Friction and wear properties of amorphous Ni-P coating prepared by electroless plating

Amorphous Ni-P coating was prepared on the surface of 5052 aluminum alloy by electroless plating, the morphologies, compositions and phases of the coating were analyzed and characterized with SEM, EDS and XRD, respectively. The friction coefficients and wear performances of Ni-P coating and 5052 aluminum alloy were investigated with wear test, the wear resistance mechanism of Ni-P coating was discussed. The results show that Ni-P coating by chemical plating is composed of atom clusters with the diameter of 10-50 μm, which can cover the substrate completely; the surface micro-hardness is 370.5HV. Ni-P coating is well bonded with the substrate, and the coating thickness is about 20 μm. Ni-P coating is composed of Ni and P atoms, in which the bonding energy of Ni atom is 853.34 eV, while that of P atom is 133.02 eV. The friction coefficient of Ni-P coating is 0.4556, the wear mass loss decreases by 83.5% compared with that of the substrate, and the wear mechanism is abrasive wear. The micro-crack initiation and propagation are produced and peeled at the wear edge, and the coating is not worn out, showing good wear performances.