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

Abstract

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 FeV50 and B4C with different contents (10–30 wt%). The formation mechanism of composite cladding and effect of B4C 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 B4C content. The microhardness of composite cladding increases significantly, and it reaches to 1653.7 HV0.5 when the B4C content is 30 wt%. Meanwhile, the friction coefficient of composite cladding decreases with increasing B4C 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 Fe2B are both hard and brittle phases, and the VC and Fe2B 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/m2, which mainly attributes to the bonding characteristics of mixed ion-covalent bonding interactions between Fe and C atoms located at interface.