Residual stresses of α-Al2O3/Ni nano-composite coating prepared by automatic brush plating technique

Brush plating is one of the remanufacturing technologies which have been widely used in engine remanufacturing. In this paper, α-Al2O3/Ni composite coatings were prepared on the inner hole face of the big end of connecting rod by a self-made automatic plating machine. To investigate the effects of process parameters on residual stresses of α-Al2O3/Ni composite coating, a L16(44) orthogonal experiment was designed and operated in which four process parameters (voltage, concentration of α-Al2O3 particles, speed, and distance between anode and workpiece) were selected as factors. ANOVA (analysis of variance) were employed to determine the effects of process parameters on the residual stresses of composite coatings. It was found that speed was the most significant factor for the residual stresses. The optimal process parameters for the desirable residual stresses were obtained, which was proved to be valid by the verification experiments. In addition, single factor experiments were employed to study the main effects of sprocess parameters on composite coatings.