轧制AZ31镁合金板材(4mm)动态压缩性能与失效行为

Dynamic Compressive Properties and Failure Behaviour of Rolled AZ31 Magnesium Alloy Sheet(4mm)

为了研究轧制AZ31镁合金板材（4mm）在高应变速率下的动态力学性能和失效行为,采用分离式霍普金森压杆装置（SHPB）在室温下应变速率为500～2600s^-1范围内对其进行了动态压缩实验,并利用金相显微镜（OM）和扫描电镜（SM）对冲击后的试样进行了显微分析。探讨了轧制AZ31镁合金板材沿轧制方向（RD）、横向（TD）和法向（ND）的动态压缩性能和失效行为。结果表明：轧制AZ31镁合金4mm板材动态压缩性能存在各向异性。沿RD和TD方向压缩的动态性能相同,沿ND方向压缩的动态断裂强度最大。AZ31镁合金4mm板材的动态压缩断裂机制为解理断裂。变形机制为沿RD和TD方向高速压缩时,{10^-12}〈11^-20〉拉伸孪晶参与变形;沿ND方向高速压缩时,{10^-11}〈11^-20〉压缩孪晶参与变形。

To investigate the dynamic compressive properties and failure behaviour of the rolled AZ31 magnesium alloy sheet（4mm）,the dynamic compressive test was carried out using split Hopkinson pressure bar（SHPB）at ambient temperature under the strain rates from 500s^-1to 2600s^-1.The compressed specimens were analyzed by metallographic microscope and scanning electron microscope.The dynamic compressive properties and failure behaviour of the rolled AZ31 magnesium alloy sheet（4mm）along rolling direction（RD）,transverse direction（TD）and normal direction（ND）were discussed.The results show that the dynamic mechanical properties of the rolled AZ31 magnesium alloy sheet（4mm）exhibit strong anisotropy.The properties along RD and TD are similar while the dynamic strength along ND is the largest.The dynamic compressive fracture mechanism of the rolled AZ31 magnesium alloy sheet（4mm）is cleavage fracture.The deformation mechanism is that tensile twinning{10^-12}〈11^-20〉are activated along RD and TD compression;compressive twinning {10^-11}〈11^-20〉are activated along ND compression.