Mg-3.04Li-0.77Sc合金的高应变率变形局部化行为  

Deformation Localization Behavior of the Mg-3.04Li-0.77Sc Alloys under High-Strain Rate

作　　者：沙桂英[1] 孙晓光[2] 刘腾[1,3] 朱宇宏[1] 冯晓刚[1] 

机构地区：[1]沈阳航空航天大学材料科学与工程学院,沈阳110136 [2]哈尔滨工业大学材料科学与工程学院,哈尔滨150001 [3]美国韦恩州立大学机械工程系,密歇根州底特律48202

出　　处：《材料研究学报》2010年第6期567-571,共5页Chinese Journal of Materials Research

基　　金：国家自然科学基金50801048;航空科学基金2007ZF54016资助项目~~

摘　　要：利用Hopkinson压杆对固溶及固溶+时效处理状态的Mg-3.04Li-0.77Sc合金进行高应变率冲击压缩实验,研究了固溶和时效处理后该合金的高应变率变形行为。结果表明,随着应变率提高,固溶及固溶+时效态Mg 3.04Li-0.77Sc合金的动态变形表现为应变率弱化效应。固溶处理可增大合金的最大应变,而时效处理可显著提高该合金的动态屈服强度。组织分析表明,在高应变率冲击载荷下,固溶及固溶+时效态Mg-3.04Li-0.77Sc合金产生了明显的剪切变形局部化现象。热软化及其促使的变形局部化和微裂纹沿变形带产生并扩展是该合金动态变形表现为应变率弱化效应的主要原因。The impact compression tests for the Mg-3.04Li-0.77Sc alloys under different treatments including solid solution treatment（T4）,and solid solution followed by aging treatment（T6）,were conducted under high-strain rate using split Hopkinson pressure bar（SHPB）.High-strain rate deformation behavior of the heat treated alloys was investigated.Results show that the dynamic deformation behavior of Mg- 3.04Li-0.77Sc alloys was noted to appear a negative strain rate effect with increasing strain rate.However, the alloy at T4 treatment improved the maximum strain while that of T6 treatment improved the dynamic yield strength evidently.The alloys after impact deformation show a visible shear localization phenomena under the high-strain rate loading.The thermal softening,and deformation localization induced by the thermal softening as well as the propagation of the micro-cracks along the shear band are responsible for the negative strain rate effect of the alloys under high-strain rate.

关 键 词：金属材料 冲击变形 Mg-Li-Sc合金 固溶 时效 应变率 

分 类 号：TG146.2[一般工业技术—材料科学与工程] TG166.4[金属学及工艺—金属材料]