Development and characterization of composite Ni–Cr–C–CaF2 laser cladding on γ-TiAl intermetallic alloy

A process of laser cladding Ni–Cr–C–CaF2 mixed powders to form a multifunctional composite coating on γ-TiAl substrate was carried out. The microstructure of the coating was examined using XRD, SEM and EDS. The coating has a unique microstructure consisting of primary dendrite or short-stick TiC and block Al4C3 carbides reinforcement as well as fine isolated spherical CaF2 solid lubrication particles uniformly dispersed in the NiCrAlTi (γ) matrix. The average microhardness of the composite coatings is approximately HV 650 and it is 2-factor greater than that of the TiAl substrate.