低温下TiZrHf系高熵合金的动态压缩力学特性与点火行为

Dynamic Compressive Mechanical Properties and Ignition Behavior of TiZrHf-based High-entropy Alloys at Low Temperatures

针对高熵合金在低温条件下力学特性以及点火行为研究不足的现状,以含微量元素Cu、Al或Ni的TiZrHf系多主元高熵合金(HEA)为研究对象,结合SHPB试验系统与高速摄像系统,开展不同温度下高熵合金的动态压缩实验及点火特性实验,获得了弹性模量、应力峰值、硬化模量以及应变率与温度、元素种类的关联规律,并明确了元素种类对火焰面积、点火延迟时间、点火对应时刻以及剧烈反应持续时间的影响规律。结果表明,低温条件下3种HEA的应力-应变曲线均经历弹性、强化以及卸载阶段;在相近载荷条件下(~20 m/s,-40℃),含Cu和Ni的2类试件均发生了点火现象,而含Al试件只有细微点火,试件的点火延迟时间均为25μs,含Cu试件的剧烈反应持续时间与点火持续时间均大于含Ni试件。

Addressing the gap in research on mechanical properties and ignition behavior of high-entropy alloys(HEAs)at low temperatures,this study investigated TiZrHf-based HEAs with trace amounts of Cu,Al,or Ni.Utilizing the split-Hopkinson pressure bar(SHPB)test system coupled with a high-speed camera system,the investigation tested HEAs for dynamic compression and ignition characteristics across at various temperatures.The study established the correlations between the elastic modulus,stress peak,hardening modulus,and strain rate with the temperature and element type.Furthermore,the study delineated how these elements influence the flame area,ignition delay time,ignition timing,and duration of intense reaction.The results indicate that at low temperatures,the stress-strain curves of all three HEAs go through phases of elasticity,hardening,and unloading;under similar loading conditions(~20 m/s,-40℃),specimens containing Cu or Ni both exhibit ignition,whereas those with Al show only minor ignition.The ignition delay time for all the specimens is measured at 25μs,with specimens containing Cu showing longer intense reaction duration and ignition duration compared to those containing Ni.