Effect of Nanoparticle Concentration on the Performance of Ni-Co-β-SiC Composite Coatings Electrodeposited on the Surface of Spindle Hook Teeth

Abstract

This study aimed to improve the surface hardness and wear resistance of spindle hook teeth with special shapes to reduce the cost of replacing the spindle on cotton pickers. For this goal, a Ni-Co-β-SiC composite coating with different concentrations of β-SiC nanoparticles (0, 1, 2, 3, and 4 g/L) was electrodeposited on the surface of spindle hook teeth. The hardness, elemental composition, and micromorphology of the spindle hook teeth were characterized by microhardness tests, an energy spectrum analyzer, and a scanning electron microscope after cutting with the spindles. The actual wear process of the coating was determined by wear simulation and scratch wear tests, and the effect of the concentration of β-SiC nanoparticles on the properties of the coating was investigated. The results show that Ni-Co-β-SiC composite coating has a typical cellular structure. The hardness first increases and then decreases, and the wear resistance (including friction coefficient, scratch area, and shape of wear area) first decreases and then increases, mainly due to the pinning role and agglomeration of β-SiC nanoparticles. When the concentration of β-SiC was 1 g/L, the hardness reached a maximum of 506.2 HV0.1, the coefficient of friction reached a minimum of 0.13, and the wear area and wear micromorphology reached the most suitable values. Therefore, this Ni-Co-β-SiC composite coating had the best microhardness and wear resistance.