显微组织和应变速率对TC4合金动态力学性能和绝热剪切带的影响  

Effects of Microstructure and Strain Rate on Dynamic Mechanical Properties and Adiabatic Shear Band of TC4 Alloy

作　　者：陈伟 章环 牟娟 朱正旺[2] 张海峰[2] 王沿东 CHENWei;ZHANG Huan;MU Juan;ZHU Zhengwang;ZHANG Haifeng;WANG Yandong(Key Laboratory for Anisotropy and Texture of Materials,Ministry of Education,School of Materials Sciences and Engineering,Northeastern University,Shenyang 110819,China;Shi-changxu Advanced Materials Innovation Center,Institute of Metal Research,Chinese Academy of Sciences,Shenyang 110016,China)

机构地区：[1]东北大学材料科学与工程学院材料各向异性与织构教育部重点实验室,沈阳110819 [2]中国科学院金属研究所师昌绪先进材料创新中心,沈阳110016

出　　处：《金属学报》2022年第10期1271-1280,共10页Acta Metallurgica Sinica

基　　金：国家自然科学基金项目Nos.51771049和51790484;国家重点实验室基金项目No.JCKYS2020602005。

摘　　要：通过热处理成功获得了等轴、片层和双态3种组织结构的TC4合金,并研究了其动态力学性能及变形机制。通过对比硬化-软化转变临界剪切应变率、最大抗剪切强度、萌发绝热剪切带的临界剪切应变速率和承载时间4个指标评估了3种组织合金的动态力学性能。结果表明,片层组织TC4合金具有较高的抗剪切强度和临界剪切应变速率以及最低的绝热剪切敏感性,其动态力学性能最佳。进一步的微观结构分析表明,3种组织合金中所形成的绝热剪切带均为脆性剪切带,且剪切带宽度随剪切应变速率的增大而减小。当剪切应变速率相同时,3种组织合金的剪切带宽度由大到小依次为:片层组织、双态组织、等轴组织。Under dynamic load,shear bands constitute the main deformation mode comparaed with quasistatic deformation.This study systematically investigates the influence of microstructures and strain rates of Ti-6Al-4V(TC4)alloys on their adiabatic shear behavior.TC4 alloys with three types of microstructures(lamellar,bimodal,and equiaxial)were successfully obtained via different thermal treatments.The dynamic mechanical properties,such as the critical shear strain rates of the hardening,softening transformation,maximum shear strength,critical shear strain rates of adiabatic shear-band nucleation and bearing time of the three types of microstructures were compared.Results indicate that compared with the lamellar bimodal and equiaxial TC4 alloys,the lamellar TC4 alloy shows the best dynamic mechanical properties,achieving higher shear strength and critical shear strain rates as well as the lowest adiabatic shear sensitivity.Microstructural analysis reveals that the adiabatic shear bands that formed in the three types of alloys are brittle.The width of the shear band decreases with increasing shear strain rate.Furthermore,at the same shear strain rate,the order of the widths of the shear bands is as follows:lamellar TC4 alloy>bimodal TC4 alloy>equiaxial TC4 alloy.

关 键 词：TC4合金 动态力学性能 绝热剪切敏感性 剪切带 

分 类 号：TG146.2[一般工业技术—材料科学与工程]