The aims of the present work are to evaluate the overaging behaviour of the investigated Cu-enriched alloy and to assess its mechanical behaviour,in terms of the tensile and fatigue strength,at room temperature and at...The aims of the present work are to evaluate the overaging behaviour of the investigated Cu-enriched alloy and to assess its mechanical behaviour,in terms of the tensile and fatigue strength,at room temperature and at 200℃,and to correlate the mechanical performance with its microstructure,in particular with the secondary dendrite arm spacing(SDAS).The mechanical tests carried out on the overaged alloy at 200℃ indicate that the addition of about 1.3 wt.%Cu to the A357 alloy enables to maintain ultimate tensile strength and yield strength values close to 210 and 200 MPa,respectively,and fatigue strength at about 100 MPa.Compared to the quaternary(Al−Si−Cu−Mg)alloy C355,the A357−Cu alloy has greater mechanical properties at room temperature and comparable mechanical behaviour in the overaged condition at 200℃.The microstructural analyses highlight that SDAS affects the mechanical behaviour of the peak-aged A357−Cu alloy at room temperature,while its influence is negligible on the tensile and fatigue properties of the overaged alloy at 200℃.展开更多
This paper aims to assess the role of Cu on Al-Si-Mg alloys, in a range of 0 - 5 wt%, qualitatively on microstructure, defect formation, in terms of porosity, and strength in the as-cast conditions. The ternary system...This paper aims to assess the role of Cu on Al-Si-Mg alloys, in a range of 0 - 5 wt%, qualitatively on microstructure, defect formation, in terms of porosity, and strength in the as-cast conditions. The ternary system of Al-Si-Mg, using the A356 alloy as a base material, were cast using the gradient solidification technique;applying three different solidification rates to produce directional solidified samples with a variety of microstructure coarsenesses. Microstructural observations reveal that as the Cu levels in the alloys are increased, the amounts of intermetallic compounds as well as the Cu concentration in the α-Al matrix are increased. Furthermore, the level of porosity is unaffected and the tensile strength is improved at the expense of ductility.展开更多
文摘The aims of the present work are to evaluate the overaging behaviour of the investigated Cu-enriched alloy and to assess its mechanical behaviour,in terms of the tensile and fatigue strength,at room temperature and at 200℃,and to correlate the mechanical performance with its microstructure,in particular with the secondary dendrite arm spacing(SDAS).The mechanical tests carried out on the overaged alloy at 200℃ indicate that the addition of about 1.3 wt.%Cu to the A357 alloy enables to maintain ultimate tensile strength and yield strength values close to 210 and 200 MPa,respectively,and fatigue strength at about 100 MPa.Compared to the quaternary(Al−Si−Cu−Mg)alloy C355,the A357−Cu alloy has greater mechanical properties at room temperature and comparable mechanical behaviour in the overaged condition at 200℃.The microstructural analyses highlight that SDAS affects the mechanical behaviour of the peak-aged A357−Cu alloy at room temperature,while its influence is negligible on the tensile and fatigue properties of the overaged alloy at 200℃.
基金The authors would like to thank the Swedish Knowledge Foundation,Stena Aluminium AB and CompTech AB for the financial support
文摘This paper aims to assess the role of Cu on Al-Si-Mg alloys, in a range of 0 - 5 wt%, qualitatively on microstructure, defect formation, in terms of porosity, and strength in the as-cast conditions. The ternary system of Al-Si-Mg, using the A356 alloy as a base material, were cast using the gradient solidification technique;applying three different solidification rates to produce directional solidified samples with a variety of microstructure coarsenesses. Microstructural observations reveal that as the Cu levels in the alloys are increased, the amounts of intermetallic compounds as well as the Cu concentration in the α-Al matrix are increased. Furthermore, the level of porosity is unaffected and the tensile strength is improved at the expense of ductility.
