Characteristics and performance of hard Ni60 alloy coating produced with supersonic laser deposition technique

摘要

A novel coating fabrication technique, known as supersonic laser deposition (SLD), which combines cold spray (CS) with laser technology, is applied to produce hard Ni60 (58-62 HRC) coating on medium carbon steel (AISI 1045 steel) substrate. Different process parameters are investigated to obtain the optimal. The Ni60 coating specimens prepared by SLD process are studied microstructurally using scanning electron microscope (SEM), energy dispersive spectrum (EDS) and X-ray diffraction (XRD). The microstructures of the coatings are compared with those of the coatings produced using laser cladding (LC). The hardness, tribological property and corrosion resistance of the Ni60 coatings produced by SLD and LC with the optimal process parameters are evaluated under Vickers hardness, pin-on-disk wear and electrochemical corrosion tests. It is demonstrated that the Ni60 coating with SLD exhibits some characteristics, such as fine microstructure as cast, stable phases and less dilution; it surpasses the coating produced with conventional LC process in sliding wear resistance; but in 1 mol/L H_2SO_4 solution, the SLD and LC coatings performed similarly in corrosion resistance. This research has proved that SLD technique enables depositing hard Ni60 on steel substrate, which is impossible for CS technique.