Soft magnetic alloy

Soft magnetic alloy
A magnetic alloy that is easily magnetized under the action of an external magnetic field, and the magnetic induction strength is substantially lost after the magnetic field is removed.
The hysteresis loop area is small and narrow, the coercive force is generally lower than 800 A/m, the resistivity is high, the eddy current loss is small, the magnetic permeability is high, and the saturation magnetic induction is high. Generally processed into sheets and strips, bars. Prepared by melt method. Mainly used as various core components in electrical and telecommunication industries (such as transformer core, relay core, choke, etc.). Commonly used soft magnetic alloys are low carbon electrical steel, Amcor iron, silicon steel sheet, nickel iron soft magnetic alloy, iron cobalt soft magnetic alloy, iron silicon soft magnetic alloy.
The main magnetic properties of soft magnetic alloys are: 1 low coercivity (Hc) and hysteresis loss (Wh); 2 high resistivity (ρ), low eddy current loss (We); 3 initial permeability (μ0) And the maximum magnetic permeability (μm); some alloys have a constant magnetic permeability (B/H) in the low magnetic field range; 4 high saturation magnetic induction (Bs); 5 some alloy hysteresis loops are rectangular, rectangular The ratio is the remanence/maximum magnetic induction (Br/Bm). These magnetic properties are closely related to the structural state and composition of the alloy. Impurities such as carbon, sulfur, nitrogen and oxygen in alloys are particularly detrimental to magnetic properties because they cause lattice distortion and are difficult to magnetize, and carbon and nitrogen also cause magnetic aging. Soft magnetic alloys generally require a large grain size of the finished product in order to reduce the Hc and Wh values. Generally, the magnetic properties of ferromagnetic metals vary with the direction of the crystal axis. For example, the <100> direction of iron is easily magnetized, and the <111> direction is difficult to magnetize. Controlling grain orientation thus allows for better magnetic properties in a particular direction of the material. The electrical resistivity (ρ) of iron is low, and the addition of certain alloying elements can increase the value of ρ, and the effect of adding silicon and aluminum is most obvious. Adding any alloying element (except cobalt) to iron will reduce its saturation magnetic induction Bs.