Super Permalloy

Introduction

Ultrapermalloy refers to a nickel-iron alloy with high permeability of 5Mo%, 79Ni%, and the rest is iron and a small amount of manganese. Its initial permeability and maximum permeability are the highest among soft magnetic materials. It can be used in radio engineering, telephone and remote control mechanical equipment, etc.

Features

Super permalloy must undergo proper heat treatment; heat preservation in pure hydrogen at 1300°C; when it is cooled to 600°C, the cooling rate must be strictly controlled. Its initial magnetic permeability can reach 50000-150000 (permalloy is 1-30000); the maximum magnetic permeability is 6-1200000, super permalloy can be made into a very thin strip; it is suitable for transformer core, because The resistance is higher, 0.6 ohm mm²/m; it can work under the condition that the frequency and pulse duration are three times higher than that of Permalloy.

Permalloy

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.

Structural magnetism

Permalloy is an iron-nickel alloy with higher magnetic permeability in a weaker magnetic field, and a nickel-iron alloy with a nickel content of more than 30%. Both have a single-phase face-centered cubic (γ) structure at room temperature, but the single-phase structure near 30% Ni is very unstable. Therefore, practical iron-nickel soft magnetic alloys have a nickel content of more than 36%. The iron-nickel alloy contains nickel near 75% (atomic fraction), and the Ni₃Fe long-range order transformation occurs in this single-phase alloy. At this time, the lattice constant and physical properties of the alloy, such as electrical resistance The rate and magnetism will change. Therefore, it is necessary to consider the impact of orderly transitions on performance. A small amount of additional elements such as Mo or Cu are usually added to the Ni₃Fe alloy to suppress the formation of long-range order.

Classification

Permalloy can be divided into 35%～40%Ni-Fe alloy, 45%～50%Ni-Fe alloy, 50%～65%Ni- Fe alloys and 70%～81% Ni-Fe alloys are in 4 categories. Each type can be made into materials with circular hysteresis loop, rectangular hysteresis loop or flat hysteresis loop.