Effect of mechanical attrition on microstructure and property of electroplated Ni coating
(1. School of Materials Science and Technology, Liaocheng University, Liaocheng 252059, China;
2. Liaocheng Research Institute of Nonferrous Metals, Liaocheng 252059, China)
2. Liaocheng Research Institute of Nonferrous Metals, Liaocheng 252059, China)
Abstract: Ni coating was deposited on carbon steel by a mechanical attrition enhanced electroplating (MAEE) process. During the electroplating, the mechanical attrition(MA) was introduced by impact of glass balls on the sample surface with a special vibrating frequency. The surface and cross-sectional images of Ni coating were observed with SEM. The microstructure and crystallinity of coating were examined with TEM and XRD. The electrochemical performance of coating was measured with polarization curves and electrochemical impedance spectroscopy (EIS) and its mechanical behaviours, such as tensile strength and hardness, were studied. The results show that the MA has significant effects on the microstructure and property of the electroplated Ni coating. By MA, the coating becomes smooth, compact, thin and has refined grains and is free of cracks and pores. Consequently, the adhesion, tensile strength, hardness and corrosion resistance of coating are improved significantly.
Key words: electroplating; mechanical attrition; Ni coating; corrosion resistance