Effect of laser parameters on properties of surface-alloyed Al substrate with Ni

Experimental investigations were carried out to examine the influence of the spot size and peak-power density of a pulsed Nd:YAG laser on the depth of the alloyed layer, the microstructure and the hardness in laser surface alloying of Al with Ni. It was found that the effect of both the peak-power density and the amount of energy absorbed from the laser beam on the depth of the alloyed layer and hardness must be considered simultaneously. In this work, the hardness of the alloyed layer was found to be 10–15 times the value for base Al.