Research on Warm Pressing Preparation and Soft Magnetic Properties Control of FINEMET Soft Magnetic Composites

The effects of forming temperature (T_c) and pressure (P_m), contents of lubricant (C_l) and binder (C_b) on the compacting density (ρ_c) and soft magnetic properties of FINEMET soft magnetic composites (FINEMET-SMCs) were systematically studied.The results show that a suitable warm pressing process can effectively improve the surface lubrication effect of magnetic powders in SMCs forming process, which is conducive to the reductions of non-magnetic porosity and the displacement resistance of magnetic domain wall in the corresponding SMCs, and finally contributes to the improvement of its soft magnetic properties. The hysteresis loss P_h plays a dominant role in the variation of total losses P_cv for the FINEMET-SMCs, wherein of P_h/P_cv > 76%.Compared with the T_c=25℃ working condition, under the optimized warm pressing process parameters of T_c=110 ℃, P_m=1200 MPa, C_l=1.5wt% and C_b=5.0wt%, the ρ_c of the FINEMET-SMCs increases by 7.7% to 5.44 kg/m³, and the SMCs exhibit excellent comprehensive soft magnetic properties.