Preparation of Al/SiC Composite Coatings on the Surface of Aluminum Alloy Through Atmospheric Plasma Spraying

In this work, Al/SiC composite coatings were deposited on the surface of aluminum alloy through atmospheric plasma spray. The effects of SiC volume in Al/SiC composite powders on the deposition behavior and the properties of the Al/SiC coatings were investigated. It was found that there were decomposition and oxidation during the deposition of pure SiC powders in the plasma flame. With the increasing of SiC contents, the deposition of the Al/SiC composite powder became harder through plasma spray. There were cracks between pure SiC and Al alloy substrate for the poor adhesion between them. The hardness of the composite coating became higher with the increasing of SiC contents. The composite coating with the volume proportion of 25:75(Al:SiC) exhibited a hardness of 880 Hv and took the effects of strengthening and protection on the surface of Al alloy.