稀土学报（英文版）
稀土學報（英文版）
희토학보（영문판）
JOURNAL OF RARE EARTHS
2014年
5期
445-450
,共6页
张国栋%李兴刚%马鸣龙%李永军%石国梁%袁家伟%张奎
張國棟%李興剛%馬鳴龍%李永軍%石國樑%袁傢偉%張奎
장국동%리흥강%마명룡%리영군%석국량%원가위%장규
Mg-Gd-Y-Nd-Al alloy%homogenization%second phase%hardness%rare earths
The microstructures and mechanical properties of the Mg-7.68Gd-4.88Y-1.32Nd-0.63Al-0.05Zr magnesium alloy were investigated both in the as-cast condition and after homogenization heat treatment from 535 to 555 oC in the time range 0-48 h by op-tical microscopy, scanning electron microscopy and hardness measurement. The as-cast alloy consisted of α-Mg matrix, Mg5(Y0.5Gd0.5) phase which is a eutectic phase, strip of Al2(Y0.6Gd0.4) phase, little Al3Zr and Mg(Y3Gd) phase. With the increasing of homogenization temperature and time, the Mg5(Y0.5Gd0.5) phase was completely dissolved into the matrix. The Al2(Y0.6Gd0.4) phase was almost not dissolved which impeded grain boundaries motion making the grain size almost not changed in the process of ho-mogenization. The optimum homogenization condition was 545 oC/16 h. The tensile strength increased, yield strength decreased and the plasticity improved obviously after 545 oC/16 h homogenization treatment.
