In-situ synthesis of TiC/graphene/Ti6Al4V composite coating by laser cladding

•The graphene reacted with Ti, and the TiC phase precipitated during laser cladding.•The formation mechanism of TiC phase has been revealed.•The interface of graphene/Ti6Al4V composite coating is well bonded by in-situ reactive. Graphene reinforced Ti6Al4V composite coating was prepared by laser cladding, and the microstructure of the composite coating was studied. The results show that in-situ synthesis between graphene and Ti occurred during the laser cladding process, and the feathery TiC was formed. The TiC is homogeneously distributed between α′ acicular martensite. When the carbon content is 0.5%, it is the hypoeutectic composition. During the solidification process, the β-Ti was formed firstly. With further cooling of the alloy, the eutectic reaction occurred in the remaining liquid phase, and the β-Ti and TiC were formed. Then β-Ti was transformed to α′ acicular martensite. There are still some graphene in the graphene/Ti6Al4V composite coating, which is well combined with Ti6Al4V matrix.