Formation of continuous surface Al–SiC p metal matrix composite by overlapping laser tracks on AA6061 alloy

Although metal matrix composite (MMC) layers have been successfully produced by a single laser track on aluminium alloys, a critical step in the application of this technique in industry is overlapping of the laser tracks to produce an MMC layer on specific areas of materials. The present work investigated overlapping laser tracks using prep laced SiC p and a mixture of SiC p and aluminium powder preplaced on AA6061 aluminium alloy surfaces, and describes the success achieved in both situations. The dependence of the surface smoothness on the overlapping technique, microstructures, and phases formed in the laser processing was studied. The effect of the spacing of two overlapped laser tracks is discussed and the laser processing conditions considered. In addition, post heat treatment on the laser glazed material was found to give rise to a significant increase in the hardness and the abrasive wear resistance of the MMC layer. MST/3236