Abstract:
A kind of Fe-based ceramic coatings with ZrB
2 and ZrC as multi scale strengthening phases on the surface of Q235 steel were fabricated by plasma cladding using Fe, Zr, and B
4C powder mixture as precursor. The phase composition, microstructure, microhardness and the wear resistance comparative test of ZrB
2-ZrC/Fe coating and Q235 steel were investigated. The microstructure evolution, the formation of the phase and the wear mechanism were discussed. The results show that ZrB
2-ZrC/Fe coatings are composed of ZrB
2, ZrC, α-Fe, Fe
3C and Fe
2B phases. ZrB
2 phase presents acicular, clubbed and petal forms. ZrC phase is irregular polygon shape. With the increasing of (Zr+B
4C) raw powder, the contents of ZrB
2 and ZrC are increasing, the size of ZrB
2 and ZrC become large. The plasma clad ZrB
2-ZrC/Fe composite coating is closely and metallurgically bonded to the Q235 steel substrate. Compared with Q235 steel substrate, the wear resistance of the coating is improved significantly, up to 5.45 times than that of the substrate. The main wear mechanism of ZrB
2-ZrC/Fe composite coating is abrasive wear, the main fracture mode of the composite coating is transgranular fracture.