| The magnetic properties of sintered Fe-Si alloys were investigated as function of composition, sintering temperature, and particle size and source of iron powder and silicon powder. Measurements of maximum permeability (μ_(max)) and coercive force (Hc) were performed with hysteresis-graph tracer. The lowest H_c and highest μ_(max) were found in specimen containing 3wt.% Si. It can be explained in terms of the intrinsic parameter K₁/M_5 and sinterability, i.e., the higher the silicon content the lower the value of K₁/M_5 but the lower the sinterability. Prealloyed silicon-iron powder, having lower melting temperature, enhanced sintering but decreased the μ_(max) and increased H_c due to the presence of fine pores in the grain. The μ_(max) and H_c were also affected by the particle size of the iron powder used. Thus the best magnetic properties were found in specimen containing 3wt.% Si prepared from fine carbonyl iron powder and pure silicon powder, sintered at 1450℃ in dry hydrogen. |
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