Effect of Laser Power on the Microstructure of Ni-P Layer Deposited on Aluminum Substrate

Abstract

Laser processing of Ni-P layer electroless deposited on aluminum substrate was carried out by Nd-YAG pulsed laser. Different laser processing parameters were selected. When lower laser power density was employed, the modified Ni-P layer was obtained, however, when employed laser power density increased, laser alloying of Ni-P layer with aluminum substrate occurred. The characteristic dendritic or lamellar microstructures were observed in the alloyed layer. The phase constituents of the alloyed zones determined by X-ray diffraction are consisted of nickel-aluminum intermetallic compounds NiAl, Al3Ni and Al3Ni2, as well as some non-equilibrium phases, depending on the employed laser power density.