Study of In-situ Synthesis TiCp/Ti Composite Coating on Alloy Ti6Al4 V by TIG Cladding

The composite coating reinforced by TiC particle was in-situ produced on the surface of TC4 Ti alloy by means of TIG cladding technique with powder-filled cored wires (Ti-strip to wrap powder of Ti, C and Al). The microstructure and composition modifications in the surface layer were carefully investigated by using SEM, EDX and XRD. The results showed that a good metallurgical bond between the coating and the substrate can be achieved; the coating is uniform, dense, continuous and almost defect-free; the particles by in-situ synthesis are dispersedly distributed in the cladded coating; TiC has there different shapes: dendritic shape, shore-bar and equiaxed or near-equiaxed shape. The microhardness of coating was irregular and the maximum value was approximately 1300 HV0.5, about 6.5 times of the initial one.