Effect of B-Si ratio and laser remelting on the microstructure and properties of Fe10Co10Ni10Cr4Mo6B Si10- coating by laser cladding

High-entropy alloy coating has huge potential application values in improving the service life of the friction parts. The effects of the B-Si ratio and laser remelting on the microstructure, phases, mechanical and wear properties of the laser cladding Fe 10 Co 10 Ni 10 Cr 4 Mo 6 B x Si 10- x coatings were investigated. When x equals 10, the coating crystalizes in a FCC structure together with lots of M x B phases. Si element adding promotes the formation of BCC phase of Fe 10 Co 10 Ni 10 Cr 4 Mo 6 B x Si 10- x coatings with the appearance of new M x Si and M x BSi y phases, but prevents the formation of M x B and M x BSi y with the decrease of B-Si ratio. When x drops to zero, the microstructure of the coating transforms into a BCC with tiny amounts of FCC and M x Si phase. With the increase of Si element content, M x (B, Si) standing for any combination of M x B, M x Si and M x BSi y phases decrease. The lowest friction coefficient (0.3786) and wear volume loss (2.46 × 10 6 μm 3 ) show that Fe 10 Co 10 Ni 10 Cr 4 Mo 6 B 5 Si 5 coating has the best wear resistance because of a higher toughness and values of H/E and H 3 /E 2 . Laser remelting once reduces the component segregation of the coating, and promotes the formation of BCC and M x (B, Si) phases. The wear resistance of the coating increases with the improvement of its wear characteristics (H/E, H 3 /E 2 and η). However, when the coating is remelted twice, the wear resistance decreases due to the drop of the hardness and wear characteristics attributed to the dominant position of FCC structure. Fine and uniform microstructure, and proper proportion of hard phases (BCC and M x (B, Si)) and soft phase (FCC) can increase the mechanical properties and wear resistance of Fe 10 Co 10 Ni 10 Cr 4 Mo 6 B x Si 10- x coatings. • The ratio of B Si affects the phase composition of the coating structure. • Laser remelting times can change the main phase of the coating structure. • The proportion of FCC, BCC, and M x (B, Si) phases affect the hardness of coating. • The properties depend on the microstructure and proportion of the phases.