摘要
基于分离式Hopkinson压杆,建立了一套可对1873 K下材料的动态力学行为进行有效测试的新型超高温高应变率压缩试验方法。该试验方法在原有基础上,通过电机来驱动入射杆和透射杆同步组装系统,利用高精度延时控制器来精确控制撞击杆发射系统以及入射杆和透射杆同步组装系统的启动时间,可实现冷接触时间的精确控制(小于10 ms)以及组装过程对试样冲击力的控制,避免了超高温下冷接触时间对测试结果的影响以及组装过程产生的冲击力引起试样的塑性变形甚至破坏。基于该超高温高应变率压缩试验方法,对粉末等离子电弧增材制造共晶高熵合金CoCrFeNiTa_(0.2)Nb0.1在宽温度(293~1473 K)、宽应变率(0.001~5000 s^(-1))范围内的力学行为进行了测试,并分析了温度和应变率对其塑性流动行为和变形机理的影响规律,获得了该材料流动应力随温度变化曲线上出现的第3型应变时效现象随应变率的变化规律及其物理模型。
A new ultra-high temperature and high strain rate compression experiment method was established based on the split-Hopkinson pressure bar,which can effectively test the dynamic mechanical behaviors of material at 1873 K.The synchronous assembly system of incident rod and transmission rod was driven by the motor,and the start-up time of the launching system of the striker and the synchronous assembly system of incident rod and transmission rod was precisely controlled by the high-precision delay controller.It can realize the precise control of cold contact time(less than 10 ms)and the control of impact force in assembly process on the sample,which can avoid the influence of cold contact time on the test results at ultra-high temperature and the plastic deformation or even destruction of the sample caused by impact force in assembly process.Based on this ultra-high temperature and high strain rate compression experiment method,the mechanical behaviors of eutectic high entropy alloy CoCrFeNiTa_(0.2)Nb0.1 fabricated by powder plasma arc additive were tested in a wide range of temperature(293-1473 K)and strain rate(0.001-5000 s^(-1)).The influence laws of temperature and strain rate on its plastic flow behavior and deformation mechanism were analyzed.The variation laws of the third-type strain aging phenomenon appearing in the curve of flow stress of the material with temperature with strain rate and its physical model were obtained.
作者
王梓荻
王建军
王志华
王强
WANG Zi-di;WANG Jian-jun;WANG Zhi-hua;WANG Qiang(Institute of Applied Mechanics,College of Mechanical and Vehicle Engineering,Taiyuan University of Technology,Taiyuan 030024,China)
出处
《塑性工程学报》
CAS
CSCD
北大核心
2023年第9期93-103,共11页
Journal of Plasticity Engineering
基金
国家自然科学基金资助项目(11902272
12172245)。
关键词
分离式霍普金森压杆
高熵合金
超高温
高应变率
split-Hopkinson pressure bar
high entropy alloy
ultra-high temperature
high strain rate
