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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。
High-rate-rate shock-compression experiments were performed on the Mg-3.04Li-0.77Sc alloy in solution and solution-treated and aged conditions by Hopkinson pressure bar. The high strain rate deformation behavior of the alloy after solution treatment and aging treatment was investigated. The results show that with the increase of strain rate, the dynamic deformation of solid solution and solution + aging Mg 3.04Li-0.77Sc alloy shows the effect of strain rate reduction. Solution treatment can increase the maximum strain of the alloy, and aging treatment can significantly improve the dynamic yield strength of the alloy. Tissue analysis shows that under the high strain rate impact loading, the solution-localized and solution-aged Mg-3.04Li-0.77Sc alloys produce obvious shear deformation localization. Thermal softening and its deformation localization and micro-crack along the deformation zone to generate and expand the dynamic deformation of the alloy showed the main reason for the strain rate weakened effect.