Cu content has been successfully optimized in a thixo-cast and directly aged(T5-treatment)Al-7 Si-0.5 Mg(wt.%)alloy.Even after the 0.5%Cu addition,plate-like Al_(2)Cu(θ’)phases,which contribute to high strengths and...Cu content has been successfully optimized in a thixo-cast and directly aged(T5-treatment)Al-7 Si-0.5 Mg(wt.%)alloy.Even after the 0.5%Cu addition,plate-like Al_(2)Cu(θ’)phases,which contribute to high strengths and large plasticity,are precipitated.The formation of a large fraction of Cu-containing brittle phases could be suppressed as well.Then,the Al-7Si-0.5Mg-0.5Cu alloy exhibits high ultimate tensile strength,0.2%proof stress,and elongation to failure of 296 MPa,209 MPa,and 8.8%,respectively.This results in a high quality index similar to that of solution-treated and subsequently aged(T6-treated)Al-7 Si-Mg alloys.A Cu addition over 1.0%further improves the strengths;however,this leads to poor ductility because of the high fraction of Cu-containing brittle phases.展开更多
基金supported by JSPS KAKENHI(Nos.JP18H03837,JP19K15321)Advanced Low Carbon Technology Research and Development Program(ALCA)(No.12102886)Nagaoka University of Technology(NUT)Presidential Research Grant。
文摘Cu content has been successfully optimized in a thixo-cast and directly aged(T5-treatment)Al-7 Si-0.5 Mg(wt.%)alloy.Even after the 0.5%Cu addition,plate-like Al_(2)Cu(θ’)phases,which contribute to high strengths and large plasticity,are precipitated.The formation of a large fraction of Cu-containing brittle phases could be suppressed as well.Then,the Al-7Si-0.5Mg-0.5Cu alloy exhibits high ultimate tensile strength,0.2%proof stress,and elongation to failure of 296 MPa,209 MPa,and 8.8%,respectively.This results in a high quality index similar to that of solution-treated and subsequently aged(T6-treated)Al-7 Si-Mg alloys.A Cu addition over 1.0%further improves the strengths;however,this leads to poor ductility because of the high fraction of Cu-containing brittle phases.
