Abstract :
The considerable effect of metallurgical factors on magnetic properties is illustrated by reference to untreated and fully processed nickel-iron and silicon-iron alloys. The factors considered are composition, i.e. major constituents and heterogeneity, purity or differences in ultimate composition, non-metallic inclusions, strain content, structural orientation, grain size andgrain shape, lattice ordering, magnetic domain orientation, and surface conditions and dimensionaleffects. These are denned and their incidence and control in manufacture discussed with particularreference to their effect on magnetic properties. The influence of the above factors on the magnetic properties, saturation intensity, maximum permeability or permeability at the knee of the B/H curve, initial permeability or threshold magnetization, d.c. hysteresis loop, particularly coercivity and remanence, total loss under a.c. magnetization at power frequencies, permeability and loss under a.c. magnetization at high frequencies is considered. The fact that they affect the various magnetic properties in different ways so that production methods have to be adjusted accordingly is emphasized.
