Insights into microstructural evolution and deformation behaviors of a gradient textured AZ31B Mg al

• 作 者: Weigui Zhang Kun Li Runqiang Chi Susheng Tan Peijie Li
• 机 构: Beijing Innowind Aerospace Equipment Co.,Ltd.,Beijing 100854,China;College of Mechanical and Vehicle
• 出 处: 材料科学技术（英文版）
• 发表日期: 2021年32期
• 关键词: AZ31B Mg alloy plate Hypervelocity impact Deformation behavior Shock wave propag

We have for the first time elucidated the microstructural evolution and deformation behaviors of a gra-dient textured AZ31B Mg alloy plate under the ultrahigh strain rate of-106 s-1 that is generated by a two-stage light gas gun with the hypervelocities of 1.6-4.4 km s-1.The hypervelocity impact cratering behaviors indicate that the cratering deformation of AZ31B Mg alloy is mainly affected by the inertia and strength of the target material.The crater prediction equation of A7Z31B Mg alloy target under im-pact velocity of 5 km s-1 is given.The 2017Al projectile completely melts in the Mg alloy target plate at the impact velocities of 3.8 km s-1 and 4.4 km s-1,and the microstructural evolution around the crater is:dynamic recrystallization zone,high-density twinning zone,low-density twinning zone,and Mg alloy matrix.It is found that the dynamic recrystallization,twinning and cracking are the main deformation behaviors for the AZ31B Mg alloy to absorb the shock wave energy and release the stress generated by the hypervelocity impact.The main plastic deformation mechanisms of the Mg alloy target during hy-pervelocity impact are twinning and dislocation slip.Microstructure analysis shows the interactions of twins-twins,dislocations-dislocations,and twins-dislocations determine the strain hardening during the hypervelocity impact process,which eventually contributes the dynamic mechanical properties.The evo-lution of microhardness around the crater further demonstrates the microstructural evolutions and their interactions under the hypervelocity impacts.