Dry sliding wear behaviour and structural characteristics of laser-annealed electroless Ni-P/Ni-Mo-P duplex coatings

This paper aims to investigate the effect of laser annealing on tribological properties of electroless Ni-P/Ni-Mo-P duplex coatings under dry-sliding condition. The microstructures were examined in terms of grain size, phase transformation and surface roughness. The results show that laser annealing improves wear resistance of the duplex coatings. The tribological behaviour of the Ni-Mo-P outer layer exhibits abrasive wear in the form of micro-furrow and micro-fracture, and controlled by the combined effect of roughness, hardness and microstructures. The wear process of the inner layer is affected by the structural characteristics of the peel-off outer layer and inner layer as well as the hardness.