The Effect of SiC Content on the Microstructure and Mechanical Properties of AlCoCrFeNiTi Laser Cladding High-Entropy Alloy Coatings

45 steel is widely used in manufacturing industry, but the properties of 45 steel sometimes fail to meet the requirements of special applications. High-entropy AlCoCrFeNiTi coatings with different SiC contents (0, 10, 20, and 30 wt.%) were deposited on 45 steel substrates by laser cladding technology. With the increase in SiC content, the coatings consisted of BCC1 + BCC2 phases when the SiC content was 0 and 10 wt.% and TiC and Ni4Ti3-reinforced phase + BCC1 when the SiC content was 20 and 30 wt.%, respectively. The microhardness and wear resistance of the coating increased with increasing SiC content. When the SiC content was 30 wt.%, the average hardness of the cladding coating was maximum 943HV0.3, which is about 3.7 times that of the substrate, and the coating possessed the lowest wear mass loss and friction factor. The wear mode changes from adhesive wear and oxidative wear to abrasive wear as the SiC content increased.