Ni-Mn系新高透磁率合金「Nimalloy」の特性におよぼすGe添加の影響について

抄録

Masumoto et al. previously discovered that alloys near in composition to Ni₃Mn exhibited a high magnetic permeability when these alloys had an optimum degree of order, and named them “Nimalloy”. A great deal of works have since been carried out on the effects of additions of various elements on the properties of nickel-manganese alloys, and consequently the highest initial permeability of 76000 and the highest maximum permeability of 441000 have been obtained.
In the present study additions of germanium to nickel-manganese alloys showed that the initial and maximum permeabilities of nickel-manganese alloys increased gradually at the beginning and then rapidly attained a maxima, and afterwards decreased gradually. The highest initial permeability of 15180 was obtained on the alloy of 77.89%Ni, 17.98%Mn and 4.13%Ge when cooled at a rate of 240°C/hr from 900°C and reheated at 400°C for 10 hr, and the highest maximum permeability of 167000 on the alloy of 78.27%Ni, 17.11%Mn and 4.62%Ge when cooled at a rate of 240°C/hr from 900°C and reheating at 400°C for 8 hr. The latter alloy shows a coercive force of 0.0046 Oe and a magnetic hysteresis loss of 12.58 erg/cm³/cycle for the maximum magnetic induction of 2000 G, and its electrical resistivity being 65.4 μΩ-cm at 20°C.