Laser in-situ preparation and mechanical properties of VC reinforced Fe-based wear-resistant composite cladding

In this paper, the in-situ VC reinforced Fe-based composite cladding was experimentally fabricated on 45 steel surface by laser cladding using the mixture of FeV 50 and B 4 C with different contents (10–30 wt%). The formation mechanism of composite cladding and effect of B 4 C content on its wear resistance were investigated through first-principles calculations. The experimental results show that the volume fraction of in-situ formed VC particles increases continuously with increasing B 4 C content. The microhardness of composite cladding increases significantly, and it reaches to 1653.7 HV 0.5 when the B 4 C content is 30 wt%. Meanwhile, the friction coefficient of composite cladding decreases with increasing B 4 C content, and the wear mode gradually changes from adhesive wear to abrasive wear, indicating the enhanced wear resistance of composite cladding. The first-principles calculations results show that the in-situ formed VC and Fe 2 B are both hard and brittle phases, and the VC and Fe 2 B can exist stably in the composite cladding. The interface between VC and Fe matrix is well bonded, and the interfacial separation work is calculated as 5.516 J/m 2 , which mainly attributes to the bonding characteristics of mixed ion-covalent bonding interactions between Fe and C atoms located at interface.