Microstructure and Tribological Properties of Plasma Cladding FeCoNiCr-x(TiC) Composite Coatings

FeCoNiCr+x(TiC) (x: mass fraction; x = 5, 10, 15, respectively) composite high-entropy alloy (HEA) coatings were fabricated by the plasma cladding method, aiming to investigate the effects of different mass fractions of TiC ceramic particles on the phase composition, microstructure evolution, hardness, and wear resistance performance of HEA coatings. The results showed that the FeCoNiCr coating consisted of a single FCC phase, and FeCoNiCr-TiC coatings consisted of FCC, TiC, and carbide phases. The Vickers hardness of the FeCoNiCr-TiC coatings increased with additional TiC ceramic particles, and was raised from 150 to 365 HV when the added TiC powder mass fraction was 15 wt.%. The coating with the highest hardness had the lowest mass loss of 1.8 × 10-6 (mm3/N × m), which is only 11% of the FeCoNiCr coating. However, cracks appear on the surface after wear. The number of the wear particles was relatively reduced when the TiC content in the coating was 10% wt.%, while the surface did not show any microcracks. The wear mechanisms of the FeCoNiCr-TiC coating were adhesive wear and abrasive wear.