相对运动速度对电刷镀镍镀层组织结构和性能的影响

Effect of Relative Moving Speed on Microstructure and Properties of Brush Electroplating Nickel

采用新型的内孔电刷镀技术对失效的发动机缸套内表面进行了再制造。利用SEM,XRD,TEM,显微硬度计和CETR显微磨损试验机,考察了不同相对运动速度下电刷镀镍镀层的组织结构和性能,并与传统电镀Watts Ni进行了对比。结果表明:镍镀层均为面心立方结构,但电镀Watts Ni镀层表面粗糙,择优取向为(200)面,而应用电刷镀制备的镍镀层表面平整致密,无针孔、麻点等缺陷,择优取向为(111)面。随着相对运动速度从0.25m/s增加到1.00m/s,电刷镀层的(200)面择优取向逐渐降低,而(111)面择优取向逐渐增大;镀层的硬度由HV420增大到HV600,镀层的磨损失重由8.7mg降低到6mg。

A novel bore brush electroplating technology was applied in remanufacturing for internal surface of failed engine cylinder body. The effect of relative moving speed on microstructure and properties of automatic brush electroplating nickel was investigated by SEM, XRD, TEM, microhardness tester and CETR friction and wear testing machine. The plating was compared with traditional Watts Ni plated. The results show that nickel plated coatings are face center cubic structure. Electroplated Ni has coarse surface and （200） preferential orientation from the Watts bath while brush electroplated nickel has compact and smooth microstructure, and （111） preferential orientation, without pinholes and nodules defects. With relative moving speed increasing from 0.25m/s to 1.00m/s, the degree of brush electroplated Ni （200） preferential orientation gradually decreases and that of （111） preferential orientation increases; the microhardness increases from HV420 to HV600, and mass loss decreases from 8.7rag to 6mg.