Papers by Author: V.F. Mazanko

Abstract: By the method of radio isotopes (method of depleting) the redistribution of 63Ni was investigated in the surface layer of iron after the Electric-spark alloying by titanium and zirconium in a carbon containing atmosphere and in air. It is proved that the Electric-spark alloying results in diffusive penetration of 63Ni both in the alloyed layer and in material of basis. The depth of isotope’s penetration depends on the nature of an anode material. Alloying by titanium results in penetration of nickel on the depth of 10 μm, that is almost 2 times more than the depth of its penetration if a zirconium anode is used. In particular, a microhardness, microstructure and phase composition of alloyed layers are examined. It is assumed that alloying of iron by zirconium results in the hardness increase. The alloyed layer equals to 10 GPa (at treatment in kerosene) and to 8,6 GPa (at treatment in propane-butane) that exceeds the microhardness values at alloying by titanium.

Abstract: Since 1975 a so-called anomalous mass-transfer in metals and alloys under pulse loading is being investigated in the Institute of Metal Physics. This phenomenon remains to be a challenge to theoreticians. Besides, one more phenomenon (observed at the same systems) was discovered – formation of metastable alloys (solutions, and, sometimes, ordered phases), with solubility limits far exceeding the equilibrium values and depending on the deformation rate. Since formation of nonequilibrium phases is also typical for alloys under irradiation, it seemed natural for us to use some of concepts and models invented in the “materials under irradiation” community. We propose 3 types of models for description of metastable solid solution formation in diffusion couple under pulse loading: 1) flux balance for both components at the interface with account of non-equilibrium defects generated during pulse loading; 2) “ballistic jump” concept, which had been invented by George Martin et al. for materials under irradiation or ball-milling, combined with another Martin’s kinetic model (1994) of diffusion; 3) modification of such a concept for the case of non-equilibrium interstitial defects. Non-equilibrium phase diagrams obtained by all 3 models are built and compared with experimental data which reflect a qualitative correspondence to one another.

Abstract: Pulse loading of diffusion couples leads to the formation of the broad metastable solid solutions. Under higher temperatures, combined with high deformation rates, intermetallics also can form. Possible mechanisms of this phenomenon are discussed. Formation of nanostructure under uniaxial compression/decompression (observed in MD simulations) seems to be one of the possibilities.