MAGNETIC PROPERTY VARIATIONS IN NICKEL CAUSED BY NONMAGNETIC INCLUSIONS

A study of the effect of non-magnetic particles on the magnetic proper ties of nickel is reported, The presence of inclusions is known to aff ect the structure sensitive magnetic properties of materials, In this work, two kinds of inclusions, namely, alumina particles and voids wer e studied and their effects on the magnetic properties were investigat ed. Powder metallurgy techniques were used to produce nickel compacts with varying amounts of alumina present. While coercivity increased wi th the volume of inclusions present, initial permeability decreased. O ther properties such as remanence and hysteresis loss did not show a s ignificant variation due to their sensitivity to the demagnetizing eff ects of the inclusions, An attempt has been made in this paper to expl ain quantitatively the variation in the magnetic properties in terms o f the amount of inclusions present. Magnetic property measurements cou ld be a useful non-destructive technique for determining porosity in m agnetic materials.