Home About us Contact
|
Home About us Contact | ||
|
|
||
Magnesium Alloys (magnesium + alloy)
Kinds of Magnesium Alloys Selected AbstractsHot Workability, Microstructural Control and Rate-Controlling Mechanisms in Cast-Homogenized AZ31 Magnesium Alloy,ADVANCED ENGINEERING MATERIALS, Issue 3 2009Yellapregada Venkata Rama Krishna Prasad Optimum conditions for microstructural control in industrial hot working of cast and homogenized AZ31 magnesium alloys are evaluated by using a processing map. The recommended window for bulk metal working of this alloy is the domain in the temperature range 300,450,°C and strain rate range 1,10,s,1, and the optimum processing parameters are 400,°C and 10,s,1, where grain-boundary self diffusion is the rate-controlling mechanism. [source] Effects of Zirconium Additions on the Microstructure of As-Cast and Aged AZ91 Magnesium AlloyADVANCED ENGINEERING MATERIALS, Issue 3 2009Farhoud Kabirian The effects of Zr addition on the microstructure of AZ91 alloy were investigated under as-cast and isothermally aged conditions. The microstructures contained a eutectic , -Mg17Al12 phase together with fine Al,Zr intermetallic compounds. These intermetallic compounds inhibited grain growth during the 420,°C isothermal aging of Zr-containing alloys. Microstructural changes caused by Zr additions were most probably due to the consumption of Al by Zr, and redistribution of Al during solidification of dendrites. [source] Mechanical Properties and Environmental Behavior of a Magnesium Alloy with a Nano-/Sub-Micron StructureADVANCED ENGINEERING MATERIALS, Issue 9 2007E. Aghion Abstract Newly developed magnesium alloys with a consolidated nano/sub-micron structure and substantially higher specific strength may be considered as an interesting candidate for super-light high-strength applications. Consolidated nano/sub-micron structure applies to alloys with a combined microstructure of nano-crystalline and sub-micron grains. The aim of the present study was to explore the mechanical and environmental behavior of a consolidated nano/sub-micron magnesium alloy with the composition of AZ31. This was required in order to evaluate the applicability of this new structured alloy for practical applications. Although the nano/sub-micron structured alloy has more than twice the hardness and strength of the conventional alloy, its ductility and corrosion resistance were significantly lower. In addition, its stress corrosion characteristics were inferior. The significant limitation of the nano-structured alloy, in terms of ductility and corrosion performance, restricts its potential use as a structural material for practical applications. [source] Analysis of Superplastic Deformation of AZ31 Magnesium Alloy,ADVANCED ENGINEERING MATERIALS, Issue 9 2007K. Abu-Farha AZ31 is a magnesium alloy possessing good mechanical properties, which makes it particularly attractive for automotive applications. Yet, in order to advance the utilization of this alloy, a broad database of its superplastic behavior is needed. This work presents the results of a comprehensive study on the elevated temperature superplastic behavior of the AZ31 magnesium alloy. Flow stress, fracture strain and strain sensitivity index maps were constructed over a wide range of strain rates, covering temperatures between 325 and 450 °C. [source] Hot Deformation Mechanisms and Microstructural Control in High-Temperature Extruded AZ31 Magnesium Alloy,ADVANCED ENGINEERING MATERIALS, Issue 7 2007A Processing map has been developed for Magnesium alloy AZ31 extruded at 450,°C which revealed that the extruded rods may be further processed into components industrially at 400,°C and at a strain rate of 10,s,1. If processed at lower strain rates in the vicinity of 0.1,s,1, unusual grain size variations with temperature and strain rate are observed, suggesting that grain size control will be difficult. [source] Detonation and Blast Wave Characteristics of Nitromethane Mixed with Particles of an Aluminium,Magnesium AlloyPROPELLANTS, EXPLOSIVES, PYROTECHNICS, Issue 2 2010Waldemar Abstract Investigation of detonation parameters, blast wave characteristics and quasi-static pressures (QSPs) for the mixtures of nitromethane and particles of an aluminium and magnesium (Al3Mg4) alloy was carried out. The mixtures of gelled nitromethane containing 15,60,wt.-% AlMg alloy were tested. Detonation velocity and Gurney energy were determined. Parameters of blast waves produced by charges of the investigated explosives were measured. QSP measurements were conducted in a steel chamber of 0.15,m3 volume filled with air. Thermochemical and gasdynamical calculations were also performed. The degree of combustion of the metallic addition with the gaseous products during detonation and expansion is discussed. [source] Progress and Challenge for Magnesium Alloys as Biomaterials,ADVANCED ENGINEERING MATERIALS, Issue 8 2008R. Zeng Abstract Magnesium alloys are very biocompatiable and show promise for use in orthopaedic implant. Significant progress of research on bioabsorbable magnesium stents and orthopaedic bones has been achieved in recent years. The issues on degradation, hydrogen evolution, and corrosion fatigue and erosion corrosion of magnesium alloys and various influencing factors in simulated body fluid (SBF) are discussed. The research progress on magnesium and its alloys as biomaterials and miscellaneous approaches to enhancement in corrosion resistance is reviewed. Finally the challenges and strategy for their application as orthopaedic biomaterials are also proposed. [source] Tensile-Compressive Creep Asymmetry of Recent Die Cast Magnesium Alloys,ADVANCED ENGINEERING MATERIALS, Issue 9 2007S. Xu The tensile-compressive creep asymmetry of die cast magnesium alloys is experimentally explored and the possible deformation mechanisms are discussed. Creep tests were performed under tension and compression at 125,°C and 150,°C on die cast Mg alloys AM50, AE44 and AJ62A. Higher tensile than compressive creep strengths were observed for all alloys except for low pressure die cast AM50 at a low creep stress of 35 MPa at 125,°C. An aging treatment of 250 hours at 180,°C was employed for AM50 samples to obtain an over-aged microstructure that would minimize the effects of dynamic precipitation of ,-Mg17Al12 on creep. The creep data for the aged samples showed significant scatter, and the trend in tensile-compressive creep asymmetry of the aged samples is not clear for the short-term creep tests under high creep stresses. [source] The Effect of Grain Size on the Deformation Behaviour of Magnesium Alloys Investigated by the Acoustic Emission Technique,ADVANCED ENGINEERING MATERIALS, Issue 5 2006J. Bohlen Extruded round bars from magnesium alloys ZM21, ZK30, ZE10 and ZEK100 with various grain sizes were tested in tension and compression. The effect of grain size on the deformation behaviour of the alloys was investigated through the Hall-Petch relation. In-situ acoustic emission measurements were conducted during testing to evaluate the mechanisms of plastic deformation. The results are discussed with respect to twinning as one important deformation mechanism in magnesium alloys. [source] Galvanisches Verzinken von MagnesiumlegierungenMATERIALWISSENSCHAFT UND WERKSTOFFTECHNIK, Issue 2 2007H. Pokhmurska magnesium alloy; zinc coating; electro plating of zinc; corrosion behaviour Abstract Magnesiumlegierungen sind sehr korrosionsanfällig, was ihre Anwendung unter korrosiven Bedingungen einschränkt. Eine Möglichkeit, um Magnesium vor aggressiven Umweltbedingungen zu schützen, ist das Beschichten. Es werden Ergebnisse über das Korrosionsverhalten der aus verschiedenen Elektrolyten galvanisch verzinkten Magnesiumknetlegierung AZ31 gezeigt. Die Bewertung der Korrosionsprozesse in chloridhaltigen Lösungen erfolgte durch elektrochemische Messungen. Durch einstündige Auslagerung der beschichteten Proben wurde festgestellt, dass dicke und dichte galvanische Zinkschichten auf AZ31 die Korrosionseigenschaften verbessern. Eine Erhöhung der Immersionszeit führt jedoch zu einer Verschlechterung der Korrosionseigenschaften. Elektrolytische Zinkschichten, die durch einen konsekutiven alkalisch / sauren Prozess erzeugt werden, stabilisieren die Schicht und verbessern somit die Korrosionsbeständigkeit des beschichteten AZ31. Zinc-Plating of Magnesium Alloys Magnesium alloys are highly susceptible to corrosion that limits their application when exposure to corrosive service conditions is needed. One of the ways to prevent corrosion is to coat the magnesium-based substrate to avoid a contact with an aggressive environment. Results concerning corrosion behaviour of wrought AZ31 magnesium alloy with electrolytic zinc coatings deposited from different electrolyte solutions are described. Evaluation of corrosion processes in chlorides containing solutions was performed by electrochemical measurements. It was found that thick and dense electrolytic zinc coatings formed on AZ31 significantly improve the corrosion behaviour of magnesium alloy after one hour immersion of zinc coated magnesium alloys in corrosive media. Further increase of immersion time leads to relatively fast decrease of corrosion properties. Electrolytic zinc coatings obtained in consecutive alkaline / acidic process demonstrate an improvement of corrosion resistance of coated AZ31. The time to coating degradation strongly increases. [source] Veränderungen der mechanischen Eigenschaften von Magnesium-Druckgusslegierungen nach langzeitiger thermischer BeanspruchungMATERIALWISSENSCHAFT UND WERKSTOFFTECHNIK, Issue 2 2004D. Regener Pressure die cast magnesium alloys; long-term annealing; microstructure; mechanical properties Abstract Die thermische Belastbarkeit von Magnesium-Druckgusslegierungen ist noch nicht ausreichend untersucht. Um die Auswirkung einer thermischen Belastung auf die Gefügestabilität und damit auf das Festigkeits- und Verformungsverhalten einschätzen zu können, werden die Legierungen AZ91, AM50 und AE42 bei 150,°C und 200,°C einer 1000 h-Langzeitglühung unterworfen. Nach der Glühung werden Zugversuche, in situ-Zugversuche und Mikrohärtemessungen bei Raumtemperatur durchgeführt und die Ergebnisse anhand der mikrostrukturellen Veränderungen diskutiert. Changes of the Mechanical Properties of Pressure Die Cast Magnesium Alloys Subjected to Long-Term Thermal Exposure The thermal resistance of pressure die cast magnesium alloys is yet not investigated sufficiently. In order to assess the effect of a thermal exposure on the microstructural stability and on the strength and deformation behaviour, the alloys AZ91, AM50 and AE42 are subjected to a long-term annealing for 1000 h at 150,°C and 200,°C. After the annealing, tensile tests, in situ tensile tests and microhardness measurements are carried out and the results are discussed on the basis of the microstructural changes. [source] ChemInform Abstract: Selection of Promising Quaternary Candidates from Mg,Mn,(Sc, Gd, Y, Zr) for Development of Creep-Resistant Magnesium Alloys.CHEMINFORM, Issue 33 2001J. Groebner Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] Numerical Determination of Heat Distribution and Castability Simulations of as Cast Mg,Al Alloys,ADVANCED ENGINEERING MATERIALS, Issue 3 2009Shehzad Saleem Khan 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. [source] Progress and Challenge for Magnesium Alloys as Biomaterials,ADVANCED ENGINEERING MATERIALS, Issue 8 2008R. Zeng Abstract Magnesium alloys are very biocompatiable and show promise for use in orthopaedic implant. Significant progress of research on bioabsorbable magnesium stents and orthopaedic bones has been achieved in recent years. The issues on degradation, hydrogen evolution, and corrosion fatigue and erosion corrosion of magnesium alloys and various influencing factors in simulated body fluid (SBF) are discussed. The research progress on magnesium and its alloys as biomaterials and miscellaneous approaches to enhancement in corrosion resistance is reviewed. Finally the challenges and strategy for their application as orthopaedic biomaterials are also proposed. [source] Galvanisches Verzinken von MagnesiumlegierungenMATERIALWISSENSCHAFT UND WERKSTOFFTECHNIK, Issue 2 2007H. Pokhmurska magnesium alloy; zinc coating; electro plating of zinc; corrosion behaviour Abstract Magnesiumlegierungen sind sehr korrosionsanfällig, was ihre Anwendung unter korrosiven Bedingungen einschränkt. Eine Möglichkeit, um Magnesium vor aggressiven Umweltbedingungen zu schützen, ist das Beschichten. Es werden Ergebnisse über das Korrosionsverhalten der aus verschiedenen Elektrolyten galvanisch verzinkten Magnesiumknetlegierung AZ31 gezeigt. Die Bewertung der Korrosionsprozesse in chloridhaltigen Lösungen erfolgte durch elektrochemische Messungen. Durch einstündige Auslagerung der beschichteten Proben wurde festgestellt, dass dicke und dichte galvanische Zinkschichten auf AZ31 die Korrosionseigenschaften verbessern. Eine Erhöhung der Immersionszeit führt jedoch zu einer Verschlechterung der Korrosionseigenschaften. Elektrolytische Zinkschichten, die durch einen konsekutiven alkalisch / sauren Prozess erzeugt werden, stabilisieren die Schicht und verbessern somit die Korrosionsbeständigkeit des beschichteten AZ31. Zinc-Plating of Magnesium Alloys Magnesium alloys are highly susceptible to corrosion that limits their application when exposure to corrosive service conditions is needed. One of the ways to prevent corrosion is to coat the magnesium-based substrate to avoid a contact with an aggressive environment. Results concerning corrosion behaviour of wrought AZ31 magnesium alloy with electrolytic zinc coatings deposited from different electrolyte solutions are described. Evaluation of corrosion processes in chlorides containing solutions was performed by electrochemical measurements. It was found that thick and dense electrolytic zinc coatings formed on AZ31 significantly improve the corrosion behaviour of magnesium alloy after one hour immersion of zinc coated magnesium alloys in corrosive media. Further increase of immersion time leads to relatively fast decrease of corrosion properties. Electrolytic zinc coatings obtained in consecutive alkaline / acidic process demonstrate an improvement of corrosion resistance of coated AZ31. The time to coating degradation strongly increases. [source] Achieving Low Temperature Superplasticity from Ca-Containing Magnesium Alloy Sheets,ADVANCED ENGINEERING MATERIALS, Issue 7 2009Woo-Jin Kim The application of hot extrusion and high-speed-ratio differential speed rolling (HRDSR) to a Ca-containing Mg -3Al1Zn magnesium alloy, processed by electromagnetic casting in the presence of electromagnetic stirring, produced a novel microstructure, composed of an ultrafine grain size of less than 1,,m and very fine (Al,Mg)2Ca particles that were uniformly and densely distributed over the matrix. The HRDSR processed alloy exhibited excellent superplasticity at relatively low temperatures (below 523,K). [source] EBSD Study on Deformation Twinning in AZ31 Magnesium Alloy During Quasi-in-Situ Compression,ADVANCED ENGINEERING MATERIALS, Issue 10 2008J. Yang In this paper, the authors use the electron back-scatter diffraction (EBSD) technique to study the evolution of texture and microstructure during the deformation twinning process of AZ31 magnesium alloy under quasi-in-situ compression to several strain levels along two different directions. The aims of the current study were to analyze the influence of initial texture, grain size and plastic strain on the deformation twinning behavior. [source] Mechanical Properties and Environmental Behavior of a Magnesium Alloy with a Nano-/Sub-Micron StructureADVANCED ENGINEERING MATERIALS, Issue 9 2007E. Aghion Abstract Newly developed magnesium alloys with a consolidated nano/sub-micron structure and substantially higher specific strength may be considered as an interesting candidate for super-light high-strength applications. Consolidated nano/sub-micron structure applies to alloys with a combined microstructure of nano-crystalline and sub-micron grains. The aim of the present study was to explore the mechanical and environmental behavior of a consolidated nano/sub-micron magnesium alloy with the composition of AZ31. This was required in order to evaluate the applicability of this new structured alloy for practical applications. Although the nano/sub-micron structured alloy has more than twice the hardness and strength of the conventional alloy, its ductility and corrosion resistance were significantly lower. In addition, its stress corrosion characteristics were inferior. The significant limitation of the nano-structured alloy, in terms of ductility and corrosion performance, restricts its potential use as a structural material for practical applications. [source] Analysis of Superplastic Deformation of AZ31 Magnesium Alloy,ADVANCED ENGINEERING MATERIALS, Issue 9 2007K. Abu-Farha AZ31 is a magnesium alloy possessing good mechanical properties, which makes it particularly attractive for automotive applications. Yet, in order to advance the utilization of this alloy, a broad database of its superplastic behavior is needed. This work presents the results of a comprehensive study on the elevated temperature superplastic behavior of the AZ31 magnesium alloy. Flow stress, fracture strain and strain sensitivity index maps were constructed over a wide range of strain rates, covering temperatures between 325 and 450 °C. [source] The effect of cerium on high-cycle fatigue properties of die-cast magnesium alloyFATIGUE & FRACTURE OF ENGINEERING MATERIALS AND STRUCTURES, Issue 12 2007Y. YANG ABSTRACT The effect of cerium (Ce) on high-cycle fatigue behaviour of die-cast magnesium alloy AZ91D was investigated. Mechanical fatigue tests were conducted at the stress ratio, R= 0.1 on specimens of AZ91D alloys with different Ce additions. The microstructure and fatigue fracture surfaces of specimens were examined using a scanning electron microscope (SEM) to reveal the micromechanisms of fatigue crack initiation and propagation. The results show that the grain size of AZ91D is refined, and the amount of porosity decreases and evenly distributes with the addition of Ce. The fatigue strength of AZ91D evaluated by the up-and-down load method increases from 96.7 MPa to 116.3 MPa (1% Ce) and 105.5 MPa (2% Ce), respectively. The fatigue cracking of AZ91D alloy initiates at porosities and inclusions of the alloy's interior, and propagates along the grain boundaries. The fatigue fracture surface of test specimens shows the mixed fracture characteristics of quasi-cleavage and dimple. [source] Effects of humidity and temperature on the fatigue behaviour of an extruded AZ61 magnesium alloyFATIGUE & FRACTURE OF ENGINEERING MATERIALS AND STRUCTURES, Issue 4 2005Z. B. SAJURI ABSTRACT Load-controlled fatigue tests were performed at 20 and 50 °C using two relative humidity levels of 55 and 80% to characterize the influence of humidity and temperature on the fatigue behaviour of an extruded AZ61 magnesium alloy. Fatigue tests were also conducted at 150 °C. No significant variation in fatigue properties was noticed with respect to temperature over the range from 20 to 50 °C for both the humidity levels. Fatigue limits in the range 140,150 MPa were observed for relative humidity of 55%. Fatigue strength decreased significantly with increase in temperature to 150 °C. Further, a significant reduction in fatigue strength with a fatigue limit of ,110 MPa was observed with increase in relative humidity to 80% at 20 and 50 °C. The crack initiation and propagation remained transgranular under all test conditions. The fatigue fracture at low stress amplitudes and high relative humidity of 80% results from the formation of corrosion pits at the surface and their growth to a critical size for fatigue-crack initiation and propagation. The observed reduction in fatigue strength at high humidity is ascribed to the effects associated with fatigue,environment interaction. [source] Inhibition of corrosion of AZ91 magnesium alloy in ethylene glycol solution in presence of chloride anionsMATERIALS AND CORROSION/WERKSTOFFE UND KORROSION, Issue 2 2005E. Slavcheva Abstract The influence of chloride ions on the corrosion of AZ91 magnesium alloy in water/ethylene glycol solutions and the inhibiting effect of lactobiono-tallowamide (LTA) were investigated using electrochemical and surface analysis methods. Potentiodynamic polarization curves in aqueous solution of ethylene glycol (50:50w%) containing 0.1 g.L,1 chloride and up to 0.5 g.L,1 LBT were obtained at room and at elevated temperatures. The chloride anions showed a distinct deteriorating effect as they caused pit initiation and accelerated the dissolution of the tested alloy. The selected organic compound demonstrated good protective properties against corrosion of AZ91 magnesium alloy and behaved as inhibitor of mixed type hindering both the cathodic and the anodic partial reactions. It showed inhibition efficiency of 77% at relatively low concentration of 0.2 g.L,1 and was considered as a promising corrosion inhibitor. The mechanism of inhibition was discussed on the basis of the electrochemical impedance spectroscopy (EIS) and XRD analysis of the surface. [source] Characteristics of anodic coatings oxidized to different voltage on AZ91D Mg alloy by micro-arc oxidization techniqueMATERIALS AND CORROSION/WERKSTOFFE UND KORROSION, Issue 2 2005Y. Wang Abstract With increasing applied voltage, three types of anodic coatings, passive film, micro-spark ceramic coating and spark ceramic coating were made by micro-arc oxidization (MAO) technique on AZ91D magnesium alloy in alkali-silicate solution. The structure, composition characteristics and the electrochemical properties of coatings were also studied with SEM, XRD and EIS (electrochemical impedance spectroscopy) technique, respectively. It is found that the electrochemical properties are closely related to the structure and composition characteristics of the anodic coatings. At the same time, the characteristics of the three types of anodic coatings differ significantly, among them, the micro-spark ceramic coating, prepared in the voltage range of 170~220V exhibits compact, homogeneous structure and highest corrosion-resistance. [source] Galvanisches Verzinken von MagnesiumlegierungenMATERIALWISSENSCHAFT UND WERKSTOFFTECHNIK, Issue 2 2007H. Pokhmurska magnesium alloy; zinc coating; electro plating of zinc; corrosion behaviour Abstract Magnesiumlegierungen sind sehr korrosionsanfällig, was ihre Anwendung unter korrosiven Bedingungen einschränkt. Eine Möglichkeit, um Magnesium vor aggressiven Umweltbedingungen zu schützen, ist das Beschichten. Es werden Ergebnisse über das Korrosionsverhalten der aus verschiedenen Elektrolyten galvanisch verzinkten Magnesiumknetlegierung AZ31 gezeigt. Die Bewertung der Korrosionsprozesse in chloridhaltigen Lösungen erfolgte durch elektrochemische Messungen. Durch einstündige Auslagerung der beschichteten Proben wurde festgestellt, dass dicke und dichte galvanische Zinkschichten auf AZ31 die Korrosionseigenschaften verbessern. Eine Erhöhung der Immersionszeit führt jedoch zu einer Verschlechterung der Korrosionseigenschaften. Elektrolytische Zinkschichten, die durch einen konsekutiven alkalisch / sauren Prozess erzeugt werden, stabilisieren die Schicht und verbessern somit die Korrosionsbeständigkeit des beschichteten AZ31. Zinc-Plating of Magnesium Alloys Magnesium alloys are highly susceptible to corrosion that limits their application when exposure to corrosive service conditions is needed. One of the ways to prevent corrosion is to coat the magnesium-based substrate to avoid a contact with an aggressive environment. Results concerning corrosion behaviour of wrought AZ31 magnesium alloy with electrolytic zinc coatings deposited from different electrolyte solutions are described. Evaluation of corrosion processes in chlorides containing solutions was performed by electrochemical measurements. It was found that thick and dense electrolytic zinc coatings formed on AZ31 significantly improve the corrosion behaviour of magnesium alloy after one hour immersion of zinc coated magnesium alloys in corrosive media. Further increase of immersion time leads to relatively fast decrease of corrosion properties. Electrolytic zinc coatings obtained in consecutive alkaline / acidic process demonstrate an improvement of corrosion resistance of coated AZ31. The time to coating degradation strongly increases. [source] In situ ellipsometric studies of formation kinetics of rare earth metal conversion coatings on magnesium alloyPHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 5 2008Lingjie Li Abstract In situ spectroscopic ellipsometry was employed to investigate the initial regime of rare earth metal (REM) conversion coatings formation on AZ31 magnesium alloy. Three REM salts solutions, 0.05 mol·dm -3 Ce(NO3)3, La(NO)3 and Sm(NO)3 solutions, were used for REM conversion coatings preparation. By deconvoluting the ellipsometric data, the surface of the fresh well-polished AZ31 magnesium alloy was found to be covered with 15.80 nm thick native (hydr)oxide film; the refractive indices and the thickness of Ce, La and Sm conversion coatings were obtained. The formation kinetics of three REM coatings follows different exponential functions and the coatings exhibit different optical properties. La conversion coating has the largest n values and the lowest k values while Sm conversion coating is just opposite. Moreover, the pH variation of the bulk conversion solutions upon the coatings formation was recorded. It is confirmed that the reduction of protons leads to the interfacial pH increasing and further results in the precipitation of REM hydroxide gel, which is critical for the REM conversion coatings formation. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Numerical Determination of Heat Distribution and Castability Simulations of as Cast Mg,Al Alloys,ADVANCED ENGINEERING MATERIALS, Issue 3 2009Shehzad Saleem Khan 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. [source] Hot Workability, Microstructural Control and Rate-Controlling Mechanisms in Cast-Homogenized AZ31 Magnesium Alloy,ADVANCED ENGINEERING MATERIALS, Issue 3 2009Yellapregada Venkata Rama Krishna Prasad Optimum conditions for microstructural control in industrial hot working of cast and homogenized AZ31 magnesium alloys are evaluated by using a processing map. The recommended window for bulk metal working of this alloy is the domain in the temperature range 300,450,°C and strain rate range 1,10,s,1, and the optimum processing parameters are 400,°C and 10,s,1, where grain-boundary self diffusion is the rate-controlling mechanism. [source] Progress and Challenge for Magnesium Alloys as Biomaterials,ADVANCED ENGINEERING MATERIALS, Issue 8 2008R. Zeng Abstract Magnesium alloys are very biocompatiable and show promise for use in orthopaedic implant. Significant progress of research on bioabsorbable magnesium stents and orthopaedic bones has been achieved in recent years. The issues on degradation, hydrogen evolution, and corrosion fatigue and erosion corrosion of magnesium alloys and various influencing factors in simulated body fluid (SBF) are discussed. The research progress on magnesium and its alloys as biomaterials and miscellaneous approaches to enhancement in corrosion resistance is reviewed. Finally the challenges and strategy for their application as orthopaedic biomaterials are also proposed. [source] Mechanical Properties and Environmental Behavior of a Magnesium Alloy with a Nano-/Sub-Micron StructureADVANCED ENGINEERING MATERIALS, Issue 9 2007E. Aghion Abstract Newly developed magnesium alloys with a consolidated nano/sub-micron structure and substantially higher specific strength may be considered as an interesting candidate for super-light high-strength applications. Consolidated nano/sub-micron structure applies to alloys with a combined microstructure of nano-crystalline and sub-micron grains. The aim of the present study was to explore the mechanical and environmental behavior of a consolidated nano/sub-micron magnesium alloy with the composition of AZ31. This was required in order to evaluate the applicability of this new structured alloy for practical applications. Although the nano/sub-micron structured alloy has more than twice the hardness and strength of the conventional alloy, its ductility and corrosion resistance were significantly lower. In addition, its stress corrosion characteristics were inferior. The significant limitation of the nano-structured alloy, in terms of ductility and corrosion performance, restricts its potential use as a structural material for practical applications. [source] Tensile-Compressive Creep Asymmetry of Recent Die Cast Magnesium Alloys,ADVANCED ENGINEERING MATERIALS, Issue 9 2007S. Xu The tensile-compressive creep asymmetry of die cast magnesium alloys is experimentally explored and the possible deformation mechanisms are discussed. Creep tests were performed under tension and compression at 125,°C and 150,°C on die cast Mg alloys AM50, AE44 and AJ62A. Higher tensile than compressive creep strengths were observed for all alloys except for low pressure die cast AM50 at a low creep stress of 35 MPa at 125,°C. An aging treatment of 250 hours at 180,°C was employed for AM50 samples to obtain an over-aged microstructure that would minimize the effects of dynamic precipitation of ,-Mg17Al12 on creep. The creep data for the aged samples showed significant scatter, and the trend in tensile-compressive creep asymmetry of the aged samples is not clear for the short-term creep tests under high creep stresses. [source] | |||||||||||||