The effect of lattice disorders on domain wall-dislocation interaction in Ni-5wt% Mn alloy

Abstract

The behaviour of domain wall-dislocation interaction in Ni-5wt% Mn alloy has been investigated in pre-annealed, quenched and γ-irradiated samples using some magnetic structure-sensitive properties. In all three samples it was found that the initial magnetic susceptibility, χ_a, and the maximum magnetic susceptibility, χ_max, were increased with the degree of plastic strain, and attributed to the formation of loops of domain wall around dislocations during the early stage of deformation. Further increase in dislocation density in the matrix during the later stage of deformation, affects the average value of the strength of interaction between the domain wall and dislocation, thus contributes to the decrease in χ_a and χ_max. The observed changes in the magnetic anisotropy,K, with plastic strain deformation is explained in terms of the magnetic hardening of the material by dislocations. Excess quenched vacancies and their clusters had an observable effect on domain wall-dislocation interaction, which is assumed to be due to the expected interaction and their pinning action that appear in the field of the nickel matrix.