Mechanical Characterization of Laser Surface Alloyed Zinc on Aluminium

Laser surface alloying of commercial pure aluminium with alloying elements finds application in automobile and aerospace industry. Mechanical characterisation study necessitates to understand the micro structural modification and mechanical behaviour on thin film of coated alloy to know the stability in terms of wear and corrosion characteristics. In this study, aluminium was coated with zinc using continous wave CO2 laser power. After alloying, it was observed that there is an improvement in hardness and scratch resistance because of the formation of intermetallics. The effect of laser energy density on surface hardness was investigated. The coefficient of friction was less for AlZn alloy and it was decreasing with increased scratch load from 20_ 70 N. The formation of refined grain structure and sound metallurgical alloying, the microstructure had contributed for surface scratch damage resistance.