Novel investigation on tribological properties of Ni-P-Ag-Al ₂O₃ hybrid nanocomposite coatings

In this research, silver and alumina particles were co-deposited within Ni-P matrix to obtain Ni-P-Ag-Al₂O₃ hybrid coating. The structure of coatings was analyzed by X-ray diffraction and the tribological properties of deposits were evaluated by pin on disc tribometer. 3D optical profiler and scanning electron microscopy were used to study wear rate and worn surfaces. The results showed that Ni-P-Ag and Ni-P-Ag-Al₂O ₃ coatings have the self-lubrication property and maximum hardness (∼1310 HV) and wear resistance were obtained for Ni-P-Al₂O ₃ coating. Also, Ni-P-Ag-Al₂O₃ hybrid nanocomposite coating had higher wear resistance than Ni-P and Ni-P-Ag coatings. Moreover, the best conditions was achieved for heat treated hybrid coating in the concentration of 30 mg/L silver and 150 mg/L alumina in the plating solution.