The constant magnetic field effect (B≤0.6 T) on creep of polycrystalline copper and its dislocation substructure has been established. The correlation of creep rate to time up to failure has been determined. The magnetic field effect on change of dislocation substructure parameters depending on the distance to the surface of failure (at a distance of 2, 4, 7, 10 and 20 mm from the surface of failure) under creep has been studied. It has been shown that magnetic field affects greatly the redistribution of dislocation substructure types and their scalar density of dislocations. The magnetic field effect on polycrystalline copper is connected with magneto-induction relaxation of dislocation structure.

The work intends to study the microstructure, chemical and phase composition and homogeneity of chemical elements distribution in the Co-Cr-Fe-Mn-Ni high-entropy alloy produced via wire-arc additive manufacturing technology. The study has revealed three structure types in the alloy: (1) a smooth shagreen-type structure (an orange peel), which turns into a stripe-like structure (2) in some areas, and a grain structure (3) to appear as lengthy thin layers with the width of 50-80 μm and an average grain size of 12.5 μm, the most probable size of grains is detected to be in the range from 10 to 15 μm, a preferred number of such grains is 31%. The chemical composition of the produced alloy is assessed using X-ray microspectroscopy. The elements identified rank in descending order of concentration: Fe (38.88 wt. %), Co (26.08 wt. %), Ni (17.34 wt. %), Cr (14.33 wt. %), Mn (3.37 wt. %). The mapping of the alloy structure demonstrates the homogeneous and uniform distribution of chemical elements.

An impact of a weak magnetic field on changes in the dislocation substructure of commercially pure copper exposed to stressing up to destruction under creep conditions was investigated. It was established that a magnetic field action on a metal exposed to creep resulted in the formation of a band dislocation substructure. In some cases grains with the dislocation chaos structure or cellular and grid substructures were revealed. In addition, quantitative differences in the dislocation substructure characteristics were also identified. A gradient nature of changes in the number of stress concentrators when moving away from the failure surface was defined. It was shown that the density of bend extinction contours characterizing the number of stress concentrators in the material decreased when moving away from the failure surface.

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