Characterization and performance of laser melted AZ91D and AM60B

Laser melting can be used to alter the surface of alloys and produce a fine microstructure, usually improving corrosion resistance. In the present work, a pulsed Nd:YAG laser was used to melt and rapidly quench the surface of die cast AZ91D and AM60B magnesium alloys with the objective of improving the corrosion resistance in salt-water (NaCl) solution. The corrosion of AZ91D and AM60B was not significantly reduced by laser melting even though the microstructure of both alloys was refined but a close examination of corroded surfaces gave indications about some corrosion enhancing factors. The physical aspect of corroded surfaces and the microstructure of laser melted specimens are presented along with the results of corrosion tests.