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The present paper reports studies of pulsed Nd:YAG laser surface  alloying of AZ31 magnesium preplasma sprayed with nickel 5% aluminum powder. Mechanical properties like microhardness and wear resistance as well as corrosion resistance of the surface alloyed layers are studied. Detailed characterization of the laser surface alloyed layers regarding microstructure and phase analysis revealed formation and distribution of Mg2Ni  intermetallic phase in grain refined α-Mg matrix. Microhardness test demonstrated that hardness of the alloyed layer increased to 290 HV as compared with 55 HV of the AZ31 base material. Furthermore, pin on disk wear test and Tafel polarization measurement showed that laser surface  alloying with nickel led to a considerable improvement in both wear and corrosion resistance for AZ31 magnesium.

The bead on plate welding specimens with the 1mm thickness was fabricated by Nd:YAG pulsed laser SW-1 . The effects of laser process parameters on the weld dimensions, metallurgical and mechanical properties of weld metal were investigated. The results showed that both weld depth and weld width increase with voltage. Unlike base metal that has coaxial grain structure, weld metal is composed of a dendritic structure. Grain growth in the heat affected zone did not occur. However, ultrafine precipitations were deposited at the HAZ which their size was approximately between 500 nm to microns. All tensile specimens failed in the fusion zone.

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