Comparison of Structure and Properties of Mo(2)FeB(2)-Based Cermets Prepared by Welding Metallurgy and Vacuum Sintering

At present, most Mo(2)FeB(2)-based cermets are prepared by vacuum sintering. However, vacuum sintering is only suitable for ordinary cylinder and cuboid workpieces, and it is difficult to apply to large curved surface and large size workpieces. Therefore, in order to improve the flexibility of preparing Mo(2)FeB(2) cermet, a flux cored wire with 70% filling rate, 304 stainless steel, 60 wt% Mo powder and 40 wt% FeB powder was prepared. Mo(2)FeB(2) cermet was prepared by an arc cladding welding metallurgy method with flux cored wire. In this paper, the microstructure, phase evolution, hardness, wear resistance and corrosion resistance of Mo(2)FeB(2) cermets prepared by the vacuum sintering (VM-Mo(2)FeB(2)) and arc cladding welding metallurgy method (WM-Mo(2)FeB(2)) were systematically studied. The results show that VM-Mo(2)FeB(2) is composed of Mo(2)FeB(2) and γ-CrFeNi.WM-Mo(2)FeB(2) is composed of Mo(2)FeB(2), NiCrFe, MoCrFe and Cr(2)B(3). The volume fraction of hard phase in WM-Mo(2)FeB(2) is lower than that of VM-Mo(2)FeB(2), and its hardness and corrosion resistance are also slightly lower than that of VM-Mo(2)FeB(2), but there are obvious pores in the microstructure of VM-Mo(2)FeB(2), which affects its properties. The results show that WM-Mo(2)FeB(2) has good diffusion and metallurgical bonding with the matrix and has no obvious pores. The microstructure is compact and the wear resistance is better than that of VM-Mo(2)FeB(2).