Effects of Ti Addition on Microstructure and Tribological Properties of In Situ Composite Carbide Coating WC-TiC/FeNi Fabricated by Plasma Transferred Arc Metallurgical Reaction

The effects of Ti addition on the microstructure and tribological properties of in situ composite carbide WC-TiC/FeNi coating were studied using XRD, SEM, EDS, and friction and dry sliding wear tests. The results show that the composite carbide WC-TiC was successfully in situ synthesized in the coating, and with Ti addition increased by 0.1 from 0.1 to 0.4 wt.%, the in situ carbide TiC increased from 3.4 to 24.4 vol.%, while the carbide WC decreased from 32.5 to 24.2 vol.%, and the coating hardness increased from 1027 to 1196 HV_4.9. The friction and dry sliding wear tests show that for WC-TiC/FeNi composite coating, the addition of Ti can not only reduce the friction coefficient, the mass loss of both the coatings and its counterpart but also improve the friction stability, service life, and wear rate (WR). The relationship between the Ti addition and the coating wear rate fits the exponential decay equation WR = 10.6 − 0.089 \(\times\) e ^(Ti/0.098). The main wear mechanisms of in situ WC-TiC/FeNi composite carbide coating are abrasive wear, oxidative wear, and micro-plow wear.