Abstract: The influence of SPS sintering temperature on microstructure and magnetic properties of the sintering bulk alloy of melt quenching Fe₇₀Cr₈Mo₂Si₅B₁₅ powders by ball
milling and MA Fe_73.5Cu₁Nb₃Si_13.5B₉ and Fe₈₀Co₄Nb₇B₉ nanocrystalline powders was studied. The results show that (1) under 30MPa/5min
conditions, the relative densities of bulk alloys increase with the increase of sintering temperatures. When Fe₇₀Cr₈Mo₂Si₅B₁₅ bulk alloy
sintered at 1000℃, its relative density reaches above 99%, and when Fe_73.5Cu₁Nb₃Si_13.5B₉ and Fe₈₀Co₄Nb₇B₉
bulk alloys sintered at 1050℃, their relative densities reach to 99%; (2) the main phase of sintering bulk alloys is α-Fe phase, and a
little second phase intermetallic compound. The grain size of α-Fe phase in bulk alloys is in nanometer range, Fe₇₀Cr₈Mo₂Si₅B₁₅
bulk alloy has the finest grain size, its average grain size is about 50nm; (3) with the sintering temperature increasing, the specific saturate magnetization B_s of these bulk alloys increases and coercive
force H_c decreases, respectively. Fe₇₀Cr₈Mo₂Si₅B₁₅ bulk alloy has the lowest H_c, 4.1kA·m^-1.

Key words: Fe-based alloys, SPS sintering, nanocrystalline, magnetic properties