Microstructures and Properties of Laser Cladding Coating of Ti-base on Magnesium Alloy Surface of Computer Components

AZ91D magnesium alloy used in computers and mobile communications. For the purpose of improving the surface properties on AZ91D magnesium alloy, Ti-based coating have been deposited on the surface of AZ91D magnesium alloy with 6 kw continuous CO2 laser. The coating microstructure, feature and distribution of element in binding region were studied with optical microscope and EDS analysis. The hardness, wear resistance and corrosion resistance of Alloy layer have also been tested. Results show that alloy layer and matrix well combined, There is no obvious boundary of element distribution. It was found that there are TiBx, B4Si compounds produced with XRD analysis. It was found that the average micro hardness value increased 625 HV0.05, wear resistance doubled, dynamic corrosion potential of polarization curve increased 0.194 V, density of corrosion current decreased 0.093 A/(cm2). Corrosion resistance increased about 96 % in 3.5 % NaCl solution by testing the performance of the cladding layer and the substrate.