中國有色金屬學(xué)報(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 20 No. 9 September 2010 |
extruded Mg-Gd-Y-Zr alloy into semisolid state
（1. State Key Laboratory for Corrosion and Protection, Institute of Metal Research,
Chinese Academy of Sciences, Shenyang 110016, China;
2. Graduate School of Chinese Academy of Sciences, Beijing 100039, China）
Abstract: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.
Key words: semisolid; Mg-Gd-Y alloy; partial remelting; microstructural evolution
