Permalloy refers to an iron-nickel alloy with a wide range of nickel content, ranging from 35% to 90%. The biggest feature of Permalloy is its high magnetic permeability in weak magnetic fields. Their saturation magnetic induction intensity is generally between 0.6-1.0T.
China's Permalloy grade is 1JXX, where J means "precision alloy", "1" means soft magnetic, followed by a number for the serial number, usually indicates the nickel content of the alloy. For example, 1J50, 1J851 and so on. Perm alloy has high permeability, so it is often used in the core of medium and high frequency transformers or devices with strict requirements for sensitivity, such as high frequency (tens of kHz) switching power transformers, precision transformers, leakage switching inductors, magnetic shielding, yokes and so on.
Permalloy can be divided into 4 categories according to composition: 35%~40% Ni-Fe alloy, 45%~50% Ni-Fe alloy, 50%~65% Ni-Fe alloy and 70%~81% Ni-Fe alloy . Each type can be made into materials with circular hysteresis loop, rectangular hysteresis loop or flat hysteresis loop.