A new magnetic alloy of high constant permeability

Several conventional alloys of constant permeability used previously were of lower values of permeability, or they would change obviously in different intensities of magnetic field and thus could not satisfy some specific requirements of electrical application. The alloys consisted of Ni 60-70 wt%, Fe 29-39wt% and Mn 0-1 wt% were investigated. The best of those alloys for certain use is 1J66 alloy in China. It is a new alloy of high constant permeability with the chemical composition as Fe 34 wt%, Ni 65 wt% and Mn 1 wt%. Its AC induction permeability
\mu_{L}= 3400
G/Oe (
f=60
Hz). Within the range of Bm=20-6800 G, the stability of AC induction permeability (
f=60
Hz)
\alpha_{\sim} = 4.3
%. The α is defined as
\alpha = \mu\max-\mu\min/\mu\min,\alpha\max
and
\mu\min
are the maximum and the minimum of permeability respectively in the range of given magnetic field. The temperature stability α
T
of μ
L
within the range of temperature from -60°C to +90°C is 2.9%. The saturation magnetic induction of 1J66 alloy equals 13500 G. The remanence
B_{r} < 150
G. The coercive force
H_{c} = 0.05
Oe. The oxygen content of 0.015- 0.04% in the alloy is considered necessary for obtaining a good stability of permeability.