摘要
Phase equilibrium relations of the Mg-Zn-Y system in the low-Y side at 400℃were investigated by alloy-equilibrated method,combined with thermal analysis.The results show that there is a liquid phase which could be in equilibrium with an a-Mg solid solution and an icosahedral quasicrystal I phase in the low-Y side of the Mg-Zn-Y system at 400℃.The liquid phase region originates from the binary Mg-Zn system and extends to 0.4 at%Y in the Mg-Zn-Y system.Besides,the hexagonal structure H phase,fee W phase and LPSO phase(X phase)are in equilibrium with a-Mg.With Y/Zn(atomic ratio,the same as follows)increasing,there exist four three-phase regions consisting of I+liquid+α-Mg,I+H+α-Mg,H+W+α-Mg and W+X+α-Mg,respectively,in the low-Y side of the isothermal section at 400℃.The twophase region a-Mg+I phase exists between I+H+aMg and I+liquid+a-Mg.In this two-phase region,the Y/Zn ratio is in the range of 0.14-0.17;and a three-phase region of a-Mg+I phase+H phase appears when Y/Zn ratio comes up to 0.17-0.27.Not I but W phase is in equilibrium with a-Mg,when Y/Zn ratio>0.27.The system is in liquid-state phase equilibrium,when Y/Zn ratio<0.14.
Phase equilibrium relations of the Mg-Zn-Y system in the low-Y side at 400℃were investigated by alloy-equilibrated method,combined with thermal analysis.The results show that there is a liquid phase which could be in equilibrium with an a-Mg solid solution and an icosahedral quasicrystal I phase in the low-Y side of the Mg-Zn-Y system at 400℃.The liquid phase region originates from the binary Mg-Zn system and extends to 0.4 at%Y in the Mg-Zn-Y system.Besides,the hexagonal structure H phase,fee W phase and LPSO phase(X phase)are in equilibrium with a-Mg.With Y/Zn(atomic ratio,the same as follows) increasing,there exist four three-phase regions consisting of I+liquid+α-Mg,I+H+α-Mg,H+W+α-Mg and W+X+α-Mg,respectively,in the low-Y side of the isothermal section at 400℃.The twophase region a-Mg+I phase exists between I+H+aMg and I+liquid+a-Mg.In this two-phase region,the Y/Zn ratio is in the range of 0.14-0.17;and a three-phase region of a-Mg+I phase+H phase appears when Y/Zn ratio comes up to 0.17-0.27.Not I but W phase is in equilibrium with a-Mg,when Y/Zn ratio> 0.27.The system is in liquid-state phase equilibrium,when Y/Zn ratio <0.14.
基金
financially supported by the National Natural Science Foundation of China(Nos.51271053 and 5137104)
the National Key Research and Development Program of China(No.2016YFB0701202).
作者简介
Hong-Xiao Li,e-mail:lihx@atm.neu.edu.cn
