1J85 permalloy refers to iron nickel alloy, which has a wide range of nickel content, ranging from 35% to 90%. The biggest characteristic of permalloy is its high weak magnetic field permeability. Their saturation magnetic induction intensity is generally between 0.6 and 1.0T. It is an iron-nickel alloy with high magnetic permeability under weak magnetic fields. Nickel iron alloys with a nickel content of over 30% are single-phase, face centered cubic at room temperature（ γ) Structure, but the single-phase structure near 30% Ni is very unstable, so practical iron nickel soft magnetic alloys have nickel content above 36%. Iron nickel alloys contain around 75% nickel (atomic fraction), and in this single-phase alloy, Ni3Fe long-range ordered transformation occurs. At this time, the lattice constant and physical properties of the alloy, such as resistivity and magnetism, will change. Therefore, it is necessary to consider the impact of ordered transformation on performance. Usually, a small amount of additional elements such as Mo or Cu are added to Ni3Fe alloys to suppress the formation of long-range ordering.
1J85 permalloy can be divided into four categories based on its composition: 35% to 40% Ni Fe alloy, 45% to 50% Ni Fe alloy, 50% to 65% Ni Fe alloy, and 70% to 81% Ni Fe alloy. Each type can be made into materials with circular hysteresis loops, rectangular hysteresis loops, or flat hysteresis loops.
Chemical composition:
| % | P | S | Ni | Mu | Cu | C | Mn | Si | Fe |
| min | 79 | 4.8 | 0.3 | 0.15 | Remainder | ||||
| max | 0.02 | 0.02 | 81 | 5.2 | 0.2 | 0.03 | 0.6 | 0.3 |
Physical performance:
| density | melting point | tensile strengthσb(Mpa) | Elongation rate A5 % | hardness |
| 8.75 g/cm3 | 1395-1425℃ | ≥560 | ≥35 | ≤205 |
Pomo alloy often refers to iron nickel series alloys, with a nickel content ranging from 30 to 90%. It is a widely used soft magnetic alloy. Through appropriate processes, magnetic properties can be effectively controlled, such as initial permeability exceeding 105, maximum permeability exceeding 106, coercive force as low as 2 ‰ Auster, and rectangular coefficient close to 1 or 0. Permalloy with face centered cubic crystal structure has good plasticity and can be processed into 1 μ M's ultra-thin tape and various usage forms. Commonly used alloys include 1J50, 1J79, 1J85, etc.
