冲击应力和脉宽对NbTiZr中熵合金层裂的影响  

Effects of Shock Peak Stress and Pulse Duration on Spall Damage of NbTiZr Medium-Entropy Alloy

作　　者：罗小平 李绪海[1] 唐泽明 李治国[1] 陈森 王媛[1] 俞宇颖[1] 胡建波[1] LUO Xiaoping;LI Xuhai;TANG Zeming;LI Zhiguo;CHEN Sen;WANG Yuan;YU Yuying;HU Jianbo(National Key Laboratory of Shock Wave and Detonation Physics,Institute of Fluid Physics,CAEP,Mianyang 621999,Sichuan,China;State Key Laboratory for Environmentally Friendly Energy Materials,Southwest University of Science and Technology,Mianyang 621010,Sichuan,China)

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全国重点实验室,四川绵阳621999 [2]西南科技大学环境友好能源材料国家重点实验室,四川绵阳621010

出　　处：《高压物理学报》2024年第6期17-26,共10页Chinese Journal of High Pressure Physics

基　　金：国家重点研发计划(2021YFB3802303)。

摘　　要：中、高熵合金因很好地兼顾了强度和韧性而备受关注,在多种极端工况下具有重要的应用前景。然而,在强冲击载荷等极端条件下,其动态力学行为和损伤失效机制仍不清楚。为此,研究了NbTiZr中熵合金在平板冲击载荷下的层裂损伤,探讨了冲击应力和加载脉宽的影响。通过波剖面分析,获得了冲击应力、加载脉宽和层裂强度信息。研究表明,NbTiZr中熵合金的层裂强度随冲击应力的增大而线性增大,随加载脉冲宽度的增大呈指数减小,介于3.77~4.80 GPa之间。利用光学显微镜、扫描电子显微镜和电子背散射衍射,分析了冲击加载后回收样品的微观组织结构,发现冲击应力和加载脉冲宽度对NbTiZr的层裂损伤形貌有显著影响,层裂损伤形式为准解理断裂,未观察到固-固相变或变形孪晶。Dynamic mechanical behaviors of high entropy alloys(HEAs)or medium-entropy alloys(MEAs)have attracted significant attention due to their exceptional strength-toughness balance and promising potential applications in extreme conditions.This work investigates the effects of peak shock stress and pulse duration on the spall damage of the NbTiZr MEA under dynamic shock loading.Peak shock stresses,pulse durations and spall strengths are determined by analyzing free surface velocity profiles,with postmortem microstructural analysis to reveal the underlying deformation and failure mechanisms.The measured spall strength of NbTiZr MEA ranges from 3.77 GPa to 4.80 GPa,showing minimal dependence on the peak shock stress but high sensitivity to the pulse duration.Furthermore,the damage morphologies are significantly influenced by pulse durations.The damage is recognized as a quasi-cleavage fracture mode.No phase transition or deformation twins are observed within the recovered NbTiZr alloy.

关 键 词：NbTiZr 层裂损伤 冲击波加载历史 微观结构 

分 类 号：O347.3[理学—固体力学] O521.2[理学—力学]