约束氢致密化处理对粉末冶金Ti-6Al-4V合金致密度与力学性能的影响  

Effects of confined hydrogen densification treatment on the density and mechanical properties of powder metallurgy Ti-6Al-4V alloy

作　　者：段中元 陈奏君 祝贤智 刘彬[1] 刘咏[1] 梁霄鹏[2] 周承商 DUAN Zhongyuan;CHEN Zoujun;ZHU Xianzhi;LIU Bin;LIU Yong;LIANG Xiaopeng;ZHOU Chengshang(Powder Metallurgy Research Institute,Central South University,Changsha 410083,China;School of Materials Science and Engineering,Central South University,Changsha 410083,China)

机构地区：[1]中南大学粉末冶金研究院,长沙410083 [2]中南大学材料科学与工程学院,长沙410083

出　　处：《粉末冶金材料科学与工程》2022年第2期171-179,共9页Materials Science and Engineering of Powder Metallurgy

基　　金：国家自然科学基金资助项目(51704336);中南大学创新驱动计划资助项目(2020CX025);中南大学粉末冶金国家重点实验室资助项目。

摘　　要：以氢化钛粉和6Al-4V预合金粉为原料,采用真空烧结法制备Ti-6Al-4V合金,然后在高纯氢气气氛中进行约束氢致密化处理,再真空退火去除合金中残余的氢。用光学显微镜观察Ti-6Al-4V合金的显微组织与形貌,测定合金的密度和拉伸性能,并用MTS-810液压伺服疲劳试验机进行疲劳性能测试。结果表明:约束氢致密化处理可使粉末冶金Ti-6Al-4V合金的残余孔隙率从2.5%降低至1.3%,致密度达到(98.7±0.3)%。约束氢致密化处理后,合金的抗拉强度从(936±18)MPa提高到(959±10)MPa,伸长率从(6.7±1.6)%提升到(12±1.1)%。同时疲劳性能得到改善,在0.5%循环应变幅条件下循环周次达到4670周次。Titanium hydride powder and 6Al-4V pre-alloyed powder were used as raw materials to prepare Ti-6Al-4V alloy by vacuum sintering.Then confined hydrogen densification treatment in a high-purity hydrogen atmosphere was carried out,and finally vacuum annealing was performed to remove the residual hydrogen in the alloy.The microstructure morphology of the alloy was observed by an optical microscope.The density and tensile properties of the alloy were determine,and the fatigue performance testing was tested using the MTS-810 hydraulic servo fatigue testing machine.The results show that the confined hydrogen densification treatment can reduce the residual porosity of the sintered Ti-6Al-4V alloy from 2.5%to 1.3%,and the relative density can reach(98.7±0.3)%.After confined hydrogen densification treatment,the tensile strength of the alloy increases from(936±18)MPa to(959±10)MPa,and the elongation increases from(6.7±1.6)%to(12±1.1)%.At the same time,the fatigue performance is improved,and the cycle times reach 4670 cycles under the condition of 0.5%cyclic strain amplitude.

关 键 词：钛合金 约束氢致密化 残余孔隙 显微组织 低周疲劳 

分 类 号：TG146.23[一般工业技术—材料科学与工程]