不同组织Ti6321钛合金在低温高应变速率下的变形和断裂行为  

Deformation and Fracture Behaviors of Ti6321 Titanium Alloy with Different Microstructures at Low Temperature and High Strain Rate Conditions

作　　者：李严星 王琳[1,2,3] 闫志维[1] 安瑞 周哲 宁子轩 程焕武 程兴旺[1,2] LI Yanxing;WANG Lin;YAN Zhiwei;AN Rui;ZHOU Zhe;NING Zixuan;CHENG Huanwu;CHENG Xingwang(School of Materials Science and Engineering,Beijing Institute of Technology,Beijing 100081,China;National Key Laboratory of Technology on Materials under Shock and Impact,Beijing Institute of Technology,Beijing 100081,China;State Key Laboratory of Explosion Science and Technology,Beijing Institute of Technology,Beijing 100081,China)

机构地区：[1]北京理工大学材料学院,北京100081 [2]北京理工大学冲击环境材料技术国家级重点实验室,北京100081 [3]北京理工大学爆炸科学与技术国家重点实验室,北京100081

出　　处：《兵工学报》2022年第12期3221-3227,共7页Acta Armamentarii

基　　金：爆炸科学与技术国家重点实验室基金项目(YBKT-17-06)。

摘　　要：针对目前关于船用钛合金在低温和高应变率速率下的研究不足的问题,通过热处理获得3种组织的Ti6321钛合金,研究不同组织在温度-80~25℃、应变速率2500 s^(-1)及3500 s^(-1)左右的变形和断裂行为。采用低温分离式霍普金森压杆实验装置进行加载,通过光学显微镜和扫描电子显微镜等表征方法,对其微观组织演化进行观察分析。研究结果表明:随着温度的降低,Ti6321钛合金强度增加,塑性减小;在室温下,双态组织具有较好的强塑性匹配;随着温度的降低,等轴组织具有较高的强度和较好的低温塑性变形能力,表现出良好的低温动态压缩性能。断裂机制研究表明等轴组织和双态组织表现出典型的韧性断裂特征;魏氏组织断口出现高低不平的解理面,表现出明显的脆性断裂倾向。To close the research gap on marine titanium alloys at low temperatures and high strain rate rates,Ti6321 titanium alloys with three structures are prepared through heat treatment.The deformation and fracture behaviors of the three alloy samples within the temperature range of-80-25℃and strain rate range of 2500-3500 s^(-1) are studied.A low-temperature split Hopkinson pressure bar is used for loading.The evolution of the microstructure is observed and analyzed by an optical microscope and scanning electron microscope.The results show that the strength of Ti6321 titanium alloy increases and the plasticity decreases as the temperature declines.The bimodal structure has good strength and plasticity matching at room temperature.With the decrease of temperature,the equiaxed structure has higher strength and better low-temperature plastic deformation capability,and shows good low-temperature dynamic compression properties.The study of the alloy s fracture mechanism shows that the equiaxed and bimodal structures exhibit typical ductile fracture characteristics.The fracture of Widmanstatten structure is an uneven cleavage surface,which has an evident tendency to brittle fracture.

关 键 词：Ti6321钛合金 低温 高应变速率 微观组织 断裂行为 

分 类 号：TG146.2[一般工业技术—材料科学与工程]