Abstract:
In this paper,TiC/Ni-Ti inter-metallic compound coatings with a metallurgical bond between a coating and mild steel substrate were prepared by reactive braze coating (RBC) of the mixed titanium, nickel and Carbon powder in vacuum braze furnace. The phases, microstructure and composition distribution of alloy coatings were studied by means of scanning electron microscopy (SEM), energy dispersive spectrum (EDS), X-ray diffraction (XRD) and through hardness testing. The results show that the microstructure of the composite coatings is made up of NiTi
2, NiTi, TiC and hcp-Ti phases, and that of the interface is composed by NiTi and hcp-Ti phases, while TiC distributes in the mid-layer of the coatings. The phases of NiTi
2, NiTi and TiC in the coatings were in-situ synthesized during braze coating process.With the raising of the carbon content,the content of NiTi and TiC increases,but the surface hardness of the coatings shifts negligibly, which is high up to 60HRC.