摘要
为了提高AZ91D镁合金的耐腐蚀性和耐磨性,用硅酸盐体系溶液和以乙酸镍为主盐的镀液在AZ91D镁合金表面制备了等离子体电解氧化和化学镀镍复合涂层.SEM分析结果表明,复合涂层表面呈典型的胞状结构,复合涂层中的镀镍层自氧化膜的紧密层和疏松层的交界处向外生长,镀镍层和氧化膜之间呈"机械咬合"式结合.XRD分析结果表明,复合涂层外层和内层的相组成主要为非晶态Ni-P合金和Mg2SiO4、MgAl2O4等.与AZ91D镁合金相比,复合涂层的显微硬度为基体的6倍;自腐蚀电位提高了约1.2 V,自腐蚀电流密度降低了2个数量级.制备复合涂层之后,AZ91D镁合金的性能得到显著的改善.
Composite coating was prepared on the surface of an AZ91D magnesium alloy by plasma electrolytic oxidation-electroless plating to improve the corrosion and wear resistance.The silicate solution and plating bath containing nickel acetate mainly were used.The results show that a typical cellular structure was formed on the surface of the composite coating in which nickel-plate grew from the juncture between the compact layer and loose layer of the film.Mechanical bonding took place between the nickel-plate and oxidation layers.The phase composition of the inner and outer layers of the composite coating was analyzed by X-ray diffraction.The results indicated that it was mainly amorphous Ni-P alloy,Mg2SiO4,and MgAl2O4.The microhardness of the composite coating was 5 times higher than that of the AZ91D magnesium alloy.The corrosion potential was raised by 1.2 V and the corrosion current density was reduced by two orders of magnitude compared with the AZ91D alloy.The performance of the AZ91D magnesium alloy is significantly improved by the composite coating.
出处
《哈尔滨工程大学学报》
EI
CAS
CSCD
北大核心
2010年第12期1674-1678,共5页
Journal of Harbin Engineering University
基金
国防基础研究基金资助项目(J1500E002)
关键词
镁合金
等离子体电解氧化
化学镀
复合涂层
微观形貌
magnesium alloy
plasma electrolytic oxidation
electroless plating
composite coating
micromorphology
