高温高应变率下纯钼动态力学性能与失效行为

Dynamic Mechanical Properties and Failure Behavior of Pure Molybdenum at High Temperature and High Strain Rate

为研究纯钼在高应变率下的动态力学性能及失效行为,在室温及高温情况下,采用分离式Hopkinson压杆试验装置(SHPB)对纯钼进行了动态压缩实验,利用扫描电子显微镜(SEM)对冲击压缩后的试样进行了断口分析。结果表明,在冲击压缩载荷作用下,纯钼动态压缩力学性能随温度的升高而降低;在已测试的温度下,室温、应变率为1 800s^(-1)时,纯钼具有相对较大的动态压缩屈服强度,为1 110MPa,且具有相对较大的动态抗压强度,为1 087MPa;在800℃、应变率为2 000s^(-1)时,纯钼具有相对较大的应变量,为17.6%;而在300℃、应变率为2 200s^(-1)时,纯钼具有较好的综合动态力学性能;高温、高应变率下纯钼的动态压缩断裂机制为准解理断裂。

In order to study the dynamic mechanical properties and failure behavior of pure molybdenum at high strain rate, a dynamic compression experiment of pure molybdenum was carried out using Split Hopkinson Pressure Bar (SHPB) at room temperature and high temperature.The specimens fracture after impact compression was analyzed by Scanning Electron Microscopy (SEM). The results show that under the impact compression load, the dynamic mechanical properties of pure molybdenum decrease with the increase of temperature. Under the test temperature, when at the room temperature and the strain rate is 1 800 s -1 , the pure molybdenum has a relatively large dynamic compressive yield strength of 1 100 MPa and a relatively large dynamic compressive strength of 1 087 MPa. At 800 ℃ and the strain rate is 2 000 s -1 , the pure molybdenum has a relatively largest strain of 17.6%. At 300 ℃ and the strain rate is 2 200 s -1 , the pure molybdenum has better comprehensive dynamic mechanical properties. The dynamic compressive fracture mechanism of pure molybdenum at high temperature and high strain rate is quasi-cleavage fracture.