Effect of Laser Heat Treatment on Mechanical Property of NiW/Ni Coating Electrodeposited on Copper Substrate

Abstract

In this paper, NiW/Ni duplex coating is electrodeposited on the surface of copper substrate. The laser heat treatment technology is used to greatly improve the mechanical property of NiW/Ni duplex coating. The electrodeposition of NiW belongs to induced codeposition. NiW is a kind of alloys with tungsten as solute and nickel as solvent that belongs to the face-centered cubic structure with granular morphology. Tungsten doped into the crystal lattice of nickel can effectively refine grain size. The laser beam has high energy density, and the instantaneous high temperature can reduce the residual stress and improve the hardness of the coating. Moreover, the coating is cooled quickly after laser scanning, which helps to refine the grain size. The NiW/Ni duplex coating after laser heat treatment has the best hardness and optimal mechanical property.