(1 .湖南工程學(xué)院 機(jī)械工程學(xué)院，湘潭 411101；
2. 中南大學(xué) 材料科學(xué)與工程學(xué)院，長(zhǎng)沙 410083)
摘 要: 采用電弧離子鍍(AIP)技術(shù)在TC4 (Ti-6Al-4V) 鈦合金表面制備NiCrAlY涂層。利用掃描電鏡(SEM)、透射電鏡(TEM)、能譜(EDS)分析、X射線衍射分析(XRD)及維氏硬度測(cè)量試驗(yàn)研究真空熱處理對(duì)NiCrAlY涂層組織與性能的影響。結(jié)果表明：真空熱處理后涂層沉積殘余應(yīng)力得到有效釋放，涂層平均晶粒尺寸從沉積態(tài)的200 nm增加至950 ℃真空熱處理后的500 nm；真空熱處理過程中發(fā)生β→γ′→γ相轉(zhuǎn)變，γ′分布于β晶界或γ晶粒內(nèi)；γ晶粒內(nèi)析出的γ′相呈細(xì)小彌散分布，與基體γ保持共格起到強(qiáng)化作用；經(jīng)700~750 ℃真空熱處理后，涂層可獲得最佳的析出強(qiáng)化效果。
關(guān)鍵字: NiCrAlY涂層；真空熱處理；顯微組織；性能
（1. School of Mechanical Engineering, Hunan Institute of Engineering, Xiangtan 411101, China;
2.School of Materials Science and Engineering, Central South University, Changsha 410083, China）
Abstract:NiCrAlY coating was deposited on TC4 titanium alloy by arc ion plating (AIP). The effect of vacuum heat treatment on the microstructure and properties of NiCrAlY coating were studied by SEM, TEM, EDS, XRD and Vickers hardness test. The results show that, during the vacuum heat treatment, the deposition residual stress of the coating can be released effectually. The average grain size of the coating increases from 200 nm for the as-deposited state to 500 nm for the vacuum heat-treated state at 950 ℃. β→γ′→γ phase transformation happens during the vacuum heat treatment. γ′ phase distributes along the β grain boundaries or in the γ grains. The fine and dispersing γ′ phase in the γ grains is coherent with the substrate, which is able to strengthen the coating substrate. The best precipitation hardening effect for NiCrAlY coating can be obtained after vacuum heat treatment at 700-750 ℃.
Key words: NiCrAlY coating; vacuum heat treatment; microstructure; property
