Improvement in 80 Ni Permalloys through solid state refining

Information is given concerning the magnetization processes in high permeability 80 Ni Permalloys which shows the importance of the magnetic structure on the magnetic properties and consequently the significant role of the impurities contained in the alloys. Some impurities are more easily extracted from the alloy by solid state refining mainly carbon and sulfur. The thermodynamic and kinetic conditions for a proper extraction of these impurities taken as examples are discussed. Some examples of the consequent improvements of the magnetic properties are given.