SiC粉末粒径及其预处理方法对Ni–SiC复合电镀层组织结构的影响

Effects of particle size and pretreatment method of SiC powder on microstructure of electroplated Ni-SiC composite coating

针对活塞杆高温、高压、高速运动的服役环境,提出对其表面进行Ni–SiC复合电镀,以提高活塞杆的耐磨损和耐腐蚀性能。研究了粉末粒径及其预处理方法对Ni–SiC复合镀层表面粗糙度、微观形貌和SiC微粒复合量的影响。结果表明,所得Ni–SiC复合镀层的外观均良好,微观组织均匀且SiC微粒弥散分布于其中,与45钢基体间结合良好、无缝隙。在SiC粉末预处理方法相同的情况下,随着SiC粒径由2μm增大到10μm,SiC的复合量呈现先缓慢后快速再缓慢增大的变化趋势。而在SiC粒径相同的情况下,表面活性剂十二烷基磺酸钠处理的SiC微粒在镀层中的复合量最高,无水乙醇处理的次之,盐酸处理的最低。

As for the severe working conditions of piston rod such as high temperature,high pressure,and fast movement,Ni–SiC composite electroplating was conducted on the surface of piston rod to improve its wear and corrosion resistance.The effects of particle size and pretreatment method of SiC powder on the surface roughness,micromorphology,and SiC content of composite coating were studied.The results showed that all the Ni–SiC composite coatings featured good appearance,uniform microstructure with well-distributed SiC particles,and strong adhesion to the 45 steel substrate without any gaps.The content of SiC in composite coating was increased slowly initially,then quickly,and slowly finally with the increasing of particle size from 2 to 10μm for the SiC powder pretreated by the same method.For the same particle size of SiC,the content of SiC powder pretreated with different chemicals in composite coating was in the following descending order:sodium dodecyl sulfonate(a surfactant),anhydrous ethanol,and hydrochloric acid.