中文摘要：

采用直流电镀、脉冲电镀和超声波辅助脉冲电镀方法,在20钢表面制备 Ni-SiC 镀层.利用扫描探针显微镜（SPM）、X 射线衍射仪（XRD）、扫描电镜（SEM）、显微硬度计及摩擦磨损试验机研究制备方法对 Ni-SiC 镀层显微组织、成分及摩擦学性能的影响.结果表明,制备方法对 Ni-SiC 镀层表面形貌有很大影响,超声波辅助脉冲电镀镀层 Ni 晶粒和 SiC 微粒的平均粒径分别为94．5和46．8 nm,其最大显微硬度为924．3 Hv.直流电镀、脉冲电镀和超声波辅助脉冲电镀 Ni-SiC 镀层的摩擦系数平均值分别为0．66,0．54和0．35,超声波辅助脉冲电镀镀层耐磨性能优良.

英文摘要：

Ni-SiC coatings were prepared on the surface of 20 steel by direct current,pulse current and ultra-sound＋ pulse current plating methods,respectively.The effect of preparation methods on microstructures, components and wear properties was investigated by using scanning probe microscope （SPM）,X-ray diffraction （SXRD）,scanning electron microscope （SEM）,microhardness tester,and friction and wear tester.The results present that plating method has great influence on microstructures of Ni-SiC coatings.The average grain size of Ni and SiC in Ni-SiC coatings prepared by ultrasound＋pulse current plating was 94.5 and 46.8 nm,respectively. And the maximum microhardness was 924.3 Hv.The friction coefficients of Ni-SiC coatings synthetised by di-rect current,pulse current and ultrasound＋ pulse current plating are 0.66,0.54 and 0.35,respectively.The coating prepared by ultrasound＋pulse current plating has better wear resistance.