Microstructure and Dry-Sliding Wear Resistance of CoCrFeNiMoTix High Entropy Alloy Coatings Produced by Laser Cladding

The new-type CoCrFeNiMoTix high-entropy alloy coatings were successfully devised and prepared on Q235 steel using laser cladding. Influence of Ti content on their microstructure and wear-resistance was studied systematically; the relevant mechanisms were deeply revealed. The CoCrFeNiMoTix coatings consisted of NiTi, FCC, and BCC phases, and with the increasing of Ti content, contents of BCC phase and FCC phase gradually increased and decreased, respectively. The CoCrFeNiMoTi0.75 coating had the highest hardness (950 HV), which was about 6.5 times higher than the substrate (Q235 steel, 150 HV). According to Archard law, metal materials’ wear resistance is generally proportional to hardness; thus, the CoCrFeNiMoTi0.75 high entropy alloy coating with the highest hardness showed the best wear resistance, exhibiting a wear mechanism of slight abrasive wear.