目的 提高镁合金表面Ni-P-SiC复合镀层的耐腐蚀性能和耐磨性能。方法 采用加入SiC微粒的Ni-P化学镀溶液，在AZ91D镁合金表面制备Ni-P-SiC复合镀层，并在不同温度下进行热处理，通过X射线衍射（XRD）、显微硬度测试、电化学腐蚀测试和摩擦磨损实验等方法分析和评价镀层的组织构成、显微硬度、耐腐蚀性能和耐磨性能。结果 Ni-P-SiC复合镀层经320 ℃热处理后，组织结构由非晶向晶体转变，并伴随有Ni3P相的析出。此温度下热处理的Ni-P-SiC复合镀层：显微硬度最高，可达1120HV，为未热处理时显微硬度(620HV)的1.81倍；自腐蚀电位为–0.697 V，较未热处理样品的（–0.727 V）有所提高；腐蚀电流密度基本最小，为0.984 μA/cm–2；磨损体积最小，为0.324×10–3 mm3。340 ℃热处理的复合镀层则磨损体积最大，为1.43×10–3 mm3。结论 在AZ91D镁合金表面制备的Ni-P-SiC复合镀层经过320 ℃热处理保温1 h后，复合镀层的硬度、耐腐蚀性能和耐磨性能均有所提高。

The work aims to improve the wear resistance and corrosion resistance of Ni-P-SiC composite coating on the surface of magnesium alloys. Ni-P electroless plating solution with SiC particles was used to prepare Ni-P-SiC composite coating on the surface of AZ91D Mg alloy, and the composite coating was heat treated at different temperature. Then the microstructure, micro-hardness, wear resistance and corrosion resistance of the composite coating were analyzed and evaluated by virtue of XRD, micro-hardness test, electrochemical corrosion test and friction-wear test. After thermally treated at 320 ℃, the microstructure of Ni-P-SiC composite coating transformed from amorphous into crystal microstructure accompanied with precipitation of Ni3P phase. Micro-hardness of the Ni-P-SiC composite coating subject to heat treatment at the temperature was up to 1120HV, 1.81 times higher than that of the coating not subject to heat treatment (620HV); Ecorr of the Ni-P-SiC composite coating was –0.697 V, higher than that of the coating not subject to heat treatment (–0.727 V); value of Jcorr was the lowest (0.984 μA/cm–2), and wear volume of Ni-P-SiC composite coating was the lowest as well (0.324×10–3/mm3). When the heat treatment temperature was 340 ℃, the wear volume of Ni-P-SiC composite coating was up to 1.43×10–3/mm3. After being heat treated at 320 ℃ for 1h, micro-hardness, corrosion resistance and wear resistance of the Ni-P-SiC composite coating prepared on the surface of AZ91D Mg alloy are all increased.