高应变速率下Mg-Gd-Y镁合金动态

为了研究Mg-Gd-Y镁合金在高应变速率下的动态拉伸性能及失效机制,采用分离式Hopkinson拉杆(SHTB)装置在室温下且应变速率为1 400~3 000 s^-1范围内对其进行了动态拉伸实验,并利用光学显微镜和扫描电子显微镜对动态拉伸后的镁合金试样进行了分析.结果表明,在动态拉伸载荷作用下,Mg-Gd-Y镁合金沿ED方向呈现连续屈服现象.应变速率增大后,Mg-Gd-Y镁合金具有正应变速率效应.在动态拉伸载荷作用下,Mg-Gd-Y镁合金的断口形貌呈解理断裂特征,镁合金的变形方式为孪生和滑移,且滑移为主要变形方式。

Dynamic tensile properties and failure behavior of Mg-Gd-Y alloy at high strain rates

In order to investigate the dynamic tensile properties and failure mechanism of Mg-Gd-Y magnesium alloy at high strain rates, the dynamic tensile test for the alloy was carried out with split Hopkinson tensile bar(SHTB)apparatus at room temperature in high strain rate ranging from 1 400 s^-1 to 3 000 s^-1. The magnesium alloy specimens after the dynamic tension were analyzed with optical microscope(OM)and scanning electron microscope(SEM). The results show that under the action of dynamic tensile load, the Mg-Gd-Y magnesium alloy yields continuously along the ED direction. When the strain rate increases, the Mg-Gd-Y magnesium alloy has the positive strain rate effect. Under the action of dynamic tensile load, the fracture surface morphology of Mg-Gd-Y magnesium alloy exhibits the cleavage fracture feature, and the deformation modes of Mg-Gd-Y magnesium alloy are slipping and twinning, while the main deformation mode is slipping.