The influence of WC content on the microstructure and properties of laser cladding CoCrFeMnNiSi1.6 high-entropy alloy coatings

In order to deeply investigate the influence mechanism of different contents of ceramic reinforced phase WC on the microstructure, microhardness, wear resistance and corrosion resistance of high-entropy alloy composite coatings. CoCrFeMnNiSi1.6-(WC)x high-entropy alloy composite coatings were prepared on the surface of AISI 1045 steel by laser cladding technique. The results showed that the coating without added WC particles consisted of FCC phase, silicide phase and BCC phase structure. The carbide phase started to appear in the coating after the addition of WC particles. The microhardness of the coatings increased gradually with the increase of WC content, and the average hardness of the composite coatings reached the highest when 40 wt% of WC particles were added, which was 782.2 HV0.5, an increase of 52 % compared with the WC0 coatings without added WC particles. With the addition of WC particles, the wear resistance of the high-entropy alloy composite coatings gradually increases and then decreases.WC3 has the lowest coefficient of friction, which is 9.23 % lower compared with the WC0 composite coating without added WC. With the addition of WC particles, the corrosion resistance of the coatings first gradually increased and then decreased. When 30 wt% of WC particles were added, the passivation film on the surface of the coating was the most stable and dense with the best corrosion resistance. The results of this paper provide a theoretical basis for the preparation of high-entropy alloy composite coatings doped with ceramic reinforced phase WC.