-Tin Alloy Sheet and Strip

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2015-01-01

    Standard Specification for Copper-Aluminum-Silicon-Cobalt Alloy, Copper-Nickel-Silicon-Magnesium Alloy, Copper-Nickel-Silicon Alloy, Copper-Nickel-Aluminum-Magnesium Alloy, and Copper-Nickel-Tin Alloy Sheet and Strip

  8. 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.

  9. Interface properties and phase formation between surface coated SKD61 and aluminum alloys

    Institute of Scientific and Technical Information of China (English)

    Se-Weon CHOI; Young-Chan KIM; Se-Hun CHANG; Ik-Hyun OH; Joon-Sik PARK; Chang-Seog KANG

    2009-01-01

    The intermediate phase formation and surface protection effects between SKD61 die mold alloys and aluminum alloys were investigated during a simulated die-casting process. The surface coatings of SKD61 alloy were carried out via Si pack cementation coatings at 900 ℃ for 10 h and the e-FeSi phase formed. When the coated SKD61 alloy was dipped in the liquid aluminum alloy (ALDC12), the surface coated SKD61 alloys showed better surface properties compared with uncoated SKD61 alloys, i.e., the intermediate phases (FeSiAl compound) were not produced for the coated SKD61 alloy. The coating layer of e-FeSi served as a diffusion barrier for the formation of FeSiAl compounds.

  10. 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.

  11. Composite purification technology and mechanism of recycled aluminum alloys

    Institute of Scientific and Technical Information of China (English)

    房文斌; 耿耀宏; 安阁英; 叶荣茂

    2002-01-01

    Iron-rich inclusions in aluminum alloys can be effectively removed by composite purification of sedimentation and filtration technology.The results show that the purposed method has no negative effects on aluminum alloys and obviously improve their mechanical properties.

  12. Casting Forming Process Simulation of Aluminum Flywheel

    Directory of Open Access Journals (Sweden)

    QIAO Yin-hu

    2013-04-01

    Full Text Available Simulating the forming process of casting in this paper, according to two kinds of analysis results of the designed model, the reasonable structure, pouring temperature and riser selecting of the flywheel are determined to ensure the quality of castings. The using of simulation software before the actual molding can get rid of the possible hidden danger, to shorten the product development cycle, save money, improve product quality.

  13. New Approaches to Aluminum Integral Foam Production with Casting Methods

    Directory of Open Access Journals (Sweden)

    Ahmet Güner

    2015-08-01

    Full Text Available Integral foam has been used in the production of polymer materials for a long time. Metal integral foam casting systems are obtained by transferring and adapting polymer injection technology. Metal integral foam produced by casting has a solid skin at the surface and a foam core. Producing near-net shape reduces production expenses. Insurance companies nowadays want the automotive industry to use metallic foam parts because of their higher impact energy absorption properties. In this paper, manufacturing processes of aluminum integral foam with casting methods will be discussed.

  14. Microstructural evolution and mechanical properties of as-cast and T6-treated AA2195 DC cast alloy

    Energy Technology Data Exchange (ETDEWEB)

    Hekmat-Ardakan, A. [Universite de Sherbrook, Sherbrook, QC, Canada J1K 2R1 (Canada); Elgallad, E.M. [Universite du Quebec a Chicoutimi, Chicoutimi, QC, Canada G7H 2B1 (Canada); Ajersch, F. [Ecole Polytechnique de Montreal, Montreal, QC, Canada H3T 1J4 (Canada); Chen, X.-G., E-mail: xgrant_chen@uqac.ca [Universite du Quebec a Chicoutimi, Chicoutimi, QC, Canada G7H 2B1 (Canada)

    2012-12-15

    The use of direct chill (DC) cast ingot plates of AA2195 alloys has been recently extended for large mold applications in the plastics and automotive industries. The microstructural evolution of the as-cast AA2195 alloy was investigated using the Factsage thermodynamic software under both equilibrium and non-equilibrium conditions, and was compared with the results from differential scanning calorimetry (DSC) analysis and microstructural observations. The as-cast microstructure exhibited the presence of Al{sub 2}CuMg, Al{sub 2}Cu and Al{sub 2}CuLi intermetallic phases formed at the aluminum dendrite boundaries, which can be completely dissolved in the {alpha}-Al matrix during the solution treatment. A significant improvement in the mechanical properties of the AA2195 cast alloy after the T6 heat treatment is attributed to the formation of nano-scale {theta} Prime (Al{sub 2}Cu) and T1 (Al{sub 2}CuLi) precipitates. However, the non-uniform distribution of T1 precipitates together with the large size and low density indicate that the role of {theta} Prime precipitates in strengthening the AA2195 cast alloy is more dominant than that of the T1 precipitates, in contrast with the strengthening mechanism of the pre-deformed AA2195-T8 rolled products.

  15. Effect of Cold Rolling on the Recrystallization Texture of Continuous Cast AA 5005 Aluminum Alloy%冷轧变形对连铸连轧5005铝合金再结晶织构的影响

    Institute of Scientific and Technical Information of China (English)

    李敬; 孙秀伟; 刘文昌

    2012-01-01

    采用X射线衍射仪研究了冷轧变形对连铸连轧5005铝合金再结晶织构的影响。结果表明:5005铝合金热轧带材具有强的B纤维轧制织构,随着冷轧变形量的增加,口纤维轧制织构的强度增大。经399℃保温3h再结晶退火处理后,5005铝合金热轧带材获得强的cube织构和弱的R织构,随着变形量的增加,cube织构强度降低,而R织构强度增加,当冷轧变形量达到93.1%时,再结晶织构由强的R织构组分及弱的cube和P织构组分构成。%The effect of cold rolling on the recrystallization texture of the hot band of continuous cast AA 5005 aluminum alloy is investigated by X-ray diffraction. The results show that the hot band possesses a strong fiber rolling texture. The strength of the fiber rolling texture increases with increasing roiling reduction. After annealing at 3990C for 3h, the recrystallization texture of AA 5005 hot band is characterized by a major cube component and a minor R component. The in- tensity of the cube orientation decreases with increasing rolling reduction,whereas the intensity of the R orientation increases. When the reduction reaches 93.1% ,the recrystallization texture con- sists of strong R component and weak cube and P components.

  16. Preferential dissolution behaviour in Ni–Cr dental cast alloy

    Indian Academy of Sciences (India)

    Viswanathan S Saji; Han Cheol Choe

    2010-08-01

    A Ni–Cr–Mo dental alloy was fabricated by three different casting methods, viz. centrifugal casting, high frequency induction casting and vacuum pressure casting. The dependence of cast microstructure on the electrochemical corrosion behaviour was investigated using potentiodynamic cyclic and potentiostatic polarization techniques, impedance spectroscopy and scanning electron microscopy. The experimental results were compared and discussed with those obtained for a Co–Cr–Mo counterpart. The results of the study showed that the variation in casting morphologies with casting methods has only marginal influence in the overall corrosion resistance of Ni–Cr and Co–Cr dental alloys. There was severe preferential dissolution of Ni rich, Cr and Mo depleted zones from the Ni–Cr–Mo alloy. The overall corrosion resistance property of the Co–Cr base alloy was better than that of the Ni–Cr base alloy.

  17. Effect of Substrate Movement Speed by Synchronous Rolling-casting Freeform Manufacturing for Metal on Microstructure and Mechanical Property of ZLl04 Aluminum Alloy Slurry

    Institute of Scientific and Technical Information of China (English)

    LUO Xiaoqiang; LI Zhengyang; CHEN Guangnan; XU Wanli; YAN Qingzhi

    2015-01-01

    Synchronous rolling-casting freeform manufacturing for Metal (SRCFMM) means that the refined liquid metal is continuously pressed out from the bottom of crucible. There is a horizontal movable plate beneath the outlet. The clearance between the outlet and the plate is about several hundred micrometers. SRCFMM, similar to additive manufacturing, implies layer by layer shaping and consolidation of feedstock to arbitrary conifgurations, normally using a computer controlled movable plate. The primary dendritic crystal is easily crushed by movement of substrate in the rolling-casting area. ZL104 was used as the test materials, determi-ning the control temperature by differential scanning thermal analysis (DSC), preparing a kind of samples by SR CFMM, then analyzing microstructures and mechanical property of the samples. Characteristics and distribution of the primary particles were assessed by optical microscopy (OM), scanning electron microscopy (SEM), energy dispersive spectrum (EDS) and image analysis software. Mechanical property of the samples was assessed by vickers hardness. The results show that the samples fabricated by SRCFMM have uniform structures and good performances with the velocity of the substrate controlled about 10 cm/s and temperature at about 580℃.

  18. Electrochemical characterization of cast titanium alloys.

    Science.gov (United States)

    Cai, Zhuo; Shafer, Ty; Watanabe, Ikuya; Nunn, Martha E; Okabe, Toru

    2003-01-01

    A reaction layer forms on cast titanium alloy surfaces due to the reaction of the molten metal with the investment. This surface layer may affect the corrosion of the alloy in the oral environment. The objective of this study was to characterize the in vitro corrosion behavior of cast titanium alloys. ASTM Grade 2 CP titanium, Ti-6Al-4V, Ti-6Al-7Nb and Ti-13Nb-13Zr alloys were cast into a MgO-based investment. Experiments were performed on castings (N=4) with three surface conditions: (A) as-cast surface after sandblasting, (B) polished surface after removal of the reaction layer, and (C) sandblasted surface after removal of the reaction layer. Open-circuit potential (OCP) measurement, linear polarization, and potentiodynamic cathodic polarization were performed in aerated (air+10% CO(2)) modified Tani-Zucchi synthetic saliva at 37 degrees C. Potentiodynamic anodic polarization was subsequently conducted in the same medium deaerated with N(2)+10% CO(2) gas 2 h before and during the experiment. Polarization resistance (R(P)) and corrosion rate (I(CORR)) were calculated. Numerical results were subjected to nonparametric statistical analysis at alpha=0.05. The OCP stabilized for all the specimens after 6 x 10(4)s. Apparent differences in anodic polarization were observed among the different surfaces for all the metals. A passivation region followed by breakdown and repassivation were seen on specimens with surfaces A and C. An extensive passive region was observed on all the metals with surface B. The Kruskal-Wallis test showed no significant differences in OCP, R(p), I(CORR) or break down potential for each of the three surfaces among all the metals. The Mann-Whitney test showed significantly lower R(P) and higher I(CORR) values for surface C compared to the other surfaces. Results indicate that the surface condition has more effect on corrosion of these alloys than the surface reaction layer. Within the oxidation potential range of the oral cavity, all the metal

  19. 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.

  20. Grain Refinement of Permanent Mold Cast Copper Base Alloys

    Energy Technology Data Exchange (ETDEWEB)

    M.Sadayappan; J.P.Thomson; M.Elboujdaini; G.Ping Gu; M. Sahoo

    2005-04-01

    Grain refinement is a well established process for many cast and wrought alloys. The mechanical properties of various alloys could be enhanced by reducing the grain size. Refinement is also known to improve casting characteristics such as fluidity and hot tearing. Grain refinement of copper-base alloys is not widely used, especially in sand casting process. However, in permanent mold casting of copper alloys it is now common to use grain refinement to counteract the problem of severe hot tearing which also improves the pressure tightness of plumbing components. The mechanism of grain refinement in copper-base alloys is not well understood. The issues to be studied include the effect of minor alloy additions on the microstructure, their interaction with the grain refiner, effect of cooling rate, and loss of grain refinement (fading). In this investigation, efforts were made to explore and understand grain refinement of copper alloys, especially in permanent mold casting conditions.

  1. Filtration of aluminum alloys and its influence on mechanical properties and shape of eutectical silicium

    Directory of Open Access Journals (Sweden)

    M. Brůna

    2008-07-01

    Full Text Available Filtration during casting of high quality aluminum alloys belongs to main refining methods. Even when there are many years of experiences and experimental works on this subject, there are still some specific anomalies. While using ceramic filtration media during casting of aluminum alloys, almost in all experiments occurred increase of strength limit and atypical increase of extension. This anomaly was not explained with classical metallurgical methods, black-white contrast after surface etching neither with color surface etching. For that reason was used deep etching on REM. By using pressed ceramic filters, by studying morphology eutectical silicon was observed modification morphology of eutectical silicon, this explains increase extension after filtration. Pressed ceramic filters were used on experimental works. Casting was executed on hardenable alloy AlSi10MgMn.

  2. Susceptibility of Aluminum Alloys to Corrosion in Simulated Fuel Blends Containing Ethanol

    Energy Technology Data Exchange (ETDEWEB)

    Thomson, Jeffery K [ORNL; Pawel, Steven J [ORNL; Wilson, Dane F [ORNL

    2013-01-01

    The compatibility of aluminum and aluminum alloys with synthetic fuel blends comprised of ethanol and reference fuel C (a 50/50 mix of toluene and iso-octane) was examined as a function of water content and temperature. Commercially pure wrought aluminum and several cast aluminum alloys were observed to be similarly susceptible to substantial corrosion in dry (< 50 ppm water) ethanol. Corrosion rates of all the aluminum materials examined was accelerated by increased temperature and ethanol content in the fuel mixture, but inhibited by increased water content. Pretreatments designed to stabilize passive films on aluminum increased the incubation time for onset of corrosion, suggesting film stability is a significant factor in the mechanism of corrosion.

  3. Microstructural refinement of hyper-eutectic Al?Si?Fe?Mn cast alloys to produce a recyclable wrought material

    OpenAIRE

    Umezawa, Osamu; Nakamoto, Munefumi; Osawa, Yoshiaki; Suzuki, Kenta; Kumai, Shinji

    2005-01-01

    Although the cascade of material flow is presently suitable for the aluminum recycling, a better utilization of secondary alloys is required. In order to establish an upgradeable recycling design for developing wrought products from secondary aluminum alloys, a fine distribution of the primary phases in hyper-eutectic Al?Si?Fe?Mn cast materials has been achieved. Two novel processes were adopted. One was repeated thermomechanical treatment (RTMT), which involves a repetition of a multi-step c...

  4. Fabrication of a Zinc Aluminum Oxide Nanowire Array Photoelectrode for a Solar Cell Using a High Vacuum Die Casting Technique

    Directory of Open Access Journals (Sweden)

    Chin-Guo Kuo

    2014-01-01

    Full Text Available Zinc aluminum alloy nanowire was fabricated by the vacuum die casting. Zinc aluminum alloy was melted, injected into nanomold under a hydraulic pressure, and solidified as nanowire shape. Nanomold was prepared by etching aluminum sheet with a purity of 99.7 wt.% in oxalic acid solution. A nanochannel within nanomold had a pore diameter of 80 nm and a thickness of 40 μm. Microstructure and characteristic analysis of the alumina nanomold and zinc-aluminum nanowire were performed by scanning electron microscope, X-ray diffraction analysis, and energy dispersive X-ray spectroscopy. Zinc aluminum oxide nanowire array was produced using the thermal oxidation method and designed for the photoelectrode application.

  5. [The corrosion resistance of aluminum and aluminum-based alloys studied in artificial model media].

    Science.gov (United States)

    Zhakhangirov, A Zh; Doĭnikov, A I; Aboev, V G; Iankovskaia, T A; Karamnova, V S; Sharipov, S M

    1991-01-01

    Samples of aluminum and its alloys, designed for orthodontic employment, were exposed to 4 media simulating the properties of biologic media. The corrosion resistance of the tested alloys was assessed from the degree of aluminum migration to simulation media solutions, which was measured by the neutron activation technique. Aluminum alloy with magnesium and titanium has shown the best corrosion resistance. PMID:1799002

  6. A High-Fe Aluminum Matrix Welding Filler Metal for Hardfacing Aluminum-Silicon Alloys

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    A high-Fe containing aluminum matrix filler metal for hardfacing aluminum-silicon alloys has been developed by using iron,nickel,and silicon as the major strengthening elements,and by measuring mechanical properties,room temperature and high temperature wear tests,and microstructural analysis.The filler metal,which contains 3.0%-5.0% Fe and 11.0%-13.0% Si,exhibits an excellent weldability.The as-cast and as-welded microstructures for the filler metal are of uniformly distribution and its dispersed network of hard phase is enriched with Al-Si-Fe-Ni.The filler metal shows high mechanical properties and wear resistance at both room temperature and high temperatures.The deposited metal has a better resistance to impact wear at 220℃ than that of substrate Al-Si-Mg-Cu piston alloy;at room temperature,the deposited metal has an equivalent resistance to slide wear with lubrication as that of a hyper-eutectic aluminum-silicon alloy with 27% Si and 1% Ni.

  7. Corrosion of aluminum alloys as a function of alloy composition

    International Nuclear Information System (INIS)

    A study was initiated which included nineteen aluminum alloys. Tests were conducted in high purity water at 3600C and flow tests (approx. 20 ft/sec) in reactor process water at 1300C (TF-18 loop tests). High-silicon alloys and AlSi failed completely in the 3600C tests. However, coupling of AlSi to 8001 aluminum suppressed the failure. The alloy compositions containing iron and nickel survived tht 3600C autoclave exposures. Corrosion rates varied widely as a function of alloy composition, but in directions which were predictable from previous high-temperature autoclave experience. In the TF-18 loop flow tests, corrosion penetrations were similar on all of the alloys and on high-purity aluminum after 105 days. However, certain alloys established relatively low linear corrosion rates: Al-0.9 Ni-0.5 Fe-0.1 Zr, Al-1.0 Ni-0.15 Fe-11.5 Si-0.8 Mg, Al-1.2 Ni-1.8 Fe, and Al-7.0 Ni-4.8 Fe. Electrical polarity measurements between AlSi and 8001 alloys in reactor process water at temperatures up to 1500C indicated that AlSi was anodic to 8001 in the static autoclave system above approx. 500C

  8. Size Effect on Magnesium Alloy Castings

    Science.gov (United States)

    Li, Zhenming; Wang, Qigui; Luo, Alan A.; Zhang, Peng; Peng, Liming

    2016-06-01

    The effect of grain size on tensile and fatigue properties has been investigated in cast Mg alloys of Mg-2.98Nd-0.19Zn (1530 μm) and Mg-2.99Nd-0.2Zn-0.51Zr (41 μm). The difference between RB and push-pull fatigue testing was also evaluated in both alloys. The NZ30K05-T6 alloy shows much better tensile strengths (increased by 246 pct in YS and 159 pct in UTS) and fatigue strength (improved by ~80 pct) in comparison with NZ30-T6 alloy. RB fatigue testing results in higher fatigue strength compared with push-pull fatigue testing, mainly due to the stress/strain gradient in the RB specimen cross section. The material with coarse grains could be hardened more in the cyclic loading condition than in the monotonic loading condition, corresponding to the lower σ f and the higher σ f/ σ b or σ f/ σ 0.2 ratio compared to the materials with fine grains. The fatigue crack initiation sites and failure mechanism are mainly determined by the applied stress/strain amplitude. In LCF, fatigue failure mainly originates from the PSBs within the surface or subsurface grains of the samples. In HCF, cyclic deformation and damage irreversibly caused by environment-assisted cyclic slip is the crucial factor to influence the fatigue crack. The Coffin-Manson law and Basquin equation, and the developed MSF models and fatigue strength models can be used to predict fatigue lives and fatigue strengths of cast magnesium alloys.

  9. Newly developed vacuum differential pressure casting of thin-walled complicated Al-alloy castings

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    The newly designed vacuum differential pressure casting (VDPC) unit was introduced, by which the capability of the VDPC process to produce thin-walled complicated Al-alloy castings, that are free from oxides, gas pore and shrinkage cavity and thus enhance overall part quality, was studied. Experimental results were compared with those of traditional gravity pouring and vacuum suction casting. The first series of experiments were focused on investigating the castability of thin section Al-alloy casting. In the second series of experiments the metallographic evidence, casting strength and soundness were examined. Finally, case studies of very interesting thin walled complicated casting applications were described. The advantages of the described technique have made possible to produce thin walled complicated Al-alloy casting (up to a section thickness of 1 mm), which is not practical for gravity pouring and vacuum suction casting.

  10. Calculation of Liquidus Temperature for Aluminum and Magnesium Alloys Applying Method of Equivalency

    OpenAIRE

    Mile B. Djurdjević; Srećko Manasijević; Zoran Odanović; Natalija Dolić

    2013-01-01

    The purpose of this paper is to develop a mathematical equation, which will be able to accurately predict the liquidus temperature of various aluminum and magnesium cast alloys on the basis of their known chemical compositions. An accurate knowledge of liquidus temperature permits a researcher to predict a variety of physical parameters pertaining to a given alloy. The analytical expressions presented in this paper are based on the “method of equivalency.” According to this concept, the influ...

  11. The influence of casting temperature on castability and structure of AJ62 alloy

    Directory of Open Access Journals (Sweden)

    A. Kiełbus

    2007-06-01

    Full Text Available Purpose: The AJ62 magnesium alloy exhibit good elevated-temperature tensile properties, excellent creep resistance and good castability. This alloy contains approximately 6% aluminum and about 2.5% strontium. Typically, it is used in automotive industry for the engine crankcase and power-train components. The aim of this paper is to present the results of the influence of pouring temperature on the fluidity and microstructure of the AJ62 magnesium alloy.Design/methodology/approach: The study was conducted on AJ62 magnesium alloys. Sand casting was performed at 695-755°C temperatures. The spiral test of fluidity was used. The microstructure was characterized by optical microscopy (Olympus GX-70 and a scanning electron microscopy (Hitachi S3400 equipped with an X-radiation detector EDS (VOYAGER of NORAN INSTRUMENTS. The phase identification of these alloys was identified by X-ray diffraction (JDX-75. Quantitative examination was conducted using the “MET-ILO” automatic image analysis programme.Findings: In as cast condition AJ62 alloy consisted of α-Mg grains with some types of intermetallic phases: (Al,Mg4Sr , Al8Mn5 and Al3Mg13Sr. The flow length and the intermetallicphases area fraction increase with increase the pouring temperature.Research limitations/implications: Future researches should contain investigations of the influence of casting temperature and heat treatment parameters on mechanical properties of AJ62 magnesium alloy.Practical implications: The established casting parameters (mainly temperature can be useful for preparing sand and die casting technology of the AJ62 magnesium alloy.Originality/value: The relationship between the initial structure, casting temperature, castability and phase composition in AJ62 magnesium alloy was specified.

  12. Galvanic aspects of aluminum sacrificial anode alloys in seawater.

    OpenAIRE

    Cummings, Jon Richard

    2012-01-01

    Galvanic aspects of aluminum sacrificial anode alloys in artificial seawater were investigated. Specifically, two mercury-bearing alloys and one tin-bearing alloy were studied. The polarization behavior of the aluminum sacrificial anode alloys coupled to HY-80 steel is discussed. Current versus time curves were obtained for aluminum/steel galvanic couples immersed in artificial seawater for specific intervals. Scanning elecron microscopy was used to characterize the anode dissolution patt...

  13. Microstructure modification by La2O3 and its effect on wear resistance properties of as-cast ZL107 alloy

    Institute of Scientific and Technical Information of China (English)

    WAN Diqing

    2010-01-01

    Modification of ZL107 aluminum alloy has been successfully achieved by using La2O3. The different casting parameters, including casting temperature as well as holding time and modifier content, were carried out to investigate the modification effects. The results show that the best modifier content is 1.0 wt.%, and the casting temperature has little effect. In addition, the wear behavior of modified and unmodified ZL107 has been compared. The wear resistance of as-cast ZL107 aluminum alloy can be significantly improved after modification.

  14. Electric pulse treatment of welded joint of aluminum alloy

    Directory of Open Access Journals (Sweden)

    A.A. Mitiaev

    2013-08-01

    Full Text Available Purpose. Explanation of the redistribution effect of residual strengthes after electric pulse treatment of ark welding seam of the aluminum alloy. Methodology. Alloy on the basis of aluminium of АК8М3 type served as the research material. As a result of mechanical treatment of the ingots after alloy crystallization the plates with 10 mm thickness were obtained. After edge preparation the elements, which are being connected were butt welded using the technology of semiautomatic argon arc welding by the electrode with a diameter of 3 mm of AK-5 alloy. Metal structure of the welded joint was examined under the light microscope at a magnification of 200 and under the scanning electronic microscope «JSM-6360 LA». The Rockwell hardness (HRF was used as a strength characteristic of alloy. Hardness measuring of the phase constituents (microhardness was carried out using the device PМТ-3, with the indenter loadings 5 and 10 g. The crystalline structure parameters of alloy (dislocation density, second kind of the crystalline grid distortion and the scale of coherent scattering regions were determined using the methods of X-ray structural analysis. Electric pulse treatment (ET was carried out on the special equipment in the conditions of the DS enterprise using two modes A and В. Findings. On the basis of researches the previously obtained microhardness redistribution effect in the area of welded connection after ET was confirmed. As a result of use of the indicated treatment it was determined not only the reduction of microhardness gradient but also the simultaneous hardening effect in the certain thermal affected areas near the welding seam. During study of chemical composition of phase constituents it was discovered, that the structural changes of alloy as a result of ET first of all are caused by the redistribution of chemical elements, which form the connections themselves. By the nature of the influence the indicated treatment can be

  15. Modeling Mechanical Properties of Aluminum Composite Produced Using Stir Casting Method

    Directory of Open Access Journals (Sweden)

    Muhammad Hayat Jokhio

    2011-01-01

    Full Text Available ANN (Artificial Neural Networks modeling methodology was adopted for predicting mechanical properties of aluminum cast composite materials. For this purpose aluminum alloy were developed using conventional foundry method. The composite materials have complex nature which posses the nonlinear relationship among heat treatment, processing parameters, and composition and affects their mechanical properties. These nonlinear relation ships with properties can more efficiently be modeled by ANNs. Neural networks modeling needs sufficient data base consisting of mechanical properties, chemical composition and processing parameters. Such data base is not available for modeling. Therefore, a large range of experimental work was carried out for the development of aluminum composite materials. Alloys containing Cu, Mg and Zn as matrix were reinforced with 1- 15% Al2O3 particles using stir casting method. Alloys composites were cast in a metal mold. More than eighty standard samples were prepared for tensile tests. Sixty samples were given solution treatments at 580oC for half an hour and tempered at 120oC for 24 hours. The samples were characterized to investigate mechanical properties using Scanning Electron Microscope, X-Ray Spectrometer, Optical Metallurgical Microscope, Vickers Hardness, Universal Testing Machine and Abrasive Wear Testing Machine. A MLP (Multilayer Perceptron feedforward was developed and used for modeling purpose. Training, testing and validation of the model were carried out using back propagation learning algorithm. The modeling results show that an architecture of 14 inputs with 9 hidden neurons and 4 outputs which includes the tensile strength, elongation, hardness and abrasive wear resistance gives reasonably accurate results with an error within the range of 2-7 % in training, testing and validation.

  16. Twin-roll strip casting of magnesium alloys in China

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The development status of twin-roll strip casting for magnesium alloys in China was summarized as well as the new progress when several kinds of twin-roll strip casting technologies were developed and used.Horizontal twin-roll casting (HTRC) of magnesium alloys has attracted much attention and has been industrialized in China.Vertical twin roll casting(VTRC) of the magnesium alloys can reach a speed of higher than 30 m/min and its research and development are just beginning and exhibit exciting potential.By comparing the process characteristics of the two technologies,the process stability of HTRC for the magnesium alloys is better,and the casting speed and the cooling rate of VTRC for the magnesium alloys are higher.The quality of the products by the two technologies needs to be improved and further investigated.

  17. Mg-Al Alloys Manufactured by Casting and Hot Working Process

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Mechanical properties of Mg-Al based alloys at different fabrication state, namely as-cast, hot rolled, and annealed, were investigated to develop the alloys that are suitable for the casting/hot working process. Experimental results indicated that the castability such as hot cracking resistance tends to improve with increasing the aluminum content. However, the elongation at elevated temperatures was observed to decrease as the Al content increases, implying difficulties in hot forming. A small amount of Zr additions could significantly enhance the room temperature mechanical properties of hot-rolled Mg-6%Al-1%Zn alloy. The tendency of remarkable grain coarsening at high temperatures was effectively reduced by the Zr additions. TEM analyses suggested that very fine Al3Zr precipitates formed in the Zr-added alloy are responsible for the obtained results.

  18. 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.

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

    Institute of Scientific and Technical Information of China (English)

    Mi Guofa; Liu Xiangyu; Wang Kuangfei; Fu Hengzhi

    2009-01-01

    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-filling and solidification 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.

  20. Development on research of advanced rare-earth aluminum alloy

    Institute of Scientific and Technical Information of China (English)

    聂祚仁; 金头男; 邹景霞; 付静波; 杨军军; 左铁镛

    2003-01-01

    The active mechanisms of rare earth element erbium ( Er ) in part of aluminum alloys were investigated. Based on the investigation of the effect of the unitary rare earth elements (Er, La, Y, Ce, Nd, Gd, and Sc) and the transition element zirconium on the aluminum alloys, it is concluded that, with Er alloyed, high purity aluminum and Al-Mg alloys are featured with refined grain structure, superior heat stability and even higher hardness or tensile strength with unchanged ductility; but Er is not beneficial to the mechanical property of Al-Cu alloy, so is Sc. It may also be concluded, to most of the aluminum alloys, Er can be an effective alloying element, like Sc; and for the lower price of Er, the cost of modifying aluminum alloys by Er will be reduced.

  1. Prediction of Hot Tear Formation in Vertical DC Casting of Aluminum Billets Using a Granular Approach

    Science.gov (United States)

    Sistaninia, M.; Drezet, J.-M.; Phillion, A. B.; Rappaz, M.

    2013-09-01

    A coupled hydromechanical granular model aimed at predicting hot tear formation and stress-strain behavior in metallic alloys during solidification is applied to the semicontinuous direct chill casting of aluminum alloy round billets. This granular model consists of four separate three-dimensional (3D) modules: (I) a solidification module that is used for generating the solid-liquid geometry at a given solid fraction, (II) a fluid flow module that is used to calculate the solidification shrinkage and deformation-induced pressure drop within the intergranular liquid, (III) a semisolid deformation module that is based on a combined finite element/discrete element method and simulates the rheological behavior of the granular structure, and (IV) a failure module that simulates crack initiation and propagation. To investigate hot tearing, the granular model has been applied to a representative volume within the direct chill cast billet that is located at the bottom of the liquid sump, and it reveals that semisolid deformations imposed on the mushy zone open the liquid channels due to localization of the deformation at grains boundaries. At a low casting speed, only individual pores are able to form in the widest channels because liquid feeding remains efficient. However, as the casting speed increases, the flow of liquid required to compensate for solidification shrinkage also increases and as a result the pores propagate and coalesce to form a centerline crack.

  2. Preparation of composite aluminum automobile radiator by inversion casting

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The inversion casting technics of producing three-ply Al-Mn/Al-Si composite strap used in automobile radiator was studied. The physical processes of inversion casting, including the flux-supporting reacting and volatilizing at high temperature, the melting and solidification when the elements of solid and liquid fresh alloys meet with each other, the mutual diffusion of elements in solid and liquid, the crystallization and forming of metallurgical combination and the following rolling process, were analyzed. At the same time, the composite mechanism of this technique was also discussed.

  3. Influence of melting and filtration processes on the structure and mechanical properties of aluminum alloys

    Directory of Open Access Journals (Sweden)

    M. Dudyk

    2008-10-01

    Full Text Available In the article are presented the results of the study on the applied upgrading processes such as refining, modification and filtration of thenear eutectics alloy EN AC- 44000, AlSi11, (AK11, cast into the chill. The upgrading processes applied to the said alloy caused, incomparison to the alloy which was not upgraded, significant differences in the shape of the crystallization curves, obtained in the graphicrecord of the ATD-AED method. It was demonstrated the existence of connections between the thermal and electric phenomena duringsolidification and crystallization of the studied silumin. The obtained results of the metallographic analysis showed the occurrence of theimpurities within the alloy structure in the form of porosity and oxides following the metallurgical processing (in pig sows. The primarystudies on microstructure of the cast ceramic filters have demonstrated the purposefulness of introduction of the filtration process to thetechnology of aluminum alloys manufacturing. The microstructures of the filters cast with the studied alloys illustrate the extent anddeployment of the impurities retained (in the filter during the process of samples casting for measurement of the mechanical strengthproperties. On the example of the near eutectics alloy AK11, it has been demonstrated, that in comparison to the refined alloy there isa possibility to obtain significant improvement of mechanical properties, and especially elongation A5 and impact strength KCV.

  4. 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.

  5. Cast bulk glassy alloys:fabrication,alloy development and properties

    Institute of Scientific and Technical Information of China (English)

    Qingsheng Zhang; Chunling Qin; Akihisa Inoue

    2010-01-01

    Metallic glasses represent an interesting group of materials as they possess outstanding physical, chemical and mechanical properties compared to their crystalline counterparts. Currently, with well designed compositions it is possible to cast liquid alloys into the glassy state at low critical cooling rates from 100 K·s-1 to 1 K·s-1 and in large critical sample sizes up to several centimeters, which significantly enhances the promise for possible applications as advanced engineering materials. This paper reviews the development of(ZrCu)-based bulk metallic glasses with large sizes by copper mold casting and their unique properties. Additionally, the ex-situ and in-situ second phases reinforced BMG composites with large plasticity are also presented.

  6. Torsional Stability of Aluminum Alloy Seamless Tubing

    Science.gov (United States)

    Moore, R L; Paul, D A

    1939-01-01

    Torsion tests were made on 51ST aluminum-alloy seamless tubes having diameter-to-thickness ratios of from 77 to 139 and length-to-diameter ratios of from 1 to 60. The torsional strengths developed in the tubes which failed elastically (all tubes having lengths greater than 2 to 6 times the diameter) were in most cases within 10 percent of the value indicated by the theories of Donnel, Timoshenko, and Sturm, assuming a condition of simply supported ends.

  7. Deuterium transport and trapping in aluminum alloys

    International Nuclear Information System (INIS)

    A simple model of diffusion and evolution of the density of deuterium in metals is presented. A model of the deuterium evolution in the presence of uniform and nonuniform distributions of traps, as well as perfectly reflecting and partially permeable boundary conditions is discussed. Computers are compared with experimental results describe deuterium distribution after fatigue crack growth of 2219 and 7075 aluminum alloys in a D2O water vapor environment and after ion implantation

  8. Aluminum alloy nanosecond vs femtosecond laser marking

    Indian Academy of Sciences (India)

    S Rusu; A Buzaianu; D G Galusca; L Ionel; D Ursescu

    2013-11-01

    Based on the lack of consistent literature publications that analyse the effects of laser marking for traceability on various materials, the present paper proposes a study of the influence of such radiation processing on an aluminum alloy, a vastly used material base within several industry fields. For the novelty impact, femtolaser marking has been carried out, besides the standard commercial nanosecond engraving. All the marks have been analysed using profilometry, overhead and cross-section SEM microscopy, respectively and EDAX measurements.

  9. Calculation of Liquidus Temperature for Aluminum and Magnesium Alloys Applying Method of Equivalency

    Directory of Open Access Journals (Sweden)

    Mile B. Djurdjević

    2013-01-01

    Full Text Available The purpose of this paper is to develop a mathematical equation, which will be able to accurately predict the liquidus temperature of various aluminum and magnesium cast alloys on the basis of their known chemical compositions. An accurate knowledge of liquidus temperature permits a researcher to predict a variety of physical parameters pertaining to a given alloy. The analytical expressions presented in this paper are based on the “method of equivalency.” According to this concept, the influence of any alloying element on the liquidus temperature of an aluminum and/or magnesium alloy can be translated into the equivalent influence of a reference element. Silicon as a reference element has been chosen for aluminum alloys and aluminum for magnesium alloys. The sum of the equivalent concentrations for other elements, when added to the influence of the actual reference element is used to calculate the liquidus temperature of the alloy. The calculated liquidus temperatures for wide ranges of alloy chemical compositions show a good correlation with corresponding measured liquidus temperatures.

  10. Microstructure of AE44 magnesium alloy before and after hot-chamber die casting

    Directory of Open Access Journals (Sweden)

    A. Kiełbus

    2007-01-01

    Full Text Available Purpose: AE44 magnesium alloy allows attractive high temperature mechanical properties, as well as diecastabilityand good corrosion resistance. It contains magnesium, aluminum, cerium and lanthanum. Typically,it is used in automotive industry for structural components working at elevated temperature (150÷175°C. Theaim of this paper is to present the results of investigations on the microstructure of the AE44 magnesium alloybefore and after hot chamber die casting.Design/methodology/approach: Die casting was carried out on 280 tone locking force hot-chamber die castingmachine. For the microstructure observation, a Olympus GX+70 metallographic microscope and a HITACHIS-3400N scanning electron microscope with a Thermo Noran EDS spectrometer equipped with SYSTEM SIXwere used.Findings: Based on the investigation carried out it was found that the AE44 magnesium alloy before diecasting is characterized by α-Mg solid solution with globular, lamellar and acicular precipitations of Al11RE3and Al3RE phases. Moreover, there was found globular Mn-rich phase existence (probably Al8CeMn4 phase.After hot-chamber die casting the microstructure of AE44 alloys consist of equiaxed dendrites of α-Mg withprecipitates of Al11RE3 and probably Al2RE phase.Research limitations/implications: Future researches should contain investigations of the influence of the hotchamber die casting process parameters on the microstructure and mechanical properties of AE44 magnesiumalloy.Practical implications: AE44 magnesium alloy can be cast with cold- and hot-chamber die casting machine.Results of investigation may be useful for preparing die casting technology of this alloy.Originality/value: The results of the researches make up a basis for the investigations of new magnesium alloyscontaining rare earth elements for hot chamber die casting designed to service in elevated temperature.

  11. Thermal coatings for titanium-aluminum alloys

    Science.gov (United States)

    Cunnington, George R.; Clark, Ronald K.; Robinson, John C.

    1993-01-01

    Titanium aluminides and titanium alloys are candidate materials for use in hot structure and heat-shield components of hypersonic vehicles because of their good strength-to-weight characteristics at elevated temperature. However, in order to utilize their maximum temperature capability, they must be coated to resist oxidation and to have a high total remittance. Also, surface catalysis for recombination of dissociated species in the aerodynamic boundary layer must be minimized. Very thin chemical vapor deposition (CVD) coatings are attractive candidates for this application because of durability and very light weight. To demonstrate this concept, coatings of boron-silicon and aluminum-boron-silicon compositions were applied to the titanium-aluminides alpha2 (Ti-14Al-21Nb), super-alpha2 (Ti-14Al-23-Nb-2V), and gamma (Ti-33Al-6Nb-1Ta) and to the titanium alloy beta-21S (Ti-15Mo-3Al-3Nb-0.2Si). Coated specimens of each alloy were subjected to a set of simulated hypersonic vehicle environmental tests to determine their properties of oxidation resistance, surface catalysis, radiative emittance, and thermal shock resistance. Surface catalysis results should be viewed as relative performance only of the several coating-alloy combinations tested under the specific environmental conditions of the LaRC Hypersonic Materials Environmental Test System (HYMETS) arc-plasma-heated hypersonic wind tunnel. Tests were also conducted to evaluate the hydrogen transport properties of the coatings and any effects of the coating processing itself on fatigue life of the base alloys. Results are presented for three types of coatings, which are as follows: (1) a single layer boron silicon coating, (2) a single layer aluminum-boron-silicon coating, and (3) a multilayer coating consisting of an aluminum-boron-silicon sublayer with a boron-silicon outer layer.

  12. The in-situ Ti alloying of aluminum alloys and its application in A356 alloys

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    This research has investigated the in-situ Ti alloying of aluminum alloys and its application to A356 alloys and wheels through the evaluation of microstructure and mechanical properties, The results showed that stable titanium content can be obtained by adding a small quantity of TiO2 into electrolyte of pure aluminum. Under this approach, a greater than 95% absorptivity of titanium was achieved, and the microstructure of the specimens was changed to fine equiaxed grains from coarse columnar grains in the pure aluminum. In comparison with the tradition A356 alloys and wheels, the corresponding microstructure in the testing A356 alloys and wheels was finer. Although the tensile strength was similar between the testing and the tradition A356 alloys and wheels, the ductility of the former (testing) is superior to that of the later (tradition), leading to an excellent combination of strength and ductility from the testing alloys and wheels.

  13. China’s Aluminum Alloy Cable Market has Taken Shape

    Institute of Scientific and Technical Information of China (English)

    2014-01-01

    <正>Aluminum alloy cable is a mature product and technology that has been used for nearly fifty years in the U.S.Through six years’promotion,it has been widely recognized and accepted in the China market since 2013,which laid the foundation for the development of the aluminum alloy cable market.Aluminum alloy cable is widely applied in the fields of civil construction and industrial and mining enterprises,especially in real estate,steel and metallurgy.

  14. The Technological Improvements of Aluminum Alloy Coloring by Electrolysis

    Institute of Scientific and Technical Information of China (English)

    LI Nai-jun

    2004-01-01

    The technological process of coloring golden-tawny on aluminum alloy by electrolysis was improved in this paper. The optimum composition of electrolyte was found, the conditions of deposition and anodic oxidation by electrolysis were studied. The oxidative membrane on aluminum alloy was satisfying, the colored aluminum alloy by electrolysis is uniformity,bright and beautiful, and the coloring by electrolysis is convenient and no pollution.

  15. Interplay among solidification, microstructure, residual strain and hot tearing in B206 aluminum alloy

    International Nuclear Information System (INIS)

    Hot tearing is a complex phenomenon attributed to alloy solidification, microstructure and stress/strain development within a casting. In this research, the conditions associated with the formation of hot tears in B206 aluminum alloy were investigated. Neutron diffraction strain mapping was carried out on three B206 castings with varying levels of titanium (i.e. unrefined, 0.02 and 0.05 wt%). Titanium additions effectively reduced grain size and transformed grain morphology from coarse dendrites to fine globular grains. Further, thermal analysis suggested that grain refinement delayed the onset of dendrite coherency in B206 and therefore enhanced the duration of bulk liquid metal feeding for the refined casting conditions. As a result, the interactive effects of such factors resulted in a more uniform distribution of strain, and subsequent higher resistance to hot tearing for the grain refined castings

  16. Interplay among solidification, microstructure, residual strain and hot tearing in B206 aluminum alloy

    Energy Technology Data Exchange (ETDEWEB)

    D’Elia, F., E-mail: f.delia10@gmail.com [Centre for Near-net-shape Processing of Materials, Ryerson University, 101 Gerrard St. East, Toronto, Ontario, Canada M5B 2K3 (Canada); Ravindran, C. [Centre for Near-net-shape Processing of Materials, Ryerson University, 101 Gerrard St. East, Toronto, Ontario, Canada M5B 2K3 (Canada); Sediako, D. [Canadian Neutron Beam Centre, Chalk River Laboratories, Chalk River, Ontario, Canada K0J 1J0 (Canada)

    2015-01-29

    Hot tearing is a complex phenomenon attributed to alloy solidification, microstructure and stress/strain development within a casting. In this research, the conditions associated with the formation of hot tears in B206 aluminum alloy were investigated. Neutron diffraction strain mapping was carried out on three B206 castings with varying levels of titanium (i.e. unrefined, 0.02 and 0.05 wt%). Titanium additions effectively reduced grain size and transformed grain morphology from coarse dendrites to fine globular grains. Further, thermal analysis suggested that grain refinement delayed the onset of dendrite coherency in B206 and therefore enhanced the duration of bulk liquid metal feeding for the refined casting conditions. As a result, the interactive effects of such factors resulted in a more uniform distribution of strain, and subsequent higher resistance to hot tearing for the grain refined castings.

  17. AI-Si-Cu-Mg(-Er)铸造铝合金的低周疲劳行为%Low-Cycle Fatigue Behavior of Cast AI-Si-Cu-Mg(-Er) Aluminum Alloy

    Institute of Scientific and Technical Information of China (English)

    车欣; 徐志军; 陈立佳; 徐海健; 李锋

    2011-01-01

    对金属型铸造Al-Si-Cu-Mg和Al-Si-Cu-Mg-Er铝合金进行了疲劳试验,并研究了其室温下的低周疲劳行为.试验结果表明:金属型铸造Al-Si-Cu-Mg和Al-Si-Cu-Mg-Er铝合金表现为循环应变硬化和循环稳定,主要取决于外加总应变的高低;稀土元素Er的加入可提高金属型铸造Al-Si-Cu-Mg合金的循环变形抗力和疲劳寿命;金属型铸造Al-Si-Cu-Mg合金的塑性应变、弹性应变与断裂时的载荷反向次数之间呈直线关系,Al-Si-Cu-Mg-Er合金的弹性应变与疲劳断裂时的载荷反向次数之间也呈直线关系,但其塑性应变与疲劳断裂时的载荷反向次数之间则呈双线性关系.%Through the strain-controlled fatigue experiments, the low-cycle fatigue behavior of permanent-mold cast Al-Si-Cu-Mg and Al-Si-Cu-Mg-Er alloys at room temperature was investigated.The experimental results show that the Al-Si-Cu-Mg and Al-Si-Cu-Mg-Er alloys exhibit the cyclic strain hardening and cyclic stability, mainly depending on the imposed total strain amplitude. For the permanent-mold cast Al-Si-Cu-Mg alloy, the addition of Er can effectively enhance both cyclic deformation resistance and fatigue life of the alloys. A single-slope linear relation between plastic strain amplitude, elastic strain amplitude and reversals to failure is observed for permanent-mold cast Al-Si-Cu-Mg alloy. However, a two-slope linear relation between plastic strain amplitude and reversals to failure is noted for the Al-Si-Cu-Mg-Er alloy, although the corresponding relation between elastic strain amplitude and reversals to failure is linear.

  18. Research progress of aluminum alloy automotive sheet and application technology

    Institute of Scientific and Technical Information of China (English)

    Ma Mingtu; You Jianghai; Lu Hongzhou; Wang Zhiwen

    2012-01-01

    Pretrcatment technology is deeply discussed to explain its importance in guaranteeing properties and form- ability of aluminum alloy automotive sheet. Some typical applications of aluminum alloy automotive sheet to automotive industry are listed. Based on the author's knowledge and recognition and research progress presently, the important re- search contents about aluminum alloy automotive sheet are emphasized. Reducing cost and price of sheet and going deeply into application research are the main work for expending the application of aluminum alloy automotive sheet in the automobile.

  19. The evaluation of dynamic cracking resistance of chosen casting alloys in the aspect of the impact bending test

    Directory of Open Access Journals (Sweden)

    J.Sadowski

    2008-10-01

    Full Text Available The increase of quality and durability of produced casting alloys can be evaluated on the base of material tests performed on a high level. One of such modern test methods are tests of the dynamic damage process of materials and the evaluation on the base of obtained courses F(f, F(t of parameters of dynamic cracking resistance KId, JId, performed with the usage of instrumented Charpy pendulums. In the paper there was presented the evaluation of dynamic cracking resistance parameters of casting alloys such as: AK12 aluminum alloy, L20G cast steel and spheroid cast iron. The methodology of the evaluation of that parameters was described and their change as well, for the AK12 alloy with the cold work different level, L20G cast steel cooled from different temperatures in the range +20oC -60oC, and for the spheroid cast iron in different stages of treatment i.e. raw state, after normalization, spheroid annealing and graphitizing annealing.Obtained parameters of dynamic cracking resistance KId, JId of tested casting alloys enabled to define the critical value of the ad defect that can be tolerated by tested castings in different work conditions with impact loadings.

  20. Microstructure and fluidity of sand cast ZRE1 alloy

    Directory of Open Access Journals (Sweden)

    T. Rzychoń

    2008-02-01

    Full Text Available Purpose: The automotive use of magnesium is currently restricted to low-temperature structural components. Rare earth additions such as Ce, Nd, La and Pr are known to improve the creep performance. The aim of the research was to determine the effect of pouring temperature on the as-cast microstructure of ZRE1 magnesium alloy.Design/methodology/approach: The study was conducted on Mg-3Zn-3RE-0.5Zr (ZRE1 alloy after cast in different conditions. The microstructure was characterized by optical microscopy (Olympus GX-70 and a scanning electron microscopy (Hitachi S3400 equipped with an X-radiation detector EDS (VOYAGER of NORAN INSTRUMENTS. The phase composition of these alloys was identified by X-ray diffraction (JDX-75. A program for image analysis Met-ilo was used for determination of area fraction of intermetallic phases.Findings: The microstructure of ZRE1 alloy consists of α-Mg solid solution with Mg12RE phase. Pouring temperature has an influence on the fluidity and microstructure.Research limitations/implications: The future research will contain creep tests and microstructural investigations of cast and die-cast alloys using TEM microscopy.Practical implications: Results of investigation may be useful for preparation of sand casting technology of the Mg-Zn-RE-Zr alloys.Originality/value: This paper includes the results of microstructural investigations and effects of pouring temperature on the fluidity of ZRE1 magnesium alloy for gravity casting technology.

  1. Solid-particle erosion behavior of cast alloys used in the mining industry

    Institute of Scientific and Technical Information of China (English)

    Hakan Atapek; Sinan Fidan

    2015-01-01

    The erosive-wear response of five commercial ferrous-based cast alloys used for crushing was examined in this study. The micro-structures of the alloys were modified to elucidate the effect of microstructural features on wear. Erosion tests were conducted using alumi-num oxide particles (90–125 µm) at 70 m/s and a normal impact angle (90°). The worn surfaces were characterized by scanning electron mi-croscopy and 3D non-contact laser profilometry. It is found that (i) a pearlitic structure exhibiting a greater plastic deformation than both bainitic and martensitic structures shows the greatest resistance to erosive wear at normal impact and (ii) the fracture characteristics of car-bide and graphite particles plays an important role in determining the erosion wear behavior of the cast alloy matrices.

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

    Institute of Scientific and Technical Information of China (English)

    Mi Guofa; Liu Yanlei; Zhao Hengtao; Fu Hengzhi

    2008-01-01

    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 filling and solidification 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 eriective feeding passage,the structure of casting was modified 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 Iocation of the die is a valid way to create suitable solidification sequence that is beneficial to the feeding.Using these methods.the shrinkage defect was completely eliminated at the critical location.

  3. Casting of microstructured shark skin surfaces and possible applications on aluminum casting parts

    Directory of Open Access Journals (Sweden)

    Todor Ivanov

    2011-02-01

    Full Text Available Within the project Functional Surfaces via Micro- and Nanoscaled Structures?which is part of the Cluster of Excellence 揑ntegrative Production Technology?established and financed by the German Research Foundation (DFG, an investment casting process to produce 3-dimensional functional surfaces down to a structural size of 1 μm on near-net-shape-casting parts has been developed. The common way to realize functional microstructures on metallic surfaces is to use laser ablation, electro discharge machining or micro milling. The handicap of these processes is their limited productivity. The approach of this project to raise the efficiency is to use the investment casting process to replicate microstructured surfaces by moulding from a laser-microstructured grand master pattern. The main research objective deals with the investigation of the single process steps of the investment casting process with regard to the moulding accuracy. Actual results concerning making of the wax pattern, suitability of ceramic mould and core materials for casting of an AlSi7Mg0.3 alloy as well as the knock-out behavior of the shells are presented. By using of the example of an intake manifold of a gasoline race car engine, a technical shark skin surface has been realized to reduce the drag of the intake air. The intake manifold consists of an air-restrictor with a defined inner diameter which is microstructured with technical shark skin riblets. For this reason the inner diameter cannot be drilled after casting and demands a very high accuracy of the casting part. A technology for the fabrication and demoulding of accurate microstructured castings are shown. Shrinkage factors of different moulding steps of the macroscopic casting part as well as the microscopic riblet structure have been examined as well.

  4. Numerical simulation of residual thermal stresses in AA7050 alloy during DC-casting using ALSIM5

    NARCIS (Netherlands)

    Lalpoor, M.; Eskin, D.G.; Katgerman, L.

    2010-01-01

    Non-homogenous cooling rates and solidification conditions during DC-casting of high strength aluminum alloys result in the formation and accumulation of residual thermal stresses with different signs and magnitudes in different locations of the billet. Rapid propagation of microcracks in the presen

  5. Non-metallic Inclusions in Continuously Cast Aluminum Killed Steels

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    In aluminum killed steels, the size, shape, quantity and formation of non-metallic inclusions in ladle steel (before and after RH vacuum treatment) and in tundish as well as in slabs were studied by EPMA (Electron Probe Microanalysis) and by analyzing the total oxygen. The results showed that in the slabs the total oxygen was quite low and the inclusions discovered were mainly small-sized angular alumina inclusions. This indicates that most inclusions have been removed by floating out during the continuous casting process. In addition, the countermeasures were discussed to decrease the alumina inclusions in the slabs further.

  6. THE FATIGUE CRACK PROPAGATION BEHAVIOR AND CRACK DEFLECTION OF A357 CASTING ALUMINUM ALLOYS%A357铸造铝合金疲劳裂纹扩展行为以及裂纹偏折

    Institute of Scientific and Technical Information of China (English)

    徐芳; 陈振中

    2011-01-01

    The fatigue crack propagation behavior of A357 casting aluminum alloys at stress ratios of 0.05 and 0.7 under T5 and T6 heat treatments were studied and crack propagation curves were modified by a crack deflection model. The research results show that the fatigue crack grows along the boundary of dendrite cells to cause a remarkable crack deflection. The fatigue crack propagation rate at r=0.05 is smaller than that at r=0.7 for both T5 and T6 heat treatments. The effect of heat treatment on the fatigue crack propagation rates cannot be seen. The fatigue crack propagation rates modified by the crack deflection model predict no change at r=0.7, while a remarkable increase of the fatigue crack propagation rates can be seen at r=0.05. It is more reasonable and accurate to use the effective stress intensity factors for Mode Ⅰand Ⅱ to describe the fatigue crack propagation rates when a crack deflection occurs.%该文研究了A357铸造铝合金在T5/T6两种热处理条件、应力比为0.05和0.7时的疲劳裂纹扩展行为,并用裂纹偏折模型对裂纹扩展速率曲线进行修正。研究结果表明,裂纹沿着树状晶边界扩展导致显著的裂纹偏折。在T5/T6两种热处理条件下,应力比r=0.05时的裂纹扩展速率均远小于应力比为0.7时的裂纹扩展速率,热处理方式对裂纹扩展速率没有影响。应力比r=0.7时,偏折裂纹模型修正后的裂纹扩展速率没有明显变化;而应力比r=0.05时,偏折裂纹模型修正后的裂纹扩展速率较修正前有显著增加。裂纹发生偏折时,采用同时考虑Ⅰ型和Ⅱ型裂纹的裂纹尖端有效应力强度因子描述裂纹扩展速率更合理也更准确。

  7. Laser perforation of aluminum alloy sheet

    Science.gov (United States)

    Migliore, Leonard; Nazary, George

    2010-02-01

    Recent advances in the design of gain modules for diode-pumped solid-state lasers have allowed the manufacture of high-powered Q-switched products. The high available pulse energy and good mode quality enable highly efficient harmonic conversion, enabling the generation of several hundred watts of average power at a wavelength of 532nm. Among the applications for which this class of product may be suited is the rapid drilling of small-diameter holes in aluminum sheet. To investigate this application, plates of several aluminum alloys were drilled under a variety of conditions. The drilled plates were sectioned and subjected to analysis by optical metallography. The initial results indicate ways in which the process may be optimized.

  8. Evaluation of Cast Al-Si-Fe alloy/Coconut Shell Ash Particulate Composites

    OpenAIRE

    S.Y. Aku; D.S. Yawas; ADOKMA, Apasi

    2013-01-01

    Al-7wt%Si-2wt%Fe alloy/Coconut shell ash(CSAp) composites having 3-15wt%coconut shell ash were fabricated by double stir-casting method.  The microstructure, hardness values and density of the composites were evaluated. The density of the composites decreased as the percentage of coconut shell ash increases in the aluminum alloy. This means that composites of lower weight component can be produced by adding CSAp.  Microstructural analysis showed fairy distribution of coconut shell a...

  9. Development of Lead-Free Copper Alloy-Graphite Castings

    Energy Technology Data Exchange (ETDEWEB)

    Rohatgi, P.K. [Univ. of Wisconsin-Milwaukee (US)

    1999-10-01

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

  10. Casting Porosity-Free Grain Refined Magnesium Alloys

    Energy Technology Data Exchange (ETDEWEB)

    Schwam, David [Case Western Reserve University

    2013-08-12

    The objective of this project was to identify the root causes for micro-porosity in magnesium alloy castings and recommend remedies that can be implemented in production. The findings confirm the key role played by utilizing optimal gating and risering practices in minimizing porosity in magnesium castings. 

  11. Impurity control and corrosion resistance of magnesium-aluminum alloy

    Energy Technology Data Exchange (ETDEWEB)

    Liu, M. [GM China Lab; Song, GuangLing [ORNL

    2013-01-01

    The corrosion resistance of magnesium alloys is very sensitive to the contents of impurity elements such as iron. In this study, a series of diecast AXJ530 magnesium alloy samples were prepared with additions of Mn and Fe. Through a comprehensive phase diagram calculation and corrosion evaluation, the mechanisms for the tolerance limit of Fe in magnesium alloy are discussed. This adds a new dimension to control the alloying impurity in terms of alloying composition design and casting conditions.

  12. Precipitate-Accommodated Plasma Nitriding for Aluminum Alloys

    Institute of Scientific and Technical Information of China (English)

    Patama Visittipitukul; Tatsuhiko Aizawa; Hideyuki Kuwahara

    2004-01-01

    Reliable surface treatment has been explored to improve the strength and wear resistance of aluminum alloy parts in automotives. Long duration time as well as long pre-sputtering time are required for plasma nitriding of aluminum or its alloys only with the thickness of a few micrometers. New plasma inner nitriding is proposed to realize the fast-rate nitriding of aluminum alloys. Al-6Cu alloy is employed as a targeting material in order to demonstrate the effectiveness of this plasma nitriding. Mechanism of fast-rate nitriding process is discussed with consideration of the role of Al2Cu precipitates.

  13. 46 CFR 59.20-1 - Carbon-steel or alloy-steel castings.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Carbon-steel or alloy-steel castings. 59.20-1 Section 59... BOILERS, PRESSURE VESSELS AND APPURTENANCES Welding Repairs to Castings § 59.20-1 Carbon-steel or alloy-steel castings. Defects in carbon-steel or alloy-steel castings may be repaired by welding. The...

  14. Interaction between alloying and hardening of cast iron surface

    Institute of Scientific and Technical Information of China (English)

    刘政军; 郝雪枫; 傅迎庆; 牟力军

    2002-01-01

    To improve wear resistance of surface will increase the service life of gray cast iron directly. This paper presents that gray cast iron surface coated with alloy powder is locally remelted by TIG arc to increase the wear resistance. The influences of arc current and scanning rate etc on surface properties are found. Under different conditions, the microstructure, hardness and wear resistance of remelted layer are analyzed and measured. The results indicate that the gray cast iron surface can be strengthened by TIG arc local remelting treatment. Especially, surface alloying hardening effect is best and surface properties are improved remarkably.

  15. The Elastic Constants for Wrought Aluminum Alloys

    Science.gov (United States)

    Templin, R L; Hartmann, E C

    1945-01-01

    There are several constants which have been devised as numerical representations of the behavior of metals under the action of loadings which stress the metal within the range of elastic action. Some of these constants, such as Young's modulus of elasticity in tension and compression, shearing modulus of elasticity, and Poisson's ratio, are regularly used in engineering calculations. Precise tests and experience indicate that these elastic constants are practically unaffected by many of the factors which influence the other mechanical properties of materials and that a few careful determinations under properly controlled conditions are more useful and reliable than many determinations made under less favorable conditions. It is the purpose of this paper to outline the methods employed by the Aluminum Research Laboratories for the determination of some of these elastic constants, to list the values that have been determined for some of the wrought aluminum alloys, and to indicate the variations in the values that may be expected for some of the commercial products of these alloys.

  16. Processing of Aluminum Alloys Containing Displacement Reaction Products

    OpenAIRE

    Stawovy, Michael Thomas

    1998-01-01

    Aluminum and metal-oxide powders were mixed using mechanical alloying. Exothermic displacement reactions could be initiated in the powders either by mechanical alloying alone or by heat treating the mechanically alloyed powders. Exponential relationships developed between the initiation time of the reaction and the mechanical alloying charge ratio. The exponential relationships were the result of changes in the intensity and quantity of collisions occurring during mechanical alloying. Di...

  17. The quality of the joint between alloy steel and unalloyed cast steel in bimetallic layered castings

    Directory of Open Access Journals (Sweden)

    T. Wróbel

    2012-01-01

    Full Text Available In paper is presented technology of bimetallic layered castings based on founding method of layer coating directly in cast process so-called method of mould cavity preparation. Prepared castings consist two fundamental parts i.e. bearing part and working part (layer. The bearing part of bimetallic layered casting is typical foundry material i.e. ferritic-pearlitic unalloyed cast steel, whereas working part (layer is plate of austenitic alloy steel sort X2CrNi 18-9. The ratio of thickness between bearing and working part is 8:1. The aim of paper was assessed the quality of the joint between bearing and working part in dependence of pouring temperature and carbon concentration in cast steel. The quality of the joint in bimetallic layered castings was evaluated on the basis of ultrasonic non-destructive testing, structure and microhardness researches.

  18. Quantitative procedure for evaluation of microstructure of cast Mg-Al-Ca-Sr magnesium alloy

    Directory of Open Access Journals (Sweden)

    T. Rzychoń

    2010-01-01

    Full Text Available In this paper the microstructural characterization of ingot MRI-230D magnesium alloy and quantitative procedure for evaluation of microstructure are presented. The optical and scanning electron microscopy were used to study the morphology of microstructural compounds in this alloy. The X-ray diffraction was used to determination of phase composition. The as-cast microstructure of MRI-230D magnesium alloy containing aluminum, calcium and strontium consists of the dendritic α-Mg and such intermetallic compounds as: Al2Ca, Al4Sr and AlxMny. In the purpose quantitative description of microstructure semi-automatic procedures using Met-Ilo image analysis were developed. Prepared semi-automatic procedures allow a fast determination of phase content in MRI-230D alloy using light microscopy and will be useful in the quality control of MRI-230D ingots.

  19. Grain refinement of permanent mold cast copper base alloys. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Sadayappan, M.; Thomson, J. P.; Elboujdaini, M.; Gu, G. Ping; Sahoo, M.

    2004-04-29

    Grain refinement behavior of copper alloys cast in permanent molds was investigated. This is one of the least studied subjects in copper alloy castings. Grain refinement is not widely practiced for leaded copper alloys cast in sand molds. Aluminum bronzes and high strength yellow brasses, cast in sand and permanent molds, were usually fine grained due to the presence of more than 2% iron. Grain refinement of the most common permanent mold casting alloys, leaded yellow brass and its lead-free replacement EnviroBrass III, is not universally accepted due to the perceived problem of hard spots in finished castings and for the same reason these alloys contain very low amounts of iron. The yellow brasses and Cu-Si alloys are gaining popularity in North America due to their low lead content and amenability for permanent mold casting. These alloys are prone to hot tearing in permanent mold casting. Grain refinement is one of the solutions for reducing this problem. However, to use this technique it is necessary to understand the mechanism of grain refinement and other issues involved in the process. The following issues were studied during this three year project funded by the US Department of Energy and the copper casting industry: (1) Effect of alloying additions on the grain size of Cu-Zn alloys and their interaction with grain refiners; (2) Effect of two grain refining elements, boron and zirconium, on the grain size of four copper alloys, yellow brass, EnviroBrass II, silicon brass and silicon bronze and the duration of their effect (fading); (3) Prediction of grain refinement using cooling curve analysis and use of this method as an on-line quality control tool; (4) Hard spot formation in yellow brass and EnviroBrass due to grain refinement; (5) Corrosion resistance of the grain refined alloys; (6) Transfer the technology to permanent mold casting foundries; It was found that alloying elements such as tin and zinc do not change the grain size of Cu-Zn alloys

  20. Influence of Al addition on structure of magnesium casting alloys

    Directory of Open Access Journals (Sweden)

    L.A. Dobrzański

    2006-04-01

    Full Text Available Purpose: In the following paper there have been the structure and properties of the MCMgAl9Zn1 magnesium cast alloy as-cast state and after a heat treatment presented.Design/methodology/approach: A casting cycle of alloys has been carried out in an induction crucible furnace using a protective salt bath Flux 12 equipped with two ceramic filters at the melting temperature of 750±10ºC, suitable for the manufactured material. The following results concern transmission and scanning microscopy, X-ray qualitative and quantitative microanalysis.Findings: The analysis of the thin foils after the ageing process has confirmed that the structure of the magnesium cast alloy consists of the solid solution α – Mg (matrix of the secondary phase β – Mg17Al12 evenly located in the structure. The structure creates agglomerates in the form of needle precipitations, partially coherent with the matrix placed mostly at the grain boundaries.Research limitations/implications: According to the alloys characteristic, the applied cooling rate and alloy additions seems to be a good compromise for mechanical properties and microstructures, nevertheless further tests should be carried out in order to examine different cooling rates and parameters of solution treatment process and aging process.Practical implications: A desire to create as light vehicle constructions as possible and connected with it low fuel consumption have made it possible to make use of magnesium alloys as a constructional material in automotive industry.Originality/value: The undertaken examinations aim at defining the influence of a chemical composition and precipitation processes on the structure and casting magnesium alloy properties in its as-cast state and after heat treatment with a different content of alloy components.

  1. The Effect of Aluminum Content on the Microstructure and Cavitation Wear of Feal Intermetallic Alloys

    Directory of Open Access Journals (Sweden)

    Jasionowski Robert

    2014-03-01

    Full Text Available Intermetallic-based alloys (so called intermetallics of the Fe-Al binary system are modern construction materials, which in recent decades have found application in many branches of the power, chemical and automotive industries. High resistance of FeAl based alloys to cavitational erosion results first of all from their high hardness in the as-cast state, large compressive stresses in the material, as well as homogeneous structure. In the present paper, the effect of aluminum content on the microstructure, texture and strain implemented upon cavitation wear of FeAl intermetallic alloys, have been analyzed by field emission gun scanning electron microscopy (FEG SEM and electron backscatter diffraction (EBSD analysis. Obtained results of structural characterization indicates that with increasing aluminium content effects of orientation randomization (weakening of //ND casting texture, grain refinement and rising of mechanical strenght (and so cavitational resistance take place.

  2. Market Opportunity of Some Aluminium Silicon Alloys Materials through Changing the Casting Process

    Directory of Open Access Journals (Sweden)

    Delfim SOARES

    2012-08-01

    Full Text Available Fatigue is considered to be the most common mechanism by which engineering components fail, and it accounts for at least 90% of all service failures attributed to mechanical causes. Mechanical properties (tensile strength, tensile strain, Young modulus, etc as well as fatigue properties (fatigue life are very dependent on casting method. The most direct effects of casting techniques are on the metallurgical microstructure that bounds the mechanical properties. One of the important variables affected by the casting technique is the cooling rate which is well known to strongly restrict the microstructure. In the present research has been done a comparison of fatigue properties of two aluminum silicon alloys obtained by two casting techniques. It was observed that the fatigue life is increasing with 24% for Al12Si and 31% for AL18Si by using centrifugal casting process instead of gravity casting. This increasing in fatigue life means that a component tailored from materials obtained by centrifugal casting will stay longer in service. It was made an estimation of the time required to recover the costs of technology in order to use the centrifuge process that will allow to obtain materials with improved properties. The amortization can be achieved by using two different marketing techniques: through the release of the product at the old price and with much longer life of the component which means "same price - longer life", or increasing price, by highlighting new product performance which means "higher price - higher properties".

  3. Microstructure and properties of 2618-Ti heat resistant aluminum alloy

    Institute of Scientific and Technical Information of China (English)

    王建华; 易丹青; 王斌

    2003-01-01

    The mechanical properties of alloy 2618 with 0.5%(mass fraction) titanium and its microstructures in different states such as as-cast and quenching-aging were investigated. Titanium was added into the alloy with Al-5%Ti master alloy that was extruded severely. Al3Ti particles in the microstructure of cast alloy 2618-Ti are very small because those of master alloy are also small. When titanium is used as an alloying element, it does not affect the morphology of Al9FeNi phase in cast alloy, but decreases the grain size of as-cast alloy remarkably. The grain size of quenching-aging alloy 2618 decreases apparently due to the existence of a great deal of dispersive Al3Ti particles. Adding 0.5%Ti has no effect on the room temperature tensile properties of alloy 2618, but apparently increases the elevated temperature instantaneous tensile properties and that of the alloy which is exposed at 250 ℃ for 100 h.

  4. Study of rare earth element effect on microstructures and mechanical properties of an Al-Cu-Mg-Si cast alloy

    Institute of Scientific and Technical Information of China (English)

    WAN Weiwei; HAN Jianmin; LI Weijing; WANG Jinhua

    2006-01-01

    The improvements of microstructures and properties of a high strength aluminum cast alloy were studied.The effects of rare earth elements on the microstructures and mechanical properties of the high strength cast alloy Al-Cu-Mg-Si were investigated.The result shows that the addition of rare earth elements can change the microstructures in refining the grain size of the alloy and making the needle-like and laminar eutectic Si to a granular Si.With the increase of the rare earth, the tensile strength and elongation of the alloy increase first and then fall down.The mechanical properties of the alloy will reach the highest value when the content of rare earth elements is about 0.7%.

  5. Effect of Yb additions on microstructures and properties of 7A60 aluminum alloy

    Institute of Scientific and Technical Information of China (English)

    FANG Hua-chan; CHEN Kang-hua; ZHANG Zhuo; ZHU Chang-jun

    2008-01-01

    Al-Zn-Mg-Cu-Zr alloys containing Yb were prepared by cast metallurgy. Effect of 0.30% Yb additions on the microstructure and properties of 7A60 aluminum alloys with T6 and T77 aging treatments was investigated by TEM, optical microscopy, hardness and electric conductivity measurement, tensile test and stress corrosion cracking test. The results show that the Yb additions to high strength Al-Zn-Mg-Cu-Zr aluminum alloys can produce fine coherent dispersoids. Those dispersoids can strongly pin dislocation and subgrain boundaries, which can significantly retard the recrystallization by inhibiting the nucleation of recrystallization and the growth of subgrains and keeping low-angle subgrain boundaries. Yb additions can obviously enhance the resistance to stress corrosion cracking and the fracture toughness property, and mildly increase the strength and ductility with T6 and T77 treatments.

  6. Effect and kinetic mechanism of ultrasonic vibration on solidification of 7050 aluminum alloy

    Directory of Open Access Journals (Sweden)

    Ripeng Jiang

    2014-07-01

    Full Text Available The work described in this paper dealt with the effect of ultrasonic vibration on the solidification of 7050 aluminum alloy. Two experiments were carried out through introducing ultrasound into the semi-continuous direct-chill (DC casting of aluminum alloy and into alloy solidifying in a crucible, respectively. Results show that ultrasonic vibration can refine grains in the whole cross-section of a billet in the first experiment and is able to increase the cooling rate within the temperature range from 625 °C to 590 °C in the other one. The mechanism of particle resonance caused by ultrasonic vibration was illustrated on the basis of theoretical analysis of the kinetics and energy conversion during the solidification. It is demonstrated that the kinetic energy of resonant particles are mainly from the latent heat energy of solidification, which can shorten the cooling time, inhibit the crystal growth and then lead to the grain refinement.

  7. Quality analysis of the Al-Si-Cu alloy castings

    Directory of Open Access Journals (Sweden)

    L.A. Dobrzański

    2007-04-01

    Full Text Available The developed design methodologies both the material and technological ones will make it possible to improve shortly the quality of materials from the light alloys in the technological process, and the automatic process flow correction will make the production cost reduction possible, and - first of all - to reduce the amount of the waste products. Method was developed for analysis of the casting defects images obtained with the X-ray detector analysis of the elements made from the Al-Si-Cu alloys of the AC-AlSi7Cu3Mg type as well as the method for classification of casting defects using the artificial intelligence tools, including the neural networks; the developed method was implemented as software programs for quality control. Castings were analysed in the paper of car engine blocks and heads from the Al-Si-Cu alloys of the AC-AlSi7Cu3Mg type fabricated with the “Cosworth” technological process. The computer system, in which the artificial neural networks as well as the automatic image analysis methods were used makes automatic classification possible of defects occurring in castings from the Al-Si-Cu alloys, assisting and automating in this way the decisions about rejection of castings which do not meet the defined quality requirements, and therefore ensuring simultaneously the repeatability and objectivity of assessment of the metallurgical quality of these alloys.

  8. Microstructure, tensile properties and fracture behavior of high temperature Al–Si–Mg–Cu cast alloys

    International Nuclear Information System (INIS)

    The high temperature tensile behavior of 354 aluminum cast alloy was investigated in the presence of Zr and Ni. The cast alloys were given a solutionizing treatment followed by artificial aging at 190 °C for 2 h. High temperature tensile tests were conducted at various temperatures from 25 °C to 300 °C. Optical microscopy and electron probe micro-analyzer were used to study the microstructure of different intermetallic phases formed. The fractographic observations of fracture surface were analyzed by scanning electron microscopy to understand the fracture mechanism. The results revealed that the intermetallics phases of (Al, Si)3(Zr, Ti), Al3CuNi and Al9NiFe are the main feature in the microstructures of alloys with Zr and Ni additions. The results also indicated that the tensile strength of alloy decreases with an increase in temperature. The combined addition of 0.2 wt% Zr and 0.2 wt% Ni leads to a 30% increase in the tensile properties at 300 °C compared to the base alloy. Zr and Ni bearing phases played a vital role in the fracture mechanism of the alloys studied

  9. Microstructure, tensile properties and fracture behavior of high temperature Al–Si–Mg–Cu cast alloys

    Energy Technology Data Exchange (ETDEWEB)

    Mohamed, A.M.A., E-mail: madel@uqac.ca [Center for Advanced Materials, Qatar University, Doha (Qatar); Department of Metallurgical and Materials Engineering, Faculty of Petroleum and Mining Engineering, Suez Canal University, Box 43721, Suez (Egypt); Samuel, F.H. [Université du Québec à Chicoutimi, Chicoutimi, QC, Canada G7H 2B1 (Canada); Al Kahtani, Saleh [Industrial Engineering Program, Mechanical Engineering Department, College of Engineering, Salman bin Abdulaziz University, Al Kharj (Saudi Arabia)

    2013-08-10

    The high temperature tensile behavior of 354 aluminum cast alloy was investigated in the presence of Zr and Ni. The cast alloys were given a solutionizing treatment followed by artificial aging at 190 °C for 2 h. High temperature tensile tests were conducted at various temperatures from 25 °C to 300 °C. Optical microscopy and electron probe micro-analyzer were used to study the microstructure of different intermetallic phases formed. The fractographic observations of fracture surface were analyzed by scanning electron microscopy to understand the fracture mechanism. The results revealed that the intermetallics phases of (Al, Si){sub 3}(Zr, Ti), Al{sub 3}CuNi and Al{sub 9}NiFe are the main feature in the microstructures of alloys with Zr and Ni additions. The results also indicated that the tensile strength of alloy decreases with an increase in temperature. The combined addition of 0.2 wt% Zr and 0.2 wt% Ni leads to a 30% increase in the tensile properties at 300 °C compared to the base alloy. Zr and Ni bearing phases played a vital role in the fracture mechanism of the alloys studied.

  10. 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.

  11. Alkaline oxide conversion coatings for aluminum alloys

    Energy Technology Data Exchange (ETDEWEB)

    Buchheit, R.G.

    1996-02-01

    Three related conversion coating methods are described that are based on film formation which occurs when aluminum alloys are exposed to alkaline Li salt solutions. Representative examples of the processing methods, resulting coating structure, composition and morphology are presented. The corrosion resistance of these coatings to aerated 0.5 M NaCl solution has been evaluated as a function of total processing time using electrochemical impedance spectroscopy (EIS). This evaluation shows that excellent corrosion resistance can be uniformly achieved using no more than 20 minutes of process time for 6061-T6. Using current methods a minimum of 80 minutes of process time is required to get marginally acceptable corrosion resistance for 2024-T3. Longer processing times are required to achieve uniformly good corrosion resistance.

  12. Microstructural evolution of direct chill cast Al-15.5Si-4Cu-1Mg-1Ni-0.5Cr alloy during solution treatment

    OpenAIRE

    He Kezhun; Yu Fuxiao; Zhao Dazhi

    2011-01-01

    Heat treatment has important influence on the microstructure and mechanical properties of Al-Si alloys. The most common used heat treatment method for these alloys is solution treatment followed by age-hardening. This paper investigates the microstructural evolution of a direct chill (DC) cast Al-15.5Si-4Cu-1Mg-1Ni-0.5Cr alloy after solution treated at 500, 510, 520 and 530℃, respectively for different times. The major phases observed in the as-cast alloy are α-aluminum dendrite, primary Si p...

  13. Semi-solid extrusion of aluminum alloy ZL116

    Institute of Scientific and Technical Information of China (English)

    Zhao Dazhi; Lu Guimin; Cui Jianzhong

    2008-01-01

    The semi-solid forward-extruding feasibility of reheated ZL116 alloy cast by the near-liquidus semicontinuous casting process was studied by analyzing the microstructures and properties of forward-extruded bars.The results show that the microstructure of the ZL116 alloy billets cast by near-liquidus semi-continuous casting is mainly made up of homogeneous,fine global-or rosette-shaped grains.The microstructure of the billets,reheated and held at 575℃,contains stable and net-spherical grains which are suitable for semi-solid thixoformina.The semi-solid forward-extruded bars of the ZL116 alloy billet are facially smooth.microstructurally fine and homogeneous.Therefore the feasibility of semi-solid foFward-extrusion of ZL116 alloy is thus excellent.

  14. Microstructure of Cast Ni-Cr-Al-C Alloy

    Directory of Open Access Journals (Sweden)

    Cios G.

    2015-04-01

    Full Text Available Nickel based alloys, especially nickel based superalloys have gained the advantage over other alloys in the field of high temperature applications, and thus become irreplaceable at high temperature creep and aggressive corrosion environments, such as jet engines and steam turbines. However, the wear resistance of these alloys is insufficient at high temperatures. This work describes a microstructure of a new cast alloy. The microstructure consists of γ matrix strengthened by γ’ fine precipitates (dendrites improving the high temperature strength and of Chromium Cr7C3 primary carbides (in interdendritic eutectics which are designed to improve wear resistance as well as the high temperature strength.

  15. Friction Pull Plug Welding in Aluminum Alloys

    Science.gov (United States)

    Brooke, Shane A.; Bradford, Vann

    2012-01-01

    NASA's Marshall Space Flight Center (MSFC) has recently invested much time and effort into the process development of Friction Pull Plug Welding (FPPW). FPPW, is a welding process similar to Friction Push Plug Welding in that, there is a small rotating part (plug) being spun and simultaneously pulled (forged) into a larger part. These two processes differ, in that push plug welding requires an internal reaction support, while pull plug welding reacts to the load externally. FPPW was originally conceived as a post proof repair technique for the Space Shuttle fs External Tank. FPPW was easily selected as the primary weld process used to close out the termination hole on the Constellation Program's ARES I Upper Stage circumferential Self-Reacting Friction Stir Welds (SR-FSW). The versatility of FPPW allows it to also be used as a repair technique for both SR-FSW and Conventional Friction Stir Welds. To date, all MSFC led development has been concentrated on aluminum alloys (2195, 2219, and 2014). Much work has been done to fully understand and characterize the process's limitations. A heavy emphasis has been spent on plug design, to match the various weldland thicknesses and alloy combinations. This presentation will summarize these development efforts including weld parameter development, process control, parameter sensitivity studies, plug repair techniques, material properties including tensile, fracture and failure analysis.

  16. PERSPECTIVES OF MOLIBDENUM CONTAINING MATERIALS APPLICATION FOR ALLOYING OF IRONCARBON ALLOYS DURING MANUFACTURING OF CRITICAL CASTINGS

    Directory of Open Access Journals (Sweden)

    A. G. Slutsky

    2015-01-01

    Full Text Available Motor is one of most important part of automobile determine its economical effectiveness of usage. On the other hand, sleeves, pistons and rings are crucible parts as they determine the service life of a motor. These parts are producing in big scale – dozens of millions pieces. Increase of cylinder sleeves physical-mechanical properties results in prolongation of motor service life and improvement of motor’s characteristics. Nowadays low alloyed cast irons with perlite structure are used to manufacture motor’s sleeves. For alloying purposes such traditional elements as Cr, Ni, Cu, and V are applied. But it is interesting to use molybdenum for cast iron alloying. It is known that alloying of alloys allows considerable increasing of consumption properties of castings. But in spite of advantages of alloys alloying the increase of molybdenum containing iron-carbon alloys production is restricted by economical reasons – high cost of alloying additions. Expenditures on alloying additions can be reduced by the application cheap secondary alloys in the charge. So, the present paper is devoted to investigation of alloying peculiarities during the treatment of ferrous alloys with molybdenum applying different initial materials.

  17. Measurement of Thermodynamic Properties of Titanium Aluminum Alloys

    Science.gov (United States)

    Mehrotra, Gopal

    1995-01-01

    This final report is a summary of the work done by Professor Mehrotra at NASA Lewis Research Center. He has worked extensively on the measurement of thermodynamic properties of titanium aluminum alloys over the past six years.

  18. Paint-Bonding Improvement for 2219 Aluminum Alloy

    Science.gov (United States)

    Daech, Alfred F.; Cibula, Audrey Y.

    1987-01-01

    Bonding of adhesives and primers to 2219 aluminum alloy improved by delaying rinse step in surface-treatment process. Delaying rinse allows formation of rougher surface for stronger bonding and greater oxide buildup.

  19. The development of recycle-friendly automotive aluminum alloys

    Science.gov (United States)

    Das, Subodh K.; Green, J. A. S.; Kaufman, J. Gilbert

    2007-11-01

    The continuing growth of aluminum alloy usage in transportation applications, notably passenger automobiles and minivans, and the demonstrated economic benefits of recycling aluminum-rich vehicles increase the need to seriously consider the desirability of designing recycling-friendly alloys. This article focuses on that aspect of the recycling process for passenger vehicles. The goals are to illustrate the opportunities afforded by identifying and taking full advantage of potential metal streams in guiding the development of new alloys that use those streams. In speculating on several possible aluminum recovery practices and systems that might be used in recycling passenger vehicles, likely compositions are identified and preliminary assessments of their usefulness for direct recycling are made. Specific compositions for possible new recycle-friendly alloys are suggested. In addition, recommendations on how the aluminum enterprise, including industry, academia, and government, can work together to achieve the aggressive but important goals described here are discussed.

  20. Modification Mechanism of Rare Earth Elements in ZA27 Casting Alloys

    Institute of Scientific and Technical Information of China (English)

    刘贵立; 李荣德

    2003-01-01

    The model of the liquid-phase ZA27 alloys was set up by molecular dynamics theory. The atomic structure of phase, RE-compounds, and the phase-liquid interface in ZA27 alloys were constructed by computer programming. Electronic structures of phase with rare earth elements dissolved and of phase-liquid interfaces with rare earth elements enrichment in ZA27 casting alloys were investigated by using the Recursion method. The ESE energy of RE elements and the structure energy of RE-compounds, phase, and the liquid-phase ZA27 alloys were calculated. The results show that rare earth elements are more stable to be in the phase interface than in phase, which explains the fact of very small solid so lubility of rare earth elements in phase, and the enrichment in the solid-liquid growth front. This makes dendrite melt and break down, dissociate and propagate. RE-compounds can act as heterogeneous nuclei for phase, leading to phase refinement. All above elucidates the modification mechanism of rare earth elements in zinc-aluminum casting alloys at electronic level.

  1. Comparison of the texture evolution in cold rolled DC and SC AA 5182 aluminum alloys

    International Nuclear Information System (INIS)

    The hot bands of direct chill cast (DC) and strip cast (SC) AA 5182 aluminum alloys were annealed at 454 deg. C for 3 h, and then cold rolled to different reductions. The ODFs of the cold rolled samples were determined by X-ray diffraction in order to compare the texture evolution of DC and SC AA 5182 aluminum alloys during rolling. The texture volume fractions were computed by a new method, in which the Euler space representing all possible crystallographic orientations in rolling was subdivided into the cube, r-cube, Goss, r-Goss, β fiber, and random orientation regions based on the slip pattern combined with the characteristics of microstructure and texture. Empirical formulae of the texture volume fractions and true strain were constructed to predict the texture of cold rolled DC and SC AA 5182 aluminum alloys. The results show that the processing method (DC vs. SC) strongly affects the texture after annealing at 454 deg. C and the texture evolution during the subsequent rolling

  2. Microstructural Feature of As-cast A-356 Alloy Modifiers with the Addition of SrO

    Institute of Scientific and Technical Information of China (English)

    MUIZ Rodrigo; FLORES Alfredo; ORTIZ Juan; RODRGUEZ Nelly; MARTNEZ Fernando; OROZCO Pilar; LUNA Jess; Equihua Fabin; Garca Adrin

    2014-01-01

    To explore the effect of strontium on the structure of as-cast A356 alloy, the strontium was incorporated to the alloy by metallothermic reduction of SrO where the mineral was added to the melt through the submerged powders injection technique. The evaluation of the modification of the eutectic silicon and the chemical analysis of samples were done using optical microscopy (OP) and inductively coupled plasma (ICP), respectively, while microstructural analyses by scanning electron microscopy (SEM), and the injection time was variable. Magnesium was added to the melt to increase the reactivity and reduce the surface tension of the molten aluminum. It was possible to increase the strontium content from 0 to 0.027%after 20 minutes treatment. This concentration was sufficient to bring about full modification structure of eutectic silicon of as cast alloy A 356 and the acceptable quality metallurgical of alloy.

  3. Investigation on the effect of titanium (Ti) addition to the Mg- AZ31 alloy in the as cast and after extrusion conditions on its metallurgical and mechanical characteristics

    Science.gov (United States)

    Zaid, Adnan I. O.; Raghad; Hememat, S.

    2016-08-01

    Magnesium-aluminum alloys are versatile materials which are used in manufacturing a number of engineering and industrial parts in the automobile and aircraft industries due to their strength - to -weight -ratios. Against these preferable characteristics, magnesium is difficult to deform at room temperature; therefore it is alloyed with other elements mainly aluminum and zinc to add some required properties particularly to achieve high strength -to- weight ratio. Grain refinement is an important technology to improve the mechanical propertiesand the microstructure uniformity of the alloys. Most of the published work on grain refinement was directed toward grain refining aluminum and zinc alloys; however, the effect of the addition of rare earth material on the grain size or the mechanical behavior of Mg alloys is rare. In this paper the effect of Ti addition on the grain size, mechanical behavior, ductility, extrusion force and energy, of Mg-AZ31 alloy both in the as cast condition and after direct extrusion is investigated.

  4. Development of manufacturing process of wrought magnesium alloy sheets by twin roll casting

    Directory of Open Access Journals (Sweden)

    H. Watari

    2007-01-01

    Full Text Available Purpose: The purpose of the work is to development of a strip casting technology for manufacturing magnesiumalloy sheets. The aim of the work is to establish a manufacturing process and technology to facilitate theeconomical manufacture of high-strength magnesium sheet alloys.Design/methodology/approach: A horizontal type twin roll caster was used to manufacture magnesium alloysheets. Pair of copper alloy roll, pure copper roll and steel roll was used for the horizontal type twin roll caster.The diameter of the rolls was 300mm and the width of rolls was 100 and 150mm.Findings: The magnesium alloy sheets could be succcessfully manufactured by the horizontal twin roll caster. Theproduct sheet thickness in the present experiment was 2.0 to 5.0mm. The equiaxed microstrucure was observed incast magnesium alloys when a pair of copper and cupper aolly rolls were used. The mean grain size of the castmagnesium alloys strip was from 30 to 60 micrometers. After hot rolling process, the grain size was reduced to about10 micrometers. The obtained magnesium alloy sheet indicated a good plastic formability by a warm-drawing test.Research limitations/implications: The superheat in the experiment was between 15ºC and 30ºC, also anappropriate hot rolling temperature was 250ºC for AZ31, AZ61 and AM60, 300ºC for AZ91.Practical implications: The proposed manufacturing process was effective from the view point of economicalmanufacturing process as well as of formation of rapid solidification microstructures. Introducing the twin rollcasting technology enable to manufacture magnesium sheet alloys with high aluminum contents, such as AZ61,AM60 and AZ91.Originality/value: AZ31, AM60, AZ61 and AZ91 wrought magnesium alloy sheets can be manufacturedeconomically by twin roll casting. These cast sheet can be hot rolled and the proposed manufacturing processenables manufacturer to manufacure thin magnesium alloy sheets with high aluminum contents such as AM60,AZ61 and AZ

  5. Comparison of thermodynamic databases for 3xx and 6xxx aluminum alloys

    Science.gov (United States)

    Ravi, C.; Wolverton, C.

    2005-08-01

    Computational thermodynamics, or Calculation of Phase Diagram (CALPHAD) methods have proven useful in applications to modeling a variety of alloy properties. However, the methods are only as accurate as the thermodynamic databases they use, and two commercial thermodynamic databases exist for aluminum alloys: Thermotech and Computherm. In order to provide a critical comparison of these databases, we used both the databases to calculate equilibrium solid-state phase fractions and phase diagram isothermal sections of several industrial aluminum alloys: a 319-type and 356 cast alloys, as well as the wrought alloys 6022 and 6111. All of these alloys may be generically described as being based on the Al-Mg-Si-Cu quaternary with other additions such as Fe, Mn, and Zn. Although many of the results are consistent between the two databases, several qualitative and quantitative differences were observed. Many of these differences are found to be due to the intermetallic compounds involving Fe, Mn, Cr, and Zn. On the other hand, thermodynamics involving only phases from the Al-Mg-Si-Cu quaternary show good agreement between the databases, although some small differences still exist, particularly involving the quaternary Q phase. To understand and assess these differences, formation enthalpies and reaction energies from the databases were compared against density functional first-principles energetics. These comparisons indicate possible avenues for future improvements of Al-alloy thermodynamic databases. Finally, we demonstrate an interesting correlation between the calculated phase fractions and the measured yield strengths across this wide family of 3xx cast and 6xxx wrought alloys.

  6. Component- and Alloy-Specific Modeling for Evaluating Aluminum Recycling Strategies for Vehicles

    Science.gov (United States)

    Modaresi, Roja; Løvik, Amund N.; Müller, Daniel B.

    2014-11-01

    Previous studies indicated that the availability of mixed shredded aluminum scrap from end-of-life vehicles (ELV) is likely to surpass the capacity of secondary castings to absorb this type of scrap, which could lead to a scrap surplus unless suitable interventions can be identified and implemented. However, there is a lack of studies analyzing potential solutions to this problem, among others, because of a lack of component- and alloy-specific information in the models. In this study, we developed a dynamic model of aluminum in the global vehicle stock (distinguishing 5 car segments, 14 components, and 7 alloy groups). The forecasts made up to the year 2050 for the demand for vehicle components and alloy groups, for the scrap supply from discarded vehicles, and for the effects of different ELV management options. Furthermore, we used a source-sink diagram to identify alloys that could potentially serve as alternative sinks for the growing scrap supply. Dismantling the relevant components could remove up to two-thirds of the aluminum from the ELV stream. However, the use of these components for alloy-specific recycling is currently limited because of the complex composition of components (mixed material design and applied joining techniques), as well as provisions that practically prevent the production of safety-relevant cast parts from scrap. In addition, dismantling is more difficult for components that are currently penetrating rapidly. Therefore, advanced alloy sorting seems to be a crucial step that needs to be developed over the coming years to avoid a future scrap surplus and prevent negative energy use and emission consequences.

  7. Microstructure And Mechanical Properties Of An Al-Zn-Mg-Cu Alloy Produced By Gravity Casting Process

    Directory of Open Access Journals (Sweden)

    Saikawa S.

    2015-06-01

    Full Text Available High-strength aluminum alloy are widely used for structural components in aerospace, transportation and racing car applications. The objective of this study is to enhance the strength of the Al-Zn-Mg-Cu alloy used for gravity casting process. All alloys cast into stepped-form sand mold (Sand-mold Casting; SC and Y-block shaped metal mold(Permanent mold Casting; PC C and then two –step aged at 398-423 K after solution treated at 743 K for 36 ks. The tensile strength and total elongation of the two-step aged SC alloys were 353-387 MPa and about 0.4% respectively. This low tensile properties of the SC alloys might be caused by remaining of undissolved crystallized phase such as Al2CuM, MgZn2 and Al-Fe-Cu system compounds. However, good tensile properties were obtained from PC alloys, tensile strength and 0.2% proof stress and elongation were 503-537 MPa, 474-519 MPa and 1.3-3.3%.

  8. Application of ZP131 powder for manufacture of casting molds using ZCast technology for Al-alloys castings

    Directory of Open Access Journals (Sweden)

    A. Marciniec

    2010-01-01

    Full Text Available The paper presents the results of studies on the possibility of replacing the special powder used for the manufacture of molds using the ZCast - 3DP technology with the universal ZP131 powder. The ZCast technology allows the direct generation of the molds using the three-dimensional printing process. The type of powder used in the process is designated as ZCast501. That enables printing the molds which can resist the temperature of an alloy poured into as high as 1100 °C. Preparing the equipment to print molds with 3DP-ZCast technology requires removing formerly used powder, cleaning and refilling the apparatus with ZCast501 powder. In case, when the 3DP equipment is used as a universal Rapid Prototyping device for building all purpose models, frequent powder refilling is time-consuming and costly. For this reason, research was conducted on the possibility of application of universal ZP131 powder as an alternative material for ZCast technology. The objective of the study was to determine the thermal resistance of such molds for aluminum alloy casting. The results showed that there is a possibility of using ZP131 powder as a material for casting molds.

  9. The intermetallic bonding between a ring carrier and aluminum piston alloy

    Energy Technology Data Exchange (ETDEWEB)

    Manasijevie, S.; Dolie, N.; Djurdjevic, M.; Misic, N.; Davitkov, N.

    2015-07-01

    This paper presents the results of investigating the formation of intermetallic bond between a ring carrier and aluminum piston alloy. The ring carrier is made of austenitic cast iron (Ni-Resist) in order to increase the wear resistance of the first ring groove and applied in highly loaded diesel engines. Metallographic examination of the quality of al fin bond was done. A metallographic investigation using an optical microscope in combination with the SEM/EDS analysis of the quality of the intermetallic bonding layer was done. The test results show that can be made successfully as well as the formation of metal connection (alfin bond) between the ring carrier and aluminum piston alloy. (Author)

  10. Cooling Rate Determination in Additively Manufactured Aluminum Alloy 2219

    Science.gov (United States)

    Brice, Craig A.; Dennis, Noah

    2015-05-01

    Metallic additive manufacturing processes generally utilize a conduction mode, welding-type approach to create beads of deposited material that can be arranged into a three-dimensional structure. As with welding, the cooling rates in the molten pool are relatively rapid compared to traditional casting techniques. Determination of the cooling rate in the molten pool is critical for predicting the solidified microstructure and resultant properties. In this experiment, wire-fed electron beam additive manufacturing was used to melt aluminum alloy 2219 under different thermal boundary conditions. The dendrite arm spacing was measured in the remelted material, and this information was used to estimate cooling rates in the molten pool based on established empirical relationships. The results showed that the thermal boundary conditions have a significant effect on the resulting cooling rate in the molten pool. When thermal conduction is limited due to a small thermal sink, the dendrite arm spacing varies between 15 and 35 µm. When thermal conduction is active, the dendrite arm spacing varies between 6 and 12 µm. This range of dendrite arm spacing implies cooling rates ranging from 5 to 350 K/s. Cooling rates can vary greatly as thermal conditions change during deposition. A cooling rate at the higher end of the range could lead to significant deviation from microstructural equilibrium during solidification.

  11. Particulate and gaseous emissions when welding aluminum alloys.

    Science.gov (United States)

    Cole, Homer; Epstein, Seymour; Peace, Jon

    2007-09-01

    Fabrication and repair of aluminum components and structures commonly involves the use of electric arc welding. The interaction of the arc and the metal being welded generates ultraviolet radiation, metallic oxides, fumes, and gases. Aluminum is seldom used as the pure metal but is often alloyed with other metals to improve strength and other physical properties. Therefore, the exact composition of any emissions will depend on the welding process and the particular aluminum alloy being welded. To quantify such emissions, The Aluminum Association sponsored several studies to characterize arc welding emissions by the gas metal arc welding (GMAW) and gas tungsten arc welding (GTAW) processes for various combinations of base and filler alloys. In all cases, the tests were conducted under conditions that could be found in a production weld shop without forced ventilation. The concentrations of each analyte that a welder could be exposed to were greatly affected by the welding process, the composition of the base and filler alloys, the position of the welder, and the welding helmet. The results obtained can be used by employers to identify and control potential hazards associated with the welding of aluminum alloys and can provide the basis for hazard communication to employees involved in the welding of these alloys.

  12. Dry and clean age hardening of aluminum alloys by high-pressure gas quenching

    Science.gov (United States)

    Irretier, A.; Kessler, O.; Hoffmann, F.; Mayr, P.

    2004-10-01

    When precipitation-hardenable aluminum parts are water quenched, distortion occurs due to thermal stresses. Thereby, a costly reworking is necessary, and for this reason polymer quenchants are often used to reduce distortion, with the disadvantage that the quenched parts have to be cleaned after quenching. In opposition to liquid quenchants, gas quenching may decrease distortion due to the better temperature uniformity during quenching. Furthermore, cleaning of the quenched parts can be avoided because it is a dry process. For this purpose, a heat-treating process was evaluated that included a high-pressure gasquenching step. Gas quenching was applied to different aluminum alloys (i.e., 2024, 6013, 7075, and A357.0), and tensile tests have been carried out to determine the mechanical properties after solution annealing, gas quenching, and aging. Besides high-pressure gas quenching, alloy 2024 was quenched at ambient pressure in a gas nozzle field. The high velocity at the gas outlet leads to an accelerated cooling of the aluminum alloy in this case. Aluminum castings and forgings can be classified as an interesting field of application of these quenching methods due to their near-net shape before the heat treatment. Cost savings would be possible due to the reduced distortion, and therefore, less reworking after the precipitation hardening.

  13. MICROSTRUCTURE ANALYSIS AND MECHANICAL PROPERTIES OF Zn-Al ALLOY ROD PRODUCED BY HEATED MOLD CONTINUOUS CASTING

    Institute of Scientific and Technical Information of China (English)

    Y. Ma; Y. Hao; F.Y. Yan; H.J.Liu

    2003-01-01

    The new technology of continuous casting by heated mold was used to produce dtirectional solidification ZA alloy lines to eliminate the inter defects of these lines and increase their mechanical properties. The results are as follows: (1) The microstructure of the ZA alloy lines is the parallel directional dendritic columnar crystal. Every dendritic crystal of eutectic alloy ZA5 was composed of many layer eutectic β and η phases. The microstructure of hypereutectic ZA alloys is primary dendritic crystal and interdendritic eutectic structure. The primary phase of ZA8 and ZA12 isβ,among them, but the primary phase of ZA22 and ZA27 is α. (2) Through the test to the as-cast ZA alloy lines made in continuous casting by heated mold, it is found that the tensile strength and hardness increase greatly, but the elongation decreases. With the increase of aluminum amount from ZA 5 to ZA 12, ZA22 and ZA27, the tensile strength increases gradually. ZA27 has the best comprehensive mechanical properties in these four kinds of ZA alloys. (3) Heat treatment can decrease the dendritic segregation and improve the elongation of ZA alloy, but make their strength decrease slightly.

  14. Modification of Magnesium Alloys by Ceramic Particles in Gravity Die Casting

    Directory of Open Access Journals (Sweden)

    Urs Haßlinger

    2014-01-01

    Full Text Available A critical drawback for the application of magnesium wrought alloys is the limited formability of semifinished products that arises from a strong texture formation during thermomechanical treatment. The ability of second phase particles embedded into the metal matrix to alter this texture evolution is of great interest. Therefore, the fabrication of particle modified magnesium alloys (particle content 0.5–1 wt.-% by gravity die casting has been studied. Five different types of micron sized ceramic powders (AlN, MgB2, MgO, SiC, and ZrB2 have been investigated to identify applicable particles for the modification. Agglomeration of the particles is revealed to be the central problem for the fabrication process. The main factors that influence the agglomerate size are the particle size and the intensity of melt stirring. Concerning handling, chemical stability in the Mg-Al-Zn alloy system, settling and wetting in the melt, and formation of the microstructure in most cases, the investigated powders show satisfying properties. However, SiC is chemically unstable in aluminum containing alloys. The high density of ZrB2 causes large particles to settle subsequent to stirring resulting in an inhomogeneous distribution of the particles over the cast billet.

  15. Controlled Directional Solidification of Aluminum - 7 wt Percent Silicon Alloys: Comparison Between Samples Processed on Earth and in the Microgravity Environment Aboard the International Space Station

    Science.gov (United States)

    Grugel, Richard N.; Tewari, Surendra N.; Erdman, Robert G.; Poirier, David R.

    2012-01-01

    An overview of the international "MIcrostructure Formation in CASTing of Technical Alloys" (MICAST) program is given. Directional solidification processing of metals and alloys is described, and why experiments conducted in the microgravity environment aboard the International Space Station (ISS) are expected to promote our understanding of this commercially relevant practice. Microstructural differences observed when comparing the aluminum - 7 wt% silicon alloys directionally solidified on Earth to those aboard the ISS are presented and discussed.

  16. Microstructure 2007of WE43 casting magnesium alloy

    Directory of Open Access Journals (Sweden)

    A. Kiełbus

    2007-03-01

    Full Text Available Purpose: WE43 is a high-strength magnesium alloy characterized by good mechanical properties both at an ambient and elevated temperature (up to 300°C. It contains mainly yttrium and neodymium. The aim of this paper is to present the results of research on the microstructure of the WE43 magnesium alloy in an as-cast condition.Design/methodology/approach: For the microstructure observation, a Reichert metallographic microscope MeF2 and a HITACHI S-3400N scanning electron microscope with a Thermo Noran EDS equipped with SYSTEM SIX were used. A qualitative phase analysis was performed with a JEOL JDX-7S diffractometer. Microstrucutral examinations were performed JEOL 3010 transmission electron microscope.Findings: Based on the investigation carried out it was found that the microstructure of WE43 alloy after continuous casting consists of α-Mg matrix and irregular precipitates of Mg41Nd5, rectangular particles of MgY phase, particles of Mg24Y5, longitudinal precipitates of β (Mg14Nd2Y compound at grain boundaries and the grain interiors. All of these phases contain yttrium and neodymium. Research limitations/implications: Future researches should contain investigations of the influence of heat treatment parameters on microstructure, corrosion resistance and mechanical properties of WE43 alloy.Practical implications: WE43 magnesium alloy is used in the aircraft industry, for wheels, engine casings, gear box casings and rotor heads in helicopters. Results of investigation may be useful for development casting technology of the Mg-Y-Nd alloys.Originality/value: The results of the researches make up a basis for the next investigations of magnesium alloys with addition of Y and Nd designed to exploitation at temperature to 300°C.

  17. Influence of solidification rate on microstructure of gravity cast AZ91 magnesium alloy

    Directory of Open Access Journals (Sweden)

    K.N. Braszczyńska-Malik

    2010-01-01

    Full Text Available Derivative thermal (ATD and microstructure analyses of gravity cast AZ91 magnesium alloy are presented. The alloy was cast into cold steel and sand moulds with the same dimensions. ATD curves – solidification curves and their first derivative – are presented. The investigated alloy exhibited a strong alloying elements segregation and the presence of solid solution and (Mg17Al12 eutectic mixture. Discontinuous precipitates of phase were also observed in the microstructure of AZ91 cast into sand mould.

  18. Mechanism and simulation of external cooling in aluminum casting-rolling process

    Institute of Scientific and Technical Information of China (English)

    GAO Zhi

    2005-01-01

    External cooling technology is one of the key technologies to realize fast-casting-rolling process of aluminum, i.e. using compulsive cooling on the external surface of rollers and aluminum plate to improve the cooling ability of system, increase casting-rolling speed, and enhance the quality of aluminum plate. Heat transfer model of casting-rolling process was proposed and the characteristics of the temperature field of roller-plate system were analyzed. The influences of external cooling surface of the plate and the roller on the temperature field of the roller and the aluminum plate and the casting-rolling speed were discussed, and the relationship between external cooling and internal cooling were also analyzed. Experiment results show that, with the increase of casting-rolling speed, the influence of cooling plate surface on increasing casting-rolling speed was gradually decreased, but that of cooling roller surface was enhanced. Different mechanisms of external cooling plate surface and roller surface for improving casting-rolling speed account for this phenomenon.

  19. Multi-wall carbon nanotubes reinforced aluminum composites synthesized by hot press sintering and squeeze casting

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xue-xi; YANG Li; DENG Chun-feng; WANG De-zun

    2006-01-01

    Multi-wall carbon nanotubes (MWNTs) have high mechanical properties and are considered a kind of realistic reinforcement for polymers, ceramics and metals. The hot press sintering and squeeze casting were adopted to synthesize MWNTs reinforced aluminum composites. In hot press sintered MWNTs/Al composites, MWNTs agglomerates distribute along aluminum powders and have low bonding strength with aluminum. But MWNTs agglomerates distribute evenlyin the squeeze cast MWNTs/Al composites. Some dispersed nanotubes bond well with aluminum matrix and few dislocations can be found in the nanotube areas,which implies little thermal residual stress in squeeze cast MWNTs/Al composites. This indicates that the strengthen mechanisms in nanometer sized MWNTs/Al composites may be different from that in micrometer sized whisker composites.

  20. Thermodynamic Modeling as a Strategy for Casting High Alloy Steels

    Institute of Scientific and Technical Information of China (English)

    Peri Reddy V; S Raman Sankaranarayanan

    2009-01-01

    Strategies based on thermodynamic calculations can be used to overcome the problems associated with oxides encountered in steel plant operations, which can lead to certain difficulties in the process such as clogging of submerged entry nozzle during continuous casting. Approaches to producing high alloy steels by continuous casting have been taken. One of the strategies to avoid the oxidation of chromium is to add a small amount of other elements (subject to other constraints), which do not cause subsequent problems. The problem has been studied using the Thermo-CalcR software, with related databases; and the results obtained for different process conditions or generic com-positions have been presented.

  1. Structure changes and mechanical properties of laser alloyed magnesium cast alloys

    Directory of Open Access Journals (Sweden)

    W. Kwaśny

    2009-02-01

    Full Text Available Purpose: The aim of this work was to investigate structure and mechanical properties of the MCMgAl12Zn1 casting magnesium alloys after laser treatment. The laser treatment was carried out using a high power diode laser (HPDL.Design/methodology/approach: The laser processing of TiC, WC, SiC particles in MCMgAl12Zn1 and the resulted microstructures and properties are discussed in this paper. The resulting microstructure in the modified surface layer was examined. Phase composition was determined by the X-ray diffraction method using XPert device. The measurements of hardness after laser melt injection was also studied.Findings: Structure of the solidyifying material after laser alloying is characteristic with occurrences of areas with the diversified morphology, dependent on solidification rate of the magnesium alloys, is characteristic of structure of the solidified material after laser alloying. The MCMgAl12Zn1 casting magnesium alloys after laser alloying demonstrate similar hardness tests results, in reference to hardness of the alloys before their laser treatment.Research limitations/implications: In this research three powders (titanium carbide, tungsten carbide and silicon carbide were used to reinforcing the surface of the MCMgAl12Zn1 casting magnesium alloys.Practical implications: High power diode laser can be used as an economical substitute for CO2 and Nd:YAG lasers to modify the surface magnesium alloy by feeding the carbide particles.Originality/value: The originality of this work is applying of High Power Diode Laser for laser treatment of cast magnesium alloy consisting in fusion penetration of the hard particles of titanium, tungsten, and silicon carbides into the remelted surface layer of the alloy.

  2. Comments on process of duplex coatings on aluminum alloys

    Institute of Scientific and Technical Information of China (English)

    Samir H.A.; QIAN Han-cheng(钱翰城); XIA Bo-cai(夏伯才); WU Shi-ming(吴仕明)

    2004-01-01

    Despite the great achievements made in improvement of wear resistance properties of aluminum alloys,their applications in heavy surface load-bearing are limited. Single coating is insufficient to produce the desired combination of surface properties. These problems can be solved through the duplex coatings. The aim of the present study is to overview the research advances on processes of duplex coatings on aluminum alloys combined with micro plasma oxidation process and with other modern processes such as physical vapour deposition and plasma assisted chemical vapour deposition and also to evaluate the performance of micro plasma oxidation coatings in improving the load-bearing, friction and wear resistance properties of aluminum alloys in comparison with other coatings. Wherein, a more detailed presentation of the processes and their performances and disadvantages are given as well.

  3. Microstructural evolution of aluminum alloy 3003 during annealing

    Institute of Scientific and Technical Information of China (English)

    WU Wen-xiang; ZHANG Xin-ming; SUN De-qin; HU Guo-qiang; LIU Guo-jin

    2006-01-01

    The microstructural evolution of cold-rolled aluminum alloy 3003 during annealing was investigated by means of micro-hardness measurement, electrical resistivity measurement, optical microscopy and transmission electron microscopy. The interaction of recrystallization and precipitation of aluminum alloy 3003 was also discussed. The results show that the recrystallized grain size of cold-rolled aluminum alloy 3003 is strongly affected by precipitation during annealing. When precipitation occurs prior to recrystallization at low temperature(300 ℃), the grain structure becomes coarse, and the precipitation process is affected by the presence of lattice defects, i.e. high cold reduction results in a large number of precipitates. When annealing at 500 ℃, however, for the recrystallization is prior to precipitation, the precipitation is independent of cold deformation reduction and a fine, equiaxed grain structure is obtained.

  4. Experimental study on activating welding for aluminum alloys

    Institute of Scientific and Technical Information of China (English)

    Huang Yong; Fan Ding

    2005-01-01

    TIG welding and EB welding for aluminum alloy 3003 were carried out to study the effects of activating flux on weld penetration of activating welding for aluminum alloys. SiO2 was used as the activating flux. It is found that, SiO2 can increase the weld penetration and decrease the weld width of FBTIG when the flux gap is small. For A-TIG welding and EB welding with focused mode, the weld penetrations and the weld widths increase simultaneously. SiO2 has little effect on the weld penetration and weld width of EB welding with defocused mode. It is believed that, change of surface tension temperature gradient is not the main mechanism of SiO2 improving weld penetration of activating welding for aluminum alloys.

  5. Low activation R-tokamak with aluminum alloy

    International Nuclear Information System (INIS)

    An aluminum alloy system is considered as an alternative of the first phase design of the R-tokamak. The 1-D calculation showed that the radiation level outside the vacuum vessel could be reduced by a factor of 30 about half a month after a D-T shot, when the aluminum alloy system is adopted instead of a stainless steel system. The aluminum system has weak mechanical strength, is highly conductive, and shows overaging effect at a certain low temperature. Accordingly, it is necessary to overcome these points. The highly conductive aluminum case leads to considerable increase in power consumption. Various problems on the toroidal coils, the vacuum system, and the limiter were studied. The optimization of the device parameters was investigated. (Kato, T.)

  6. Analysis of heavy alloying elements segregation in gravity cast experimental Mg-Al-Zn-RE alloy

    Directory of Open Access Journals (Sweden)

    A. Żydek

    2010-01-01

    Full Text Available Microstructure of experimental AZ91 alloy with an addition of rare earth elements (RE at a level of 4 wt.% was examined by means of light microscopy. The investigated AZ91 + 4 wt.% RE alloy was fabricated by adding cerium rich mish metal to molten commercial AZ91 alloy. In the microstructure of the resulting alloy, besides α solid solution, α + γ eutectic and discontinuous precipitates of γ phase, also the Al11RE3 phase with needle-like morphology and the polygonal Al10RE2Mn7 phase were revealed. No segregation of rare earth elements was found in the investigated gravity cast alloy, which was confirmed by statistical analysis of cerium concentrations in selected parts of the cast. Similar results were obtained for manganese. Ce and Mn concentrations were determined by a spectrophotometric method.

  7. Superplasticity in powder metallurgy aluminum alloys and composites

    International Nuclear Information System (INIS)

    Superplasticity in powder metallurgy Al alloys and composites has been reviewed through a detailed analysis. The stress-strain curves can be put into 4 categories: classical well-behaved type, continuous strain hardening type, continuous strain softening type and complex type. The origin of these different types of is discussed. The microstructural features of the processed material and the role of strain have been reviewed. The role of increasing misorientation of low angle boundaries to high angle boundaries by lattice dislocation absorption is examined. Threshold stresses have been determined and analyzed. The parametric dependencies for superplastic flow in modified conventional aluminum alloys, mechanically alloyed alloys and Al alloy matrix composites is determined to elucidate the superplastic mechanism at high strain rates. The role of incipient melting has been analyzed. A stress exponent of 2, an activation energy equal to that for grain boundary diffusion and a grain size dependence of 2 generally describes superplastic flow in modified conventional Al alloys and mechanically alloyed alloys. The present results agree well with the predictions of grain boundary sliding models. This suggests that the mechanism of high strain rate superplasticity in the above-mentioned alloys is similar to conventional superplasticity. The shift of optimum superplastic strain rates to higher values is a consequence of microstructural refinement. The parametric dependencies for superplasticity in aluminum alloy matrix composites, however, is different. A true activation energy of superplasticity in aluminum alloy matrix composites, however, is different. A true activation energy of 313 kJ/mol best describes the composites having SiC reinforcements. The role of shape of the reinforcement (particle or whisker) and processing history is addressed. The analysis suggests that the mechanism for superplasticity in composites is interface diffusion controlled grain boundary sliding

  8. Laser surface treatment of cast Al-Si-Cu alloys

    OpenAIRE

    K. Labisz

    2013-01-01

    Purpose: The test results presented in this chapter concern formation of the quasi-composite MMCs structure on the surface of elements from aluminium cast alloys AC-AlSi9Cu and AC-AlSi9Cu4 by fusion of the carbide or ceramic particles WC, SiC, ZrO2 and Al2O3 in the surface of alloys. In addition, within the scope of the tests the phase transformations and precipitation processes present during laser remelting and fusion at appropriately selected parameters: laser power, the ra...

  9. Laser surface treatment of cast Al-Si-Cu alloys

    Directory of Open Access Journals (Sweden)

    K. Labisz

    2013-12-01

    Full Text Available Purpose: The test results presented in this chapter concern formation of the quasi-composite MMCs structure on the surface of elements from aluminium cast alloys AC-AlSi9Cu and AC-AlSi9Cu4 by fusion of the carbide or ceramic particles WC, SiC, ZrO2 and Al2O3 in the surface of alloys. In addition, within the scope of the tests the phase transformations and precipitation processes present during laser remelting and fusion at appropriately selected parameters: laser power, the rate of fusion and quantity of the ceramic powder fed have been partially examined. Design/methodology/approach: In general, the laser surface processing should result in achievement of the surface layer with the most favourable physical and mechanical properties, in particular enhancement of surface hardness, improvement of abrasion resistance and resistance to corrosion is assumed in relation to the selected aluminium alloys after standard thermal processing. Findings: The presented results of the surface layer include analysis of the mechanisms responsible for formation of the layer, and particularly concern remelting of the substrate and its crystallisation at various parameters of the High Power Diode Laser (HPDL and the technological conditions of the surface processing, remelting and fusion of the particles in the surface of cast alloys ACAlSi9Cu and ACAlSi9Cu4. For the purpose of testing the structure of the obtained surface layers the test methods making use of the light microscopy method supported with computer image analysis, transmission and scanning electron microscopy, X-ray analysis, X-ray microanalysis, as well as methods for testing the mechanical and usable properties have been used. Practical implications: What is more, development of the technology of surface refinement of cast alloys Al-Si-Cu with the laser fusion methods will allow for complex solving of the problem related to enhancement of the surface layer properties, taking into account both economic

  10. Effect of pre-treatment on recrystallization and recrystallization textures of cold rolled CC AA 5182 aluminum alloy

    International Nuclear Information System (INIS)

    The effect of pre-treatment on recrystallization and recrystallization textures of cold rolled continuous cast (CC) AA 5182 aluminum alloy as well as on the earing behavior was investigated. The progress of recrystallization was tracked by means of measurements of tensile properties. The texture of cold rolled and annealed samples was determined by X-ray diffraction. The results show that the recrystallization temperature of cold rolled CC AA 5182 aluminum alloy without pre-treatment is about 24 deg. C higher than that of the alloy with pre-treatment. The recrystallization textures of cold rolled CC AA 5182 aluminum alloy are characterized by the R, cube and Goss orientations. The recrystallization textures of cold rolled CC AA 5182 aluminum alloy without pre-treatment exhibit stronger cube and Goss components and a weaker R component than those of the alloy with pre-treatment. The deformed and recovered samples without pre-treatment possess a significantly higher 45 deg. earing than the samples with pre-treatment, while the recrystallized samples without pre-treatment possess a slightly lower 45 deg. earing than the samples with pre-treatment

  11. Description Of Alloy Layer Formation On A Cast Steel Substrate

    Directory of Open Access Journals (Sweden)

    Szajnar J.

    2015-09-01

    Full Text Available A description of alloy layer formation on a steel substrate is presented. Two types of formation are considered: diffusion of carbon and chromium into the solid from the pad in the direction of the cast steel within the FeCrC (grains and diffusion in a layer of liquid chromium cast iron formed in a preceding step. The influence of silicon in the pad on the pad’s transformation into the liquid is also examined. Solidus and liquidus temperatures of high carbon ferrochromium are determined. The larger the content of Si is used in the experiment, the lower the solidus temperature of the FeCrC alloy is observed. This results from the higher intensity of the elements’ diffusion and faster formation of the liquid.

  12. Process on cold crucible electromagnetic casting for titanium alloy

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The parameters and factors that influence the surface quality and macrostructure of titanium alloy with reactive properties under liquid state were studied experimentally using a cold crucible electromagnetic casting method. The variations in the process parameters have great impact on the surface quality and macrostructure of cast billets. Billets with crack free and smooth surfaces as well as directional solidified primary structures were obtained after the selection of optimized process parameters. The formation mechanisms of defects such as cracks and non-directional structural morphology were interpreted briefly. Finally, the casting of billets with good outer qualities and inner column grains has been attained successfully, which in turn gives a solid foundation for further development of the technology.

  13. Process on cold crucible electromagnetic casting for titanium alloy

    Directory of Open Access Journals (Sweden)

    CHEN Rui-run

    2007-08-01

    Full Text Available The parameters and factors that influence the surface quality and macrostructure of titanium alloy with reactive properties under liquid state were studied experimentally using a cold crucible electromagnetic casting method. The variations in the process parameters have great impact on the surface quality and macrostructure of cast billets. Billets with crack free and smooth surfaces as well as directional solidified primary structures were obtained after the selection of optimized process parameters. The formation mechanisms of defects such as cracks and non-directional structural morphology were interpreted briefly. Finally, the casting of billets with good outer qualities and inner column grains has been attained successfully, which in turn gives a solid foundation for further development of the technology.

  14. Forming analysis and application for aluminum-alloy material

    Institute of Scientific and Technical Information of China (English)

    Wei Yuansheng

    2012-01-01

    The increase in car ownership brought about by energy shortages, and environmental crises became more acute. The most effective way to achieve energy saving and emission reduction of car is to improve engine efficiency. In addition to that, lightweight body is the key. Aluminum, magnesium alloy as significant materials of lightweight, and the application amount in the car body is a significant upward trend. However, there is high cost of material, with im- mature applied technology and a series of bottleneck problems. All of them affect general application of lightweight mate- rials. This paper focuses on forming process issues for aluminum, magnesium alloy and the solutions to achieve.

  15. Thermodynamics of Titanium-Aluminum-Oxygen Alloys Studied

    Science.gov (United States)

    Copland, Evan H.; Jacobson, Nathan S.

    2001-01-01

    Titanium-aluminum alloys are promising intermediate-temperature alloys for possible compressor applications in gas-turbine engines. These materials are based on the a2-Ti3Al + g-TiAl phases. The major issue with these materials is high oxygen solubility in a2-Ti3Al, and oxidation of unsaturated alloys generally leads to mixed non-protective TiO2+Al2O3 scales. From phase diagram studies, oxygen saturated a2-Ti3Al(O) is in equilibrium with Al2O3; however, oxygen dissolution has a detrimental effect on mechanical properties and cannot be accepted. To better understand the effect of oxygen dissolution, we examined the thermodynamics of titanium-aluminum-oxygen alloys.

  16. Effect of casting/mould interfacial heat transfer during solidification of aluminium alloys cast in CO2-sand mould

    Science.gov (United States)

    Kulkarni, S. N.; Radhakrishna, D. K.

    2011-06-01

    The ability of heat to flow across the casting and through the interface from the casting to the mold directly affects the evolution of solidification and plays a notable role in determining the freezing conditions within the casting, mainly in foundry systems of high thermal diffusivity such as chill castings. An experimental procedure has been utilized to measure the formation process of an interfacial gap and metal-mould interfacial movement during solidification of hollow cylindrical castings of Al-4.5 % Cu alloy cast in CO2-sand mould. Heat flow between the casting and the mould during solidification of Al-4.5 % Cu alloy in CO2-sand mould was assessed using an inverse modeling technique. The analysis yielded the interfacial heat flux ( q), heat transfer coefficient ( h) and the surface temperatures of the casting and the mould during solidification of the casting. The peak heat flux was incorporated as a dimensionless number and modeled as a function of the thermal diffusivities of the casting and the mould materials. Heat flux transients were normalized with respect to the peak heat flux and modeled as a function of time. The heat flux model proposed was to estimate the heat flux transients during solidification of Al-4.5 % Cu alloy cast in CO2-sand moulds.

  17. Heat transfer at the mold-metal interface in permanent mold casting of aluminum alloys project. Annual project status report for the period October 1, 1997 to September 30, 1998

    Energy Technology Data Exchange (ETDEWEB)

    Pehlke, R.D.; Hao, S.W.

    1998-09-30

    In the first year of this three-year project, substantial progress has been achieved. This project on heat transfer coefficients in metal permanent mold casting is being conducted in three areas. They are the theoretical study at the University of Michigan, the experimental investigations of squeeze casting and semi-solid casting at CMI-Tech Center, and the experimental investigation of low pressure permanent mold casting at Amcast Automotive. U-M did an initial geometry which was defined for ProCAST to solve, and then a geometry half the size was defined and solved using the same boundary conditions. A conceptual mold geometry was examined and is represented as an axisymmetric element.Furthermore, the influences of the localized heat transfer coefficients on the casting process were carefully studied. The HTC Evaluator has been proposed and initially developed by the U-M team. The Reference and the Database Modules of the HTC Evaluator have been developed, and extensively tested. A series of technical barriers have been cited and potential solutions have been surveyed. At the CMI-Tech Center, the Kistler direct cavity pressure measurement system has been purchased and tested. The calibrations has been evaluated. The probe is capable of sensing a light finger pressure. The experimental mold has been designed and modified. The experimental mold has been designed and modified. The first experiment is scheduled for October 14, 1998. The geometry of the experimental hockey-puck casting has been given to the U-M team for numerical analysis.

  18. INCREASE OF EFFICIENCY OF MODIFIERS FOR GRAY CAST-IRON

    Directory of Open Access Journals (Sweden)

    O. S. Komarov

    2012-01-01

    Full Text Available It is established that for the purpose of increase of modifying efficiency of the melt from gray cast iron it is possible to use mechanically alloyed aluminum powder with superdispersed particles of aluminum and graphite oxide.

  19. Producing Foils From Direct Cast Titanium Alloy Strip

    Science.gov (United States)

    Stuart, T. A.; Gaspar, T. A.; Sukonnik, I. M.; Semiatan, S. L.; Batawi, E.; Peters, J. A.; Fraser, H. L.

    1996-01-01

    This research was undertaken to demonstrate the feasibility of producing high-quality, thin-gage, titanium foil from direct cast titanium strip. Melt Overflow Rapid Solidification Technology (MORST) was used to cast several different titanium alloys into 500 microns thick strip, 10 cm wide and up to 3 m long. The strip was then either ground, hot pack rolled or cold rolled, as appropriate, into foil. Gamma titanium aluminide (TiAl) was cast and ground to approximately 100 microns thick foil and alpha-2 titanium aluminide (Ti3AI) was cast and hot pack rolled to approximately 70 microns thick foil. CP Ti, Ti6Al2Sn4Zr2Mo, and Ti22AI23Nb (Orthorhombic), were successfully cast and cold-rolled into good quality foil (less than 125 microns thick). The foils were generally fully dense with smooth surfaces, had fine, uniform microstructures, and demonstrated mechanical properties equivalent to conventionally produced titanium. By eliminating many manufacturing steps, this technology has the potential to produce thin gage, titanium foil with good engineering properties at significantly reduced cost relative to conventional ingot metallurgy processing.

  20. Influence of heat treatment on microstructure and tensile properties of a cast Al-Cu-Si-Mn alloy

    Directory of Open Access Journals (Sweden)

    Liu Zhixue

    2013-11-01

    Full Text Available Solution and aging treatments are important approaches to improve mechanical properties and microstructure of aluminum-base alloys. In this research, a new type high strength Al-Cu-Si-Mn cast alloy was prepared. The effect of different solution and aging treatment temperatures on microstructure and mechanical properties of the Al-Cu-Si-Mn cast alloy were studied by means of microstructure observation and mechanical properties testing. Results showed that after solution treated at different temperatures for 12 h and aged at 175 ℃ for 12 h, with the increase of the solution temperature, both the tensile strength and the elongation of the alloy firstly increase and then decrease, and reach their peak values at 530 ℃. When the solution temperature is below 530 ℃, the microstructure of the alloy consists of α phase, undissolved θ phase and T phase; while when it exceeds 530 ℃, the microstructure only consists of α phase and T phase. After solution treated at 530 ℃ for 12 h and aged at different temperatures for 12 h, both the tensile strength and the elongation of the alloy firstly increase and then decrease with the increasing of temperature, and reach their peak values at 175 ℃. Therefore, the optimal heat treatment process for the alloy in this study is 12 h solution at 530 ℃ and 12 h aging at 175 ℃, and the corresponding tensile strength is 417 MPa, elongation is 4.0%.

  1. Characterization of Ni–Cr alloys using different casting techniques and molds

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Wen-Cheng, E-mail: wencchen@fcu.edu.tw [Advanced Medical Devices and Composites Laboratory, Department of Fiber and Composite Materials, College of Engineering, Feng Chia University, Taichung 40724, Taiwan (China); Teng, Fu-Yuan [Department of Dentistry, Kaohsiung Armed Forces General Hospital, Kaohsiung 802, Taiwan (China); School of Dentistry, College of Dental Medicine, Kaohsiung Medical University, Kaohsiung 807, Taiwan (China); Hung, Chun-Cheng [School of Dentistry, College of Dental Medicine, Kaohsiung Medical University, Kaohsiung 807, Taiwan (China); Department of Dentistry, Kaohsiung Medical University Hospital, Kaohsiung 807, Taiwan (China)

    2014-02-01

    This study differentiated the mechanical properties of nickel–chromium (Ni–Cr) alloys under various casting techniques (different casting molds and casting atmospheres). These techniques were sampled by a sand mold using a centrifugal machine in ambient air (group I) and electromagnetic induction in an automatic argon castimatic casting machine (group II). The specimen casting used a graphite mold by a castimatic casting machine (group III). The characteristics of the Ni–Cr alloys, yield and ultimate tensile strength, bending modulus, microhardness, diffraction phase, grindability, ability to spring back, as well as ground microstructure and pattern under different casting conditions were evaluated. The group III specimens exhibited the highest values in terms of strength, modulus, hardness, and grindability at a grind rate of 500 rpm. Moreover, group III alloys exhibited smaller grain sizes, higher ability to spring back, and greater ductility than those casted by sand investment (groups I and II). The main factor, “casting mold,” significantly influenced all mechanical properties. The graphite mold casting of the Ni–Cr dental alloys in a controlled atmosphere argon casting system provided an excellent combination of high mechanical properties and good ability to spring back, and preserved the ductile properties for application in Ni–Cr porcelain-fused system. The results can offer recommendations to assist a prosthetic technician in selecting the appropriate casting techniques to obtain the desired alloy properties. - Highlights: • Properties of Ni–Cr alloys using various casting techniques are characterized. • Alloys cast by graphite mold exhibited higher recovery angle and more ductility. • Alloys cast by graphite mold exhibited higher strength and grinding rate. • Alloys in this study increase operative room to adjust the precision for prosthesis.

  2. High Pressure Die Casting of Aluminium and Magnesium Alloys : Grain Structure and Segregation Characteristics

    OpenAIRE

    Laukli, Hans Ivar

    2004-01-01

    Cold chamber high pressure die casting, (HPDC), is an important commercial process for the production of complex near net shape aluminium and magnesium alloy castings. The work presented in the thesis was aimed at investigating the microstructure formation in this type of casting. The solidification characteristics related to the process and the alloys control the formation of grains and defects. This again has a significant impact on the mechanical properties of the castings.The investigatio...

  3. Phase-oriented surface segregation in an aluminium casting alloy

    International Nuclear Information System (INIS)

    There have been many reports of the surface segregation of minor elements, especially Mg, into surface layers and oxide films on the surface of Al alloys. LM6 casting alloy (Al-12%Si) represents a challenging system to examine such segregation as the alloy features a particularly inhomogeneous phase structure. The very low but mobile Mg content (approximately 0.001 wt.%), and the surface segregation of modifiers such as Na, mean the surface composition responds in a complex manner to thermal treatment conditions. X-ray photoelectron spectroscopy (XPS) has been used to determine the distribution of these elements within the oxide film. Further investigation by dynamic secondary ion mass spectrometry (DSIMS) confirmed a strong alignment of segregated Na and Mg into distinct phases of the structure.

  4. Roles of Alloy Composition and Grain Refinement on Hot Tearing Susceptibility of 7××× Aluminum Alloys

    Science.gov (United States)

    Bai, Q. L.; Li, Y.; Li, H. X.; Du, Q.; Zhang, J. S.; Zhuang, L. Z.

    2016-08-01

    During the production of high-strength 7××× aluminum alloys, hot tearing has set up serious obstacles for attaining a sound billet/slab. In this research, some typical 7××× alloys were studied using constrained rod casting together with the measurement of thermal contraction and load development in the freezing range, aiming at investigating their hot tearing susceptibility. The results showed that the hot tearing susceptibility of an alloy depends not only on the thermal contraction in freezing range, which can decide the accumulated thermal strain during solidification, but also on the amount of nonequilibrium eutectics, which can effectively accommodate the thermally induced deformation. Our investigations reveal that Zn content has very profound effect on hot tearing susceptibility. The Zn/Mg ratio of the alloys also plays a remarkable role though it is not as pronounced as Zn content. The effect of Zn/Mg ratio is mainly associated with the amount of nonequilibrium eutectics. Grain refinement will considerably reduce the hot tearing susceptibility. However, excessive addition of grain refiner may promote hot tearing susceptibility of semi-solid alloy due to deteriorated permeability which is very likely to be caused by the heavy grain refinement and the formation of more intermetallic phases.

  5. Part A - low-aluminum-content iron-aluminum alloys. Part B - commercial-scale melting and processing of FAPY alloy

    Energy Technology Data Exchange (ETDEWEB)

    Sikka, V.K.; Howell, C.R.; Hall, F.; Valykeo, J. [Hoskins Manufacturing Co., Hamburg, MI (United States)

    1996-06-01

    The FAPY is a Fe-16 at. % Al alloy of nominal composition. The aluminum content of the alloy is such that it remains single phase ({alpha}) without the formation of an ordered phase (DO{sub 3}). The alloy has good oxidation resistance at temperatures up to 1000{degrees}C and has shown significantly superior performance as heating elements as compared to the commonly used nickel-based alloy, Nichrome. Although wire for the heating elements has been fabricated from small (15-1b) laboratory heats, for its commercial applications, the wire needs to be producible from large (1200 to 1500-1b) air-melted heats. The purpose of this study was to produce commercial size heats and investigate their mechanical properties and microstructure in the as-cast, hot-worked, and cold-worked conditions. The results of this study are expected to provide: (1) insight into processing steps for large heats into wire under commercial conditions, and (2) the mechanical properties data on commercial size heats in various product forms.

  6. Effect of Silicon on the casting properties of Al-5.0%Cu alloy

    Institute of Scientific and Technical Information of China (English)

    LI Weijing; CUI Shihai; HAN Jianmin; XU Chao

    2006-01-01

    Poor casting properties restrict the application of high strength casting Al-5.0%Cu alloy.The addition of element can improve the casting properties of this alloy.Effect of Si on the casting properties of Al-5.0%Cu alloy was studied.It has been found that the addition of Si can improve the casting properties of Al-5.0%Cu alloy obviously.With the increase of Si content, the hot cracking tendency of the alloy decreases significantly, and the fluidity of the alloy increases firstly and then decreases slowly.When the content of Si element is higher than 2wt.%, the fluidity of the alloy increases greatly with the increasing of Si content.

  7. Mechanical Properties of Solid-State Recycled 4xxx Aluminum Alloy Chips

    Science.gov (United States)

    Tokarski, Tomasz

    2016-08-01

    The direct production of aluminum from bauxite ores is known to be a very energetic-intensive operation compared to other metallurgical processes. Due to energy issues and the rapid increase in aluminum demand, new kinds of aluminum production processes are required. Aluminum waste recycling, which has an advantage of lowering the cost of electric power consumption, is considered to be an alternative route for material manufacturing. In this work, the way of reusing aluminum EN-AC 44000 alloy scraps by hot extrusion was presented. Metal chips of different sizes and morphology were cold compacted into billet form and then hot extruded. Mechanical properties investigations combined with microstructure observations were performed. Mechanical anisotropy behavior of material was evaluated on the base of tensile test experiments performed on samples machined at 0°, 45°, and 90°, respectively, to the extrusion direction. It was found that the initial size of the chips has an influence on the mechanical properties of the received profiles. Samples produced from fine chips revealed higher tensile strength in comparison to larger chips, which can be attributed to a refined microstructure containing fine, hard Si particles and Fe-rich intermetallic phases. Finally, it was found that anisotropic behavior of chip-based profiles is similar to conventionally cast and extruded materials which prove good bonding quality between chips.

  8. Mechanical Properties of Solid-State Recycled 4xxx Aluminum Alloy Chips

    Science.gov (United States)

    Tokarski, Tomasz

    2016-06-01

    The direct production of aluminum from bauxite ores is known to be a very energetic-intensive operation compared to other metallurgical processes. Due to energy issues and the rapid increase in aluminum demand, new kinds of aluminum production processes are required. Aluminum waste recycling, which has an advantage of lowering the cost of electric power consumption, is considered to be an alternative route for material manufacturing. In this work, the way of reusing aluminum EN-AC 44000 alloy scraps by hot extrusion was presented. Metal chips of different sizes and morphology were cold compacted into billet form and then hot extruded. Mechanical properties investigations combined with microstructure observations were performed. Mechanical anisotropy behavior of material was evaluated on the base of tensile test experiments performed on samples machined at 0°, 45°, and 90°, respectively, to the extrusion direction. It was found that the initial size of the chips has an influence on the mechanical properties of the received profiles. Samples produced from fine chips revealed higher tensile strength in comparison to larger chips, which can be attributed to a refined microstructure containing fine, hard Si particles and Fe-rich intermetallic phases. Finally, it was found that anisotropic behavior of chip-based profiles is similar to conventionally cast and extruded materials which prove good bonding quality between chips.

  9. Titanium-zirconium-phosphonate hybrid film on 6061 aluminum alloy

    Institute of Scientific and Technical Information of China (English)

    Shuanghong WANG; Lei WANG; Changsheng LIU

    2011-01-01

    Three titanium-zirconium-phosphonate hybrid films were formed on AA6061 aluminum alloy by immersing in fluorotitanic acid and fluorozirconic acid based solution containing different phosphonic acids for protective coatings of aluminium alloy. The corrosion resistance of three hybrid films as the substitute for chromate film were evaluated and compared. The neutral salt spray test was explored,the immersion test was conducted and electrochemical test was also executed. The hybrid films exhibited well-pleasing corrosion resistance and adhesion to epoxy resin paints. It was found out that the hybrid films could efficiently be a substitute for chromate based primer over aluminium alloy.

  10. Lead induced intergranular fracture in aluminum alloy AA6262

    NARCIS (Netherlands)

    De Hosson, JTM

    2003-01-01

    The influence of lead on the fracture behavior of aluminum alloy AA6262 is investigated. Under certain conditions, the mode of fracture changes from transgranular microvoid coalescence to an intergranular mechanism. Three different intergranular fracture mechanisms are observed: liquid metal embritt

  11. Testing of 2219-T87 aluminum alloy at 40K

    International Nuclear Information System (INIS)

    The tensile and fracture properties of heavy section (1.5 inches thick) 2219-T87 plate aluminum alloy at 40K were determined. Transverse and longitudinal crack growth parameters were measured. Tensile specimens were taken at L, T, and ST orientations and tensile data is tabulated. K/sub Ic/ tests results and fatigue-crack growth data are summarized

  12. Fracture behavior of low-density replicated aluminum alloy foams

    NARCIS (Netherlands)

    Amsterdam, E.; Goodall, R.; Mortensen, A.; Onck, P. R.; De Hosson, J. Th. M.

    2008-01-01

    Tensile tests have been performed on replicated aluminum alloy foams of relative density between 4.5% and 8%. During the test the electrical resistance was measured with a four-point set-up and the displacements along the gage section were measured using a digital image correlation (DIC) technique.

  13. Study made of ductility limitations of aluminum-silicon alloys

    Science.gov (United States)

    Bailey, W. A.; Frederick, S. F.

    1967-01-01

    Study of the relation between microstructure and mechanical properties of aluminum-silicon alloys determines the cause of the variations in properties resulting from differences in solidification rate. It was found that variations in strength are a consequence of variations in ductility and that ductility is inversely proportional to dendrite cell size.

  14. Sliding Wear Behavior of Plasma Sprayed Zirconia Coating on Cast Aluminum against Silicon Carbide Ceramic

    Institute of Scientific and Technical Information of China (English)

    Thuong-Hien LE; Young-Hun CHAE; Seock-Sam KIM

    2005-01-01

    The sliding wear behaviors of ZrO2-22 wt pct MgO (MZ) and ZrO2-8 wt pct Y2O3 (YZ) coatings deposited on a cast aluminum alloy with bond layer (NiCrCoAlY) by plasma spray were investigated under dry test conditions at room temperature. Under all load conditions, the wear mechanisms of the MZ and YZ coatings were almost the same.The material transfer and pullout were involved in the wear process of the studied coatings under the test conditions.The wear rate of the MZ coating was less than that of the YZ coating. While increasing the normal load, the wear rates of the MZ and YZ coatings increased. SEM was used to examine the worn surfaces and to elucidate likely wear mechanisms. Energy dispersive X-ray spectroscopy (EDX) analysis of the worn surfaces indicated that material transfer occurred in the direction from the SiC ball to the disk. Fracture toughness had a significant influence on the wear performance of the coatings. It was suggested that the material transfer played an important role in the wear behavior.

  15. New all aluminum alloy ultrahigh vacuum system and fittings

    International Nuclear Information System (INIS)

    The Al-ICF ALFLAT FLANGE corresponds to the ordinary stainless steel Conflat flange. The Al-ICF ALFLAT FLANGE is made of special aluminum alloy 2219-T87 by forging. It has the highest strength at elevated high temperature among all aluminum alloys as well as superior weldability and stress corrosion cracking resistivity. CrN or TiC coating on the flange surface by ion plating. The CrN or TiC treatment on the surface gave nearly protection against sticking between the knife edge of the flange and the aluminum gasket and surface scratching. Sealing surface of the knife edge for the Helicoflex is finished to a smooth mirror surface by a diamond tool. (author)

  16. System for ultra high vacuum made of aluminum alloys

    International Nuclear Information System (INIS)

    We have developed the system for ultra high vacuum made of aluminum alloys for proton and electron synchrotron. This is the first system for ultra high vacuum in which bakable metal seal flange and small diametral bellows of aluminum alloys have been put to practical use. The system consists of the flange protected by a CrN thin film and made of 2219-T87 alloy, the chamber made of 6063-T6 alloy, the aluminum metal gasket of Helico Flex and the bellows made of 5052 alloy. As a result of experiments at the National Laboratory for High Energy Physics (KEK), it had been confirmed that this system shows the special qualities of ultra high vacuum operation, resistance to hard radiation and baking and cooling operations. Up to now, this system has been widely used for the beam lines of the booster synchrotron utilization facility, K1, K2, linac, PI 1 and EP2-B extension of the KEK proton synchrotron. We investigate that this system is applicable to nuclear energy utilization facility and general vacuum apparatus. (author)

  17. Cleavage crystallography of liquid metal embrittled aluminum alloys

    Science.gov (United States)

    Reynolds, A. P.; Stoner, G. E.

    1991-01-01

    The crystallography of liquid metal-induced transgranular cleavage in six aluminum alloys having a variety of microstructures has been determined via Laue X-ray back reflection. The cleavage crystallography was independent of alloy microstructure, and the cleavage plane was 100-plane oriented in all cases. It was further determined that the cleavage crystallography was not influenced by alloy texture. Examination of the fracture surface indicated that there was not a unique direction of crack propagation. In addition, the existence of 100-plane cleavage on alloy 2024 fracture surfaces was inferred by comparison of secondary cleavage crack intersection geometry on the 2024 surfaces with the geometry of secondary cleavage crack intersections on the test alloys.

  18. New Approaches to Aluminum Integral Foam Production with Casting Methods

    OpenAIRE

    Ahmet Güner; Mustafa Merih Arıkan; Mehmet Nebioglu

    2015-01-01

    Integral foam has been used in the production of polymer materials for a long time. Metal integral foam casting systems are obtained by transferring and adapting polymer injection technology. Metal integral foam produced by casting has a solid skin at the surface and a foam core. Producing near-net shape reduces production expenses. Insurance companies nowadays want the automotive industry to use metallic foam parts because of their higher impact energy absorption properties. In this paper, m...

  19. Microstructures of ancient and modern cast silver–copper alloys

    Energy Technology Data Exchange (ETDEWEB)

    Northover, S.M., E-mail: s.m.northover@open.ac.uk [Materials Engineering, The Open University, Walton Hall, Milton Keynes MK7 6AA (United Kingdom); Northover, J.P., E-mail: peter.northover@materials.ox.ac.uk [Department of Materials, University of Oxford, Parks Rd, Oxford OX1 3PH,UK (United Kingdom)

    2014-04-01

    The microstructures of modern cast Sterling silver and of cast silver objects about 2500 years old have been compared using optical microscopy (OM), scanning electron microscopy (SEM), transmission electron microscopy (TEM), scanning transmission electron microscopy (STEM), energy dispersive X-ray microanalysis (EDX) and electron backscatter diffraction (EBSD). Microstructures of both ancient and modern alloys were typified by silver-rich dendrites with a few pools of eutectic and occasional cuprite particles with an oxidised rim on the outer surface. EBSD showed the dendrites to have a complex internal structure, often involving extensive twinning. There was copious intragranular precipitation within the dendrites, in the form of very fine copper-rich rods which TEM, X-ray diffraction (XRD), SEM and STEM suggest to be of a metastable face-centred-cubic (FCC) phase with a cube–cube orientation relationship to the silver-rich matrix but a higher silver content than the copper-rich β in the eutectic. Samples from ancient objects displayed a wider range of microstructures including a fine scale interpenetration of the adjoining grains not seen in the modern material. Although this study found no unambiguous evidence that this resulted from microstructural change produced over archaeological time, the copper supersaturation remaining after intragranular precipitation suggests that such changes, previously proposed for wrought and annealed material, may indeed occur in ancient silver castings. - Highlights: • Similar twinned structures and oxidised surfaces seen in ancient and modern cast silver • General precipitation of fine Cu-rich rods apparently formed by discontinuous precipitation is characteristic of as-cast silver. • The fine rods are cube-cube related to the matrix in contrast with the eutectic. • The silver-rich phase remains supersaturated with copper. • Possibly age-related grain boundary features seen in ancient cast silver.

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

    Energy Technology Data Exchange (ETDEWEB)

    Dr. Subodh K. Das; Shridas Ningileri

    2006-03-17

    This project led to an improved understanding of the mechanisms of dross formation. The microstructural evolution in industrial dross samples was determined. Results suggested that dross that forms in layers with structure and composition determined by the local magnesium concentration alone. This finding is supported by fundamental studies of molten metal surfaces. X-ray photoelectron spectroscopy data revealed that only magnesium segregates to the molten aluminum alloy surface and reacts to form a growing oxide layer. X-ray diffraction techniques that were using to investigate an oxidizing molten aluminum alloy surface confirmed for the first time that magnesium oxide is the initial crystalline phase that forms during metal oxidation. The analytical techniques developed in this project are now available to investigate other molten metal surfaces. Based on the improved understanding of dross initiation, formation and growth, technology was developed to minimize melt loss. The concept is based on covering the molten metal surface with a reusable physical barrier. Tests in a laboratory-scale reverberatory furnace confirmed the results of bench-scale tests. The main highlights of the work done include: A clear understanding of the kinetics of dross formation and the effect of different alloying elements on dross formation was obtained. It was determined that the dross evolves in similar ways regardless of the aluminum alloy being melted and the results showed that amorphous aluminum nitride forms first, followed by amorphous magnesium oxide and crystalline magnesium oxide in all alloys that contain magnesium. Evaluation of the molten aluminum alloy surface during melting and holding indicated that magnesium oxide is the first crystalline phase to form during oxidation of a clean aluminum alloy surface. Based on dross evaluation and melt tests it became clear that the major contributing factor to aluminum alloy dross was in the alloys with Mg content. Mg was

  1. Development of environmentally friendly cast alloys. High-zinc Al alloys

    Directory of Open Access Journals (Sweden)

    W.K. Krajewski

    2010-10-01

    Full Text Available Purpose: The main purpose of this paper is presenting the results obtained in years 2007 – 2010 in frame of the project Marie Curie Transfer of Knowledge – CastModel. The project was focused, among others, at elaborating new, environmentally friendly cast alloys based on the Al-Zn system. Particularly, efforts were aimed at improving ductility of the sand cast high-zinc aluminium alloys (HZnAl by using the newly elaborated master alloys, based on the Al-Zn-Ti system.Design/methodology/approach: The presented work is focused on the nucleation of the high-zinc Al-20 wt% Zn (HZnAl AlZn20 alloy, known as the high damping one, aiming at improving plastic properties of the sand castings. The melted alloy was nucleated with AlTi5B1 (TiBAl and AlTi3C0.15 (TiCAl refiners as well as with the newly introduced ZnAl-Ti3 one. During the research the following experimental techniques were used: LM, SEM-EBSD, EDS, TA, DSC, Quantitative Metallography, UTS, Elongation and Attenuation coefficient measurements.Findings: During the performed examinations it was found out that significant increasing of the grain population of the inoculated alloy increases plasticity represented by elongation. The attenuation coefficient of the nucleated alloy, measured using an Olympus Epoch XT device, preserves its high value. The results obtained allow to characterize the examined AlZn20 alloy as promissive, having good strength and damping properties as well as the environmentally friendly alloy because of its comparatively low melting temperatures.Practical implications: The grain-refined high-zinc aluminium alloys can be used as the high damping substitutes of the traditional, more energy consumable Fe-based foundry alloys.Originality/value: The newly elaborated ZnAl-Ti based master alloys show high refining potency and quick dissolution in low melting temperatures of about 500°C, and are the promissive alternatives of the traditional AlTi-based ones.

  2. Dynamic Crystallization: An Influence on Degree of Prior Deformation and Mechanical Strength of 6063 Aluminum Alloy

    Directory of Open Access Journals (Sweden)

    Gbenebor, O.P

    2012-09-01

    Full Text Available This research is aimed at investigating the influence dynamic solidification of melts on degree of mechanical deformation and mechanical strength of 6063 aluminum alloy. Cylindrical samples of 14mm diameter and 140mm long were die cast following two techniques – vibration and static. Prior deformation via forging was imposed on each solidified sample to achieve 7%, 14%, 21% and 28% thickness reductions respectively for each casting technique. Average deformation load, average hammer velocities and the average energy absorbed were recorded. Tensile properties of each sample were studied via the use of Monsanto tensometer. Mechanical agitation of mould and its content increased the machinability of the alloy even at higer pre deformation. This was justified by the failure of the 28% reduction sample cast on static floor during machining to a tensile piece. The energy absorbed during deformation influences the tensile strength of the material. This increases with increase in percentage deformation except for 28% reduction whose magnitude was lower than that subjected to 21% reduction; vibrated samples possessed superior properties. From results obtained, vibrating a sample and subjecting to 21% pre-deformation possessed the best tensile strength.

  3. Improvement of Sprue Bush Used in Low-Pressure Casting Aluminum Alloy Wheels%铝合金轮毂低压铸造浇口套的改进

    Institute of Scientific and Technical Information of China (English)

    刘宏磊; 梁勇; 刘玉; 刘智峰; 徐涛

    2012-01-01

    通过对陶瓷浇口套与传统金属浇口套对工艺稳定性对比,详细说明了不同材质浇口套在轮毂浇铸系统中的重要作用,并进行了理论分析.在低压铸造过程中,传统的金属浇口浇存在腐蚀快、导热快,铸造工艺难以调整并且波动大,受环境和原料温度影响大.陶瓷浇口套耐腐蚀性强、保温性强、耐高温,有效地保证了补缩通道的温度,使铸件其他部位的冷却强度明显提高后不影响铸件的补缩,生产效率得到明显提高,铸件品质显著提高;并且最终凝固的冒口部位废料重量仅为传统金属材料的一半.%In this paper, comparing ceramic sprue bush with traditional metal sprue bush on stability of the process, the important roles of the different materials sprue bushes on gating system were illustrated in details and analyzed theoretically. In the low-pressure casting process, corrosion and fast heat conduction existed in the traditional metal sprue bush, the casting process is difficult to adjust and large fluctuation, affected by environmental temperature and raw materials; ceramic sprue bush has better corrosion resistance, thermal insulation and high temperature resistance, can effectively ensure the feeding channel temperature, so that casting other parts' cooling strength improve obviously, which does not influence the casting shrinkage, and production efficiency and casting quality improve significantly. At last the riser part of the final solidified waste weight is only half of the traditional metal materials.

  4. The Influence of Casting Conditions on the Microstructure of As-Cast U-10Mo Alloys: Characterization of the Casting Process Baseline

    Energy Technology Data Exchange (ETDEWEB)

    Nyberg, Eric A.; Joshi, Vineet V.; Lavender, Curt A.; Paxton, Dean M.; Burkes, Douglas

    2013-12-13

    Sections of eight plate castings of uranium alloyed with 10 wt% molybdenum (U-10Mo) were sent from Y-12 to the Pacific Northwest National Laboratory (PNNL) for microstructural characterization. This report summarizes the results from this study.

  5. Cavitation erosion mechanism of titanium alloy radiation rods in aluminum melt.

    Science.gov (United States)

    Dong, Fang; Li, Xiaoqian; Zhang, Lihua; Ma, Liyong; Li, Ruiqing

    2016-07-01

    Ultrasound radiation rods play a key role in introducing ultrasonic to the grain refinement of large-size cast aluminum ingots (with diameter over 800 mm), but the severe cavitation corrosion of radiation rods limit the wide application of ultrasonic in the metallurgy field. In this paper, the cavitation erosion of Ti alloy radiation rod (TARR) in the semi-continuous direct-chill casting of 7050 Al alloy was investigated using a 20 kHz ultrasonic vibrator. The macro/micro characterization of Ti alloy was performed using an optical digital microscopy and a scanning electron microscopy, respectively. The results indicated that the cavitation erosion and the chemical reaction play different roles throughout different corrosion periods. Meanwhile, the relationship between mass-loss and time during cavitation erosion was measured and analyzed. According to the rate of mass-loss to time, the whole cavitation erosion process was divided into four individual periods and the mechanism in each period was studied accordingly. PMID:26964935

  6. Deformation and Damage of Two Aluminum Alloys from Ballistic Impact

    Science.gov (United States)

    Anderson, Charles E., Jr.; Dannemann, Kathryn A.

    2002-07-01

    A series of impact experiments were conducted on 4.76-mm-thick aluminum plates to investigate the deformation and damage behavior of two aluminum alloys, 6061-T6 and 7075-T6. The Sierra 165 lead-filled bullet was used to load the plates. Impact velocities were varied from approximately 260 m/s to 370 m/s. The flow stress for 7075-T6 aluminum is approximately twice that for 6061-T6 aluminum; however, the ballistic limit velocities differ by only 10%. The 7075-T6 aluminum plates exhibit less deformation than the 6061-T6 plates at the same impact velocity, but at some critical velocity, a through-thickness crack appears in the 7075-T6 plate, ultimately leading to plate perforation. In contrast, the 6061-T6 plates continue to deform and fail by ductile tearing. These differences in damage/failure result in the two alloys having much closer ballistic limit velocities than expected based on differences in strength.

  7. 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.

  8. Intermetallic phase particles in cast AlSi5Cu1Mg and AlCu4Ni2Mg2 aluminium alloys

    Directory of Open Access Journals (Sweden)

    G. Mrówka-Nowotnik

    2009-08-01

    Full Text Available Purpose: In the technical Al alloys even small quantity of impurities - Fe and Mn - causes the formation of new phase components. Intermetallic particles form either on solidification or whilst the alloy is at a relatively high temperature in the solid state, e.g. during homogenization, solution treatment or recrystallization. The exact composition of the alloy and casting condition will directly influence the selection and volume fraction of intermetallic phases. The main objective of this study was to analyze the morphology and composition of complex microstructure of intermetallic phases in cast AlSi5Cu1Mg and AlCu4Ni2Mg2 aluminium alloys.Design/methodology/approach: In this study, several methods were used such as: optical light microscopy (LM, scanning (SEM electron microscopy in combination with X-ray analysis (EDS using polished sample, and X-ray diffraction (XRD to identify intermetallics in cast AlSi5Cu1Mg and AlCu4Ni2Mg2 aluminum alloys.Findings: The results show that the microstructure of cast AlSi5Cu1Mg and AlCu4Ni2Mg2 aluminum alloys in T6 condition consisted a wide range of intermetallic phases. By using various instruments (LM, SEM, XRD and techniques (imagine, EDS following intermetallic phases were identified: β-Al5FeSi, α-Al15(FeMn3Si - in AlSi5Cu1Mg alloy and Al7Cu4Ni, Al12Cu23Ni, Al2CuMg, AlCuFeNi - in AlCu4Ni2Mg2 alloy.Research limitations/implications: In order to complete and confirm obtained results it is recommended to perform further analysis of the investigated aluminium alloys. Therefore it is planned to include in a next studies, microstructure analysis of the alloys by using transmission electron microscopy technique (TEM.Practical implications: Since the morphology, crystallography and chemical composition affect the intermetallic properties, what involves changes of alloy properties, from a practical point of view it is important to understand their formation conditions in order to control final constituents of

  9. Microstructure and Mechanical Properties of Hyper-eutectic Al-Si Alloys Fabricated by Spray Casting

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Microstructure and mechanical properties of hyper-eutectic Al-Si alloy fabricated by spray casting were investigated and then these results were compared with those by squeeze cast. The spray-cast specimen was found to have finer Si particles (~5μm) compared to the squeeze-cast specimen (10-25μm). The tensile strength and elongation of the spray-cast specimen are also higher than those of the squeeze cast one. It was considered that the increased mechanical properties of the spray-cast specimen were mainly due to finer size of the Si particles distributed in Al matrix.

  10. Influence of hydrogen content on the behavior of grain refinement in hypereutectic aluminum-silicon alloy

    Institute of Scientific and Technical Information of China (English)

    Lina Hu; Xiufang Bian; Youfeng Duan

    2004-01-01

    Dissolved hydrogen is harmful to mechanical properties of refined hypereutectic aluminum-silicon alloys. In the present work, by using a stepped-form mold and the hydrogen-detecting instrument HYSCAN Ⅱ, the relationship between the initial hydrogen content in the melt and the refinement effect on the casting of hypereutectic aluminum-silicon alloy was investigated. The experimental results show that the cooling rate, the hydrogen content and the grain refinement effect are three interactive factors. When the hydrogen content is above 0.20 mL/100 g and the cooling rate is lower than that in 50 mm-thick step, hydrogen dissolved in the alloy melt influences the grain refinement effect. With increasing the cooling rate, the critical hydrogen content increases too. It is expected that much hydrogen in the melt make the net interfacial energy larger than or equal to zero, resulting in the shielding of the particles AlP during solidification and that the critical gas content is closely related to the critical radius of embryo bubbles.

  11. Investigations of microstructure and dislocations of cast magnesium alloys

    Directory of Open Access Journals (Sweden)

    T. Tański

    2010-09-01

    Full Text Available Purpose: The microstructures and the dislocation arrangements in the cast magnesium alloy have been investigated using transmission electron microscopy and high-resolution transmission electron microscopy. In this paper are presented also the results of phase morphology investigation of an new developed Mg alloy. Such studies are of great interest for the metal industry, mainly the automobile industry, were the improvement of cast elements quality is crucial for economic and quality reason and depends mainly on properly performed controlling process of the production parameters. There are presented especially the effect of heat treatment on the size and distribution of the precipitation occurred in the matrix.Design/methodology/approach: The basic assumptions of this work are realised an Universal Metallurgical Simulator and Analyzer. The solidification process itself is analysed using the UMSA device by appliance of the Derivative Thermo Analysis. The thermal analysis was performed at a low but regulated cooling rate in a range of 0.2 ºC to ca. 3 ºC. Cooling curve for the thermal analysis was performed using a high sensitivity thermocouples of the K type, covered with a stainless steel sheath. The data were acquired by a high speed data acquisition system linked to a PC computer. Two different types of samples were used, bulk-cylindrical, and thin-walled cylindrical. Metallographic investigation were made on cross section samples of a engine bloc. Non-equilibrium heating and cooling process conditions were applied to achieve changes in shape and distribution of the phases such as Al2Cu and Si.Findings: During the investigation Dislocation networks are found to increase with deformation in all cases. The dislocation networks have been found in the g- Mg17Al12 phase as well as in the matrix in the investigation magnesium alloys. The crystallographic orientation relationship are: (1 01 α-Mg ║ (10 Mg17Al12 and [11 0] α-Mg ║ [111] Mg17Al12

  12. Microstructures of erbium modified aluminum-copper alloys

    Energy Technology Data Exchange (ETDEWEB)

    Berghof-Hasselbaecher, Ellen; Schmidt, Gerald; Galetz, Mathias; Schuetze, Michael [DECHEMA-Forschungsinstitut, Frankfurt am Main (Germany); Masset, Patrick J. [Fraunhofer UMSICHT-ATZ Entwicklungszentrum, Sulzbach-Rosenberg (Germany); Zhang, Ligang [Technische Univ. Bergakademie Freiberg (Germany). ZIK Virtuhcon; Liu, Libin; Jin, Zhanpeng [Central South Univ., Changsha, Hunan (China)

    2012-07-01

    Alloying with rare earth metals improves to the mechanical properties and corrosion resistance of aluminium base alloys at high temperatures. The rare earth metal erbium may be used for grain refinement. Within a project of computer-aided alloy development based on the CALPHAD (CALculation of PHAse Diagrams) method various alloys were melted on the Al-rich side of the ternary system Al-Cu-Er under argon atmosphere and their microstructures were characterized in the as-cast state or after long-term isothermal annealing (400 C/960 h) by means of different investigation techniques. As a result, the phases fcc (Al), {tau}{sub 1}-Al{sub 8}Cu{sub 4}Er, {theta}-CuAl{sub 2}, {eta}-CuAl, and Al{sub 3}Er were identified, their compositions and fractions were quantified, and their hardnesses were determined. The experimental obtained microstructures agree very well with the calculated solidification behaviors of the cast alloys. The knowledge gained from this work about the phase compositions and microstructures can also be utilized for the fine optimization of the phase diagram. (orig.)

  13. Thermodynamic calculation on metallic thermoreduction during preparation of aluminum-rare master alloys

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A thermodynamic calculation method on metallic thermoreduction during preparation of aluminum-rare metal alloys was presented. Taking preparation of aluminum-scandium master alloys using aluminum and magnesium thermoreduction of scandiumchloride as an example, this method was applied and the results were testified by experiment.

  14. Advanced powder metallurgy aluminum alloys via rapid solidification technology

    Science.gov (United States)

    Ray, R.

    1984-01-01

    Aluminum alloys containing 10 to 11.5 wt. pct. of iron and 1.5 to 3 wt. pct. of chromium using the technique of rapid solidification powder metallurgy were studied. Alloys were prepared as thin ribbons (.002 inch thick) rapidly solidified at uniform rate of 10(6) C/second by the melt spinning process. The melt spun ribbons were pulverized into powders (-60 to 400 mesh) by a rotating hammer mill. The powders were consolidated by hot extrusion at a high reduction ratio of 50:1. The powder extrusion temperature was varied to determine the range of desirable processing conditions necessary to yield useful properties. Powders and consolidated alloys were characterized by SEM and optical metallography. The consolidated alloys were evaluated for (1) thermal stability, (2) tensile properties in the range, room temperature to 450 F, and (3) notch toughness in the range, room temperature to 450 F.

  15. Laser treatment of aluminum copper alloys: A mechanical enhancement

    International Nuclear Information System (INIS)

    Aluminum-copper alloys are commonly used as structural components for the car and aircraft industry. They combine low density, high strength, high fracture toughness and good machinability. Moreover, the strength and wear-resistance of the surface of alloys are improved by a high power laser beam. In this way the molten surface will be self-quenched by conduction of heat into the bulk. This technique ensures solidification velocities of 0.01--1 m/s. These high solidification velocities have a significant influence on the size and distribution of the morphology. This work concentrates on Al-Cu alloys, in which the Cu content ranges between 0--40 wt.%, and is aimed at describing the mechanical and microstructural properties of these alloys upon variation of the laser scan velocity in the range of 0.0125 to 0.125 m/s

  16. Fatigue Characteristics and Quality Index of A357 Type Semi-Solid Aluminum Castings Used for Automotive Application

    Science.gov (United States)

    Bouazara, M.; Bouaicha, A.; Ragab, Kh. A.

    2015-08-01

    The present work aims to investigate the fatigue characteristics of automotive lower suspension arm made of semi-solid A357 aluminum castings using metallurgical and analytical approaches. The fatigue life calculations of analytical model are used to identify and introduce the model parameters based on the suspension arm material followed by analyzing the load-number of cycles fatigue curve. The critical stress areas capable of initiating cracks during fatigue tests are detected using ABAQUS software followed by the installation of strain gages on the suspension arm to calculate maximum stress. The fatigue experiments are carried out to compare the results of the analytical method with the experimental endurance curves traced by lower suspension arm samples. Microstructure characteristics of the semi-solid A357 under T6 heat treatment conditions are examined using scanning electron microscope. The results show that the fatigue life and the quality index of alloys investigated are affected by casting technique, castings design, microstructural characterization, and heat treatment condition.

  17. Pattern Recognition of Thermal Analysis Cooling Curves and Quality Evaluation of Melt Cast Alloys

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The development of thermal analysis techniques for evaluation of cast alloy melt quality and its current applications in the foundry were reviewed. The characteristics of the current thermal analysis techniques were analyzed. A new comprehensive method for cooling curve recognition has been proposed. The evaluation of cast alloy melt quality was realized.

  18. Fatigue crack propagation of new aluminum lithium alloy bonded with titanium alloy strap

    Institute of Scientific and Technical Information of China (English)

    Sun Zhenqi; Huang Minghui

    2013-01-01

    A new type of aluminum lithium alloy (A1-Li alloy) Al-Li-S-4 was investigated by test in this paper.Alloy plate of 400 mm × 140 mm × 6 mm with single edge notch was made into samples bonded with Ti-6Al-4V alloy (Ti alloy) strap by FM 94 film adhesive after the surface was treated.Fatigue crack growth of samples was investigated under cyclic loading with stress ratio (R) of 0.1 and load amplitude constant.The results show that Al-Li alloy plate bonded with Ti alloy strap could retard fatigue crack propagation.Retardation effect is related with width and thickness of strap.Flaws have an observable effect on crack propagation direction.

  19. Microstructure and Thermomechanical Properties of Magnesium Alloys Castings

    Directory of Open Access Journals (Sweden)

    P. Lichý

    2012-04-01

    Full Text Available Magnesium alloys thanks to their high specific strength have an extensive potential of the use in a number of industrial applications. The most important of them is the automobile industry in particular. Here it is possible to use this group of materials for great numbers of parts from elements in the car interior (steering wheels, seats, etc., through exterior parts (wheels particularly of sporting models, up to driving (engine blocks and gearbox mechanisms themselves. But the use of these alloys in the engine structure has its limitations as these parts are highly thermally stressed. But the commonly used magnesium alloys show rather fast decrease of strength properties with growing temperature of stressing them. This work is aimed at studying this properties both of alloys commonly used (of the Mg-Al-Zn, Mn type, and of that ones used in industrial manufacture in a limited extent (Mg-Al-Sr. These thermomechanical properties are further on complemented with the microstructure analysis with the aim of checking the metallurgical interventions (an effect of inoculation. From the studied materials the test castings were made from which the test bars for the tensile test were subsequently prepared. This test took place within the temperature range of 20°C – 300°C. Achieved results are summarized in the concluding part of the contribution.

  20. Investigation of the Precipitation Behavior in Aluminum Based Alloys

    KAUST Repository

    Khushaim, Muna S.

    2015-11-30

    The transportation industries are constantly striving to achieve minimum weight to cut fuel consumption and improve overall performance. Different innovative design strategies have been placed and directed toward weight saving combined with good mechanical behavior. Among different materials, aluminum-based alloys play a key role in modern engineering and are widely used in construction components because of their light weight and superior mechanical properties. Introduction of different nano-structure features can improve the service and the physical properties of such alloys. For intelligent microstructure design in the complex Al-based alloy, it is important to gain a deep physical understanding of the correlation between the microstructure and macroscopic properties, and thus atom probe tomography with its exceptional capabilities of spatially resolution and quantitative chemical analyses is presented as a sophisticated analytical tool to elucidate the underlying process of precipitation phenomena in aluminum alloys. A complete study examining the influence of common industrial heat treatment on the precipitation kinetics and phase transformations of complex aluminum alloy is performed. The qualitative evaluation results of the precipitation kinetics and phase transformation as functions of the heat treatment conditions are translated to engineer a complex aluminum alloy. The study demonstrates the ability to construct a robust microstructure with an excellent hardness behavior by applying a low-energy-consumption, cost-effective method. The proposed strategy to engineer complex aluminum alloys is based on both mechanical strategy and intelligent microstructural design. An intelligent microstructural design requires an investigation of the different strengthen phases, such as T1 (Al2CuLi), θ′(Al2Cu), β′(Al3Zr) and δ′(Al3Li). Therefore, the early stage of phase decomposition is examined in different binary Al-Li and Al-Cu alloys together with different

  1. Corrosion Behavior of AlSi10Mg Alloy Produced by Additive Manufacturing (AM vs. Its Counterpart Gravity Cast Alloy

    Directory of Open Access Journals (Sweden)

    Avi Leon

    2016-06-01

    Full Text Available The attractiveness of additive manufacturing (AM relates to the ability of this technology to rapidly produce very complex components at affordable costs. However, the properties and corrosion behavior, in particular, of products produced by AM technology should at least match the properties obtained by conventional technologies. The present study aims at evaluating the corrosion behavior and corrosion fatigue endurance of AlSi10Mg alloy produced by selective laser melting (SLM in comparison with its conventional counterpart, gravity cast alloy. The results obtained indicate that the corrosion resistance of the printed and cast alloys was relatively similar, with a minor advantage to the printed alloy. The corrosion fatigue endurance of the printed alloy was relatively improved compared to the cast alloy. This was mainly attributed to the significant differences between the microstructure and defect characteristics of those two alloys.

  2. Cracking susceptibility of aluminum alloys during laser welding

    Directory of Open Access Journals (Sweden)

    Lara Abbaschian

    2003-06-01

    Full Text Available The influence of laser parameters in welding aluminum alloys was studied in order to reduce hot cracking. The extension of cracks at the welding surface was used as a cracking susceptibility (CS index. It has been shown that the CS changes with changing welding velocity for binary Al-Cu alloys. In general, the CS index increased until a maximum velocity and then dropped to zero, generating a typical lambda-curve. This curve is due to two different mechanisms: 1 the refinement of porosities with increasing velocity and 2 the changes in the liquid fraction due to decreasing microsegregation with increasing velocities.

  3. Research of Plasma Spraying Process on Aluminum-Magnesium Alloy

    Directory of Open Access Journals (Sweden)

    Patricija Kavaliauskaitė

    2016-04-01

    Full Text Available The article examines plasma sprayed 95Ni-5Al coatings on alu-minum-magnesium (Mg ≈ 2,6‒3,6 % alloy substrate. Alumi-num-magnesium samples prior spraying were prepared with mechanical treatment (blasting with Al2O3. 95Ni-5Al coatings on aluminum-magnesium alloys were sprayed with different parameters of process and coating‘s thickness, porosity, micro-hardness and microstructure were evaluated. Also numerical simulations in electric and magnetic phenomena of plasma spray-ing were carried out.

  4. MICROSTRUCTURE AND PROPERTIES OF ZL201 ALLOY OBTAINED BY NEAR-LIQUIDUS ELECTROMAGNETIC CASTING

    Institute of Scientific and Technical Information of China (English)

    P. Wang; L.F. Sh; G.M. Lu; J.Z. Cui

    2005-01-01

    The microstructures of ZL201 alloy slurry prepared by near-liquidus electromagnetic casting(NLEMC), electromagnetic casting(EMC), and near-liquidus casting(NLC) were investigated by means of electron microscopy and image analysis. Mechanical properties of as-cast alloys were determined. The results show that the NLEMC induces a fine, uniform, and equiaxed grain structure with a mean equal-area-circle grain diameter of 32.8μm. The as-cast alloy has a hardness of HV122.8 and a tensile strength of 368MPa. Both of them are better than those of the alloys prepared by EMC and by NLC. The mechanism of grain refinement in the NLEMC alloy slurry was discussed.

  5. Friction and wear of titanium alloys and copper alloys sliding against titanium 6-percent-aluminum - 4-percent-vanadium alloy in air at 430 C

    Science.gov (United States)

    Wisander, D. W.

    1976-01-01

    Experiments were conducted to determine the friction and wear characteristics of aluminum bronzes and copper-tin, titanium-tin, and copper-silver alloys sliding against a titanium-6% aluminum-4% vanadium alloy (Ti-6Al-4V). Hemispherically tipped riders of aluminum bronze and the titanium and copper alloys were run against Ti-6Al-4V disks in air at 430 C. The sliding velocity was 13 cm/sec, and the load was 250 g. Results revealed that high tin content titanium and copper alloys underwent significantly less wear and galling than commonly used aluminum bronzes. Also friction force was less erratic than with the aluminum bronzes.

  6. In situ purification, alloying and casting methodology for metallic plutonium

    Science.gov (United States)

    Lashley, Jason C.; Blau, Michael S.; Staudhammer, Karl P.; Pereyra, Ramiro A.

    Plutonium metal that has been double ER (electrorefined/electrorefining) was further purified via zone refining, using a floating molten zone to minimize the introduction of impurities. The temperature of the molten zone was 750°C, and the atmosphere was 10 -5 Pa. A total of ten zone refining passes were made at a travel rate of 1.5 cm/h. There were 19 elements reduced to quantities below the minimum detectable limits (MDL) by zone refining, while P, K, and W were significantly reduced. The zone-refined metal was then used in an in situ distillation, alloying, and casting step to prepare tapered specimens for single-crystal growth experiments. Specifically, 241Am was distilled from Pu metal by levitating Pu metal with 1 wt% Ga in the melt in a Crystallox vertical electromagnetic levitation crucible at 10 -5 Pa. The Pu is alloyed with Ga to stabilize the δ phase (fcc symmetry) upon solidification. The Pu was chill-cast directly from the electromagnetic levitation field into 1- cm tapered specimens. A water-cooled ceramic mold was used, and the Pu metal was cooled at a rate of 100°C/min. A microstructure examination of the specimen showed 10 × 25 μm acicular grains with a density of 15.938 g/cm 3 (±0.002 g/cm 3).

  7. Microstructure and mechanical properties of a new type of austempered boron alloyed high silicon cast steel

    OpenAIRE

    Chen Xiang; Li Yanxiang

    2013-01-01

    In the present paper, a new type of austempered boron alloyed high silicon cast steel has been developed, and its microstructures and mechanical properties at different temperatures were investigated. The experimental results indicate that the boron alloyed high silicon cast steel comprises a dendritic matrix and interdendritic eutectic borides in as-cast condition. The dendritic matrix is made up of pearlite, ferrite, and the interdendritic eutectic boride is with a chemical formula of M2B (...

  8. A Study on the Microstructures and Toughness of Fe-B Cast Alloy Containing Rare Earth

    Science.gov (United States)

    Yi, Dawei; Zhang, Zhiyun; Fu, Hanguang; Yang, Chengyan; Ma, Shengqiang; Li, Yefei

    2015-02-01

    This study investigates the effect of cerium on the microstructures, mechanical properties of medium carbon Fe-B cast alloy. The as-cast microstructure of Fe-B cast alloy consists of the eutectic boride, pearlite, and ferrite. Compared with the coarse eutectic borides in the unmodified alloy, the eutectic boride structures in the modified alloy are greatly refined. Cerium promotes the formation of Ce2O3 phase. Ce2O3 can act as effective heterogeneous nuclei of primary austenite, and refine austenite and boride. After heat treatment, the impact toughness of the modified alloy is higher than that of the unmodified alloy because there are more broken borides in the modified alloy. Meanwhile, the fracture mechanism of medium carbon Fe-B alloy is depicted and analyzed by using fractography.

  9. Residual stress profiling of an aluminum alloy by laser ultrasonics

    Institute of Scientific and Technical Information of China (English)

    PAN Yondong; QIAN Menglu; XU Weijiang; M. OURAK

    2004-01-01

    A residual-stress profile along the thickness of an aluminum alloy sheet is determined by laser-ultrasonic technique. Surface acoustic waves are generated by a Nd:YAG pulse laser and detected by a Heterodyne interferometer on a lateral free surface of the sheet. The distribution of residual stress is determined by measuring the relative variation of the wavevelocities at different location of the sample along its thickness. This technique is validated by three different residual stress profiles obtained experimentally.

  10. Experimental Studies of Cold Roll Bonded Aluminum Alloys

    OpenAIRE

    Lauvdal, Steinar

    2011-01-01

    This master’s thesis is based on experimental studies of the parameters influencing cold roll bonding (CRB) of the aluminum alloys AA1200 and AA3103,in the work hardened and annealed condition. The effect on the bond strength from the preparations parameters as degreasing agent, scratch brushing and exposure time for oxide growth is investigated in comparison to former studies. Further the effect of rolling speed and effect from contributing factors from the different testing methods is ...

  11. Linear Anomaly in Welded 2219-T87 Aluminum Alloy

    Science.gov (United States)

    Jemian, Wartan A.

    1987-01-01

    Study of causes and significance of two types of linear anomalies sometimes appearing in radiographs of welds described in preliminary report. Manifested as light or dark linear features parallel to weld line in radiograph of weld. Contains diagrams and descriptions of phenomena occurring during welding process. Includes microdensitometer traces from x-radiographs of actual welds and from computer simulations based calculation of x-ray transmission through assumed weld structures. Concludes anomalies not unique to 2219-T87 aluminum alloy.

  12. Residual stress in quenched 7075 aluminum alloy thick plates

    Institute of Scientific and Technical Information of China (English)

    林高用; 张辉; 朱伟; 彭大暑; 梁轩; 周鸿章

    2003-01-01

    The influence of quenching water temperature, pre-stretching amount and aging temperature and times on residual stress in 7075 aluminum thick plate was studied by the measurement of residual stress using drilling hole method. The results indicate that residual stress decreases by 30% with increasing quenching water temperature from 40 ℃ to 80 ℃, 20% with increasing aging temperature from 100 ℃ to 180 ℃,and 20% with increasing aging times from 5 h to 25 h. Also, residual stress decreases to zero with increasing pre-stretching amount to approximately 2%. Hence, residual stress in 7075 aluminum thick plate is reduced by the control of quenching water temperature at 80 ℃ and with pre-stretching amount of about 2%. An optimal aging temperature and time should be systemically investigated to obtain combination of high mechanical performances and lower residual stress for manufacturing of 7075 aluminum alloy thick plates.

  13. An Influence of Ageing on the Structure, Corrosion Resistance and Hardness of High Aluminum ZnAl40Cu3 Alloy

    Directory of Open Access Journals (Sweden)

    Michalik R.

    2016-03-01

    Full Text Available Zn-Al-Cu alloys are used primarily because of their tribological properties as an alternative material for bronze, cast iron and aluminum alloy bearings and as a construction material. Particularly interesting are high aluminum zinc alloys. Monoeutectic zinc and aluminum alloys are characterized by the highest hardness, tensile strength and wear resistance of all of the zinc alloys. A significant problem with the use of the Zn-Al-Cu alloys is their insufficient resistance to electrochemical corrosion. Properties of Zn-Al-Cu alloys can be improved by heat treatment. The purpose of examination was to determine the effect of heat treatment (aging at various temperatures on the microstructure and corrosion resistance of the ZnAl40Cu3 alloy. The scope of the examination included: structural examinations, determination of hardness using Brinell’s method and corrosion resistance examinations. Ageing at higher temperatures causes a creation of areas where is an eutectoid mixture. The study showed that ageing causes a decrease in hardness of ZnAl40Cu3 alloy. This decrease is even greater, when the temperature of ageing is lower. The studies have shown a significant influence of ageing on the corrosion resistance of the alloy ZnAl40Cu3. Maximum corrosion resistance were characterized by the sample after ageing at higher temperatures.

  14. Advanced metrology of surface defects measurement for aluminum die casting

    OpenAIRE

    D. Myszka; S. J. Świłło

    2011-01-01

    The scientific objective of the research is to develop a strategy to build computer based vision systems for inspection of surface defects inproducts, especially discontinuities which appear in castings after machining. In addition to the proposed vision inspection method theauthors demonstrates the development of the advanced computer techniques based on the methods of scanning to measure topography ofsurface defect in offline process control. This method allow to identify a mechanism respon...

  15. Butt-welding Residual Stress of Heat Treatable Aluminum Alloys

    Institute of Scientific and Technical Information of China (English)

    C.M. Cheng

    2007-01-01

    This study, taking three types of aluminum alloys 2024-T351, 6061-T6 and 7075-T6 as experimental materials, conducted single V-groove GTAW (gas tungsten arc welding) butt-welding to analyze and compare the magnitude and differences of residual stress in the three aluminum alloys at different single V-groove angles and in restrained or unrestrained conditions. The results show that the larger the grooving angle of butt joint, the higher the residual tensile stress. Too small grooving angle will lead to dramatic differences due to the amount of welding bead filler metal and pre-set joint geometry. Therefore, only an appropriate grooving angle can reduce residual stress. While welding, weldment in restrained condition will lead to a larger residual stress. Also, a residual stress will arise from the restraint position. The ultimate residual stress of weldment is determined by material yield strength at equilibrium temperature. The higher the yield strength at equilibrium temperature, the higher the material residual stress. Because of its larger thermal conductivity, aluminum alloy test specimens have small temperature differential. Therefore, the residual tensile stress of all materials is lower than their yield strength.

  16. Influence of additives on the microstructure and tensile properties of near-eutectic Al-10.8%Si cast alloy

    International Nuclear Information System (INIS)

    The continuing quest for aluminum castings with enhanced mechanical properties for applications in the automotive industries has intensified the interest in aluminum-silicon alloys. In Al-Si alloys, the properties are influenced by the shape and distribution of the eutectic silicon particles in the matrix, as also by the iron intermetallics and copper phases that occur upon solidification. The detailed microstructure and tensile properties of as-cast and heat-treated new experimental alloy belonging to cast Al-Si near-eutectic alloys have been investigated as a function of Fe, Mn, Cu, and Mg content. Microstructural examination was carried out using optical microscopy, image analysis, and electron probe microanalysis (EPMA), wavelength dispersive spectroscopic (WDS) analysis facilities. Tensile properties upon artificial aging in the temperature range of 155-240 oC for 5 h were also investigated. The results show that the volume fraction of Fe-intermetallics increases as the iron or manganese contents increase. Compact polygonal or star-like particles form when the sludge factor is greater than 2.1. The Al2Cu phase was observed to dissolve almost completely during solution heat treatment of all the alloys studied, especially those containing high levels of Mg and Fe, while Al5Cu2Mg8Si6, sludge, and α-Fe phases were found to persist after solution heat treatment. The β-Al5(Fe,Mn)Si phase dissolved partially in Sr-modified alloys, and its dissolution became more pronounced after solution heat treatment. At 0.5% Mn, the β-Fe phase forms when the Fe content is above 0.75%, causing the tensile properties to decrease drastically. The same results are obtained when the levels of both Fe and Mn are increased beyond 0.75%, because of sludge formation. On the other hand, the tensile properties of the Cu-containing alloys are affected slightly at high levels of Mg as a result of the formation of Al5Cu2Mg8Si6 which decreases the amount of free Mg available to form the Al2Cu

  17. Hot extrusion for Al-Si-(Fe, Cu) hyper-eutectic cast alloys

    OpenAIRE

    Yokoyama, Hisanaga; Umezawa, Osamu; Nagai, Kotobu; Kokubo, Kunio

    1999-01-01

    For hyper-eutectic Al-Si-(Fe, Cu) cast materials in large scale ingots, we have studied microstructural modification by thermomechanical treatment to produce a heavily deformable material. Cast materials contained coarse primary Si crystals in a few hundred micron diameter or acicular intermetallic compound in several hundred micron length. Even by multiple-step cold-rolling, sample fracture of the cast alloys occurred with more extrusion step to the cast materials. A novel process, repeated ...

  18. Microstructure and mechanical properties of aluminum alloy matrix composite reinforced with nano-particle MgO

    Energy Technology Data Exchange (ETDEWEB)

    Yar, A. Ansary, E-mail: arash_ansaryyar@yahoo.co [Department of Materials, Islamic Azad University, South Tehran Branch, P.O. Box 11365-4435, Tehran (Iran, Islamic Republic of); Montazerian, M.; Abdizadeh, H. [School of Metallurgy and Materials Engineering, University of Tehran, P.O. Box 11365-4563, Tehran (Iran, Islamic Republic of); Baharvandi, H.R. [Malek Ashtar University of Technology, P.O. Box 16765-3454, Tehran (Iran, Islamic Republic of)

    2009-09-18

    In this research, aluminum alloy (A356.1) matrix composites reinforced with 1.5, 2.5 and 5 vol% nano-particle MgO were fabricated via stir casting method. Fabrication was performed at various casting temperatures, viz. 800, 850 and 950 deg. C. Optimum amount of reinforcement and casting temperature were determined by evaluating the density, microstructure and mechanical properties of composites. The composites were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). Hardness and compression tests were carried out in order to identify mechanical properties. The results reveal that the composites containing 1.5 vol% reinforcement particle fabricated at 850 deg. C have homogenous microstructure as well as improved mechanical properties.

  19. Silicon effects on formation of EPO oxide coatings on aluminum alloys

    Energy Technology Data Exchange (ETDEWEB)

    Wang, L. [Department of Mechanical, Automotive and Materials Engineering, University of Windsor, Windsor, ON, N9B 3P4 (Canada); Nie, X. [Department of Mechanical, Automotive and Materials Engineering, University of Windsor, Windsor, ON, N9B 3P4 (Canada)]. E-mail: xnie@uwindsor.ca

    2006-01-03

    Electrolytic plasma processes (EPP) can be used for cleaning, metal-coating, carburizing, nitriding, and oxidizing. Electrolytic plasma oxidizing (EPO) is an advanced technique to deposit thick and hard ceramic coatings on a number of aluminum alloys. However, the EPO treatment on Al-Si alloys with a high Si content has rarely been reported. In this research, an investigation was conducted to clarify the effects of silicon contents on the EPO coating formation, morphology, and composition. Cast hypereutectic 390 alloys ({approx} 17% Si) and hypoeutectic 319 alloys ({approx} 7% Si) were chosen as substrates. The coating morphology, composition, and microstructure of the EPO coatings on those substrates were investigated using scanning electron microscopy (SEM) with energy dispersive X-ray (EDX) analysis and X-ray diffraction (XRD). A stylus roughness tester was used for surface roughness measurement. It was found that the EPO process had four stages where each stage was corresponding to various coating surface morphology, composition, and phase structures, characterised by different coating growth mechanisms.

  20. Solidification crack susceptibility of aluminum alloy weld metals

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The susceptibilities of the three aluminum alloys to solidification crack were studied with trans-varestraint tests and tensile tests at elevated temperature. Their metallurgical characteristics, morphologies of the fractured surface and dynamic cracking behaviors at elevated temperature were analyzed with a series of micro-analysis methods. The results show that dynamic cracking models can be classified into three types. The first model has the healing effect which is called type A. The second is the one with deformation and breaking down of metal bridge, called type B. The last one is with the separation of liquid film along grain boundary, called type C.Moreover, the strain rate has different effects on crack susceptibility of aluminum alloys with different cracking models. ZL101 and 5083 alloys belong to type A and type C cracking model respectively, in which strain rate has greater effect on eutectic healing and plastic deformation of metal bridge. 6082 alloy is type B cracking model in which the strain rate has little effect on the deformation ability of the liquid film.

  1. Russian aluminum-lithium alloys for advanced reusable spacecraft

    Science.gov (United States)

    Charette, Ray O.; Leonard, Bruce G.; Bozich, William F.; Deamer, David A.

    1998-01-01

    Cryotanks that are cost-affordable, robust, fuel-compatible, and lighter weight than current aluminum design are needed to support next-generation launch system performance and operability goals. The Boeing (McDonnell Douglas Aerospace-MDA) and NASA's Delta Clipper-Experimental Program (DC-XA) flight demonstrator test bed vehicle provided the opportunity for technology transfer of Russia's extensive experience base with weight-efficient, highly weldable aluminum-lithium (Al-Li) alloys for cryogenic tank usage. As part of NASA's overall reusable launch vehicle (RLV) program to help provide technology and operations data for use in advanced RLVs, MDA contracted with the Russian Academy of Sciences (RAS/IMASH) for design, test, and delivery of 1460 Al-Li alloy liquid oxygen (LO2) cryotanks: one for development, one for ground tests, and one for DC-XA flight tests. This paper describes the development of Al-Li 1460 alloy for reusable LO2 tanks, including alloy composition tailoring, mechanical properties database, forming, welding, chemical milling, dissimilar metal joining, corrosion protection, completed tanks proof, and qualification testing. Mechanical properties of the parent and welded materials exceeded expectations, particularly the fracture toughness, which promise excellent reuse potential. The LO2 cryotank was successfully demonstrated in DC-XA flight tests.

  2. Mold Materials For Permanent Molding of Aluminum Alloys

    Energy Technology Data Exchange (ETDEWEB)

    John F Wallace; David Schwam; Wen Hong dxs11@po.cwru.edu

    2001-09-14

    A test that involves immersion of the potential mod materials for permanent molds has been developed that provides a thermal cycle that is similar to the experienced during casting of aluminum in permanent molds. This test has been employed to determine the relative thermal fatigue resistance of several different types of mold materials. Four commercial mold coatings have been evaluated for their insulating ability, wear resistance and roughness. The results indicate that composition and structure of the mold materials have considerable effect on their thermal fatigue cracking behavior. Irons with a gray iron structure are the most prone to thermal fatigue cracking followed by compacted graphite irons with the least thermal fatigue cracking of the cast irons experienced by ductile iron. The composition of these various irons affects their behavior.

  3. Mechanical properties of hot rolled 2519 aluminum alloy plate

    Institute of Scientific and Technical Information of China (English)

    彭大暑; 陈险峰; 林启权; 张辉

    2003-01-01

    The effects of differences of temper on mechanical properties of T6, T7 and T8 plates of aluminum alloy 2519 were studied. The stress corrosion cracking(SCC) sensitivity was evaluated with parameters such as Kσ and Kδ.Tensile tests were divided into two groups: one was performed on tensile specimens without pre-corrosion, the other was performed on tensile specimens which were pre-corroded in 3.5%NaCl+1%H2O2 solution at 25 ℃.The results show that SCC resistance of alloy 2519 ranks in the order of T8>T7>T6 and the mechanical properties rank in the order of T6>T8>T7. SEM fractographs of the failed specimen show that the SCC sensitivity can be determined by the distribution of the second phase particles and size and the shape of grains in the alloy.

  4. Enhancement of superplastic formability in a high strength aluminum alloy

    Science.gov (United States)

    Agrawal, S. P.; Turk, G. R.; Vastava, R.

    1988-01-01

    A 7475 aluminum alloy was developed for superplastic forming (SPF). By lowering the Fe and Si contents in this alloy significantly below their normal levels and optimizing the thermomechanical processing to produce sheet, over 2000 percent thickness strain to failure was obtained. The microstructure, elevated-temperature uniaxial and biaxial tension, and cavitation behavior of the alloy were determined. In addition, a constitutive model was used to form a generic structural shape from which mechanical test specimens were removed and post-SPF characteristics were evaluated. The constitutive model included both material strain hardening and strain rate hardening effects, and was verified by accurately predicting forming cycles which resulted in successful component forming. Stress-life fatigue, stress rupture, and room and elevated temperature tensile tests were conducted on the formed material.

  5. Radiation Damages in Aluminum Alloy SAV-1 under Neutron Irradiation

    Science.gov (United States)

    Salikhbaev, Umar; Akhmedzhanov, Farkhad; Alikulov, Sherali; Baytelesov, Sapar; Boltabaev, Azizbek

    2016-05-01

    The aim of this work was to study the effect of neutron irradiation on the kinetics of radiation damages in the SAV-1 alloy, which belongs to the group of aluminum alloys of the ternary system Al-Mg-Si. For fast-neutron irradiation by different doses up to fluence 1019 cm-2 the SAV-1 samples were placed in one of the vertical channels of the research WWR type reactor (Tashkent). The temperature dependence of the electrical resistance of the alloy samples was investigated in the range 290 - 490 K by the four-compensation method with an error about 0.1%. The experimental results were shown that at all the temperatures the dependence of the SAV-1 alloy resistivity on neutron fluence was nonlinear. With increasing neutron fluence the deviation from linearity and the growth rate of resistivity with temperature becomes more appreciable. The observed dependences are explained by means of martensitic transformations and the radiation damages in the studied alloy under neutron irradiation. The mechanisms of radiation modification of the SAV-1 alloy structure are discussed.

  6. Dilution of molybdenum on aluminum during laser surface alloying

    Energy Technology Data Exchange (ETDEWEB)

    Vora, Hitesh D.; Rajamure, Ravi Shanker [Laboratory of Laser Material Processing and Synthesis, Department of Materials Science and Engineering, University of North Texas, 1155 Union Circle 305310, Denton, TX 76203-5017 (United States); Soundarapandian, Santhanakrishnan [Department of Mechanical Engineering, Indian Institute of Technology Madras, Chennai 600036 (India); Srinivasan, S.G. [Laboratory of Laser Material Processing and Synthesis, Department of Materials Science and Engineering, University of North Texas, 1155 Union Circle 305310, Denton, TX 76203-5017 (United States); Dahotre, Narendra B., E-mail: Narendra.Dahotre@unt.edu [Laboratory of Laser Material Processing and Synthesis, Department of Materials Science and Engineering, University of North Texas, 1155 Union Circle 305310, Denton, TX 76203-5017 (United States)

    2013-09-05

    Highlights: •Laser surface alloying significantly increased the solubility of transition metal. •Laser surface alloying produced dense coating with good metallurgical bonding. •Laser process parameters greatly influenced the evolution of various intermetallics. •Computationally predicted results closely matched with experimental findings. •Ability to generalize present model to other metal-transition metal systems. -- Abstract: A multiphysics based computational model was developed to predict the dilution of molybdenum (Mo) on an aluminum (Al) substrate during the laser surface alloying process. The influence of laser surface alloying processing parameters such as input energy, scanning speed, and overlapping ratio on dilution of Mo in Al was explored via computational model. The computational model, closely predicts the melt pool geometry (width and depth) that subsequently helps in estimating dilution. It was observed that the dilution increases with the increase in laser power, while it decreases with the increase in scanning speed. The phase and microstructural analyses revealed the existence of Al{sub 5}Mo intermetallic for most of the laser surface alloying processing conditions. However, at higher (3.18 × 10{sup 7} J/m{sup 2}) and lower (1.91 × 10{sup 7} J/m{sup 2}) laser energy densities, the Al{sub 8}Mo{sub 3} intermetallic was also evolved. These experimental observations validate the model’s predictions and points to its reliability in predicting the expected intermetallics in Al–Mo system for various laser surfacing alloying processing conditions.

  7. Influence of Solid Fraction on Gravity Segregation of Sn in Al-20Sn Alloy Casting

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The influence of solid fraction of Al-20Sn alloy mushy on gravity segregation of Sn in casting was studied and, the relationship between solid fraction and the temperature of alloy mushy and that between solid fraction of alloy mushy and size of Sn particle in ingot were determined. The results show that the relationship between solid fraction and the temperature of alloy mushy was fs=1683-4.86t+0.0035t2. The extent of gravity segregation of Sn in casting reduced gradually with the increasing of solid fraction of alloy mushy. When solid fraction of alloy mushy was arger than 40%, the gravity segregation of Sn in casting could be removed basically, and the relationship between solid fraction of alloy mushy and size of Sn particle in ingot was s=-0.64fs+70.8.

  8. Characterization of pores in high pressure die cast aluminum using active thermography and computed tomography

    Science.gov (United States)

    Maierhofer, Christiane; Myrach, Philipp; Röllig, Mathias; Jonietz, Florian; Illerhaus, Bernhard; Meinel, Dietmar; Richter, Uwe; Miksche, Ronald

    2016-02-01

    Larger high pressure die castings (HPDC) and decreasing wall thicknesses are raising the issue of casting defects like pores in aluminum structures. Properties of components are often strongly influenced by inner porosity. As these products are being established more and more in lightweight construction (e.g. automotive and other transport areas), non-destructive testing methods, which can be applied fast and on-site, are required for quality assurance. In this contribution, the application of active thermography for the direct detection of larger pores is demonstrated. The analysis of limits and accuracy of the method are completed by numerical simulation and the method is validated using computed tomography.

  9. Effect of vapor phase corrosion inhibitor on microbial corrosion of aluminum alloys.

    Science.gov (United States)

    Yang, S S; Ku, C H; Bor, H J; Lin, Y T

    1996-02-01

    Vapor phase corrosion inhibitors were used to investigate the antimicrobial activities and anticorrosion of aluminum alloy. Aspergillus flavus, A. niger, A. versicolor, Chaetomium globosum and Penicillium funiculosum had moderate to abundant growth on the aluminum alloy AA 1100 at Aw 0.901, while there was less growth at Aw 0.842. High humidity stimulated microbial growth and induced microbial corrosion. Dicyclohexylammonium carbonate had a high inhibitory effect on the growth of test fungi and the microbial corrosion of aluminum alloy, dicyclohexylammonium caprate and dicyclohexylammonium stearate were the next. Aluminum alloy coating with vapor phase corrosion inhibitor could prevent microbial growth and retard microbial corrosion. PMID:10592784

  10. From 2007 to 2010,China Will Manufacture More Than 10,000 Aluminum Alloy Railcars

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    <正>The clear advantage of the aluminum alloy rail- cars is the weight reduction.The deadweight of the aluminum alloy railcars usually does not exceed 8.5t each.The 52 motor train units used in the sixth nationwide railway speedup are all made of aluminum alloys except for the train units used in the line between Guangzhou and Shenzhen.It is estimated that in 2010,there are more than 10,000 railcars made of aluminum alloys,which will consume about 105kt alumi- num.

  11. 铸嘴结构对3004铝合金铸轧流热场的影响及其优化设计%Effect of nozzle structure on fluid-thermal field of 3004 aluminum alloy melt in cast-rolling and its optimum design

    Institute of Scientific and Technical Information of China (English)

    戴青松; 邓运来; 胥福顺; 张新明

    2015-01-01

    In view of the inferior liquidity of 3004 aluminum alloy melt in cast-rolling, difficult to distribute in feed tip nozzle and easy to cause defect of sheet, viscosity of 3004 aluminum alloy melt was measured by viscometer for high temperature melt, fluid-thermal field of melt in nozzle cavity was analyzed by finite element simulation analysis software (COMSOL Multiphysics) based on the actual physical parameters and production condition, and nozzle structure was optimized according to the simulation results and it was verified by experiment. The results show that the relationship between viscosityμand temperatureθfrom 660℃ to 750℃ can be expressed asμ=10−3×exp(0.059+621.379/θ). The vortex emerges in nozzle cavity and fluid-thermal field distributes unevenly at the output of nozzle when the angle is 8° between block and horizontal direction and the gap is 30 mm between block and spacers. While melts flow smoothly and fluid-thermal field is relatively uniform when the block is horizontal and the gap is 50 mm. The experiments show that the optimum proposal is feasible and the simulation results are accurate.%针对3004铝合金铸轧生产中熔体流动性差、铸嘴布流困难、易造成板面缺陷的现象,采用高温熔体黏度测量仪对3004铝合金熔体黏度进行测量,根据实测物理参数与生产工况,采用COMSOL Multiphysics软件对熔体在2种不同结构铸嘴中的流热场进行有限元模拟分析,根据模拟结果对铸嘴结构进行优化设计与实验检测。研究结果表明:在660~750℃范围内其黏度μ与温度θ的关系可表达为μ=10−3×exp(0.059+621.379/θ);当铸嘴入口2边的挡块与水平方向成8°倾斜角,挡块与分流块间间距为30 mm时,铸嘴型腔内容易产生涡流,流热场分布不均匀;当铸嘴入口2边挡块水平设置,挡块与分流块间间距为50 mm时,熔体流动平缓,流热场分布较均匀。实验验证了模拟结果的准确性与优化方案的可行性。

  12. Effects of shot peening on internal friction in CP aluminum and aluminum alloy 6008

    Energy Technology Data Exchange (ETDEWEB)

    Flejszar, Aneta; Ludian, Tomasz; Mielczarek, Agnieszka; Riehemann, Werner; Wagner, Lothar [Clausthal Univ. of Science and Technology, Inst. of Materials Science and Technology, Clausthal-Zellerfeld (Germany)

    2009-06-15

    The strain-amplitude-dependent damping of bending beams of aluminum alloy 6008 and CP aluminum was measured at room temperature after different heat treatments and after shot peening. Shot peening led to an increase of damping in almost the whole measured amplitude strain range from 10{sup -6} to 10{sup -3} for CP aluminum. Strong ageing effects at room temperature were observed immediately after the shot peening process, namely an increase of the amplitude dependent part and a decrease of the amplitude-independent part of damping. After about 2700 h, ageing of the samples had saturated. For aluminum alloy 6008 much smaller ageing effects were found being due to compensating effects like formation of Cottrell clouds, precipitation of G.P. - zones, and the reduction of foreign atoms in solid solution. The found amplitude-dependent damping can be explained by the reversible movement of dislocations between strong pinning points like, e.g., precipitates and weak pinning points like solid solute atoms as proposed by the dislocation damping theory of Granato and Luecke. Using this model the found ageing effects can be explained by the diffusion of solid solute atoms to the dislocations. (orig.)

  13. Filling ability of semi-solid A356 aluminum alloy slurry in rheo-diecasting

    Institute of Scientific and Technical Information of China (English)

    Yuelong Bai; Weimin Mao; Songfu Gao; Guoxing Tang; Jun Xu

    2008-01-01

    The effects of slurry temperature, injection pressure, and piston velocity on the rheo-filling ability of semisolid A356 al-loys were studied by the reho-diecasting methods. The results show that the slurry temperature of the semi-solid A356 aluminum al-loy has an important effect on the filling ability; the higher the slurry temperature, the better is the filling ability, and the appropriate slurry temperature for rheo-filling is in the range of 585-595~C. The injection pressure also has a great effect on the filling ability, and it is appropriate to the rheo-fiUing when the injection pressure is in the range of 15-25 MPa. The piston velocity also has a great effect on the filling ability, and it is appropriate to the rheo-filling when the piston velocity is in the range of 0.072-0.12 m/s. The Idling ability of the slurry prepared by low superheat pouring with weak electromagnetic stirring is very good and the microstructural distribution in the rheo-formed die castings is homogeneous, which is advantageous to the high quality die casting.

  14. Metallurgical Mechanisms Controlling Mechanical Properties of Aluminum Alloy 2219 Produced by Electron Beam Freeform Fabrication

    Science.gov (United States)

    Domack, Marcia S.; Tainger, Karen M.

    2006-01-01

    The electron beam freeform fabrication (EBF3) layer-additive manufacturing process has been developed to directly fabricate complex geometry components. EBF3 introduces metal wire into a molten pool created on the surface of a substrate by a focused electron beam. Part geometry is achieved by translating the substrate with respect to the beam to build the part one layer at a time. Tensile properties demonstrated for electron beam deposited aluminum and titanium alloys are comparable to wrought products, although the microstructures of the deposits exhibit cast features. Understanding the metallurgical mechanisms controlling mechanical properties is essential to maximizing application of the EBF3 process. Tensile mechanical properties and microstructures were examined for aluminum alloy 2219 fabricated over a range of EBF3 process variables. Unique microstructures were observed within the deposited layers and at interlayer boundaries, which varied within the deposit height due to microstructural evolution associated with the complex thermal history experienced during subsequent layer deposition. Microstructures exhibited irregularly shaped grains with interior dendritic structures, described based on overall grain size, morphology, distribution, and dendrite spacing, and were correlated with deposition parameters. Fracture features were compared with microstructural elements to define fracture paths and aid in definition of basic processing-microstructure-property correlations.

  15. Properties of Dispersion Casting of Y2O3 Particles in Hypo, Hyper and Eutectic Binary Al-Cu Alloys

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    In the present work, the dispersion casting of Y2O3 particles in aluminum-copper alloy was investigated in terms of microstructural changes with respect to Cu contents of 20 (hypo), 33 (eutectic) and 40 (hyper)wt pct by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). For the fabrication of Al-Cu alloy dispersed Y2O3 ceramic particles, stir casting method was employed. In case of Al-20 wt pct Cu alloy (hypoeutectic), SEM images revealed that primary Al was grown up in the beginning. After that, eutectic phase with well dispersed ceramic particles was formed. In case of eutectic composition, Y2O3 particles were uniformly dispersed in the matrix. When the Cu is added into Al up to 40 wt pct (hypereutectic), primary θ phase was grown up without any Y2O3 ceramic particles in the early stage of solidification. Thereafter,eutectic phase was formed with well dispersed ceramic particles. It can be concluded that Y2O3 ceramic particles is mostly dispersed in case of eutectic composition in Al-Cu alloy.

  16. Thixoforming of 6066 aluminum alloy by multi-layer spray deposition

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Two thixoforming technologies of 6066 aluminum alloy (Al-1.37Si-1.37Mg-0.77Cu-0.07Mn) produced by multi-layer spray deposition process were studied. The spray-formed materials are of equiaxed and very fine grain (10~20  μm). And the grain size coarsens slower than that of conventional casting materials at temperature below the liquidus, which may relate to high temperature particles distributed along the grain boundaries. Extrusion and hot pressing were used as the thixoforming processes respectively. After extrusion the materials show a microstructure of mean grain size below 20  μm without obvious recrystallization. The mechanical properties achieved via extrusion and pressing in semi-solid state attain that of common wrought materials with shorter peak aging time of 4~5  h, about half of that in conventional condition.

  17. Preparation of semi-solid slurry containing fine and globular particles for wrought aluminum alloy 2024

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The semi-solid slurry of wrought aluminum alloy 2024 was prepared by a well developed rheocasting process, low superheat pouring with shearing field(LSPSF). The appreciate combination of pouring temperature and rotation speed of barrel, can give rise to a transition of the growth morphology of primary α(Al) from coarse-dendritic to coarse-particle-like and further to fine-globular. The combined effects of both localized rapid cooling and vigorous mixing during the initial stage of solidification can enhance wall nucleation and nuclei survival, which leads to the formation of fine-globular primary α(Al). By using semi-solid slurry prepared by LSPSF, direct squeeze cast cup-shaped component with improved mechanical properties such as yield strength of 198MPa, ultimate tensile strength of 306 MPa and elongation of 10.4%, can be obtained.

  18. Semisolid casting with ultrasonically melt-treated billets of Al-7mass%Si alloys

    Directory of Open Access Journals (Sweden)

    Yoshiki Tsunekawa

    2012-02-01

    Full Text Available The demand for high performance cast aluminum alloy components is often disturbed by increasing impurity elements, such as iron accumulated from recycled scraps. It is strongly required that coarse plate-like iron compound of モ-Al5FeSi turns into harmless form without the need for applying refining additives or expensive virgin ingots. The microstructural modification of Al-7mass%Si alloy billets with different iron contents was examined by applying ultrasonic vibration during the solidification. Ultrasonically melt-treated billets were thixocast right after induction heating up to the semisolid temperature of 583 ìC, the microstructure and tensile properties were evaluated in the thixocast components. Globular primary メ-Al is required to fill up a thin cavity in thixocasting, so that the microstructural modification by ultrasonic melt-treatment was firstly confirmed in the billets. With ultrasonic melt-treatment in the temperature range of 630 ìC to 605 ìC, the primary メ-Al transforms itself from dendrite into fine globular in morphology. The coarse plate-like モ-Al5FeSi compound becomes markedly finer compared with those in non-treated billets. Semisolid soaking up to 583 ìC, does not appreciably affect the size of モ-Al5FeSi compounds; however, it affects the solid primary メ-Al morphology to be more globular, which is convenient for thixocasting. After thixocasting with preheated billets, eutectic silicon plates are extremely refined due to the rapid solidification arising from low casting temperature. The tensile strength of thixocast samples with different iron contents does not change much even at 2mass% of iron, when thixocast with ultrasonically melt-treated billets. However, thixocast Al-7mass%Si-2mass%Fe alloy with non-treated billets exhibits an inferior strength of 80 MPa, compared with 180 MPa with ultrasonically melt-treated billets. The elongation is also improved by about a factor of two in thixocastings with

  19. The Effect of Impurities on the Processing of Aluminum Alloys

    Energy Technology Data Exchange (ETDEWEB)

    Zi-Kui Liu; Shengjun Zhang; Qingyou Han; Vinod Sikka

    2007-04-23

    For this Aluminum Industry of the Future (IOF) project, the effect of impurities on the processing of aluminum alloys was systematically investigated. The work was carried out as a collaborative effort between the Pennsylvania State University and Oak Ridge National Laboratory. Industrial support was provided by ALCOA and ThermoCalc, Inc. The achievements described below were made. A method that combines first-principles calculation and calculation of phase diagrams (CALPHAD) was used to develop the multicomponent database Al-Ca-K-Li-Mg-Na. This method was extensively used in this project for the development of a thermodynamic database. The first-principles approach provided some thermodynamic property data that are not available in the open literature. These calculated results were used in the thermodynamic modeling as experimental data. Some of the thermodynamic property data are difficult, if not impossible, to measure. The method developed and used in this project allows the estimation of these data for thermodynamic database development. The multicomponent database Al-Ca-K-Li-Mg-Na was developed. Elements such as Ca, Li, Na, and K are impurities that strongly affect the formability and corrosion behavior of aluminum alloys. However, these impurity elements are not included in the commercial aluminum alloy database. The process of thermodynamic modeling began from Al-Na, Ca-Li, Li-Na, K-Na, and Li-K sub-binary systems. Then ternary and higher systems were extrapolated because of the lack of experimental information. Databases for five binary alloy systems and two ternary systems were developed. Along with other existing binary and ternary databases, the full database of the multicomponent Al-Ca-K-Li-Mg-Na system was completed in this project. The methodology in integrating with commercial or other aluminum alloy databases can be developed. The mechanism of sodium-induced high-temperature embrittlement (HTE) of Al-Mg is now understood. Using the thermodynamic

  20. The effect of cast-to-cast variations on the quality of thin section nickel alloy welded joints

    International Nuclear Information System (INIS)

    The welding behaviour of 26 commercial casts of Alloy 800 has been quantified for mechanised, autogenous, full penetration, bead-on-strip tungsten inert gas welding tests. Weld front and back widths have been measured and correlated with minor element variations. Casts with similar welding responses have been sorted into groups. The behaviour of the weld pool, surface slags and arc have been compared and a convection controlled model has been used to account for differences between the groups of casts. The main factors governing laboratory process control variability have been identified and a statistical method has been used to identify all the components of weld variance. An optimum size of welding test matrix has been proposed to determine typical cast-to-cast variations at high significance levels. (author)

  1. Bearing Strengths of Some Wrought-aluminum Alloys

    Science.gov (United States)

    Moore, R L; Wescoat, C

    1943-01-01

    Although a number of investigations of the bearing strength of aluminum alloys have been made, the problem remains one of considerable interest to the aircraft industry. For this reason it has seemed advisable to make additional tests of the commonly used aircraft alloys in an effort to establish a better basis for the selection of allowable bearing values. Current design practice does not recognize the effect of edge distance upon bearing strengths, and for this reason edge distance was one of the principal variables considered in this investigation. The increasing emphasis being placed upon permanent set limitations makes it essential that more information on bearing yield phenomena be obtained. The object of this investigation was to determine bearing yield and ultimate strengths of the following aluminum alloy products: 17S-T, 24S-T, Alclad 24S-T, 24S-RT, 52S-0, 52S-1/2H, 52S-H, 53S-T, and 61S-T extrusions. Ratios of these bearing properties to tensile properties were also determined.

  2. Fabrication of superhydrophobic nanostructured surface on aluminum alloy

    Energy Technology Data Exchange (ETDEWEB)

    Jafari, R.; Farzaneh, M. [Universite du Quebec a Chicoutimi, Chicoutimi, QC (Canada)

    2011-01-15

    A superhydrophobic surface was prepared by consecutive immersion in boiling water and sputtering of polytetrafluoroethylene (PTFE or Teflon registered) on the surface of an aluminum alloy substrate. Immersion in boiling water was used to create a micro-nanostructure on the alloy substrate. Then, the rough surface was coated with RF-sputtered Teflon film. The immersion time in boiling water plays an important role in surface morphology and water repellency of the deposited Teflon coating. Scanning electron microscopy images showed a ''flower-like'' structure in first few minutes of immersion. And as the immersion time lengthened, a ''cornflake'' structure appeared. FTIR analyses of Teflon-like coating deposited on water treated aluminum alloy surfaces showed fluorinated groups, which effectively reduce surface energy. The Teflon-like coating deposited on a rough surface achieved with five-minute immersion in boiling water provided a high static contact angle ({proportional_to}164 ) and low contact angle hysteresis ({proportional_to}4 ). (orig.)

  3. Influence of Technical Parameters on the Properties of Micro-arc Oxidation Film on Casted Aluminum-Silicon Alloy%工艺参数对铸造铝-硅合金微弧氧化层特性的影响

    Institute of Scientific and Technical Information of China (English)

    卢立红; 沈德久; 王玉林

    2001-01-01

    Ceramic coating was obtained by micro-arc oxidation on thesubstrate of casted aluminum-silicon alloy. The influence of current density and intensifying time on the thickness, the surface roughness and the hardness of the ceramic layer, and the influence of intensifying time on the forming velocity of the layer are studied in this paper. The results show that both the thickness and the surface roughness of the layer increase. There is a limit value in the thickenss with the increase in current density and intensifying time. The hardness increases and there is a limit value with the increase in the current density. In lower current density, the forming velocity of the ceramic layer does not vary with the intensifying time, while it decreases with the increment of intensifying time in higher current density, and its value approximates zero in the end. The higher the current density is, the faster the decrease of forming velocity.%用微弧氧化的方法在铸造铝-硅合金基体上获得陶瓷层。分别研究了电流密度及强化时间对陶瓷层厚度、表面粗糙度及硬度的影响,以及强化时间对成膜速度的影响。结果表明:陶瓷层厚度、表面粗糙度都随电流密度及强化时间的增大而增大,膜厚随二者增加有一极限值:硬度随电流密度增加而增加,也有一极限值:成膜速度在较低电流密度时不随时间而变,在较高电流密度时,成膜速度随时间增加而下降,最终趋于零,电流密度越高,下降速度越快。

  4. Microstructural characterization of as-cast hf-b alloys

    Directory of Open Access Journals (Sweden)

    João Carlos Jânio Gigolotti

    2012-04-01

    Full Text Available An accurate knowledge of several metal-boron phase diagrams is important to evaluation of higher order systems such as metal-silicon-boron ternaries. The refinement and reassessment of phase diagram data is a continuous work, thus the reevaluation of metal-boron systems provides the possibility to confirm previous data from an investigation using higher purity materials and better analytical techniques. This work presents results of rigorous microstructural characterization of as-cast hafnium-boron alloys which are significant to assess the liquid composition associated to most of the invariant reactions of this system. Alloys were prepared by arc melting high purity hafnium (minimum 99.8% and boron (minimum 99.5% slices under argon atmosphere in water-cooled copper crucible with non consumable tungsten electrode and titanium getter. The phases were identified by scanning electron microscopy, using back-scattered electron image mode and X-ray diffraction. In general, a good agreement was found between our data and those from the currently accepted Hafnium-Boron phase diagram. The phases identified are αHfSS and B-RhomSS, the intermediate compounds HfB and HfB2 and the liquide L. The reactions are the eutectic L ⇔ αHfSS + HfB and L ⇔ HfB2 + B-Rhom, the peritectic L + HfB2 ⇔ HfB and the congruent formation of HfB2.

  5. Heat Treatment in High Chromium White Cast Iron Ti Alloy

    Directory of Open Access Journals (Sweden)

    Khaled M. Ibrahim

    2014-01-01

    Full Text Available The influence of heat treatment on microstructure and mechanical properties of high chromium white cast iron alloyed with titanium was investigated. The austenitizing temperatures of 980°C and 1150°C for 1 hour each followed by tempering at 260°C for 2 hours have been performed and the effect of these treatments on wear resistance/impact toughness combination is reported. The microstructure of irons austenitized at 1150°C showed a fine precipitate of secondary carbides (M6C23 in a matrix of eutectic austenite and eutectic carbides (M7C3. At 980°C, the structure consisted of spheroidal martensite matrix, small amounts of fine secondary carbides, and eutectic carbides. Titanium carbides (TiC particles with cuboidal morphology were uniformly distributed in both matrices. Irons austenitized at 980°C showed relatively higher tensile strength compared to those austenitized at 1150°C, while the latter showed higher impact toughness. For both cases, optimum tensile strength was reported for the irons alloyed with 1.31% Ti, whereas maximum impact toughness was obtained for the irons without Ti-addition. Higher wear resistance was obtained for the samples austenitized at 980°C compared to the irons treated at 1150°C. For both treatments, optimum wear resistance was obtained with 1.3% Ti.

  6. DSC Analysis of LT-3 Aluminum Alloy Vacuum Brazing

    Institute of Scientific and Technical Information of China (English)

    FENG Tao; WU Lu-hai; LOU Song-nian; LI Ya-jiang

    2005-01-01

    LT-3 aluminum alloy is a kind of two-side cladding aluminum special used in vacuum brazing. Differential Scanning Calorimeter (DSC) was used to measure the exothermic and endothermic reaction during the brazing process that the cortex metal and the base metal are melted and re-crystal. The analysis results inidicate that eutectic reaction is the main reaction in the melted cortex metal crystallization process. But the main reaction in the melted base metal crystallization process is the reaction that a-A1 segregated out. According to the experimental details, the critical work of nucleation is 3.82 × 1017J, the critical radius of nucleation is 8.69 × 1010 m, the volume of critical crystal nucleus is 2.75× 10-27 m3 and the per unit cell in critical crystal nucleus is 43.

  7. Effects of production parameters on characteristics of magnesium alloy sheets manufactured by twin-roll casting

    Directory of Open Access Journals (Sweden)

    H. Watari

    2006-04-01

    Full Text Available Purpose: : The purpose of the work is to establish a manufacturing process and technology to facilitate the economical manufacture of high-quality magnesium sheet alloys.Design/methodology/approach: Magnesium alloy AZ31B was used to investigate the appropriate manufacturing conditions for use in twin-roll strip casting. Temperatures of the molten materials and roll speeds were varied to find the appropriate manufacturing conditions. The effects of manufacturing conditions on possible forming were clarified in terms of roll speeds and roll gaps between upper and lower rolls.Findings: In the hot-rolling process, a temperature exceeding 200°C was chosen to keep cast products from cracking. An appropriate annealing temperature was effective for homogenizing the microstructure of the rolled cast sheets after the strip casting process. The grain size of the manufactured wrought magnesium alloys sheet was less than 10 micrometers. The obtained magnesium alloy sheet exhibited an equivalent limiting drawing ratio in a warm-drawing test.Research limitations/implications: AZ31 were used to investigate the appropriate manufacturing conditions for use in twin-roll strip casting. Casting temperatures were varied from 630°C to 670°C to find the best casting conditions. Roll casting speeds were varied from 5m/min to 30 m/min in order to examine which roll speed was appropriate for solidifying the molten magnesium.Practical implications: It was found that the cast magnesium sheet manufactured by roll strip casting could be used for plastic forming if the appropriate magnesium sheets were produced after the roll casting process.Originality/value: This paper showed the effectiveness of twin roll casting for magnesium alloys by a horizontal roll caster.

  8. Nanoreinforced Cast Al-Si Alloys with Al2O3, TiO2 and ZrO2 Nanoparticles

    Directory of Open Access Journals (Sweden)

    Iman S. El-Mahallawi

    2015-05-01

    Full Text Available This study presents a new concept of refining and enhancing the properties of cast aluminum alloys by adding nanoparticles. In this work, the effect of adding alumina (Al2O3, titanium dioxide (TiO2 and zirconia (ZrO2 nano-particles (40 nm to the aluminum cast alloy A356 as a base metal matrix was investigated. Alumina, titanium dioxide and zirconia nano-powders were stirred in the A356 matrix with different fraction ratios ranging from (0%–5% by weight at variable stirring speeds ranging from (270, 800, 1500, 2150 rpm in both the semisolid (600 °C and liquid (700 °C state using a constant stirring time of one minute. The cast microstructure exhibited change of grains from dendritic to spherical shape with increasing stirring speed. The fracture surface showed the presence of nanoparticles at the interdendritic spacing of the fracture surface and was confirmed with EDX analysis of these particles. The results of the study showed that the mechanical properties (strength, elongation and hardness for the nanoreinforced castings using Al2O3, TiO2 and ZrO2 were enhanced for the castings made in the semi-solid state (600 °C with 2 weight% Al2O3 and 3 weight% TiO2 or ZrO2 at 1500 rpm stirring speed.

  9. Strengthening Aluminum Alloys for High Temperature Applications Using Nanoparticles of Al203 and Al3-X Compounds (X= Ti, V, Zr)

    Science.gov (United States)

    Lee, Jonathan A.

    2007-01-01

    In this paper the effect of nanoparticles A12O3 and A13-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 chemical stability and low diffusions rates in aluminum matrix at high temperatures. The strengthening mechanism for aluminum alloy is based on the mechanical blocking of dislocation movements by these nanoparticles. Samples were prepared from A12O3 nanoparticle preforms, which were produced using ceramic injection molding process and pressure infiltrated by molten aluminum. A12O3 nanoparticles can also be homogeneously mixed with aluminum powder and consolidated into samples through hot pressing and sintering. On the other hand, the Al3-X nanoparticles are produced as precipitates via in situ reactions with molten aluminum alloys using conventional casting techniques. The degree of alloy strengthening using nanoparticles will depend on the materials, particle size, shape, volume fraction, and mean inter-particle spacing.

  10. Current research progress in grain refinement of cast magnesium alloys: A review article

    Energy Technology Data Exchange (ETDEWEB)

    Ali, Yahia; Qiu, Dong [School of Mechanical and Mining Engineering, University of Queensland, St Lucia, QLD 4072 (Australia); Jiang, Bin; Pan, Fusheng [College of Materials Science and Engineering, Chongqing University, Chongqing 400030 (China); Zhang, Ming-Xing, E-mail: Mingxing.Zhang@uq.edu.au [School of Mechanical and Mining Engineering, University of Queensland, St Lucia, QLD 4072 (Australia)

    2015-01-15

    Grain refinement of cast magnesium alloys, particularly in magnesium–aluminium (Mg–Al) based alloys, has been an active research topic in the past two decades, because it has been considered as one of the most effective approaches to simultaneously increase the strength, ductility and formability. The development of new grain refiners was normally based on the theories/models that were established through comprehensive and considerable studies of grain refinement in cast Al alloys. Generally, grain refinement in cast Al can be achieved through either inoculation treatment, which is a process of adding, or in situ forming, foreign particles to promote heterogeneous nucleation rate, or restricting grain growth by controlling the constitutional supercooling or both. But, the concrete and tangible grain refinement mechanism in cast metals is still not fully understood and there are a number of controversies. Therefore, most of the new developed grain refiners for Mg–Al based alloys are not as efficient as the commercially available ones, such as zirconium in non-Al containing Mg alloys. To facilitate the research in grain refinement of cast magnesium alloys, this review starts with highlighting the theoretical aspects of grain refinement in cast metals, followed by reviewing the latest research progress in grain refinement of magnesium alloys in terms of the solute effect and potent nucleants.

  11. Current research progress in grain refinement of cast magnesium alloys: A review article

    International Nuclear Information System (INIS)

    Grain refinement of cast magnesium alloys, particularly in magnesium–aluminium (Mg–Al) based alloys, has been an active research topic in the past two decades, because it has been considered as one of the most effective approaches to simultaneously increase the strength, ductility and formability. The development of new grain refiners was normally based on the theories/models that were established through comprehensive and considerable studies of grain refinement in cast Al alloys. Generally, grain refinement in cast Al can be achieved through either inoculation treatment, which is a process of adding, or in situ forming, foreign particles to promote heterogeneous nucleation rate, or restricting grain growth by controlling the constitutional supercooling or both. But, the concrete and tangible grain refinement mechanism in cast metals is still not fully understood and there are a number of controversies. Therefore, most of the new developed grain refiners for Mg–Al based alloys are not as efficient as the commercially available ones, such as zirconium in non-Al containing Mg alloys. To facilitate the research in grain refinement of cast magnesium alloys, this review starts with highlighting the theoretical aspects of grain refinement in cast metals, followed by reviewing the latest research progress in grain refinement of magnesium alloys in terms of the solute effect and potent nucleants

  12. Electrochemical behavior of Co-Cr and Ni-Cr dental cast alloys

    Institute of Scientific and Technical Information of China (English)

    Viswanathan S. SAJI; Han-Cheol CHOE

    2009-01-01

    The cast structures influencing the electrochemical corrosion behavior of Co-Cr and Ni-Cr dental alloys were studied using potentiodynamic polarization and AC impedance in 0.9% (mass fraction) NaCl solution at (37±1) ℃. The phase and microstructure of the alloys that were fabricated using two different casting methods viz. centrifugal casting and high frequency induction casting, were examined using X-ray diffraction analysis, scanning electron microscopy and energy dispersive spectroscopy. The roles of alloying elements and the passive film homogeneity on the corrosion resistance of Co-Cr-Mo and Ni-Cr-Mo dental cast alloys were reviewed. The results of electrochemical study show that the dependence of corrosion resistance on the microstructure associated with the casting methods is marginal. The Co-Cr alloy exhibits more desirable corrosion resistance properties than the Ni-Cr alloy. There is severe preferential dissolution of Ni-rich, Cr and Mo depleted zones in the Ni-Cr alloy.

  13. Development of a Two-Phase Model for the Hot Deformation of Highly-Alloyed Aluminum

    Energy Technology Data Exchange (ETDEWEB)

    A. J. Beaudoin; J. A. Dantzig; I. M. Robertson; B. E. Gore; S. F. Harnish; H. A. Padilla

    2005-10-31

    Conventional processing methods for highly alloyed aluminum consist of ingot casting, followed by hot rolling and thermal treatments. Defects result in lost productivity and wasted energy through the need to remelt and reprocess the material. This research centers on developing a fundamental understanding for deformation of wrought 705X series alloys, a key alloy system used in structural airframe applications. The development of damage at grain boundaries is characterized through a novel test that provides initiation of failure while preserving a controlled deformation response. Data from these mechanical tests are linked to computer simulations of the hot rolling process through a critical measure of damage. Transmission electron microscopy provides fundamental insight into deformation at these high working temperatures, and--in a novel link between microscale and macroscale response--the evolution of microstructure (crystallographic orientation) provides feedback for tuning of friction in the hot rolling process. The key product of this research is a modeling framework for the analysis of industrial hot rolling.

  14. Electrodeposition of aluminum and aluminum-magnesium alloys at room temperature

    Institute of Scientific and Technical Information of China (English)

    阚洪敏; 祝跚珊; 张宁; 王晓阳

    2015-01-01

    Electrodeposition of aluminum from benzene-tetrahydrofuran−AlCl3−LiAlH4 was studied at room temperature. Galvanostatic electrolysis was used to investigate the effect of various parameters on deposit morphology and crystal size, including current density, temperature, molar ratio of benzene/tetrahydrofuran and stirring speed. The deposit microstructure was adjusted by changing the parameters, and the optimum operating conditions were determined. Dense, bright and adherent aluminum coatings were obtained over a wide range of current densities (10−25 mA/cm2), molar ratio of benzene and tetrahydrofuran (4:1 to 7:8) and stirring speeds (200−500 r/min). Smaller grain sizes and well-adhered deposits were obtained at lower temperatures. Aluminum-magnesium alloys could potentially be used as hydrogen storage materials. A novel method for Al−Mg deposition was proposed by using pure Mg anodes in the organic solvents system benzene-tetrahydrofuran−AlCl3−LiAlH4. XRD shows that the aluminum−magnesium alloys are mainly Al3Mg2 and Al12Mg17.

  15. Effect of pressure on heat transfer coefficient at the metal/mold interface of A356 aluminum alloy

    DEFF Research Database (Denmark)

    Fardi Ilkhchy, A.; Jabbari, Masoud; Davami, P.

    2012-01-01

    The aim of this paper is to correlate interfacial heat transfer coefficient (IHTC) to applied external pressure, in which IHTC at the interface between A356 aluminum alloy and metallic mold during the solidification of casting under different pressures were obtained using the inverse heat...... conduction problem (IHCP) method. The method covers the expedient of comparing theoretical and experimental thermal histories. Temperature profiles obtained from thermocouples were used in a finite difference heat flow program to estimate the transient heat transfer coefficients. The new simple formula...... was presented for correlation between external pressure and heat transfer coefficient. Acceptable agreement with data in literature shows the accuracy of the proposed formula....

  16. Development of high plasticity Al-Si alloy and its casting process

    Institute of Scientific and Technical Information of China (English)

    郭国文; 李元元; 陈维平; 张大童; 龙雁

    2002-01-01

    Aiming to meet the challenge of the shape complexity and high plasticity demanded for the upper connective plate(UCP) in motorcycle, a high plasticity Al-Si alloy named HGZL-02 was developed by optimizing the chemical composition and casting process. Premium UCP castings were obtained by using optimized casting process. Results show that fine and dense microstructure are obtained in the UCP castings. An average of 224MPa in ultimate tensile strength, 149MPa in yield strength and 13.2% in elongation are achieved for T6 heat-treated UPS castings.

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

    Directory of Open Access Journals (Sweden)

    T. Szykowny

    2010-01-01

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

  18. Corrosion damage evolution and residual strength of corroded aluminum alloys

    Institute of Scientific and Technical Information of China (English)

    Youhong Zhang; Guozhi Lv; Hui Wang; Bomei Si; Yueliang Cheng

    2008-01-01

    The LY12CZ aluminum alloy specimens were eurroded under the conditions of different test temperatures and exposure durations. After corrosion exposure, fatigue tests were performed. Scanning electron microscopy and optical microscope analyses on corrosion damage were carried out. The definition of surface corrosion damage ratio was provided to describe the extent of surface corrosion damage. On the basis of the measured data sets of the corrosion damage ratio, the probabilistic model of corrosion damage evolution was built. The corrosion damage decreased the fatigue life by a factor of about 1.25 to 2.38 and the prediction method of residual strength of the corroded structure was presented.

  19. Effect of Coolant Water Flow Rate on Aluminum Alloys Corrosion

    Energy Technology Data Exchange (ETDEWEB)

    Golosov, O.A. [Institute of Nuclear Materials, Zarechny, Sverdlovsk region, 624250 (Russian Federation)

    2011-07-01

    One of the most important factors limiting a life-time of fuel elements in high-flux research reactors are a corrosion rate of fuel cladding material and a formation rate of oxide film. This study presents the results of the corrosion tests with and without irradiation. The aluminum alloys systems Al-Fe-Ni, Al-Fe-Ni-Cu-Mg and Al-Mg-Si-Cu were irradiated in the water flow of a velocity from 1.3 to 14.2m/s at 200 {sup o}C for time within 570 to 2000 hours. (author)

  20. Solar selective black nickel-cobalt coatings on aluminum alloys

    Energy Technology Data Exchange (ETDEWEB)

    Shashikala, A.R.; Sharma, A.K.; Bhandari, D.R. [Thermal System Group, ISRO Satellite Centre, Bangalore 560 017 (India)

    2007-04-16

    Solar selective black nickel-cobalt plating on pre cleaned aluminum alloy substrates with nickel undercoat were investigated. Process optimization was carried out by the hull cell experiments investigating the influence of operating variables on the optical selectivity of the coating. The coatings were characterized with scanning electron microscope, X-ray diffraction, energy dispersive X-ray spectroscopic and polarization studies. Evaluation of the coatings was carried out by adhesion, measurement of coating thickness and optical properties, humidity, thermal cycling, thermo-vacuum performance and thermal stability tests. (author)

  1. Sensors Array Technique for Monitoring Aluminum Alloy Spot Welding

    Institute of Scientific and Technical Information of China (English)

    王蕤; 罗震; 单平; 步贤政; 袁书现; 敖三三

    2010-01-01

    In this paper,the sensors array technique is applied to the quality detection of aluminum alloy spot welding.The sensors array has three forms,i.e.,linear magnetic sensors array,annular magnetic sensors array and cross magnetic sensors array.An algorithm based on principal component analysis is proposed to extract the signal eigenvalues.The three types of magnetic sensors array are used in the experiment of monitoring the signal.After the eigenvalues are extracted,they are used to build a relationship with ...

  2. Corrosion fatigue of 2219-T87 aluminum alloy

    Science.gov (United States)

    Mcmillan, V. C.

    1986-01-01

    Corrosion fatigue studies were conducted on bare, chemical conversion coated, and anodized 2219-T87 aluminum alloy. These tests were performed using a rotating beam machine running at a velocity of 2500 rpm. The corrosive environments tested were distilled water, 100 ppm NaCl, and 3.5 percent NaCl. Results were compared to the endurance limit in air. An evaluation of the effect of protective coatings on corrosion fatigue was made by comparing the fatigue properties of specimens with coatings to those without.

  3. Recrystallization model for hot-rolling of 5182 aluminum alloy

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A recrystallization model for hot-rolling of 5182 aluminum alloy was presented by means of the fractional softening during double interval deformation. It is found that the recrystallization rate depends on strain rate more sensitively than deformation temperature, and the time for full recrystallization is very short as strain rate is greater than 1 s-1. Using the recrystallization—time—temperature curves, the desirable hot rolled microstructure can be obtained by controlling the rolling speed, temperature and cooling rate before cooling during the last pass in reversing mill.

  4. Damage percolation during stretch flange forming of aluminum alloy sheet

    Science.gov (United States)

    Chen, Zengtao; Worswick, Michael J.; Keith Pilkey, A.; Lloyd, David J.

    2005-12-01

    A multi-scale finite element (FE)-damage percolation model was employed to simulate stretch flange forming of aluminum alloys AA5182 and AA5754. Material softening and strain gradients were captured using a Gurson-based FE model. FE results were then fed into the so-called damage percolation code, from which the damage development was modelled within measured microstructures. The formability of the stretch flange samples was predicted based upon the onset of catastrophic failure triggered by profuse void coalescence within the measured second-phase particle field. Damage development is quantified in terms of crack and void areal fractions, and compared to metallographic results obtained from interrupted stretch flange specimens. Parametric study is conducted on the effect of void nucleation strain in the prediction of formability of stretch flanges to "calibrate" proper nucleation strains for both alloys.

  5. A Rare Earth High-iron Aluminum Alloy Cable Company to Settle in Chongqing

    Institute of Scientific and Technical Information of China (English)

    2014-01-01

    <正>On September 14,the reporter learnt from the Seminar on Application of New Rare Earth High-iron Aluminum Alloy Cable Technologies for Energy Conservation and Environmental Protection held by Chongqing Electric Industry Association that a rare earth high-iron aluminum alloy cable company with

  6. GAS-CREATION OF SEPARATING COVERINGS FOR MOULDS FOR DIE CASTING OF ALUMINIUM ALLOYS

    OpenAIRE

    A. M. Mihaltsov; A. A. Pivovarchik; A. A. Subota

    2016-01-01

    The methods of experiments on determination of gascreating ability of different separating coverings for the moulds of aluminium alloys die casting are given and described in the article, and the results of investigation are given as well.

  7. Development of a discriminatory biocompatibility testing model for non-precious dental casting alloys.

    LENUS (Irish Health Repository)

    McGinley, Emma Louise

    2011-12-01

    To develop an enhanced, reproducible and discriminatory biocompatibility testing model for non-precious dental casting alloys, prepared to a clinically relevant surface finishing condition, using TR146 oral keratinocyte cells.

  8. Interfacial characterization of resistance spot welded joint of steel and aluminum alloy

    Institute of Scientific and Technical Information of China (English)

    Zhang Weihua; Sun Daqian; Yin Shiqiang; Han Lijun; Qiu Xiaoming; Chen Qinglei

    2010-01-01

    The dissimilar material resistance spot welding of galvanized high strength steel and aluminum alloy had been conducted. The welded joint exhibited a thin reaction layer composed of Fe2Al5 and Fe4Al13 phases at steel/aluminum interface. The welded joint presented a tensile shear load of 3.3 kN with an aluminum alloy nugget diameter of 5.7 ram. The interfucial failure mode was observed for the tensile shear specimen and fracture occurred at reaction layer and aluminum alloy fusion zone beside the interface. The reaction layer with compounds was the main reason for reduction of the welded joint mechanical property.

  9. Evolution of Fe Bearing Intermetallics During DC Casting and Homogenization of an Al-Mg-Si Al Alloy

    Science.gov (United States)

    Kumar, S.; Grant, P. S.; O'Reilly, K. A. Q.

    2016-06-01

    The evolution of iron (Fe) bearing intermetallics (Fe-IMCs) during direct chill casting and homogenization of a grain-refined 6063 aluminum-magnesium-silicon (Al-Mg-Si) alloy has been studied. The as-cast and homogenized microstructure contained Fe-IMCs at the grain boundaries and within Al grains. The primary α-Al grain size, α-Al dendritic arm spacing, IMC particle size, and IMC three-dimensional (3D) inter-connectivity increased from the edge to the center of the as-cast billet; both α c-AlFeSi and β-AlFeSi Fe-IMCs were identified, and overall α c-AlFeSi was predominant. For the first time in industrial billets, the different Fe-rich IMCs have been characterized into types based on their 3D chemistry and morphology. Additionally, the role of β-AlFeSi in nucleating Mg2Si particles has been identified. After homogenization, α c-AlFeSi predominated across the entire billet cross section, with marked changes in the 3D morphology and strong reductions in inter-connectivity, both supporting a recovery in alloy ductility.

  10. Single-aging characteristics of 7055 aluminum alloy

    Institute of Scientific and Technical Information of China (English)

    WANG Tao; YIN Zhi-min; SHEN Kai; LI Jie; HUANG ji-wu

    2007-01-01

    The microstructures and properties of 7055 aluminum alloy were studied at different single-aging for up to 48 h using hardness test, tensile test, electrical conductivity measurement, XRD and TEM microstructure analysis. The results show that at the early stage of aging, the hardness and strength of the alloy increase rapidly, the peak hardness and strength are approached after 120 ℃ aging for 4 h, then maintained at a high level for a long time. The suitable single-aging treatment of 7055 alloy is 480 ℃, 1 h solution treatment and water quenching, then aging at 120 ℃ for 24 h. Under those condition, the tensile strength, yield strength, elongation and electrical conductivity of the studied alloy are 513 MPa, 462 MPa, 9.5% and 29%(IACS), respectively. During aging, the solid solution decomposes and precipitation occurs. At the early aging stage of 120 ℃, GP zones form and then grow up gradually with increasing ageing time. η' phase forms after ageing for 4 h and η phase starts to occur after 24 h aging.

  11. Thin Wall Ductile Iron Castings: Technological Aspects

    Directory of Open Access Journals (Sweden)

    E Fraś

    2013-01-01

    Full Text Available The paper discusses the reasons for the current trend of substituting ductile iron castings by aluminum alloys castings.However, it has been shown that ductile iron is superior to aluminum alloys in many applications. In particular it has beendemonstrated that is possible to produce thin wall wheel rim made of ductile iron without the development of chills, coldlaps or misruns. In addition it has been shown that thin wall wheel rim made of ductile iron can have the same weight, andbetter mechanical properties, than their substitutes made of aluminum alloys.

  12. Derivative thermo analysis of the Al-Si cast alloy with addition of rare earths metals

    Directory of Open Access Journals (Sweden)

    M. Krupiński

    2010-01-01

    Full Text Available In this paper the dependence between chemical composition, structure and cooling rate of Al–Si aluminium cast alloy was investigated. For studying of the structure changes the thermo-analysis was carried out, using the UMSA (Universal Metallurgical Simulator and Analyzer device. For structure investigation optical and electron scanning microscopy was used, phase and chemical composition of the Al cast alloy also using qualitative point-wise EDS microanalysis.

  13. Effect of Squeeze Cast Process Parameters on Fluidity of Hypereutectic Al-Si Alloy

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The effects of processing variables on the fluidity of hypereutectic Al-Si alloy melt during squeeze casting were investigated. The maximum fluidity of Al-16.0%Si alloy during squeeze casting was obtained under the applied pressure of 30 MPa. The fluidity increased with superheat. The fluidity increased with silicon content in the range from 12.0% to 20.0%. That was decreased respectively by eutectic modification and primary silicon refinement.

  14. Derivative thermo analysis of the Al-Si cast alloy with addition of rare earths metals

    OpenAIRE

    M. Krupiński; K. Labisz; L.A. Dobrzański; Z. Rdzawski

    2010-01-01

    In this paper the dependence between chemical composition, structure and cooling rate of Al–Si aluminium cast alloy was investigated. For studying of the structure changes the thermo-analysis was carried out, using the UMSA (Universal Metallurgical Simulator and Analyzer) device. For structure investigation optical and electron scanning microscopy was used, phase and chemical composition of the Al cast alloy also using qualitative point-wise EDS microanalysis.

  15. Effect of inter-critical quenching on mechanical properties of casting low-alloy steel

    OpenAIRE

    Liu Zhongli; Shang Yong

    2013-01-01

    For some casting low-alloy steels, traditional quenching and tempering heat treatments can improve the strength; however, sometimes the ductility is not satisfied. Therefore, some kind of effective heat treatment method seems necessary; one which could improve the ductility, but not seriously affect the strength. In this paper, the effect of inter-critical quenching (IQ) on the mechanical properties of casting low-alloy steel was studied. IQ was added between quenching and tempering heat trea...

  16. High-strength and high-RRR Al-Ni alloy for aluminum-stabilized superconductor

    CERN Document Server

    Wada, K; Sakamoto, H; Yamamoto, A; Makida, Y

    2000-01-01

    The precipitation type aluminum alloys have excellent performance as the increasing rate in electric resistivity with additives in the precipitation state is considerably low, compared to that of the aluminum alloy with additives in the solid-solution state. It is possible to enhance the mechanical strength without remarkable degradation in residual resistivity ratio (RRR) by increasing content of selected additive elements. Nickel is the suitable additive element because it has very low solubility in aluminum and low increasing rate in electric resistivity, and furthermore, nickel and aluminum form intermetallic compounds which effectively resist the motion of dislocations. First, Al-0.1wt%Ni alloy was developed for the ATLAS thin superconducting solenoid. This alloy achieved high yield strength of 79 MPa (R.T.) and 117 MPa (4.2 K) with high RRR of 490 after cold working of 21% in area reduction. These highly balanced properties could not be achieved with previously developed solid-solution aluminum alloys. ...

  17. A perspective of microplasma oxidation (MPO) and vapor deposition coatings in surface engineering of aluminum alloys

    Institute of Scientific and Technical Information of China (English)

    AWAD Samir Hamid; QIAN Han-cheng

    2004-01-01

    Over the past years, great achievements have been made in the development of coating technologies for surface improvement of aluminum alloys. Despite these achievements, the role in the market strongly depends on the ability of surface coating technology under technical and economic considerations to meet the increased demands for heavy tribological applications of aluminum alloys. Microplasma oxidation (MPO) technology has recently been studied as a novel and effective means to provide thick and hard ceramic coating with improved properties such as excellent load-bearing and wear resistance properties on aluminum alloys. The present work covers the evaluation of the performances of current single and duplex coatings combining MPO, physical vapor deposition (PVD), and plasma assisted chemical vapor deposition (PACVD) coatings on aluminum alloys. It suggests that the MPO coating is a promising candidate for design engineers to apply aluminum alloys to heavy load-bearing applications. The prospective future for the research on MPO coatings is introduced as well.

  18. Air cushion furnace technology for heat treatment of high quality aluminum alloy auto body sheet

    Institute of Scientific and Technical Information of China (English)

    Li Yong; Wang Zhaodong; Ma Mingtu; Wang Guodong; Fu Tianliang; Li Jiadong; Liang Xiong

    2014-01-01

    The process characteristics of heat treatment of aluminum alloy auto body sheet and the working prin-ciple of air cushion furnace were introduced. The process position and irreplaceable role of air cushion furnace in the aluminum alloy auto body sheet production was pointed out after the difficulty and key points in the whole production process of auto body sheet were studied. Then the development process of air cushion furnace line of aluminum alloy sheet was reviewed,summarized and divided to two stages. Based on the research of air cushion furnace,the key technology of it was analyzed,then the key points on process,equipment and control models of air cushion furnace for aluminum alloy auto body sheet in future were put forward. With the rapid de-velopment of automotive industry,there will be certainly a new upsurge of research and application of air cush-ion furnace for heat treatment of aluminum alloy auto body sheet.

  19. Interfacial study of semi-solid aluminum alloy and stainless steel sheathed extrusion

    Institute of Scientific and Technical Information of China (English)

    LIU Hong-wei; GUO Cheng; LIU Xu-feng; SHAO Guang-jie

    2006-01-01

    Using sheathed extrusion technique, the bonding and forming of semi solid aluminum alloy with stainless steel sheath are successfully realized. The relationship between the interfacial shear strength and the solid fraction of semi solid aluminum alloy at different extrusion ratios is analyzed; the interfacial and fracture structure of the sheath material are studied by optical microscopy(OM) and scanning electric microscopy(SEM). The result shows that interfacial shear strength increases with the increase of extrusion ratio, the maximum value of the interfacial shear strength is obtained when solid fraction of aluminum alloy is 30%,solid phase and liquid phase of the semi solid aluminum alloy are bonded with stainless steel by turns along the interface, and the aluminum alloy can not be peeled from the stainless steel completely, which means nicer bonding occurs at the interface.

  20. Influence of casting defects on fatigue strength of an investment cast Ti-6Al-4V alloy

    Directory of Open Access Journals (Sweden)

    Léopold Gaëlle

    2014-06-01

    Full Text Available The influence of casting defects on fatigue strength of an investment cast Ti-6Al-4V alloy is investigated. The most common of these defects are: pinhole, linear defect and inclusion. Each of them is currently defined by its size, morphology and position from the surface but is different from each other for a same type. An experimental campaign is defined with different types of defect. The first part of the campaign is focused on the influence of an artificial and spherical defect, considering two different surface conditions. It is shown that fatigue behaviour of this alloy is very sensitive to the surface condition of this artificial defect despite stress concentrations at the tip of the defect. The second part of the campaign is focused on casting defects: reduction of fatigue life is quantified and it is shown that an electro-discharge machined defect cannot be representative of pinhole.

  1. Energy Saving Melting and Revert Reduction Technology (Energy-SMARRT): Light Metals Permanent Mold Casting

    Energy Technology Data Exchange (ETDEWEB)

    Fasoyinu, Yemi [CanmetMATERIALS

    2014-03-31

    Current vehicles use mostly ferrous components for structural applications. It is possible to reduce the weight of the vehicle by substituting these parts with those made from light metals such as aluminum and magnesium. Many alloys and manufacturing processes can be used to produce these light metal components and casting is known to be most economical. One of the high integrity casting processes is permanent mold casting which is the focus of this research report. Many aluminum alloy castings used in automotive applications are produced by the sand casting process. Also, aluminum-silicon (Al-Si) alloys are the most widely used alloy systems for automotive applications. It is possible that by using high strength aluminum alloys based on an aluminum-copper (Al-Cu) system and permanent mold casting, the performance of these components can be enhanced significantly. This will also help to further reduce the weight. However, many technological obstacles need to be overcome before using these alloys in automotive applications in an economical way. There is very limited information in the open literature on gravity and low-pressure permanent mold casting of high strength aluminum alloys. This report summarizes the results and issues encountered during the casting trials of high strength aluminum alloy 206.0 (Al-Cu alloy) and moderate strength alloy 535.0 (Al-Mg alloy). Five engineering components were cast by gravity tilt-pour or low pressure permanent mold casting processes at CanmetMATERIALS (CMAT) and two production foundries. The results of the casting trials show that high integrity engineering components can be produced successfully from both alloys if specific processing parameters are used. It was shown that a combination of melt processing and mold temperature is necessary for the elimination of hot tears in both alloys.

  2. Microstructure of Magnesium alloy AZ91-HP cast in permanent and non-permanent moulds

    DEFF Research Database (Denmark)

    Tiedje, Niels; Sørensen, Rasmus Kirkegaard; Albachari, Sami

    2003-01-01

    Casting of different geometries were made with AZ91-HP in different moulding media, so that a range of cooling conditions were obtained. Cooling curves were measured and compared to the microstructures found in the castings. It was shown that segregation in the alloy is highly dependent on coolin...

  3. Interdiffusion in binary cast and powders W-Re and Mo-Re alloys

    International Nuclear Information System (INIS)

    Concentration dependences of diffusion coefficients in the cast and powder alloys of the W-Re and Mo-Re systems are obtained. It is shown, that in spite of the fact that the diffusion coefficients values in dispersed materials are higher than in the cast ones, the peculiarities of the concentration dependences are common for both cases

  4. The technology of precision casting of titanium alloys by centrifugal process

    OpenAIRE

    A. Karwiński; W. Leśniewski; S. Pysz; P. Wieliczko

    2011-01-01

    The article describes the development of a procedure for the preparation of foundry ceramic moulds and making first test castings. The presented studies included:development of technological parameters of the ceramic mould preparation process using water-based zirconium binders and zirconia ceramic materials, where moulds are next used for the centrifugal casting of titanium alloys melted in vacuum furnaces, designing of pouring process using simulation software, making test castings,testing ...

  5. Corrosion and protection of heterogeneous cast Al-Si (356) and Al-Si-Cu-Fe (380) alloys by chromate adn cerium inhibitors

    Science.gov (United States)

    Jain, Syadwad

    In this study, the localized corrosion and conversion coating on cast alloys 356 (Al-7.0Si-0.3Mg) and 380 (Al-8.5Si-3.5Cu-1.6Fe) were characterized. The intermetallic phases presence in the permanent mold cast alloy 356 are primary-Si, Al5FeSi, Al8Si6Mg3Fe and Mg2Si. The die cast alloy 380 is rich in Cu and Fe elements. These alloying elements result in formation of the intermetallic phases Al 5FeSi, Al2Cu and Al(FeCuCr) along with primary-Si. The Cu- and Fe-rich IMPS are cathodic with respect to the matrix phase and strongly govern the corrosion behavior of the two cast alloys in an aggressive environment due to formation of local electrochemical cell in their vicinity. Results have shown that corrosion behavior of permanent mould cast alloy 356 is significantly better than the die cast aluminum alloy 380, primarily due to high content of Cu- and Fe-rich phases such as Al2Cu and Al 5FeSi in the latter. The IMPS also alter the protection mechanism of the cast alloys in the presence of inhibitors in an environment. The presence of chromate in the solution results in reduced cathodic activity on all the phases. Chromate provides some anodic inhibition by increasing pitting potentials and altering corrosion potentials for the phases. Results have shown that performance of CCC was much better on 356 than on 380, primarily due to inhomogeneous and incomplete coating deposition on Cu- and Fe- phases present in alloy 380. XPS and Raman were used to characterize coating deposition on intermetallics. Results show evidence of cyanide complex formation on the intermetallic phases. The presence of this complex is speculated to locally suppress CCC formation. Formation and breakdown of cerium conversion coatings on 356 and 380 was also analyzed. Results showed that deposition of cerium hydroxide started with heavy precipitation on intermetallic particles with the coatings growing outwards onto the matrix. Electrochemical analysis of synthesized intermetallics compounds in the

  6. Structure changes and mechanical properties of laser alloyed magnesium cast alloys

    OpenAIRE

    W. Kwaśny; T. Tański,; Sz. Malara; J. Domagała; L.A. Dobrzański

    2009-01-01

    Purpose: The aim of this work was to investigate structure and mechanical properties of the MCMgAl12Zn1 casting magnesium alloys after laser treatment. The laser treatment was carried out using a high power diode laser (HPDL).Design/methodology/approach: The laser processing of TiC, WC, SiC particles in MCMgAl12Zn1 and the resulted microstructures and properties are discussed in this paper. The resulting microstructure in the modified surface layer was examined. Phase composition was...

  7. Stress corrosion cracking susceptibility of 7A52 aluminum alloy

    Institute of Scientific and Technical Information of China (English)

    ZHAO Jun-jun; WANG Wei-xin; CAI Zhi-hai; ZHANG Ping

    2006-01-01

    The stress corrosion sensitivity of 7A52 aluminum alloy was investigated in the artificial sea water through slow stain rate test(SSRT). The stress corrosion cracking(SCC) susceptibility was estimated with the loss of elongation and stress corrosion sensitivity index. The results show that the susceptibility of 7A52 aluminum alloy is always high when the strain rate is in the range of 10-5-10-7s-1. It reaches the maximum at the strain rate of 8.7×10-7s-1, and the sensitivity index reaches 0.346. The characteristics of stress corrosion can be observed clearly on the fracture of tensile specimen. The process of SCC is depicted according to the fracture morphology. The SCC initiates at the edge of the specimen. Then the SCC grows rapidly because of the anode dissolving and stress concentration. When the area of specimen cannot support the tensile stress, it ruptures suddenly. The secondary cracks and quasi-cleavage surface can be found on the fracture morphology.susceptibility

  8. Fatigue crack growth in an aluminum alloy-fractographic study

    Science.gov (United States)

    Salam, I.; Muhammad, W.; Ejaz, N.

    2016-08-01

    A two-fold approach was adopted to understand the fatigue crack growth process in an Aluminum alloy; fatigue crack growth test of samples and analysis of fractured surfaces. Fatigue crack growth tests were conducted on middle tension M(T) samples prepared from an Aluminum alloy cylinder. The tests were conducted under constant amplitude loading at R ratio 0.1. The stress applied was from 20,30 and 40 per cent of the yield stress of the material. The fatigue crack growth data was recorded. After fatigue testing, the samples were subjected to detailed scanning electron microscopic (SEM) analysis. The resulting fracture surfaces were subjected to qualitative and quantitative fractographic examinations. Quantitative fracture analysis included an estimation of crack growth rate (CGR) in different regions. The effect of the microstructural features on fatigue crack growth was examined. It was observed that in stage II (crack growth region), the failure mode changes from intergranular to transgranular as the stress level increases. In the region of intergranular failure the localized brittle failure was observed and fatigue striations are difficult to reveal. However, in the region of transgranular failure the crack path is independent of the microstructural features. In this region, localized ductile failure mode was observed and well defined fatigue striations were present in the wake of fatigue crack. The effect of interaction of growing fatigue crack with microstructural features was not substantial. The final fracture (stage III) was ductile in all the cases.

  9. Flexural-torsional buckling behavior of aluminum alloy beams

    Institute of Scientific and Technical Information of China (English)

    Xiaonong GUO; Zhe XIONG; Zuyan SHEN

    2015-01-01

    This paper presents an investigation on the flexural-torsional buckling behavior of aluminum alloy beams (AAB). First, based on the tests of 14 aluminum alloy beams under concentrated loads, the failure pattern, load- deformation curves, bearing capacity and flexural-torsional buckling factor are studied. It is found that all the beam specimens collapsed in the flexuml-torsional buckling with excessive deformation pattern. Moreover, the span, loading location and slenderness ratio influence the flexural-torsional buckling capacity of beams significantly. Secondly, besides the experiments, a finite element method (FEM) analysis on the flexural-torsional buckling behavior of AAB is also conducted. The main parameters in the FEM analysis are initial imperfection, material property, cross-section and loading scheme. According to the analytical results, it is indicated that the FEM is reasonable to capture mechanical behavior of AAB. Finally, on the basis of the experimental and analytical results, theoretical formulae to estimate the flexural- torsional buckling capacity of AAB are proposed, which could improve the application of present codes for AAB.

  10. New developments on optimizing properties of high-Zn aluminium cast alloys

    Science.gov (United States)

    Krajewski, W. K.; Buras, J.; Krajewski, P. K.; Greer, A. L.; Schumacher, P.; Haberl, K.

    2016-07-01

    Foundry alloys with Al-based matrices have a wide range of uses in today's global economy and there is a high demand for castings of Al alloys, including Al-Zn alloys. In this paper, investigations on the grain refinement of high-Zn aluminium cast alloys are presented. Aluminium alloys with relatively high zinc content have a tendency to be coarse-grained, especially in the case of castings with low cooling rates such as are found in sand moulds. The coarse-grained structure degrades the plasticity, specifically the elongation. Therefore, for aluminium alloys of high (10-30 wt.%) zinc content, inoculation is attractive, aiming to break up the primary dendrites of the a-phase solid solution of zinc in aluminium. Such dendrites are the principal microstructural component in these alloys. On the other hand, a finer grain structure usually reduces the damping (e.g. as measured by attenuation of ultrasound) in these alloys. In the present investigations, a binary sand-cast Al-20 wt.% Zn alloy was inoculated with different additions of AlTi3C0.15 (TiCAl) and ZnTi-based master alloys. The sand-cast samples were subjected to mechanical-property measurements (tensile strength and elongation), image analysis to determine grain size, and measurements of the attenuation of 1 MHz ultrasound. It is found that both of the master alloys used cause significant refinement of the a-AlZn primary dendrites and change their morphology from linear-branched to semi-globular, increase the elongation by about 40%, and decrease the attenuation coefficient by about 25% in comparison with the initial alloy without inoculation.

  11. Investigation of Corrosion Behavior Of 6013 Aluminum Alloys For Artificial Aged Microwave Furnace

    Directory of Open Access Journals (Sweden)

    Muzaffer Erdoğan

    2014-01-01

    Full Text Available Low density and high strength aluminum alloys can be achieved today is a type of an alloy. These alloys are more resistant, particularly the aging process is the precipitate formed. In this study, increased strength 6013 aluminum alloy in a microwave furnace yaşlandırarak artificial. Volume samples in a microwave oven aging method and aging has provided a homogeneous way.6013 aluminum alloys, pure argon gas atmosphere in a microwave furnace hardness after being subjected to artificial aging process analysis, the internal structure (optical microscope, SEM, characterization of the studied. Aging of the phases, the presence server in the XRD of the samples was determined by curves. Corrosion of artificial aged samples has been analyzed by the internal structure of the phases present. Depending on the time of artificial aging of aluminum alloy 6013 samples in a microwave furnace in the mechanical properties of the sediment affected the corrosion resistance values.

  12. Fatigue Resistance of Liquid-assisted Self-repairing Aluminum Alloys Reinforced with Shape Memory Alloys

    Science.gov (United States)

    Wright, M. Clara; Manuel, Michele; Wallace, Terryl

    2013-01-01

    A self-repairing aluminum-based composite system has been developed using a liquid-assisted healing theory in conjunction with the shape memory effect of wire reinforcements. The metal-metal composite was thermodynamically designed to have a matrix with a relatively even dispersion of a low-melting eutectic phase, allowing for repair of cracks at a predetermined temperature. Additionally, shape memory alloy (SMA) wire reinforcements were used within the composite to provide crack closure. Investigators focused the research on fatigue cracks propagating through the matrix in order to show a proof-of-concept Shape Memory Alloy Self-Healing (SMASH) technology for aeronautical applications.

  13. Thermal Decoating of Aerospace Aluminum Alloys for Aircraft Recycling

    Science.gov (United States)

    Muñiz Lerma, Jose Alberto; Jung, In-Ho; Brochu, Mathieu

    2016-06-01

    Recycling of aircraft aluminum alloys can be complex due to the presence of their corrosion protection coating that includes inorganic compounds containing Cr(VI). In this study, the characterization and thermal degradation behavior of the coating on aluminum substrates coming from an aircraft destined for recycling are presented. Elements such as Sr, Cr, Si, Ba, Ti, S, C, and O were found in three different layers by EDS elemental mapping corresponding to SrCrO4, Rutile-TiO2, SiO2, and BaSO4 with an overall particle size D 50 = 1.96 µm. The thermal degradation profile analyzed by TGA showed four different stages. The temperature of complete degradation at the fourth stage occurred at 753.15 K (480 °C) at lower heating rates. At higher heating rates and holding an isotherm at the same temperature, the residence time to fully decompose the aircraft coating has been estimated as 4.0 ± 0.2 minutes. The activation energy calculated by the Flynn-Wall-Ozawa and the modified Coats-Redfern methods for multiple fraction of decomposition showed a non-constant behavior indicating the complexity of the reaction. Finally, the concentration of Cr(VI) released to the environment during thermal decoating was obtained by UV-Vis spectroscopy. It was found that 2.6 ± 0.1 µg of Cr(VI)/mm2 of aluminum substrate could be released unless adequate particle controls are used.

  14. Changes of Tempering Microstructure and Properties of Fe-Cr-V-Ni-Mn-C Cast Alloys

    Institute of Scientific and Technical Information of China (English)

    LIU Yan-xia; MA Yong-qing; WANG Yue-hua; ZHANG Zhan-ping; ZHANG Yang

    2004-01-01

    The changes of tempering microstructure and properties of Fe-Cr-V-Ni-Mn-C cast alloys with martensite matrix and much retained austenite are studied. The results showed that when tempering at 200℃ the amount of retained austenite in the alloys is so much that is nearly to as-cast, and a lot of retained austenite decomposes when tempering at 350℃ and the retained austenite decomposes almost until tempering at 560℃. When tempering at 600℃, the retained austenite in the alloys all decomposes. At 560℃ the hardness is highest due to secondary hardening. The effect of nickel and manganese on the microstructure and properties of Fe-Cr-V-C cast alloy were also studied. The results show that the Fe-Cr-V-C cast alloy added nickel and manganese can obtain martensite matrix and much retained austenite microstructure, and nickel can also prevent pearlite transformation. With the increasing content of nickel and manganese, the hardness of as-cast alloy will decreases gradually, so one can improve the hardness of alloy by tempering process. When the content of nickel and manganese is 1.3~1.7%, the hardness of secondary hardening is the highest (HRC64). But when the content of nickel and manganese increase continually, the hardness of secondary hardening is low slightly, and the tempering temperature of secondary hardening rises.

  15. Ultrasonic semi-solid coating soldering 6061 aluminum alloys with Sn-Pb-Zn alloys.

    Science.gov (United States)

    Yu, Xin-ye; Xing, Wen-qing; Ding, Min

    2016-07-01

    In this paper, 6061 aluminum alloys were soldered without a flux by the ultrasonic semi-solid coating soldering at a low temperature. According to the analyses, it could be obtained that the following results. The effect of ultrasound on the coating which promoted processes of metallurgical reaction between the components of the solder and 6061 aluminum alloys due to the thermal effect. Al2Zn3 was obtained near the interface. When the solder was in semi-solid state, the connection was completed. Ultimately, the interlayer mainly composed of three kinds of microstructure zones: α-Pb solid solution phases, β-Sn phases and Sn-Pb eutectic phases. The strength of the joints was improved significantly with the minimum shear strength approaching 101MPa. PMID:26964943

  16. Numerical simulation of mold-filling capability for a thin- walled aluminum die casting

    Science.gov (United States)

    Sun, L.; Subasic, E.; Jakumeit, J.

    2015-06-01

    Mold-filling capability is an important property of casting materials. Especially in thin-walled die casting, fast cooling of the melt by contact to the die makes complete filling difficult to ensure. Simulation is an important tool enabling investigation of filling problems, even before the die is manufactured. However, the prediction of misruns is challenging. Flow and solidification have to be computed as closely coupled. The effects of surface tension, the wetting angle and reduced melt flow due to solidification must be modeled with high precision. To meet these requirements, a finite-volume method using arbitrary polyhedral control volumes is used to solve flow and solidification as closely coupled. The Volume-of-Fluid approach is used to capture the phase separation between gas, melt and solid in connection with a High-Resolution Interface-Capturing scheme to obtain sharp interfaces between phases. To model the resistance of the dendrite network to the melt flow, an additional source term in the momentum equation was implemented. The Bolt test was performed for A356 alloys at a range of different casting temperatures. Numerical prediction of incomplete filling in the bottleneck regions agreed well with experimental findings using 3D camera scanning. The simulation enables derivation of the dependence of critical wall-thickness, i.e. the thickness which is fillable, on casting temperature and metallostatic pressure. This could prove useful in predicting filling problems ahead of casting.

  17. Modeling of the Microstructure Evolution in Continuously Cast Al-Pb Alloys

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A numerical model is presented describing the microstructure evolution of an immiscible alloy under the continuous casting conditions. Calculations are carried out to investigate the microstructure evolution in a vertical strip cast sample of Al+5wt pct Pb alloy. The numerical results show that there exists a peak value for the supersaturation in front of the solid/liquid interface, and the minority phase droplets are nucleated in a region around this peak. Under strip casting conditions the Marangoni migration dominates the motion of droplets. This leads to an accumulation of the minority phase droplets in front of the solid/liquid interface.

  18. Optimization of Squeeze Casting Parameters for 2017 A Wrought Al Alloy Using Taguchi Method

    Directory of Open Access Journals (Sweden)

    Najib Souissi

    2014-04-01

    Full Text Available This study applies the Taguchi method to investigate the relationship between the ultimate tensile strength, hardness and process variables in a squeeze casting 2017 A wrought aluminium alloy. The effects of various casting parameters including squeeze pressure, melt temperature and die temperature were studied. Therefore, the objectives of the Taguchi method for the squeeze casting process are to establish the optimal combination of process parameters and to reduce the variation in quality between only a few experiments. The experimental results show that the squeeze pressure significantly affects the microstructure and the mechanical properties of 2017 A Al alloy.

  19. Anisotropic Effects on Constitutive Model Parameters of Aluminum Alloys

    Science.gov (United States)

    Brar, Nachhatter; Joshi, Vasant

    2011-06-01

    Simulation of low velocity impact on structures or high velocity penetration in armor materials heavily rely on constitutive material models. The model constants are required input to computer codes (LS-DYNA, DYNA3D or SPH) to accurately simulate fragment impact on structural components made of high strength 7075-T651 aluminum alloys. Johnson-Cook model constants determined for Al7075-T651 alloy bar material failed to simulate correctly the penetration into 1' thick Al-7075-T651plates. When simulations go well beyond minor parameter tweaking and experimental results are drastically different it is important to determine constitutive parameters from the actual material used in impact/penetration experiments. To investigate anisotropic effects on the yield/flow stress of this alloy we performed quasi-static and high strain rate tensile tests on specimens fabricated in the longitudinal, transverse, and thickness directions of 1' thick Al7075-T651 plate. Flow stresses at a strain rate of ~1100/s in the longitudinal and transverse direction are similar around 670MPa and decreases to 620 MPa in the thickness direction. These data are lower than the flow stress of 760 MPa measured in Al7075-T651 bar stock.

  20. Surface properties of aluminum alloy as material for ultrahigh vacuum

    International Nuclear Information System (INIS)

    The characteristics of aluminum alloy (2017 alloy) for the vacuum chambers of TRISTAN were studied. Machining, electric discharge machining and chemical polishing were made successively on the samples of the 2017 alloy. The observation of surface state, the analysis of surface composition and high temperature desorption experiment were performed. The measurement of surface roughness with a probe, the observation with a scanning electron microscope (SEM), and the measurement of surface roughness factor (SRF) were carried out as the study of the surface state. The analysis of surface composition was made by the Auger electron spectrometry. It was found that the surfaces of samples treated by discharge machining were rough and have thick oxide layer. When chemical polishing was applied to these samples, the surfaces became smooth, and the oxide layer became thin. By heating the samples to raise the temperature, the desorption of H2O, CO and CO2 was caused. The amount of desorption was in close relation with the SRF. (Kato, T.)

  1. Friction stir welding characteristics of two aluminum alloys

    Institute of Scientific and Technical Information of China (English)

    刘会杰; 藤井英俊; 前田将克; 野城清

    2003-01-01

    The friction stir welding characteristics of the strain-hardened AA1050-H24 and precipitate-hardened AA2017-T351 aluminum alloys were examined in order to reveal the effects of the alloy properties on the friction stir welding behavior of the base materials. The results show that (1) for AA1050-H24, the weld possesses a smooth surface and clear ripples, there is no elliptical weld nugget in the weld, there is not discernible interface between the stir zone and the thermo-mechanically affected zone(TMAZ), and the internal defect of the weld looks like a long crack and is located in the lower part of the weld; (2) for AA2017-T351, the weld usually possesses a rough surface and visible ripples, the elliptical weld nugget clearly exists in the weld and there is obvious plastic flow and a discernible interface between the nugget and the TMAZ, and the internal defect of the weld is composed of many voids and distributed in the middle part of the weld; (3) the effective ranges of the welding parameters for AA1050-H24 and AA2017-T351 are both narrow, especially for the latter; and (4) the tensile strength efficiencies of the joints for the two typical alloys are similar, i e 79% for AA1050-H24 and 82% for AA2017-T351.

  2. Numerical simulation and process optimization for producing large-sized castings

    Institute of Scientific and Technical Information of China (English)

    Wang Junqing; Sun Xun; Guan Yang; Wang Penghua; Li Hailan; Bai Limei; Sun Xinzhi

    2008-01-01

    3-D velocity and temperature fields of mold filling and solidification processes of large-sized castings were calculated, and the efficiency and accuracy of numerical calculation were studied. The mold filling and solidification processes of large-sized stainless steel, iron and aluminum alloy castings were simulated by using of new scheme; their casting processes were optimized, and then applied to produce castings.

  3. Effect of melt treatment on microstructure and impact properties of Al–7Si and Al–7Si–2.5Cu cast alloys

    Indian Academy of Sciences (India)

    K G Basavakumar; P G Mukunda; M Chakraborty

    2007-10-01

    The microstructures and impact toughness of Al–7Si and Al–7Si–2.5Cu cast alloys were studied after various melt treatments like grain refinement and modification. The results indicate that combined grain refined and modified Al–7Si–2.5Cu alloys have microstructures consisting of uniformly distributed -Al grains, interdendritic network of fine eutectic silicon and fine CuAl2 particles in the interdendritic region. These alloys exhibited improved impact toughness in as cast condition when compared to those treated by individual addition of grain refiner or modifier. The improved impact toughness of Al–7Si–2.5Cu alloys are related to breakage of the large aluminum grains and uniform distribution of eutectic silicon and fine CuAl2 particles in the interdendritic region resulting from combined refinement and modification. This paper attempts to investigate the influence of microstructural changes in the Al–7Si and Al–7Si–2.5Cu cast alloys by grain refinement, modification and combined action of both on the impact toughness.

  4. 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.

  5. Study on hardness and microstructural characteristics of sand cast Al–Si–Cu alloys

    Indian Academy of Sciences (India)

    Muzaffer Zeren; Erdem Karakulak

    2009-12-01

    In this study, the influence of Cu content on the hardness and microstructural characteristics of sand cast Al–Si–Cu alloys have been investigated. Al–Si alloys with 2% and 5% Cu have been utilized for this purpose. Solidification of Al–Si–Cu alloys have been realized by melting in a gas furnace with a crucible and casting in green sand molds at 690°C. The solution treatment has been performed at 500°C for 7 h and then specimens were quenched in water. The samples have been aged at 190°C for 15 h to observe the effect of aging on mechanical properties.

  6. New Technique of Casting-rolling Strips for Semi-solid Magnesium Alloys

    Institute of Scientific and Technical Information of China (English)

    Shuisheng XIE; Maopeng GENG; Xinmin ZHOU; Ying ZHANG; Songyang ZHANG; Yanchun WANG; Guojie HUANG

    2005-01-01

    The conjugation of semi-solid process technique and casting-rolling technique applied to produce the magnesium strips was studied. The semi-solid slurry hasbeen prepared continuously by the mechanical method and its temperature was controlled strictly at the same time. AZ91D and AZ31 casting magnesium alloys were applied to the experiment.The casting-rolling strips with non-dendritic structure were obtained and its main mechanical property is better. The process ability of the casting-rolling strips was studied. It is significative to link the semi-solid process techniques and casting-rolling techniques, through which we can get high quality magnesium alloy strips with non- dendritic structure and improve the overall properties of the products.

  7. Structure and Properties of Cast Near-Congruent Copper-Manganese Alloys

    Science.gov (United States)

    Chaput, Kevin; Trumble, Kevin P.

    2014-10-01

    Microstructure development in the casting of copper-manganese alloys based on the congruent point at 34.6 wt pct Mn and 1146 K (873 °C) has been studied. The alloys were prepared by induction melting of electrolytic Cu and Mn in clay-graphite crucibles in open air. Under conventional casting conditions, the alloys exhibit fine cellular (non-dendritic) solidification morphology with a distinct absence of solidification shrinkage microporosity, and they maintain these attributes over a composition range of approximately 3 wt pct Mn about the congruent point. The high Mn concentration in the alloy admits carbon into solution in the melt, resulting in formation of manganese carbide Mn7C3 particles having two different forms (globular and angular) in the cast microstructure. The Mn carbide was eliminated or controlled to low levels by melting in an alumina or a silicon carbide crucible, or in a clay-graphite crucible at lower temperatures. Microstructure development in casting the alloy was analyzed in terms of the available phase diagrams and thermochemical data. Hardness and tensile testing indicated a potent solid solution strengthening effect of Mn and high ductility in the as-cast condition, with additional hardness (strength) when the alloy contains the Mn carbide phase.

  8. A modified Johnson–Cook model of dynamic tensile behaviors for 7075-T6 aluminum alloy

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Ding-Ni, E-mail: siping4840@126.com [The College of Information, Mechanical and Electrical Engineering, Shanghai Normal University, Shanghai 200234 (China); Shangguan, Qian-Qian [The College of Information, Mechanical and Electrical Engineering, Shanghai Normal University, Shanghai 200234 (China); Xie, Can-Jun [Commercial Aircraft Corporation of China, Ltd., Shanghai 200120 (China); Liu, Fu [Shanghai Aircraft Design and Research Institute of COMAC, Shanghai 201210 (China)

    2015-01-15

    Highlights: • The dynamic mechanical behaviors at various strain rates were measured. • The strain rate hardening effect of 7075-T6 aluminum alloy is significant. • A new Johnson–Cook constitutive model of 7075-T6 aluminum alloy was obtained. • Numerical simulations of tensile tests at different rates were conducted. • Accuracy of the modified Johnson–Cook constitutive equation was proved. - Abstract: The dynamic mechanical behaviors of 7075-T6 aluminum alloy at various strain rates were measured by dynamic tensile tests using the electronic universal testing machine, high velocity testing system and split Hopkinson tensile bar (SHTB). Stress–strain curves at different rates were obtained. The results show that the strain rate hardening effect of 7075-T6 aluminum alloy is significant. By modifying the strain rate hardening term in the Johnson–Cook constitutive model, a new Johnson–Cook (JC) constitutive model of 7075-T6 aluminum alloy was obtained. The improved Johnson–Cook model matched the experiment results very well. With the Johnson–Cook constitutive model, numerical simulations of tensile tests at different rates for 7075-T6 aluminum alloy were conducted. According to tensile loading and stress–strain relation of 7075-T6 aluminum alloy, calculation results were compared with experimental results. Accuracy of the modified Johnson–Cook constitutive equation was further proved.

  9. A modified Johnson–Cook model of dynamic tensile behaviors for 7075-T6 aluminum alloy

    International Nuclear Information System (INIS)

    Highlights: • The dynamic mechanical behaviors at various strain rates were measured. • The strain rate hardening effect of 7075-T6 aluminum alloy is significant. • A new Johnson–Cook constitutive model of 7075-T6 aluminum alloy was obtained. • Numerical simulations of tensile tests at different rates were conducted. • Accuracy of the modified Johnson–Cook constitutive equation was proved. - Abstract: The dynamic mechanical behaviors of 7075-T6 aluminum alloy at various strain rates were measured by dynamic tensile tests using the electronic universal testing machine, high velocity testing system and split Hopkinson tensile bar (SHTB). Stress–strain curves at different rates were obtained. The results show that the strain rate hardening effect of 7075-T6 aluminum alloy is significant. By modifying the strain rate hardening term in the Johnson–Cook constitutive model, a new Johnson–Cook (JC) constitutive model of 7075-T6 aluminum alloy was obtained. The improved Johnson–Cook model matched the experiment results very well. With the Johnson–Cook constitutive model, numerical simulations of tensile tests at different rates for 7075-T6 aluminum alloy were conducted. According to tensile loading and stress–strain relation of 7075-T6 aluminum alloy, calculation results were compared with experimental results. Accuracy of the modified Johnson–Cook constitutive equation was further proved

  10. Corrosion Behaviour of Heat-Treated Aluminum-Magnesium Alloy in Chloride and EXCO Environments

    Directory of Open Access Journals (Sweden)

    S. O. Adeosun

    2012-01-01

    Full Text Available Machines designed to operate in marine environment are generally vulnerable to failure by corrosion. It is therefore imperative that the corrosion susceptibility of such facilities is evaluated with a view to establishing mechanism for its mitigation. In this study, the corrosion behaviour of as-cast and retrogression-reagion (RRA specimens of aluminum alloy containing 0.4–2.0 percent magnesium additions in NaCl, FeCl3, and EXCO solutions was investigated. The corrosion simulation processes involved gravimetric and electrochemical techniques. Results show substantial inducement of Mg2Si precipitates at a relatively higher magnesium addition, 1.2–2.0 percent, giving rise to increased attack. This phenomenon is predicated on the nature of the Mg2Si crystals being anodic relative to the alloy matrix which easily dissolved under attack by chemical constituents. Formation of Mg2Si intermetallic without corresponding appropriate oxides like SiO2 and MgO, which protect the precipitates from galvanic coupling with the matrix, accentuates susceptibility to corrosion.

  11. Synthesis of bulk nanostructured aluminum alloy component through vacuum plasma spray technique

    Energy Technology Data Exchange (ETDEWEB)

    Laha, T. [Mechanical and Materials Engineering, Florida International University, 10555 West Flagler Street, EC 3464, Miami, FL 33174 (United States); Agarwal, A. [Mechanical and Materials Engineering, Florida International University, 10555 West Flagler Street, EC 3464, Miami, FL 33174 (United States)]. E-mail: agarwala@fiu.edu; McKechnie, T. [Plasma Processes Inc., Huntsville, AL 35811 (United States); Rea, K. [Mechanical, Materials and Aerospace Engineering, University of Central Florida, Orlando, FL 32816 (United States); Seal, S. [Mechanical, Materials and Aerospace Engineering, University of Central Florida, Orlando, FL 32816 (United States)

    2005-12-15

    The benefits of large-size engineering components with nanocrystalline structure (providing improved strength) are yet to be realized due to processing difficulties and associated grain growth problems. In this work, a free-standing bulk nanocrystalline structure of hypereutectic aluminum alloy (Al-21wt.%Si) has been fabricated through the vacuum plasma spray (VPS) forming technique using micron-size powder feedstock. Optical microscopy, scanning electron microscopy and transmission electron microscopy have been used to investigate the evolution of multi-scale microstructure as the result of rapid solidification in VPS forming process. The characterization implies the presence of nanosized eutectic Al-Si grains (25-100 nm) with uniformly distributed ultrafine primary silicon particles of submicron size. The effect of microstructural evolution on mechanical properties has been studied by tensile testing and microhardness measurement. A considerable improvement in ultimate tensile strength and hardness of the sprayed deposit has been observed in comparison with conventionally cast hypereutectic Al-17wt.%Si alloys.

  12. Effect of Sn on as-cast ageing behavior of Al-Si-Mg alloy

    Institute of Scientific and Technical Information of China (English)

    王桂青; 边秀房; 段佑峰; 张均艳

    2003-01-01

    The effect of minor additions of Sn on the as-cast ageing behavior of Al-11Si-0.35Mg alloy was investigated. It is shown that precipitation has been retarded in Sn containing alloy and more time is needed to reach its peak hardness,which is bigger than that of the base alloy. Analysis of the kinetic data shows that Sn addition does not change the growth dependent parameter n, but increases the nucleation density dependent parameter k. TEM results show that there are little precipitates in Sn containing alloy at the initial stage of as-cast ageing. However, the Sn addition increases the net density of precipitates during as-cast ageing, because there are many dislocation loops formed as ageing progresses and Sn segregated at the edges of dislocation loops, which acts as the nuclei of precipitates.

  13. Fracture characteristics of structural aerospace alloys containing deep surface flaws. [aluminum-titanium alloys

    Science.gov (United States)

    Masters, J. N.; Bixler, W. D.; Finger, R. W.

    1973-01-01

    Conditions controlling the growth and fracture of deep surface flaws in aerospace alloys were investigated. Static fracture tests were performed on 7075-T651 and 2219-T87 aluminum, and 6Ai-4V STA titanium . Cyclic flaw growth tests were performed on the two latter alloys, and sustain load tests were performed on the titanium alloy. Both the cyclic and the sustain load tests were performed with and without a prior proof overload cycle to investigate possible growth retardation effects. Variables included in all test series were thickness, flaw depth-to-thickness ratio, and flaw shape. Results were analyzed and compared with previously developed data to determine the limits of applicability of available modified linear elastic fracture solutions.

  14. Advanced casting technologies for lightweight automotive applications

    Directory of Open Access Journals (Sweden)

    Alan A. Luo

    2010-11-01

    Full Text Available This paper provides an overview of alloy and process developments in aluminum and magnesium castings for lightweight automotive applications. Wear-resistant aluminum alloys, creep-resistant and high strength/ductility magnesium alloys have been developed for automotive applications. On the process front, vacuum-assisted die casting and high vacuum die casting technologies have been developed for high-integrity body and chassis applications. Thin-wall and hollow casting components are being produced by low-pressure die casting processes for structural applications. Overcasting technology is gaining traction and has enabled mixed material designs for automotive sub-systems such as engine cradles and instrument panel beams. Simulation tools developed to predict the interfacial interactions of the dissimilar components and the structural integrity of the overcast systems are being validated in the casting trials.

  15. Discrepancy measurements of copings prepared by three casting methods and two different alloys, on ITI implants

    Directory of Open Access Journals (Sweden)

    Siadat H.

    2008-04-01

    Full Text Available Background and Aim: An important criterion for success assessment of implant-supported prostheses is marginal fit. Vertical and horizontal discrepancy can result in loosening of the prosthetic screw, crestal bone resorption, peri-implantitis and loss of osseointegration. Despite careful attention to waxing, investing, and casting, marginal discrepancies are inevitable. The aim of this study was to evaluate the marginal gap and overhang in three casting methods with two different alloys in ITI implants.Materials and Methods: In this experimental in vitro study 48 analog abutments were randomly divided into six groups as follows: 1 burn out cap + BegoStar, 2 impression cap + BegoStar, 3 conventional wax up + BegoStar, 4 burn out cap + Verabond2, 5 impression cap + Verabond2, 6 conventional wax up + Verabond2. Waxing was done in 0.7 mm thickness verified by a digital gauge and a putty index was made for all groups. Reamer was used for correction of the finish line after casting in all groups. Castings were seated on analog abutments and embedded in acrylic resin. Specimens were sectioned by isomet instrument and polished and cleaned by ultrasonic cleaner for 10 min. The marginal gap and overextended margins of castings were examined under a  Scanning Electron Microscope (SEM (X200. The mean gap and margin overextension were calculated for each group. Data were analyzed by multivariate analysis and Bonferroni post-hoc test with p<0.05 as the level of significance.Results: No significant difference in gap size was observed among the three casting methods with two alloys (P=0.056. The marginal gap was not different in the studied casting methods (P=0.092. Gold alloy crowns showed lower marginal gaps compared to base metal alloy crowns (P<0.001. No significant difference in overhang size was observed among casting methods with two alloys (P=0.093. Base metal alloy crowns showed less overhang compared to gold alloy crowns (P<0.001. There was a

  16. Standard guide for conducting exfoliation corrosion tests in aluminum alloys

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    1992-01-01

    1.1 This guide differs from the usual ASTM standard in that it does not address a specific test. Rather, it is an introductory guide for new users of other standard exfoliation test methods, (see Terminology G 15 for definition of exfoliation). 1.2 This guide covers aspects of specimen preparation, exposure, inspection, and evaluation for conducting exfoliation tests on aluminum alloys in both laboratory accelerated environments and in natural, outdoor atmospheres. The intent is to clarify any gaps in existent test methods. 1.3 The values stated in SI units are to be regarded as the standard. The inch-pound units given in parentheses are for information only. 1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

  17. Compressive formability of 7075 aluminum alloy rings under hydrostatic pressure

    Institute of Scientific and Technical Information of China (English)

    LIU Gang; WANG Li-liang; YUAN Shi-jian; WANG Zhong-ren

    2006-01-01

    In order to investigate the influence of hydrostatic pressure on compression limit of the ring, numerical simulation and experimental research were carried out. The effect of hydrostatic pressure on the deformation of aluminum alloy 7075 ring was obtained by numerical simulation. The die set for compressing ring under high hydrostatic pressure was designed and manufactured. Experimental results show that the compression limit increases linearly as the hydrostatic pressure increases in a certain range. At 100 MPa the maximum compressive strain is increased by 32.42%. At strain limit, the cracks initiate from the corner of the outer wall to the middle of the inner wall along the direction of the maximum shear stress.

  18. Subsequent yield loci of 5754O aluminum alloy sheet

    Institute of Scientific and Technical Information of China (English)

    WANG Hai-bo; WAN Min; WU Xiang-dong; YAN Yu

    2009-01-01

    Complex loading paths were realized with cruciform specimens and biaxial loading testing machine. Experimental method for determining the subsequent yield locus of sheet metal was established. With this method, the subsequent yield loci of 5754O aluminum alloy sheet were obtained under complex loading paths. Theoretical subsequent yield loci based on Yld2000-2d yield criterion and three kinds of hardening modes were calculated and compared with the experimental results. The results show that the theoretical subsequent yield loci based on mixed hardening mode describe the experimental subsequent yield loci well, whereas isotropic hardening mode, which is widely used in sheet metal forming fields, predicts values larger than the experimental results. Kinematic hardening mode predicts values smaller than the experimental results and its errors are the largest.

  19. Amorphous coatings deposited on aluminum alloy by plasma electrolytic oxidation

    Institute of Scientific and Technical Information of China (English)

    GUAN Yong-jun; XIA Yuan

    2005-01-01

    Amorphous [Al-Si-O] coatings were deposited on aluminum alloy by plasma electrolytic oxidation (PEO). The process parameters, composition, micrograph, and mechanical property of PEO amorphous coatings were investigated. It is found that the growth rate of PEO coatings reaches 4.44 μm/min if the current density is 0.9 mA/mm2. XRD results show that the PEO coatings are amorphous in the current density range of 0.3 - 0.9mA/mm2. EDS results show that the coatings are composed of O, Si and Al elements. SEM results show that the coatings are porous. Nano indentation results show that the hardness of the coatings is about 3 - 4 times of that of the substrate, while the elastic modulus is about the same with the substrate. Furthermore, a formation mechanism of amorphous PEO coatings was proposed.

  20. Microstructural stability of ultrafine grained cold sprayed 6061 aluminum alloy

    Energy Technology Data Exchange (ETDEWEB)

    Rokni, M.R., E-mail: mohammadreza.rokni@mines.sdsmt.edu [Department of Materials and Metallurgical Engineering, Advanced Materials Processing Center, South Dakota School of Mines and Technology (SDSM and T), SD (United States); Widener, C.A. [Department of Materials and Metallurgical Engineering, Advanced Materials Processing Center, South Dakota School of Mines and Technology (SDSM and T), SD (United States); Champagne, V.R. [U.S. Army Research Laboratory, Weapons and Materials Research Directorate, Aberdeen Proving Ground, MD (United States)

    2014-01-30

    The microstructural stability of ultrafine grained (UFG) cold spray 6061 aluminum deposits produced by high pressure cold spray were investigated by in situ heating to a fully annealed state via a hot-stage transmission electron microscope (TEM). It was possible to observe the precise locations and temperatures of different microstructural changes, like dislocation movement and other restoration processes. Even after heating up to the annealing temperature for this alloy, the deposited layer in the perpendicular direction was found to preserve the UFG structures, which were the result of different recrystallization mechanisms caused by the high strains present during cold spraying. Extensive solute segregation at the grain boundaries acted as an obstruction for grain boundary migration in this direction, thereby preventing grain growth. However, in the direction parallel to the deposited surface, the UFGs were not resistant to grain coursing like the other direction, since the grain boundaries had much less solute segregation.

  1. Applications of pattern recognition in aluminum alloy texture characterization

    Science.gov (United States)

    Liu, Guizhong; Rehbein, D. K.; Foley, James C.; Thompson, R. B.

    2000-05-01

    This paper presents a methodology to extract texture information in Aluminum alloys using pattern recognition algorithm. The orientation of the samples can be obtained by the orientation Image Microscope (OIM) technique. The ISO DATA pattern recognition algorithm is implemented to classify the OIM data into different clusters. Based on the classification results, the probability density function (pdf) is estimated. Then, the pdf is expanded as a series of Legendre functions with coefficients, i.e., the orientation distribution coefficients (ODC) as texture parameters. Three of these ODC's are of special interests, namely W400, W420, and W440. This paper includes results from ultrasonic NDE and this novel algorithm.—Ames Laboratory is operated for U.S. Department of Energy by Iowa State University under Contract W-7405-ENG-82. This work was supported by the Office of Basic Energy Sciences as a part of the Center of Excellence of the Synthesis and Processing of Advanced Materials.

  2. High cycle fatigue characteristics of 2124-T851 aluminum alloy

    Institute of Scientific and Technical Information of China (English)

    LI Xue; YIN Zhimin; NIE Bo; ZHONG Li; PAN Qinglin; JIANG Feng

    2007-01-01

    The fatigue crack growth rate, fracture toughness and fatigue S-N curve of 2124-T851 aluminum alloy at high cycle fatigue condition were measured and fatigue fracture process and fractography were studied using optical microscopy (OM), X-ray diffraction (XRD) technique, trans-mission electron microscopy (TEM) and scanning electron microscopy (SEM). The results show that at room tempera-ture and R = 0.1 conditions, the characteristics of fatigue fracture could be observed. Under those conditions, the fatigue strength and the fracture toughness of a 2124-T851 thick plate is 243 MPa and 29.64 MPa·m1/2,respectively.At high cycle fatigue condition, the higher the stress amplitude,the wider the space between fatigue striations, the faster the rate of fatigue crack developing and going into the intermittent fracture area, and the greater the ratio between the intermittent fracture area and the whole fracture area.

  3. Elevated temperature crack growth in advanced powder metallurgy aluminum alloys

    Science.gov (United States)

    Porr, William C., Jr.; Gangloff, Richard P.

    1990-01-01

    Rapidly solidified Al-Fe-V-Si powder metallurgy alloy FVS0812 is among the most promising of the elevated temperature aluminum alloys developed in recent years. The ultra fine grain size and high volume fraction of thermally stable dispersoids enable the alloy to maintain tensile properties at elevated temperatures. In contrast, this alloy displays complex and potentially deleterious damage tolerant and time dependent fracture behavior that varies with temperature. J-Integral fracture mechanics were used to determine fracture toughness (K sub IC) and crack growth resistance (tearing modulus, T) of extruded FVS0812 as a function of temperature. The alloy exhibits high fracture properties at room temperature when tested in the LT orientation, due to extensive delamination of prior ribbon particle boundaries perpendicular to the crack front. Delamination results in a loss of through thickness constraint along the crack front, raising the critical stress intensity necessary for precrack initiation. The fracture toughness and tensile ductility of this alloy decrease with increasing temperature, with minima observed at 200 C. This behavior results from minima in the intrinsic toughness of the material, due to dynamic strain aging, and in the extent of prior particle boundary delaminations. At 200 C FVS0812 fails at K levels that are insufficient to cause through thickness delamination. As temperature increases beyond the minimum, strain aging is reduced and delamination returns. For the TL orientation, K (sub IC) decreased and T increased slightly with increasing temperature from 25 to 316 C. Fracture in the TL orientation is governed by prior particle boundary toughness; increased strain localization at these boundaries may result in lower toughness with increasing temperature. Preliminary results demonstrate a complex effect of loading rate on K (sub IC) and T at 175 C, and indicate that the combined effects of time dependent deformation, environment, and strain aging

  4. Effect of temperature and displacement rate on behaviour of as-cast AA5182 and Al–3.3%Cu alloys under tensile loading near solidus temperature

    Indian Academy of Sciences (India)

    Suyitno

    2013-08-01

    Hot cracking develops in the still semi-solid casting during the last stages of solidification. The micromechanism of its origin is not generally accepted. There exists considerable doubt whether it is initiated by a void or develops as an instantaneous crack. The aim of this work is to study the mechanism of fracture behaviour of aluminum alloys around solidus temperature. Tensile tests were performed on notched specimens of as-cast AA5182 and Al–3.3%Cu alloys using a Gleeble 3500® thermomechanical simulator. The effect of temperature and strain rate on the propagation of fracture in the semi-solid state has been studied to establish fracture mechanism. The transition from ductile to brittle mode of fracture has been observed around the solidus temperature. The fracture is intergranular and propagates through interdendritic channels.

  5. Laser Surface Alloying of Copper, Manganese, and Magnesium with Pure Aluminum Substrate

    Science.gov (United States)

    Jiru, Woldetinsay G.; Sankar, M. Ravi; Dixit, Uday S.

    2016-03-01

    Laser surface alloying is one of the recent technologies used in the manufacturing sector for improving the surface properties of the metals. Light weight materials like aluminum alloys, titanium alloys, and magnesium alloys are used in the locomotive, aerospace, and structural applications. In the present work, an experimental study was conducted to improve the surface hardness of commercially pure aluminum plate. CO2 laser is used to melt pre-placed powders of pure copper, manganese, and magnesium. Microstructure of alloyed surface was analyzed using optical microscope. The best surface alloying was obtained at the optimum values of laser parameters, viz., laser power, scan speed, and laser beam diameter. In the alloyed region, microhardness increased from 30 HV0.5 to 430 HV0.5, while it was 60 HV0.5 in the heat-affected region. Tensile tests revealed some reduction in the strength and total elongation due to alloying. On the other hand, corrosion resistance improved.

  6. Effects of zincate treatment on adhesion of electroless Ni-P coating onto various aluminum alloys

    Institute of Scientific and Technical Information of China (English)

    Makoto HINO; Koji MURAKAMI; Yutaka MITOOKA; Ken MURAOKA; Teruto KANADANI

    2009-01-01

    The effects of alloying elements on zincate treatment and adhesion of electroless Ni-P coating onto various aluminum alloy substrates were examined. Surface morphology of zinc deposits in the 1st zincate treatment and its adhesion were changed depending on the alloying element. The zinc deposits in the 2nd zincate treatment became thinly uniform, and the adhesion between aluminum alloy substrate and Ni-P coating was improved irrespective of the alloying element. XPS analysis revealed the existence of zinc on the surface of each aluminum alloy substrate after the pickling in 5% nitric acid. This zinc on the surface should be an important factor influencing the morphology of zinc deposit at the 2nd zincate treatment and its adhesion.

  7. Corrosion Behavior of Commercial Aluminum Alloy Processed by Equal Channel Angular Pressing

    OpenAIRE

    Atef Korchef; Abdelkrim Kahoul

    2013-01-01

    A commercial aluminum alloy was subjected to severe plastic deformation through equal channel angular pressing (ECAP). The alloy contains a low volume fraction of α-AlFeSi located essentially at the grain boundaries. The corrosion behavior of the ECAP’ed alloy was investigated in NaCl solution using potentiodynamic polarization and immersion tests. The effects of scan rate and NaCl concentration on the alloy susceptibility to corrosion were also studied. The results obtained were compared wit...

  8. 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.

  9. In-plane anisotropy of 1545 aluminum alloy sheet

    Institute of Scientific and Technical Information of China (English)

    PENG Yong-yi; YIN Zhi-min; YANG Jin; DU Yu-xuan

    2005-01-01

    The microstructures and the tensile mechanical properties in the rolling plane of 1545 aluminum alloy sheet at different orientations with respect to the rolling direction were studied by means of tensile test,X-ray diffractometer(XRD),optical microscope and transmission electron microscope.The in-plane anisotropy of tensile mechanical properties was calculated and the inverse pole figures of the rolling plane,transversal section and longitudinal section were obtained by Harris method.The results show that the 1545 Al alloy sheet has remarkable in-plane anisotropy of mechanical properties and the main texture component is{110}texture.On the basis of the model that regards the sheet containing only{110}texture as a monocrystal,the relationship of in-plane anisotropy and the anisotropy of crystallography was analyzed.The study shows that it is the combined effects of the anisotropy of crystallography and microstructures that cause the in-plane anisotropy of mechanical properties,but the main cause is the crystallographic texture.

  10. Effects of aluminum additions to gas atomized reaction synthesis produced oxide dispersion strengthened alloys

    Science.gov (United States)

    Spicher, Alexander Lee

    The production of an aluminum containing ferritic oxide dispersion strengthened (ODS) alloy was investigated. The production method used in this study was gas atomization reaction synthesis (GARS). GARS was chosen over the previously commercial method of mechanical alloying (MA) process due to complications from this process. The alloy compositions was determined from three main components; corrosion resistance, dispersoid formation, and additional elements. A combination of Cr and Al were necessary in order to create a protective oxide in the steam atmosphere that the boiler tubing in the next generation of coal-fired power plants would be exposed to. Hf and Y were chosen as dispersoid forming elements due to their increased thermal stability and potential to avoid decreased strength caused by additions of Al to traditional ODS materials. W was used as an additive due to benefits as a strengthener as well as its benefits for creep rupture time. The final composition chosen for the alloy was Fe-16Cr-12Al-0.9W-0.25Hf-0.2Y at%. The aforementioned alloy, GA-1-198, was created through gas atomization with atomization gas of Ar-300ppm O2. The actual composition created was found to be Fe-15Cr-12.3Al-0.9W-0.24Hf-0.19Y at%. An additional alloy that was nominally the same without the inclusion of aluminum was created as a comparison for the effects on mechanical and corrosion properties. The actual composition of the comparison alloy, GA-1-204, was Fe-16Cr-0Al-0.9W-0.25Hf-0.24Y at%. An investigation on the processing parameters for these alloys was conducted on the GA-1-198 alloy. In order to predict the necessary amount of time for heat treatment, a diffusion study was used to find the diffusion rate of oxygen in cast alloys with similar composition. The diffusion rate was found to be similar to that of other GARS compositions that have been created without the inclusion of aluminum. The effect of heat treatment time was investigated with temperatures of 950°C, 1000

  11. Application of the Billet Casting Method to Determine the Onset of Incipient Melting of 319 Al Alloy Engine Blocks

    Science.gov (United States)

    Lombardi, A.; Ravindran, C.; MacKay, R.

    2015-06-01

    The increased use of Al for automotive applications has resulted from the need to improve vehicle fuel efficiency. Aluminum alloy engine blocks fulfil the need of lightweighting. However, there are many challenges associated with thermo-mechanical mismatch between Al and the gray cast iron cylinder liners, which result in large tensile residual stress along the cylinder bores. This requires improced mechanical properties in this region to prevent premature engine failure. In this study, replicating billet castings were used to simulate the engine block solution heat treatment process and determine the onset of incipient melting. Microstructural changes during heat treatment were assessed with SEM and EDX, while thermal analysis was carried out using differential scanning calorimetry. The results suggest that solution heat treatment at 500 °C was effective in dissolving secondary phase particles, while solutionizing at 515 or 530 °C caused incipient melting of Al2Cu and Al5Mg8Cu2Si6. Incipient melting caused the formation ultra-fine eutectic clusters consisting of Al, Al2Cu, and Al5Mg8Cu2Si6 on quenching. In addition, DSC analysis found that incipient melting initiated at 507 °C for all billets, although the quantity of local melting reduced with microstructural refinement as evidenced by smaller endothermic peaks and energy absorption. The results from this study will assist in improving engine block casting integrity and process efficiency.

  12. Mathematical model and numerical simulation of aluminum casting and solidification in magnetic fields with allowance for free surface dynamics

    Science.gov (United States)

    Minakov, A. V.; Pervukhin, M. V.; Platonov, D. V.; Khatsayuk, M. Yu.

    2015-12-01

    A complex mathematical model of aluminum casting and solidification in a variable electromagnetic field is constructed. The model is based on the solution of magnetohydrodynamic equations and the VOF method. Test results are presented for the model and the numerical algorithm proposed. The numerical results are compared with experimental data and computations of other authors and are found to be in good agreement. The model is used to simulate aluminum solidification under an electromagnetic field. The physical processes influencing ingot formation are analyzed.

  13. Study of formation mechanism of incipient melting in thixo-cast Al–Si–Cu–Mg alloys

    Energy Technology Data Exchange (ETDEWEB)

    Du, Kang, E-mail: du126kang@126.com; Zhu, Qiang, E-mail: zhu.qiang@grinm.com; Li, Daquan, E-mail: lidaquan@grinm.com; Zhang, Fan, E-mail: sk_zf@163.com

    2015-08-15

    Mechanical properties of thixo-cast Al–Si–Cu–Mg alloys can be enhanced by T61 heat treatment. Copper and magnesium atoms in aluminum matrix can form homogeneously distributed precipitations after solution and aging treatment which harden the alloys. However, microsegregation of these alloying elements could form numerous tiny multi-compound phases during solidification. These phases could cause incipient melting defects in subsequent heat treatment process and degrade the macro-mechanical properties of productions. This study is to present heterogeneous distribution of Cu, Si, and Mg elements and formation of incipient melting defects (pores). In this study, incipient melting pores that occurred during solution treatment at various temperatures, even lower than common melting points of various intermetallic phases, were identified, in terms of a method of investigating the same surface area in the samples before and after solution treatment in a vacuum environment. The results also show that the incipient melting mostly originates at the clusters with fine intermetallic particles while also some at the edge of block-like Al{sub 2}Cu. The fine particles were determined being Al{sub 2}Cu, Al{sub 5}Cu{sub 2}Mg{sub 8}Si{sub 6} and Al{sub 8}Mg{sub 3}FeSi{sub 2}. Tendency of the incipient melting decreases with decreases of the width of the clusters. The formation mechanism of incipient melting pores in solution treatment process was discussed using both the Fick law and the LSW theory. Finally, a criterion of solution treatment to avoid incipient melting pores for the thixo-cast alloys is proposed. - Highlights: • In-situ comparison technique was used to analysis the change of eutectic phases. • The ralationship between eutectic phase size and incipient melting was studied. • Teat treatment criterion for higher incipient melting resistance was proposed.

  14. Japanese R&D on new cast alloys and materials

    Energy Technology Data Exchange (ETDEWEB)

    Hayden, H.W.

    1996-05-01

    On the basis of observations of the JTEC team, it appears that Japanese universities and research institutes are leading long-term R&D thrusts for development of new materials casting technologies. Significant efforts include amorphous metals, intermetallics, application of MHD in continuous casting of steel, and energy efficient furnace technology. Industrial R&D seems focused more on process improvements than on new product technologies, but significant efforts in new cast materials included cast metal matrix composites, materials substitutions for thinner wall products, and advanced ceramic products for foundry industry applications.

  15. Wear resistance analysis of the aluminum 7075 alloy and the nanostructured aluminum 7075 - silver nanoparticles composites

    Directory of Open Access Journals (Sweden)

    Estrada-Ruiz R.H.

    2016-01-01

    Full Text Available Nanostructured composites of the aluminum 7075 alloy and carbon-coated silver nanoparticles were synthetized by the mechanical milling technique using a high-energy mill SPEX 8000M; the powders generated were compacted, sintered and hot-extruded to produce 1 cm-diameter bars. The composites were then subjected to a wear test using a pin-on-disc device to validate the hypothesis that second phase-ductile nanometric particles homogenously distributed throughout the metalmatrix improve the wear resistance of the material. It was found that silver nanoparticles prevent the wear of the material by acting as an obstacle to dislocations movement during the plastic deformation of the contact surface, as well as a solid lubricant when these are separated from the metal-matrix.

  16. Solidification and casting

    CERN Document Server

    Cantor, Brian

    2002-01-01

    INDUSTRIAL PERSPECTIVEDirect chillcasting of aluminium alloysContinuous casting of aluminium alloysContinuous casting of steelsCastings in the automotive industryCast aluminium-silicon piston alloysMODELLING AND SIMULATIONModelling direct chill castingMold filling simulation of die castingThe ten casting rulesGrain selection in single crystal superalloy castingsDefects in aluminium shape castingPattern formation during solidificationPeritectic solidificationSTRUCTURE AND DEFECTSHetergeneous nucleation in aluminium alloysCo

  17. Discharge behaviors during plasma electrolytic oxidation on aluminum alloy

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Run [Key Laboratory for Beam Technology and Materials Modification of Ministry of Education, College of Nuclear Science and Technology, Beijing Normal University, Beijing 100875 (China); Beijing Radiation Center, Beijing 100875 (China); Zhenjiang Watercraft College, Zhenjiang 212000, Jiangsu (China); Wu, Jie [Key Laboratory for Beam Technology and Materials Modification of Ministry of Education, College of Nuclear Science and Technology, Beijing Normal University, Beijing 100875 (China); Beijing Radiation Center, Beijing 100875 (China); Xue, Wenbin, E-mail: xuewb@bnu.edu.cn [Key Laboratory for Beam Technology and Materials Modification of Ministry of Education, College of Nuclear Science and Technology, Beijing Normal University, Beijing 100875 (China); Beijing Radiation Center, Beijing 100875 (China); Qu, Yao; Yang, Chaolin; Wang, Bin; Wu, Xianying [Key Laboratory for Beam Technology and Materials Modification of Ministry of Education, College of Nuclear Science and Technology, Beijing Normal University, Beijing 100875 (China); Beijing Radiation Center, Beijing 100875 (China)

    2014-11-14

    A plasma electrolytic oxidation (PEO) process was performed on the 2024 aluminum alloy in silicate electrolyte to fabricate ceramic coatings under a constant voltage. Optical emission spectroscopy (OES) was employed to evaluate the characteristics of plasma discharge during PEO process. The plasma electron temperature and density were obtained by analyzing the spectral lines of OES, and the atomic ionization degree in discharge zone was calculated in terms of Saha thermal ionization equation. The illumination intensity of plasma discharge and the temperature in the interior of alloy were measured. Combining the surface morphology and cross-sectional microstructure with the optical emission spectra and illumination at different discharge stage, a discharge model in the growth of PEO ceramic coatings was proposed. It is found that there are two discharge modes of type A with small spark size and type B with large spark size, and the latter only appears in the intermediate stage of PEO process. The illumination intensity has a maximum value in the initial stage of oxidation with many sparks of discharge type A. The electron temperature in plasma discharge zone is about 3000 K–7000 K and atomic ionization degree of Al is about 2.0 × 10{sup −5}–7.2 × 10{sup −3}, which depend on discharge stage. The discharge type B plays a key role on the electron temperature and atomic ionization degree. The electron density keeps stable in the range of about 8.5 × 10{sup 21} m{sup −3}–2.6 × 10{sup 22} m{sup −3}. - Highlights: • The characteristics of PEO plasma discharge was evaluated by OES. • Electron temperature, concentration, atomic ionization degree were calculated. • Discharge model for the growth of PEO coatings was proposed. • Temperature in the interior of alloy during PEO process was measured.

  18. Quantification of recrystallization texture evolution in cold rolled AA 5182 aluminum alloy

    International Nuclear Information System (INIS)

    The evolution of recrystallization textures in cold rolled AA 5182 aluminum alloy was investigated by X-ray diffraction. The transformation kinetics of recrystallization textures during isothermal annealing was quantified by using an Avrami type equation

  19. Quantification of recrystallization texture evolution in cold rolled AA 5182 aluminum alloy

    Energy Technology Data Exchange (ETDEWEB)

    Liu, W.C.; Zhai, T.; Man, C.-S.; Morris, J.G

    2003-09-15

    The evolution of recrystallization textures in cold rolled AA 5182 aluminum alloy was investigated by X-ray diffraction. The transformation kinetics of recrystallization textures during isothermal annealing was quantified by using an Avrami type equation.

  20. Aluminum-Lithium Alloy 2050 for Reduced-Weight, Increased-Stiffness Space Structures Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Touchstone Research Laboratory, along with Alcan Rolled Products ? Ravenswood WV, has identified the Aluminum-Lithium Alloy 2050 as a potentially game-changing...

  1. ENVIRONMENTALLY COMPLIANT CORROSION-ACTIVATED INHIBITOR SYSTEM FOR ALUMINUM ALLOYS - PHASE I

    Science.gov (United States)

    The federal government is estimated to spend $1 billion on painting/repainting aircraft annually. Aircraft have surfaces composed of aluminum alloys that are highly susceptible to corrosion and must be protected with corrosion-preventative treatments that typically conta...

  2. Facile formation of superhydrophobic aluminum alloy surface and corrosion-resistant behavior

    Science.gov (United States)

    Feng, Libang; Yan, Zhongna; Qiang, Xiaohu; Liu, Yanhua; Wang, Yanping

    2016-03-01

    Superhydrophobic surface with excellent corrosion resistance was prepared on aluminum alloy via boiling water treatment and surface modification with stearic acid. Results suggested that the micro- and nanoscale hierarchical structure along with the hydrophobic chemical composition surface confers the aluminum alloy surface with good superhydrophobicity, and the water contact angle and the water sliding angle can reach 156.6° and 3°, respectively. The corrosion resistance of the superhydrophobic aluminum alloy was first characterized by potentiodynamic polarization, and then the long-term corrosion resistance was investigated by immersing the sample in NaCl solution for 90 days. The surface wettability, morphology, and composition before and after immersion were examined, and results showed that the superhydrophobic aluminum alloy surface possessed good corrosion resistance under the experimental conditions, which is favorable for its practical application as an engineering material in seawater corrosion conditions. Finally, the mechanism of the superhydrophobicity and excellent corrosion resistance is deduced.

  3. Computational Modeling aided Near Net Shape Manufacturing for Aluminum Alloys Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This program will focus on developing and validating computational models for near-net shape processing of aluminum alloys. Computational models will be developed...

  4. Statistical analysis of constituent particles in 7075-T6 aluminum alloy

    Science.gov (United States)

    Harlow, D. G.; Wei, R. P.; Wang, M. Z.

    2006-11-01

    Pitting corrosion is a primary degradation mechanism that affects the durability and integrity of aluminum alloy structures especially in aircraft. The heterogeneity of aluminum alloys is directly responsible for pitting corrosion because about 200 constituent particles per mm2 are on polished surfaces. Corrosion pits commence at surface particles and evolve into severe pits by sustained growth through particle clusters. Severe pits are nuclei for subsequent corrosion fatigue cracking. Thus, heterogeneous clusters of constituent particles are critical to the quality of aluminum alloys subjected to deleterious environments. Models for structural reliability including corrosion fundamentally depend on quantitative descriptions of the spatial statistics of the particles and particle clusters, including their location, size, and density. The primary purpose of this effort is to statistically estimate the distribution functions of the key geometrical properties of the constituent particles in 7075-T6 aluminum alloy and their role in pitting corrosion.

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

    Science.gov (United States)

    Hsu, Huey S.

    1988-04-14

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

  6. Effect of process parameters on mechanical properties of friction stir spot welded magnesium to aluminum alloys

    International Nuclear Information System (INIS)

    Highlights: • Lap-shear failure load of ∼2.5 kN was achieved in dissimilar Mg to Al spot welds. • Failure load depends on both welding geometrical features and IMCs formation. • Thin and discontinuous IMCs formed in stir zone are beneficial for weld strength. • Low heat input and good material mixing/interlocking is essential for high strength. - Abstract: Friction stir spot welding was applied to dissimilar cast magnesium (Mg) alloy AM60B and wrought aluminum (Al) alloy 6022-T4 under various welding conditions. The influence of tool rotation rate and shoulder plunge depth on lap-shear failure load was examined. Welds were made at four different tool rotation rates of 1000, 1500, 2000 and 2500 revolution per minute (rpm) and various tool shoulder plunge depths from 0 mm to 0.9 mm. The cross section of each weld exhibited the formation of intermetallic compounds (IMCs) in the stir zone. An increase in tool rotation rate decreased the width of the stir zone and resulted in lower lap-shear failure loads. The stir zone width increased and interlocking of IMCs was observed with an increase in tool shoulder plunge depth at 1000 rpm. High lap-shear failure loads were achieved in welds having a large stir zone width with formation of discontinuous IMCs at the tip of the interfacial hook. An average lap-shear failure load of 2.5 kN was achieved for welds made at 1000 rpm and 0.9 mm shoulder plunge. The present study suggests that the mechanical properties of friction stir spot welded dissimilar alloys are greatly influenced by the stir zone width, interfacial hooks and IMCs which are all weld process dependent

  7. Superplasticity of the aluminum alloys containing the Al{sub 3}Ni eutectic particles

    Energy Technology Data Exchange (ETDEWEB)

    Portnoy, V.K. [Department of Physical Metallurgy Non-Ferrous Metals, National University of Science and Technology ' ' MISIS' ' , Moscow (Russian Federation); Mikhaylovskaya, A.V.

    2012-09-15

    The structures and parameters of superplasticity of aluminum alloys containing fine and coarse eutectic Al{sub 3}Ni particles were investigated. Traditional hot and cold rolling were used for sheet producing. The research alloys have low- or high - alloying solid solution. Superplasticity characterization of the alloy with high-alloying solid solution is much better beside alloys with low-alloying solid solution. Alloying by zirconium improves superplasticity in some investigated alloys. Some alloys with partially recrystallized structure show d = 500-700% at T = 0.95 Tm with the constant strain rates to the range of (1.10{sup -3}-1.10{sup -2}) s{sup -1}. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  8. Effect of Zr on behavior of compressive creep in as cast ZA27 alloy

    Institute of Scientific and Technical Information of China (English)

    魏晓伟; 沈保罗

    2003-01-01

    The effect of Zr on the behavior of compressive creep in as cast ZA27 alloy was investigated in the temperature range of 20-160 ℃ and under different compressive stresses in the range of 50-137.5 MPa with special apparatus. The results show that the primary compressive creep strains and steady creep rates of ZA27-Zr alloy and ZA27 alloy increase with increasing temperature and stress. However, the primary compressive creep strain and steady creep rate of the ZA27-Zr alloy are lower than that of the ZA27 alloy below 100 ℃, but higher at 160 ℃. The compressive creep behaviors in both ZA27-Zr alloy and ZA27 alloy obey an empirical equation lnt=C-nlnσ+Q/RT, and the exponent stress n is 3.63 for ZA27-Zr alloy and 3.46 for ZA27 alloy, respectively, the activation energy Q is 87.32 kJ/mol for ZA27-Zr alloy and 81.09 kJ/mol for ZA27 alloy. Different material structural constants are associated with different compressive creep behaviors in the alloy. The compressive creep rate in the alloy is controlled by the lattice diffusion of zinc and dislocation limb.

  9. Study of localized corrosion in aluminum alloys by the scanning reference electrode technique

    Science.gov (United States)

    Danford, M. D.

    1995-01-01

    Localized corrosion in 2219-T87 aluminum (Al) alloy, 2195 aluminum-lithium (Al-Li) alloy, and welded 2195 Al-Li alloy (4043 filler) have been investigated using the relatively new scanning reference electrode technique (SRET). Anodic sites are more frequent and of greater strength in the 2195 Al-Li alloy than in the 2219-T87 Al alloy, indicating a greater tendency toward pitting for the latter. However, the overall corrosion rates are about the same for these two alloys, as determined using the polarization resistance technique. In the welded 2195 Al-Li alloy, the weld bean is entirely cathodic, with rather strongly anodic heat affected zones (HAZ) bordering both sides, indicating a high probability of corrosion in the HAZ parallel to the weld bead.

  10. Corrosion Damage of Aluminum Alloy in Unsymmetric Uimethyl Hydrazine and Dinitrogen Tetroxide Liquid Propellant

    Directory of Open Access Journals (Sweden)

    Zhang Youhong

    2016-01-01

    Full Text Available The high strength aluminum alloy double cantilever beam (DCB specimens were corroded under the conditions of different liquid propellant environment. After the stress corrosion exposure, the scanning electron microscopy and energy-dispersal analyses on corrosion damage were carried out. The corrosion damage sensitivity and the stress corrosion character of the LD10 high strength aluminum alloy in N2O4, UDMH and 3.5% NaCl corrosion solution were analyzed.

  11. Biaxial Testing of 2219-T87 Aluminum Alloy Using Cruciform Specimens

    Science.gov (United States)

    Dawicke, D. S.; Pollock, W. D.

    1997-01-01

    A cruciform biaxial test specimen was designed and seven biaxial tensile tests were conducted on 2219-T87 aluminum alloy. An elastic-plastic finite element analysis was used to simulate each tests and predict the yield stresses. The elastic-plastic finite analysis accurately simulated the measured load-strain behavior for each test. The yield stresses predicted by the finite element analyses indicated that the yield behavior of the 2219-T87 aluminum alloy agrees with the von Mises yield criterion.

  12. Advanced powder metallurgy aluminum alloys via rapid solidification technology, phase 2

    Science.gov (United States)

    Ray, Ranjan; Jha, Sunil C.

    1987-01-01

    Marko's rapid solidification technology was applied to processing high strength aluminum alloys. Four classes of alloys, namely, Al-Li based (class 1), 2124 type (class 2), high temperature Al-Fe-Mo (class 3), and PM X7091 type (class 4) alloy, were produced as melt-spun ribbons. The ribbons were pulverized, cold compacted, hot-degassed, and consolidated through single or double stage extrusion. The mechanical properties of all four classes of alloys were measured at room and elevated temperatures and their microstructures were investigated optically and through electron microscopy. The microstructure of class 1 Al-Li-Mg alloy was predominantly unrecrystallized due to Zr addition. Yield strengths to the order of 50 Ksi were obtained, but tensile elongation in most cases remained below 2 percent. The class 2 alloys were modified composition of 2124 aluminum alloy, through addition of 0.6 weight percent Zr and 1 weight percent Ni. Nickel addition gave rise to a fine dispersion of intermetallic particles resisting coarsening during elevated temperature exposure. The class 2 alloy showed good combination of tensile strength and ductility and retained high strength after 1000 hour exposure at 177 C. The class 3 Al-Fe-Mo alloy showed high strength and good ductility both at room and high temperatures. The yield and tensile strength of class 4 alloy exceeded those of the commercial 7075 aluminum alloy.

  13. Microstructures of Mg-Al-Zn and Al-Si-Cu cast alloys

    Directory of Open Access Journals (Sweden)

    T. Tański a

    2010-01-01

    Full Text Available Purpose: The aim of this paper was to investigate the structure of the MCMgAl6Zn1 magnesium and ACAlSi9Cu aluminium cast alloy in as-cast state.Design/methodology/approach: The following results concern the microstructure of the cast magnesium and aluminium alloys using ZEISS SUPRA 25, Opton DSM-940 scanning and LEICA MEF4A light microscopy, X-ray qualitative microanalysis as well as X-ray analysis.Findings: The analysis of the structure magnesium alloy consists of the solid solution α – Mg (matrix of the secondary phase g – Mg17Al12 evenly located in the structure. The structure creates agglomerates in the form of needle precipitations, partially coherent with the matrix placed mostly at the grain boundaries. The AC AlSi9Cu and AC AlSi9Cu4 cast aluminium alloys are characterised by a dendritic structure of the α solid solution - as the alloy matrix, as well are characterised by a discontinuous β–Si phase forming the α+β eutectic grains, with a morphology depending on the silicon and copper mass concentration.Research limitations/implications: Taking into account the fact that some of the properties are of great importance only for the surface of the material, the future investigation will concern modelling of the alloy surface using surface layers deposition methods like physical vapour deposition methods.Practical implications: A desire to create as light vehicle constructions as possible and connected low fuel consumption have made it possible to make use of magnesium and aluminium alloys as constructional material in automotive industry.Originality/value: Contemporary materials should possess high mechanical properties, physical and chemical, as well as technological ones, to ensure long and reliable use. The above mentioned requirements and expectations regarding the contemporary materials are met by the non-ferrous metals alloys used nowadays, including the magnesium and aluminium alloys.

  14. Tensile Properties of Al-Cu 206 Cast Alloys with Various Iron Contents

    Science.gov (United States)

    Liu, K.; Cao, X.; Chen, X.-G.

    2014-05-01

    The Al-Cu 206 cast alloys with varying alloy compositions ( i.e., different levels of Fe, Mn, and Si) were investigated to evaluate the effect of the iron-rich intermetallics on the tensile properties. It is found that the tensile strength decreases with increasing iron content, but its overall loss is less than 10 pct over the range of 0.15 to 0.5 pct Fe at 0.3 pct Mn and 0.3 pct Si. At similar iron contents, the tensile properties of the alloys with dominant Chinese script iron-rich intermetallics are generally higher than those with the dominant platelet phase. In the solution and artificial overaging condition (T7), the tensile strength of the 206 cast alloys with more than 0.15 pct Fe is satisfactory, but the elongation does not sufficiently meet the minimum requirement of ductility (>7 pct) for critical automotive applications. However, it was found that both the required ductility and tensile strength can be reached at high Fe levels of 0.3 to 0.5 pct for the alloys with well-controlled alloy chemistry and microstructure in the solution and natural aging condition (T4), reinforcing the motivation for developing recyclable high-iron Al-Cu 206 cast alloys.

  15. A study of microstructure and properties of cast Fe-10Cr-1.5B alloy

    Directory of Open Access Journals (Sweden)

    Zhang Haibin

    2014-05-01

    Full Text Available In the present study, the microstructure and mechanical properties of cast Fe-10Cr-1.5B (FCB alloy after different heat treatments were studied. The results showed that the as-cast microstructure of FCB alloy consists of ?Fe, M(M=Cr, Fe, Mn2(B, C and M(M=Cr, Fe, Mn7(C, B3 type borocarbides, and small amounts of pearlite and austenite. After oil quenching treatment, metal matrix transformed into the martensite from the mixture of martensite, pearlite and austenite. There are many M(M=Cr,Fe,Mn23(C,B6 type borocarbide precipitates in the metal matrix, and eutectic borocarbide appears with an apparent disconnection and isolated phenomenon. When the quenching temperature reaches 1,050 oC, the hardness of FCB alloy is the highest, but the change of quenching temperature has no obvious effect on impact toughness of FCB alloy. After tempering, the eutectic microstructure of FCB alloy appears with a "two links" trend. With the increase of tempering temperature, the hardness of FCB alloy decreases gradually and impact toughness increases gradually. Cast FCB alloy oil-quenched from 1,050 oC and tempered from 200 oC has excellent combined properties; its hardness and impact toughness are 61.5 HRC and 8.8 J.m-2 respectively.

  16. Numerical simulation of different pulse width of long pulsed laser on aluminum alloy

    Science.gov (United States)

    Li, Mingxin; Jin, Guangyong; Zhang, Wei; Chen, Guibo; Bi, Juan

    2015-03-01

    Established a physical model to simulate the melt ejection induced by long pulsed laser on aluminum alloy and use the finite element method to simulate the whole process. This simulation is based on the interaction between single pulsed laser with different pulse width and different peak energy and aluminum alloy material. By comparing the theoretical simulation data and the actual test data, we discover that: the theoretical simulation curve is well consistent with the actual experimental curve, this two-dimensional model is with high reliability; when the temperature at the center of aluminum alloy surface increases and evaporation happens after the surface temperature at the center of aluminum alloy surface reaches boiling point and later the aluminum alloy material sustains in the status of equilibrium vaporization; the keyhole appears on the surface of the target, an increment of the keyhole, the maximum temperature at the center of aluminum alloy surface gradually moves inwardly. This research may provide the theoretical references to the understanding of the interaction between millisecond pulsed laser and many kinds of materials, as well as be beneficial to the application of the laser materials processing and military field.

  17. 改良铸造铝硅合金常温耐腐蚀性能的研究%Study of the Corrosion Resistance of Modified Casting Al-Si Alloy at Room Temperature

    Institute of Scientific and Technical Information of China (English)

    范应光; 陈汝霞; 杨启杰; 苏广才; 黄思娟

    2013-01-01

    在传统ZL101铸造铝硅合金的基础上,通过添加Cu、Ni、Mn、V、RE等合金元素,研制了改良铸造铝硅合金,并对该改良合金常温(25℃)下在酸、碱、盐腐蚀介质中的耐腐蚀性能进行了研究.研究结果表明,常温下在酸、碱、盐腐蚀介质中,改良铸造铝硅合金耐腐蚀性能均优于ZL101合金.%On the basis of traditional ZL101 casting aluminum-silicon alloy, by adding alloying elements such as Cu, Ni, Mn, V, RE, a modified casting Al-Si alloy was developed, and the corrosion resistance of the improved alloy at room temperature (25 ℃) under acid, alkali and salt solutions were studied. The results show that the corrosion resistance of the improved casting aluminum-silicon alloy at room temperature under acid, alkali and salt solutions is superior to ZL101 alloy.

  18. Precipitate evolution in friction stir welding of 2219-T6 aluminum alloys

    International Nuclear Information System (INIS)

    Precipitate evolution in friction stir welding of 2219-T6 aluminum alloys was characterized by transmission electron microscopy. In the weld nugget zone and the thermo-mechanically affected zone some metastable precipitates overaged to equilibrium phase while others solutionized into the aluminum solid solution. In the heat-affected zone the precipitates coarsened.

  19. Microstructures and constituents of super-high strength aluminum alloy ingots made through LFEC process

    Directory of Open Access Journals (Sweden)

    WANG Shuang

    2007-11-01

    Full Text Available Ingots of a new super-high strength Al-Zn-Mg-Cu-Zr alloy were produced respectively by low frequency electromagnetic casting (LFEC and by conventional direct chill (DC casting process. Microstructure and constituents of the ingots were studied. The results indicated that the LFEC process significantly refines microstructure and constituents of the alloy, and to some extent, decreases the area (or volume fraction of constituents and eutectic structure precipitated at grain boundaries. But, no difference in the type of constituents was observed between LFEC and DC ingots. The results also showed LFEC process can improve the as-cast mechanical properties.

  20. Equal Channel Angular Deformation (ECAD) of As-Cast AM60 Magnesium Alloy

    Institute of Scientific and Technical Information of China (English)

    Peng LUO; Xiaolin WU; Kenong XIA

    2003-01-01

    As-cast AM60 magnesium alloy ingot with grains coarser than those of as-extruded AZ series is more liable to produce cracks under ECAD with severe shear strain. A feasible scheme of equal channel angular deformation (ECAD) for as-cast AM60 magnesium alloy ingot was proposed in this paper. The tests were conducted on Instron machine with hydraulic back-force machine. Through analysing load vs displacement curves, the effects of ECAD processing conditions on deformability and microstructure of as-cast magnesium AM60 billets were discussed. During testing,the back-force employment was helpful to keep ECAD processing more stable. And with back-force, it was observed that the number of ECAD passes in different routes could tremendously affect the deformability and microstructure of magnesium specimens. It was concluded that ECAD processing is entirely feasible for as-cast magnesium AM60alloy under severe shear strain, and back-force employment, multi-passes deformation and lubrication of graphite paper are the factors primarily beneficial to improvement of deformability and refinement of grained structure. This work provides a way to produce magnesium alloy with fine-grained structure directly from casting ingot by ECAD technique.