冲击加载下Zr_(51)Ti_5Ni_(10)Cu_(25)Al_9金属玻璃的塑性行为  

Plastic behavior of Zr_(51)Ti_5Ni_(10)Cu_(25)Al_9 metallic glass under planar shock loading

作　　者：俞宇颖[1] 习锋[1] 戴诚达[1] 蔡灵仓[1] 谭华[1] 李雪梅[1] 胡昌明[1] 

机构地区：[1]中国工程物理研究院流体物理研究所冲击波物理与爆轰物理重点实验室,绵阳621900

出　　处：《物理学报》2012年第19期382-387,共6页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:10732010;10972206;11172281;10802080);国家自然科学基金委员会与中国工程物理研究院联合基金(批准号:10776029/A06);冲击波物理与爆轰物理重点实验室(批准号:9140C6701021102);中国工程物理研究院科学发展基金(批准号:2010A0101001和2010B0101002)资助的课题~~

摘　　要：进行了10一27 GPa应力范围内Zr_(51)Ti_5 Ni_(10)Cu_(25)Al_9金属玻璃的平面冲击实验以研究其高压-高应变率加载下的塑性行为.由样品自由面粒子速度剖面的分析获得了冲击加载过程的轴向应力,并通过轴向应力与静水压线的比较获得剪应力.实验结果表明,尽管存在明显的松弛效应,但Zr基金属玻璃的Hugoniot弹性极限随着冲击应力的增加而增加.然而,塑性波阵面上的剪应力则显示先硬化而后软化现象,而且软化的幅度随冲击应力的增加而增加.冲击加载下Zr基金属玻璃的上述剪应力变化特征与分子动力学模拟结果比较一致,但与压剪实验结果和一维应力冲击实验结果明显不同.Planar shock compression experiments are performed on a Zr-based bulk metallic glass （BMG）, Zr51Ti5Ni10Cu25Al9 at peak shock stresses from 10 GPa to 27 GPa to investigate its plastic behavior under high pressure and high strain-rate. The particle velocity profiles measured at the free surface of the samples are analyzed to estimate longitudinal stresses of the Zr-based BMG in the shock loading process,and then shear stresses are obtained by comparing longitudinal stresses with a hydrostat. Though there is an obvious relaxation effect after elastic front, the Hugoniot elastic limit of the Zr-based BMG is found to increase with shock stress increasing. However, the shear stresses across the plastic shock front display stress hardening above the Hugoniot elastic limit followed by a stress relaxation （softening） to Hugoniot state, and the relaxation level also increases with shock stress increasing. The changes of shear stresses under planar shock compression are consistent with the results from molecular dynamic simulations, but obviously different from the pressure-shear impact experimental results or uniaxial stress impact experimental results.

关 键 词：塑性行为 冲击加载 金属玻璃 剪应力 

分 类 号：TG139.8[一般工业技术—材料科学与工程]