Plasma sprayed TiC-Ti5Si3-Ti3SiC2 composite coatings from Ti-SiC-graphite powders with different SiC particle size

The TiC-Ti5Si3-Ti3SiC2 coating was successfully prepared by reactive plasma spraying with agglomerated Ti-SiC-graphite powders as raw material. The effect of SiC particle size on the microstructure and properties of plasma sprayed TiC-Ti5Si3-Ti3SiC2 coating was studied. The results were that, as the size of SiC particles decreased, the TiC content of the reaction product phase increased, while the content of Ti5Si3 and Ti3SiC2 decreased. Compared to coarse SiC, the coating prepared with fine SiC as the raw material had a reduced surface roughness, the highest density, (porosity:11.76%), and highest hardness, (1132 HV0.2). In addition, the coating prepared with small size SiC exhibited more uniform elemental distribution. Moreover, it had the best wear resistance with a weight loss of 0.4 mg, which was similar to 1/40 of 45 steel substrate.