电沉积Ni-SiC纳米复合镀层的显微组织分析

Microstructure Analysis of Ni-SiC Nanocomposite Coating by Electrodeposition

采用超声波辅助脉冲电沉积复合镀技术在铜基表面制备Ni-SiC纳米复合镀层。研究了超声波的施加和不同电极摆放方式对镀层显微组织和性能的影响。结果表明:超声波和第二相颗粒共同作用可以显著细化复合镀层显微组织,显微硬度可达到HV760;复合镀层镍衍射晶面(200)和(220)峰位的变化,说明晶粒生长过程中的择优取向得到了抑制;在其他施镀条件相同时,与电极垂直摆放相比较,电极水平放置时复合镀层厚度减至为12.0μm,且显微硬度下降为HV343。分析原因是,电极水平摆放时第二相颗粒的自沉降作用覆盖阴极表面,阻碍镍的沉积,从而降低了复合镀层中SiC的含量。

The Ni-SiC nanocomposite coatings were electrodeposited on copper substrate aided with ultrasonic.The effects of ultrasonic and the arrangement way of electrodes on the microstructure and properties of the composite coatings were discussed.The results indicated that the composite coatings were significantly refined by ultrasonic and secondary particles,the microhardness increased to HV760,and diffraction crystal plane of nickel（200） and（220） was varied,therefore,preferred orientation was inhibited in the process of grain growth.Compared to that the electrodes were placed in vertical,the thickness of the coating was 12.0μm and microhardness was HV343.This was attributed to the sedimentation of secondary particles covered cathode surface and reduced the deposition of nickel,when the electrodes were placed in horizon.