The antiphase domain structure and parameters of the solid solution in the alloys with superstructure L12

By methods of transmission electron diffraction microscopy the antiphase domain structure was investigated and its distributions upon sizes were received in Pd3Fe and Ni3Mn alloys at the different long-range atomic order degree. The dislocation structure and phase composition of alloys were also investigated. The parameters of the solid solution such as the long-range atomic order degree and microdistortions were determined by X-ray. The different means of long-range atomic order degree are achived by deviations from the stoichiometric composition in Ni3Mn alloy and by varying of the annealing regimes. The average sizes of antiphase domain increase, their boundaries are become blurring and the manganese oxide particles are allocated on the grain boundaries and antiphase domains with the decreasing of the long-range atomic order degree in the non-stoichiometric composition Ni3Mn alloy. In the Pd3Fe the long-range atomic order degree decreases at the increasing of isothermal annealing duration. It was accompanied by an increasing of the antiphase domain average sizes and blurring their boundaries as in the Ni3Mn. Besides the long-range atomic order degree decreasing was accompanied by stacking fault emergencing and average scalar and excess dislocation densities increasing. The observed changes in the alloys microstructure lead to microdistortions increasing. The relationships between long-range atomic order degree, antiphase domains and microdistortions were established. The antiphase domain average sizes and microdistortions increase at the long-range atomic order degree decreasing.