(北京交通大学 机械与电子控制工程学院，北京 100044)
摘 要: 在KOH-KF-NaAlO2为组分的电解液中添加BN颗粒，采用微弧氧化技术，在LY12铝合金表面制备自润滑复合膜层(Al2O3/BN)。研究自润滑复合膜的形貌与微观结构以及工艺参数对复合膜中BN体积分数的影响，讨论BN颗粒的沉积机制，并分析复合膜的摩擦性能。结果表明：自润滑复合膜主要由α-Al2O3、γ-Al2O3及BN组成；随着电压和BN质量浓度的增加，BN体积分数先增大后趋缓，电解液组分浓度对膜层BN的体积分数影响不大；当BN体积分数为10%，摩擦时间为120 min时，膜层摩擦因数降至0.173，BN颗粒的加入能有效减小摩擦，改善复合膜的摩擦性能。
关键字: 铝合金；BN颗粒；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
