Fe-Ni-Si系状態図ならびにセンパーム合金に現われる3元化合物σ相について

抄録

By means of microscopic observation as well as magnetic and dilatometric analyses, the constitution of ternary alloys of iron-rich Fe-Ni-Si system was investigated and its equilibrium diagram concerning solid phase reaction was determined. The σ-phase, reported on in the previous paper⁽¹⁾, was found to be ferromagnetic and formed by a peritectoid reaction α+γ→σ, having a maximum temperature at about 920°C, at an original composition of about 29%Ni, 11%Si and 60%Fe, corresponding to the chemical formula Fe₁₁Ni₅Si₄, after solidifying through an eutectic reaction, Melt→α+γ. It was also found that the composition of a constant permeability alloy “Senperm” in this system, extends over such a region where it shows a homogeneous α-phase at higher temperatures and then precipitates σ-phase with lowering temperature owing to its solubility change; this fact seems to corroborate our reasonings in the 1st report.