利用电刷镀技术制备了纳米Al2O3/Ni复合镀层,研究了镀层与GCr15摩擦副从室温到500 ℃的微动磨损特性,并采用扫描电子显微镜观察了磨痕微观形貌.结果表明：镀层的微动运行区域包括部分滑移区、混合区和滑移区;在微动初期迅速增大的摩擦因数在稳定阶段有所降低;随着试验温度的上升,摩擦因数显著降低,但当试验温度为500 ℃时,摩擦因数又有所上升;复合电刷镀层的显微硬度随温度升高而显著下降,导致其抗磨损性能降低.复合电刷镀层在室温下的微动损伤主要表现为剥层,而在200 ℃以上时主要表现为剥层和粘着.

n-Al2O3/Ni composite coatings were prepared on 30CrMnSi steel substrate by electro-brush plating,using a nickel brush plating electrolyte containing n-Al2O3 particles (about 30 nm) of 20 g·L-1.Fretting wear behavior of the coatings against GCr15 under the dry sliding condition up to 500 ℃ was investigated on a PLINT test rig.Fretting wear mechanism of the coatings was discussed,based on the morphological observation of the worn surface with scanning electron microscopy.Results show that the fretting regimes of the coating consiste of partial slip,mixed regime and slip.The friction coefficient in the initial stage increase sharply and decrease to some degree in the stable stage.The friction coefficient is obviously reduced with the temperature change from room temperature to 400 ℃,but the friction coefficient increase to some degree when the testing temperature was 500 ℃.Fretting wear resistance of the coatings decrease markedly with the increase of testing temperature,due to the obvious decrease of microhardness of the coatings.The predominant fretting wear mechanisms of the coatings at room temperature and above 200 ℃ respectively are delamination and combination of delamination and adhesion.