摘要
通过喷丸处理(SP)在TC4钛合金表面制备强化过渡层,再采用微弧氧化(MAO)制备出喷丸+微弧氧化(SP+MAO)涂层。对比研究TC4钛合金表面微弧氧化涂层及喷丸+微弧氧化涂层的显微结构、相组成和疲劳性能。结果表明:喷丸处理后,材料表面粗糙度上升。位错不断增殖、积塞直至发生交割而起到表层晶粒细化的作用,距表面深度为5μm处硬度达最大值472.84HV0.1、提高了40%,表层残余压应力从基体的-98.8 MPa提升到-548.9MPa。相比微弧氧化涂层,喷丸+微弧氧化涂层表面粗糙度由0.54μm上升到0.79μm,平均厚度从4.1μm增加至12.6μm。喷丸+微弧氧化试样的疲劳寿命为13321周次,远高于微弧氧化试样的疲劳寿命3638周次,略高于原始试样疲劳寿命13067周次。这表明采用喷丸作为预处理可以改善微弧氧化工艺对试样疲劳性能的影响。
The surface reinforced transition layers were prepared by shot peening(SP) on the surface of TC4 titanium alloy, and then shot peening(SP)+micro-arc oxidation(MAO) composite coatings were prepared by MAO. The microstructure, phase composition and fatigue properties of MAO coatings and SP+MAO composite coatings were studied. The results show that the surface roughness of the TC4 titanium alloy greatly increases after shot peening. The surface grain refinement is attributed to dislocation multiplication and accumulation until delivery. The maximum hardness of 472.84 HV0.1(increased by 40% compared with substrate) is obtained at 5μm below the surface, and the residual compressive stress of the surface increases from-98.8 MPa to-548.9 MPa. Compared with the MAO coating,the surface roughness of SP+MAO coating increases from 0.54 μm to 0.79 μm, and the average thickness increases from4.1 μm to 12.6 μm. The fatigue life of the SP+MAO sample is 14365 cycles, which is slightly higher than that of the TC4 substrate sample of 13067 cycles, and much higher than that of the MAO sample of 3638 cycles. This indicates that using shot peening as pretreatment can improve the fatigue performance of the MAO technology by micro-arcoxidation.
作者
罗军明
陈宇海
黄俊
徐吉林
LUO Jun-ming;CHEN Yu-hai;HUANG Jun;XU Ji-lin(School of Materials Science and Engineering, Nanchang Hangkong University, Nanchang 330063, China)
出处
《中国有色金属学报》
EI
CAS
CSCD
北大核心
2019年第6期1210-1218,共9页
The Chinese Journal of Nonferrous Metals
基金
国家自然科学基金资助项目(51764041)~~
关键词
TC4钛合金
喷丸处理
微弧氧化
残余压应力
疲劳性能
TC4 titanium alloy
shot peening
micro-arcoxidation
residual compressive stress
fatigue property
