高应变速率下Mg-Gd-Y镁合金动态拉伸性能与失效行为  

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

作　　者：于金程[1] 刘正[1] 董阳[1] 王志[1] 

机构地区：[1]沈阳工业大学材料科学与工程学院,沈阳110870

出　　处：《沈阳工业大学学报》2015年第6期650-655,共6页Journal of Shenyang University of Technology

基　　金：国家重点基础研究发展计划(973计划)资助项目(2013CB632205);辽宁省科技攻关计划资助项目(2013201018)

摘　　要：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1400～3000S。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．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 carded 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.

关 键 词：Mg—Gd—Y镁合金 分离式Hopkinson拉杆 高应变速率 动态力学性能 失效行为 变形机制 滑移 孪生 

分 类 号：TG146.2[一般工业技术—材料科学与工程]