目的 为了改善LZ91镁锂合金的耐蚀性能，以扩大其适用范围。方法 在前期试验的基础上，通过正交实验探索不同镀镍配方及工艺对LZ91镁锂合金化学镀镍过程，及镍磷合金镀层形貌、孔隙率、自腐蚀电流密度等的影响。结果 优化工艺条件为：主盐乙酸镍20 g/L，还原剂次亚磷酸钠20 g/L，络合剂柠檬酸6 g/L，氟化氢铵20 g/L，氢氟酸12 mL/L，氨水少量，温度85 ℃，pH=7.4。采用优化后的工艺镀镍得到镀层的厚度为5~7 μm，表面孔隙率较低，自腐蚀电位为?0.3806 V，较未处理Mg-Li合金正移1.356 V，自腐蚀电流密度为1.97×10?7 A/cm2，较未处理Mg-Li合金降低两了个数量级，96 h盐雾测试性能符合军工标准。结论 采用优化后工艺所得的镀层能够起到改善合金耐蚀性能的作用。

The work aims to improve corrosion resistance and expand application scope of LZ91 Mg-Li alloy. Based on pre-experiments, the effects of different formulations and processes of nickel plating on the process of electroless nickel plating, morphology, porosity, corrosion current density of Ni-P alloy coating were studied by means of orthogonal experiment. Optimized process conditions of nickel plating were confirmed: primary nickel acetate of 20 g/L, reducing hypophosphite of 20 g/L, complexing agent citric of 6 g/L, ammonium hydrogen fluoride of 20 g/L, hydrofluoric acid of 12 mL/L, a small amount of ammonia, temperature of 85 ℃ and pH=7.4. Admirable nickel coating was obtained in the optimized process conditions with the thickness of 5~7 μm, low surface porosity, self-corrosion potential of –0.3806 V (increased by 1.356 V compared with untreated Mg-Li alloy) and self corrosion current density of 1.97×10–7 A/cm2 (decreased by two orders of magnitudes). Owing to protection by the coating, the sample passed 96 h-salt spray test successfully and met military standards. Corrosion resistance of Mg-Li alloy can be improved by the coating made by taking advantage of optimized process.