Microstructure evolution during reheating of extruded Mg-Gd-Y-Zr alloy into semisolid state  

作　　者：高磊 梁松茂 陈荣石 韩恩厚 

机构地区：[1]State Key Laboratory for Corrosion and Protection,Institute of Metal Research,Chinese Academy of Sciences [2]Graduate School of Chinese Academy of Sciences

出　　处：《Transactions of Nonferrous Metals Society of China》2010年第9期1585-1590,共6页中国有色金属学报（英文版）

基　　金：Project(2007CB613704) supported by the National Basic Research Program of China

摘　　要：The microstructure evolution of an extruded Mg-8.57Gd-3.72Y-0.54Zr （mass fraction, %, GW94） alloy during reheating into the semisolid state was investigated using optical microscopy （OM）, scanning electron microscopy （SEM）, and energy dispersive X-ray spectroscopy （EDX）. Typical semisolid microstructure with globular solid particles distributed in the liquid matrix is obtained over 600 ℃. The solid content of （Gd＋Y） in the primary a-Mg particles decreases with increasing the semisolid temperature. With the prolongation of isothermal holding time, the liquid fraction does not change significantly, while the grains grow up and spheroidize. Three methods used to determine the liquid fraction as a function of temperature, namely quantitative metallography on quenched microstructures, cooling curve thermal analysis, and thermodynamic calculations were further compared.The microstructure evolution of an extruded Mg-8.57Gd-3.72Y-0.54Zr (mass fraction, %, GW94) alloy during reheating into the semisolid state was investigated using optical microscopy (OM), scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDX).Typical semisolid microstructure with globular solid particles distributed in the liquid matrix is obtained over 600 °C.The solid content of (Gd+Y) in the primary α-Mg particles decreases with increasing the semisolid temperature.With the prolongation of isothermal holding time, the liquid fraction does not change significantly, while the grains grow up and spheroidize.Three methods used to determine the liquid fraction as a function of temperature, namely quantitative metallography on quenched microstructures, cooling curve thermal analysis, and thermodynamic calculations were further compared.

关 键 词：SEMISOLID Mg-Gd-Y alloy partial remelting microstructural evolution 

分 类 号：TG379[金属学及工艺—金属压力加工]