(北京交通大學(xué) 機(jī)械與電子控制工程學(xué)院，北京 100044)
摘 要: 在KOH-KF-NaAlO2為組分的電解液中添加BN顆粒，采用微弧氧化技術(shù)，在LY12鋁合金表面制備自潤滑復(fù)合膜層(Al2O3/BN)。研究自潤滑復(fù)合膜的形貌與微觀結(jié)構(gòu)以及工藝參數(shù)對復(fù)合膜中BN體積分?jǐn)?shù)的影響，討論BN顆粒的沉積機(jī)制，并分析復(fù)合膜的摩擦性能。結(jié)果表明：自潤滑復(fù)合膜主要由α-Al2O3、γ-Al2O3及BN組成；隨著電壓和BN質(zhì)量濃度的增加，BN體積分?jǐn)?shù)先增大后趨緩，電解液組分濃度對膜層BN的體積分?jǐn)?shù)影響不大；當(dāng)BN體積分?jǐn)?shù)為10%，摩擦?xí)r間為120 min時(shí)，膜層摩擦因數(shù)降至0.173，BN顆粒的加入能有效減小摩擦，改善復(fù)合膜的摩擦性能。
關(guān)鍵字: 鋁合金；BN顆粒；微弧氧化；摩擦
（School of Mechanical, Electronic and Control Engineering, Beijing Jiaotong University, Beijing 100044, China）
Abstract:Al2O3/BN self-lubricating composite coatings were prepared on the surface of LY12 alloy by micro-arc oxidation in the KOH-KF-NaAlO2 electrolyte solution with BN particles. The morphology and microstructure of composite coatings were analyzed, the effects of process parameters on volume fraction of BN were investigated, the deposition mechanism of BN particles was discussed, and the tribological behaviors of composite coatings were also evaluated. The results show that the self-lubricating composite coating on LY12 is mainly composed of α-Al2O3, γ-Al2O3 and BN. Volume fraction of BN of composite coatings firstly increase, then level off with enhancing voltage and increasing mass concentration of BN, but the concentration of electrolyte components has certain influence on volume fraction of BN. Under the condition of 10% for volume fraction of BN and 120 min for friction time, friction coefficient of the composite coating reaches 0.173, which indicates that the addition of BN particles can effectively reduce friction and improve the friction properties of the self-lubricating composite coating.
Key words: aluminum alloy; BN particle; micro-arc oxidation; friction
