石墨烯添加剂对ZL109铝合金活塞微弧氧化复合膜层摩擦性能的影响

在电解液中加入不同浓度石墨烯添加剂,通过微弧氧化在ZL109铝合金表面制备了石墨烯复合陶瓷膜,通过测厚仪和硬度计对膜层进行检测;然后对最佳浓度处理试件进行摩擦磨损试验,分析其摩擦因数、表面形貌以评价石墨烯添加剂对微弧氧化复合陶瓷膜摩擦性能的影响和作用机理。结果表明:石墨烯添加剂的加入使微弧氧化膜层具有更加优异表面性能和抗磨减摩性能,在浓度为6 g/L时膜层厚度达29.68 μm,硬度达到990.12 HV0.3,摩擦因数稳定在0.19,较普通陶瓷膜摩擦因数显著降低,达34.48%。在磨擦过程中,石墨烯对摩擦副表面的凹槽和划痕进行了填充,表面珩磨纹更加细密;同时,复合添加剂在磨擦过程中形成了C元素薄膜,起到了自修复作用。

Effect of graphene on friction properties of miro-arc oxidation films produced on ZL109 aluminum alloy piston

Graphene composite ceramic film was prepared on the surface of ZL109 aluminum alloy by micro arc oxidation with different concentration of graphene additive in the electrolyte. The film was tested by thickness gauge and hardness tester. Then, the friction and wear tests were carried out on the optimized concentration treated samples, and the friction coefficient and surface morphology were analyzed to evaluate the friction performance of the composite ceramic film prepared by micro arc oxidation with graphene additive and its action mechanism. The results show that the graphene additive makes the micro-arc oxidation film layer have better surface properties, anti-wear and friction reducing properties. When the concentration is 6 g/L, the film thickness reaches 29.68 μm, the hardness reaches 990.12 HV0.3, and the friction coefficient is stable at 0.19. The friction coefficient is significantly lower than that of ordinary ceramic coatings, up to 34.48%. During the friction process, graphene fills the grooves and scratches on the surface of the friction pair, and the surface honing is finer. At the same time, the composite additive forms a carbon film during the friction process, which plays a self-repairing role.