目的 提高镁合金化学镀层的力学性能。方法 选择出一组优良镁合金化学镀Ni-P工艺参数，在Ni-P镀液中加入不同的纳米金刚石浓度。通过观察所得镀层的微观组织形貌，对比镀层形貌组织；通过对复合镀层进行热处理，分析镀层组织结构的变化；通过测定金刚石加入前后镀层的摩擦系数，检测了复合镀层的耐磨损性能；通过查看镀层腐蚀斑点数目，检测复合镀层的耐腐蚀性能。结果 随着纳米金刚石浓度的增加，复合镀层的形貌越好，当纳米金刚石加入量达到6 g/L时，所得复合镀层的微观形貌均匀、致密。热处理使镀层结构由非晶态变为结晶态，显微硬度明显提高。金刚石的加入致使镀层的摩擦系数降低且稳定，相比化学镀Ni-P镀层，加入金刚石后的复合镀层的腐蚀斑点数较少。结论 纳米金刚石的加入大大提高了镀层的力学性能。

The work aims to improve mechanical properties of magnesium alloy electroless plating. Different concentrations of nano-diamond were added in Ni-P plating solution by selecting reasonable Ni-P plating process parameters of magnesium alloy electroless plating. The coating morphology was compared by observing microstructure morphology of the obtained coating. Changes of coating structure were analyzed based on heat treatment of the composite coating. Wear resistance of the composite coating was detected by measuring friction coefficients of the coating before and after thediamond was added. Corrosion resistance of the composite coating was detected by checking quantity of corrosion spots on the coating. With the increase of nanodiamond concentration, morphology of the composite coating improved. The microstructure morphology was uniform and dense when 6 g/L of nano-diamond was added. Coating structure transformed from non-crystalline to crystalline and microhardness increased significantly as a result heat treatment. The friction coefficient of coating reduced and was stable when diamond was added. Compared with Ni-P coating subject to eletroless plating, less corrosion spots were present on the composite coating after nano-diamond was added. Mechanical properties of the coating are improved greatly since nano-diamond is added.