In-situ formation of TiC particles reinforced Ni_3(Si,Ti) composite coating produced by laser cladding

The laser cladding technique was used to form Ni3(Si,Ti) composite coating reinforced by in-situ formation TiC particles on GH864 Ni-based alloy substrate.By means of SEM,EDAX and XRD,the effect of(Ti+C) addition on the microstructure and microhardness of the coating was investigated.The experimental results show that an excellent bonding between the coating and the substrate can be ensured by the strong metallurgical interface.The clad coating is very good and free from cracks and pores.The microstructure of the coating is mainly composed of Ni(Si),Ni3(Si,Ti) and TiC.The average microhardness of the coating is improved in terms of addition quantity of TiC in coating structure.When the addition quantity of(Ti+C) is 20wt%,the microhardness of coating was up to 780Hv that is 2.4 times of the substrate.