AZ91D镁合金表面Ni-铅基巴氏合金双镀层的摩擦磨损性能

Friction and Wear Behavior of Electroless Nickel/Hot-Dipping Lead-Based Babbitt Alloy Dual Layer Coating on the Surface of Magnesium Alloy

为了改善镁合金的摩擦学性能,采用化学镀镍与热浸镀铅基巴氏合金相结合的方法,在AZ91D镁合金表面获得了Ni-铅基巴氏合金双镀层。用JEOLJSM-7001F型扫描电镜观察了镀层的形貌,以CETRUMT-2型球盘试验机研究了干摩擦条件下AZ91D镁合金基体和Ni-铅基巴氏合金镀层的摩擦学性能及摩擦后的表面磨痕轮廓特征。研究发现,镁合金基体与Ni-铅基巴氏合金镀层载荷为0.5 N时平均摩擦系数分别为0.397和0.145,磨损率分别为3.180×10-3,9.826×10-5mm3/(m·N);载荷为2 N时摩擦系数分别为0.346和0.254,磨损率分别为1.991×10-3,7.763×10-5mm3/(m·N)。结果表明,Ni-铅基巴氏合金双层镀层使镁合金表面的减摩性能得到显著提高,同时也有效地提高了基体的耐磨性能。

Electroless Ni/hot-dipping Pb-based Babbit alloy dual layer coating was prepared on the surface of AZ91D Mg alloy by combining nickel electroless plating technology with hot-dipping technology so as to improve the wear resistance of the Mg alloy.The friction and wear behavior of as-prepared dual layer coating under dry sliding condition was evaluated with a CETRUMT-2 ball-on-disc friction and wear tester.The morphology of as-prepared dual layer coating and its worn surface was observed with a scanning electron microscope.Results indicate that electroless Ni/hot-dipping Pb-based Babbit alloy dual layer coating is able to significantly reduce the friction coefficient and increase the wear resistance of the Mg alloy substrate.Namely,Mg alloy substrate and the dual layer coating have an average friction coefficient of 0.397 and 0.145 under a load of 0.5 N,and their wear rate at 0.5 N is 3.180×10-3 mm3/(m·N) and 9.826×10-5 mm3/(m·N),respectively.At a load of 2.0 N,they have an average friction coefficient of 0.346 and 0.254,respectively,as well as a wear rate of 1.991×10-3 mm3/(m·N) and 7.763×10-5 mm3/(m·N),respectively.