Fe-Co-based coating with high hardness and high saturation magnetization deposited by co-axial powder feeding plasma transferred arc welding

Abstract

Fe-Co-based monolayer coating with extremely high saturation magnetization (Ms) exceeding 1.9 T was deposited on AISI 1010 substrate by a co-axial powder feeding plasma transferred arc welding (PTAW), using (Fe0.8Co0.2)85B14Si1 feedstock powders. The phase composition, microstructure, microhardness and magnetic properties of the coating were investigated. The results show that the coating has a dendrites-eutectics composite structure, the columnar or equiaxed sorbitic pearlite dendritic cores surrounded by network-like eutectics (α-Fe + Fe2B). The body-centered cubic (BCC) α-Fe contributes to a high Ms of 1.92 ± 0.005 T, and Fe2B in eutectics causes a high coercivity (Hc) of 49.2 ± 0.2 Oe and a higher microhardness HV0.3 (>4.60 GPa). This work reveals the potential of fabricating Fe-Co-based soft magnetic alloy with high hardness and high Ms via PTAW.