表面渗氧强化对TC4钛合金力学性能的影响  

Effects of surface oxygenation enhancement on mechanical properties of TC4 titanium alloy

作　　者：冒海荣 费昊 姜勇[1] 巩建鸣[1] MAO Hairong;FEI Hao;JIANG Yong;GONG Jianming(Jiangsu Key Laboratory of Design and Manufacture of Extreme Pressure Equipment,School of Mechanical and Power Engineering,Nanjing Tech University,Nanjing 211800,China)

机构地区：[1]南京工业大学机械与动力工程学院江苏省极端承压装备设计与制造重点实验室,江苏南京211800

出　　处：《南京工业大学学报（自然科学版）》2022年第6期640-646,共7页Journal of Nanjing Tech University(Natural Science Edition)

基　　金：江苏省研究生实践创新项目(SJCX20_0397)。

摘　　要：采用氧增强扩散渗氧强化技术对TC4钛合金进行表面强化处理,利用显微硬度计测量渗氧层中的硬度分布,利用光学显微镜(OP)研究渗氧前后材料的微观组织变化,通过单轴拉伸试验研究表面渗氧强化处理对材料力学性能的影响。结果表明:经渗氧强化处理后,表面形成约150μm的渗氧强化层,表面硬度较基体提高一倍以上,约为950 HV,但力学性能下降明显,其中屈服强度下降约16%,抗拉强度下降约13%,延伸率下降约35%。材料力学性能降低的原因主要是渗氧强化处理过程中的高温作用,导致基体晶粒长大;表面渗氧强化层在小应变阶段即发生脆性开裂。The TC4 titanium alloy surfaces were enhanced by oxygen boost diffusion technology.To characterize the performance after surface strengthen treatment,surface hardness distribution was measured by microhardness measuring instrument,microstructure evolution was observed by optical microscope(OP)and mechanical properties were measured by uniaxial tensile tests.Results showed that the surface hardness reached more than twice that of the untreated sample due to 150μm hardened layer(up to 950 HV).However,the mechanical properties decreased obviously.The yield strength,tensile strength and elongation after fracture decreased by about 16%,13%and 35%,respectively.The main reasons for the decrease in mechanical properties were as follows:the high temperature during the process of oxygen strengthening resulting in the growth of grains;brittle cracking of surface oxygenation strengthening layer at low strain.

关 键 词：TC4钛合金 力学性能 渗氧强化层 表面渗氧强化 脆性开裂 氧增强扩散 

分 类 号：TH142.3[一般工业技术—材料科学与工程] TG178[机械工程—机械制造及自动化] TB303[金属学及工艺—金属表面处理]