Fracture behavior of high strength Mg-Gd-Y-Zr magnesium alloy

来源期刊：中国有色金属学报(英文版)2010年第7期

论文作者：高磊 陈荣石 韩恩厚

文章页码：1217 - 1221

Key words：magnesium alloy; rare earth; Mg-Gd-Y alloys; mechanical properties; fracture behavior; heat treatment

Abstract: The fracture behavior of a permanent mould casting Mg-8.57Gd-3.72Y-0.54Zr (mass fraction, %) (GW94) alloy was investigated under different thermal conditions, including as-cast, solution-treated, peak-aged, and over-aged states. Scanning electron microscopy (SEM) and optical microscopy (OM) were employed to examine the crack nucleation and fracture model. The results indicate that the GW94 alloy shows different behaviors of crack initiation and fracture under different thermal conditions. During tensile test at room temperature, the fracture model of the as-cast GW94 alloy is quasi-cleavage, while that of the solution-treated alloy is transgranular cleavage. It is a mixed pattern of transgranular and intergranular fracture for both the aged conditions. Large cavities formed at grain boundaries are observed in the peak-aged sample tested at 300 °C, corresponding to the intergranular fracture. Localized plastic deformation at grain boundaries is also observed and corresponds to the high elongation at 300 °C.

基金信息：the National Basic Research Program of China