Abstract:
A specified amount of rare earth cerium oxide (CeO
2) and graphene oxide (GO) was incorporated into the Watts nickel-type plating solution to facilitate the preparation of a Ni-GO-CeO
2 plating on the TC4 titanium alloy substrate. The study focused on the influence of rare earth CeO
2 on the microstructure, grain size, microhardness, and friction and wear properties of the composite plating layer. The findings indicate that as the concentration of CeO
2 increases, the presence of holes and cracks in the plating layer significantly decreases. Notably, the imperfections in the plating layer were completely eliminated when the CeO
2 content reached 3wt%. However, further increasing the CeO
2 content beyond 3wt% leads to the agglomeration of CeO
2 within the plating layer, which subsequently results in the reappearance of holes and cracks. XRD analysis and microhardness test results indicated that when the CeO
2 content was 3wt%, the composite plating exhibited the smallest Ni grain size at 42 nm, which is 28% smaller than that of the undoped CeO
2 layer. Correspondingly, the microhardness peaked at 384.84 HV, marking a 15.83% increase compared to the undoped CeO
2 layer. However, with further CeO
2 doping beyond 3wt%, there was an increase in Ni grain size and a decrease in microhardness. The friction characteristics of the composite plating revealed optimal performance when the CeO
2 content was 3wt%. At this concentration, the friction coefficient reached its lowest value at 0.225, which is 24.24% lower than that of the undoped CeO
2 plating, with only slight abrasive wear observed. However, increasing the CeO
2 content beyond 3wt% led to a deterioration in the friction performance of the plating.