LAUSR

Abstract In the present work, Ni-based plasma sprayed coating was prepared on the surface of AISI 1045 steel and subsequently remelted by induction heating method. On base of this, the rolling/sliding contact fatigue behaviors of the two coatings under different contact stress were studied. The results indicated that, the induction remelting improved the microstructure and microhardness of the coating, and changed the bonding form between the coating and the substrate from mechanical bonding to metallurgical one. The rolling/sliding contact fatigue performance of the sprayed coating was very poor and interfacial delamination was the only failure mode. However, that of the remelted coating was remarkably superior to the sprayed coating. Moreover, with the increase of contact stress, the fatigue life of the remelted coating decreased, but its Weibull distribution of fatigue life became more concentrated. The main failure modes of the remelted coating under different contact stress were pitting and spalling. The failure mechanism of the sprayed coating was that the weak interface bonding and the combined action of residual stress and shear stress resulted in the interfacial delamination. For the remelted coating, pitting was attribute to the combined action of contact stress and high-pressure oil wave, while the spalling resulted from the synergistic action of the residual stress and shear stress.