(南昌航空大學(xué) 材料科學(xué)與工程學(xué)院，南昌 330063)
摘 要: 通過噴丸處理(SP)在TC4鈦合金表面制備強(qiáng)化過渡層，再采用微弧氧化(MAO)制備出噴丸+微弧氧化(SP+MAO)涂層。對(duì)比研究TC4鈦合金表面微弧氧化涂層及噴丸+微弧氧化涂層的顯微結(jié)構(gòu)、相組成和疲勞性能。結(jié)果表明：噴丸處理后，材料表面粗糙度上升。位錯(cuò)不斷增殖、積塞直至發(fā)生交割而起到表層晶粒細(xì)化的作用，距表面深度為5 μm處硬度達(dá)最大值472.84HV0.1、提高了40%，表層殘余壓應(yīng)力從基體的-98.8 MPa提升到-548.9 MPa。相比微弧氧化涂層，噴丸+微弧氧化涂層表面粗糙度由0.54 μm上升到0.79 μm，平均厚度從4.1 μm增加至12.6 μm。噴丸+微弧氧化試樣的疲勞壽命為13321周次，遠(yuǎn)高于微弧氧化試樣的疲勞壽命3638周次，略高于原始試樣疲勞壽命13067周次。這表明采用噴丸作為預(yù)處理可以改善微弧氧化工藝對(duì)試樣疲勞性能的影響。
關(guān)鍵字: TC4鈦合金；噴丸處理；微弧氧化；殘余壓應(yīng)力；疲勞性能
（School of Materials Science and Engineering, Nanchang Hangkong University, Nanchang 330063, China）
Abstract: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 472.84HV0.1 (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 from 4.1 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.
Key words: TC4 titanium alloy; shot peening; micro-arcoxidation; residual compressive stress; fatigue property
