国防科技大学理学院， 湖南 长沙 410073
College of Science，National University of Defense Technology， Changsha 410073， China
为研究高应变率下铸态TiZrNbV难熔高熵合金的层裂行为，获取准确的动态本构参数。采用20 mm一级轻气炮平板撞击实验研究了铸态TiZrNbV难熔高熵合金的层裂特性，对回收试样进行扫描电镜分析，从微观角度获得了铸态TiZrNbV高熵合金在不同应变率下的层裂特性，并基于层裂实验自由面速度历史标定得到了铸态TiZrNbV高熵合金的GTN-JC本构模型参数。结果表明，TiZrNbV难熔高熵合金的层裂强度随着加载应变率和平台应力的增加而增加，其值为0.93~2.23 GPa；回收试样的几何必要位错密度随着加载速度的提高显著增加。所得参数在模拟铸态TiZrNbV高熵合金层裂行为方面表现良好，模拟结果中自由面速度曲线在第一次拉伸阶段前均较为吻合，可以满足对试样层裂破坏的动态分析，能为铸态TiZrNbV高熵合金的工程应用提供参考。
The cast TiZrNbV refractory high entropy alloy （RHEA） has high structural strength and good energy release characteristics. As an energetic structural material， it needs to withstand complex dynamic load environments in engineering applications. Studying the spalling behavior of TiZrNbV refractory high entropy alloy and obtaining accurate dynamic constitutive parameters are vital for its engineering application. The spalling characteristics of TiZrNbV RHEA were studied by flat plate impact experiment using a 20mm light gas gun. Parameters such as spalling strength， Hugoniot elastic limit （HEL）， and plastic strain rate were obtained， based on the free surface velocity history. The recycled specimens were analyzed using scanning electron microscopy （SEM）， and the spalling characteristics of TiZrNbV RHEA at different strain rates were analyzed from both macro and micro perspectives. It was shown that the geometrically necessary dislocation of the samples significantly increased with the increase of loading velocity. The spalling strength of TiZrNbV RHEA increases with the loading strain rate and the loading stress， with values ranging from 0.93 GPa to 2.23GPa. The GTN-JC constitutive model parameters of TiZrNbV RHEA were obtained by calibrating the free surface velocity history of the spallation experiment with a flyer velocity of 580 m·s-1. The spallation behavior of the sample under 610 m·s-1 flyer velocity loading was calculated by using the fitted parameters. It was indicated that the free surface velocity curve of the spallation experiment performed well in simulating the spallation behavior of coarse-grained TiZrNbV RHEA. The simulation results show that the free surface velocity curve is consistent before the first tensile stage， which can be used for the dynamic analysis of sample spalling failure. The obtained parameters can provide reference for the engineering application of TiZrNbV RHEA.
陈荣,马荣,王峥,等. 铸态TiZrNbV难熔高熵合金的层裂行为[J]. 含能材料,DOI:10.11943/CJEM2023133.复制