Mössbauer Study of Thin Iron Film Beryllization

Beryllium coating of the iron foil is made by means of magnetron sputtering. Mössbauer studies are performed by means of two registration techniques: conversion electron Mössbauer spectroscopy (CEMS) and the γ-ray technique in absorption geometry. Performed investigations confirm the original thermodynamic approach to creation of thermally stable multi-layer materials.

     

Calculation of the thermodynamic properties of the phases and analysis of their stability for the Ni-Al system in the model functional electron density method

We have calculated the thermodynamic properties of the ground state of the ordered and disordered phases in the Ni-Al system and a number of complex structures with noncubic symmetry within the framework of the model electron density functional method and the assumed calculation scheme for the multiparticle interatomic interaction potentials. The calculations which were done agree well with experimental data and allow one to explain the rules for alloy formation in this system.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 4, pp. 100–110, April, 1996.     

Multiparticle interatiomic interaction potentials for alloys using the model electron density functional method

A method for calculating multiparticle interatomic interaction potentials for binary alloys within the framework of a model electron density functional is presented. An expression for the total ground state energy of metals and alloys is obtained. It is shown that in simplicity of the computational scheme and speed of computation, this approach does not yield to the method of inserted atoms, but has a more rigorous physical basis in comparison with the latter.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 4, pp. 90–99, April, 1996.     

Calculation of the thermodynamic properties of noble-metal alloys in the model electron-density functional method

The thermodynamic properties of the stable and metastable phases of theCu−Au, Ag−Au, andCu−Ag systems have been calculated in the representation of the many-body interatomic interaction potential within the framework of the model electron-density functional method. The calculated values of the thermodynamic properties are in good agreement with experimental data and help explain the laws of alloy formation in the given systems. Factors that affect the magnitude of the tetragonal distortion of theL1 ₀ structure of equiatomic alloys have been investigated. The possibility of a transition by the Bayne scheme from theL1 ₀ structure toB2 for alloyCuAu upon application of an external uniaxial [001] stress is discussed. Institute of Strength Physics and Materials Science, Siberian Division of the Russian Academy of Sciences. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 5, p. 9–19, May, 1997.     

Thermal Induced Processes in Laminar System of Stainless Steel – Beryllium

The paper reports on investigation of the laminar system ‘stainless steel 12Cr18Ni10Ti – Be’ at thermal treatment. There have been determined sequences of phase transformations along with relative amount of iron-containing phases in the samples subjected to thermal beryllization. It has been revealed that thermal beryllization of stainless steel thin foils results in γ→α transformation and formation of the beryllides NiBe and FeBe₂. It has also been revealed that direct γ→α- and reverse α→γ-transformations are accompanied by, correspondingly, formation and decomposition of the beryllide NiBe. It is shown that distribution of the formed phases within sample bulk is defined by local concentration of beryllium. Based on obtained experimental data there is proposed a physical model of phase transformations in stainless steel at thermal beryllization.     

Effect of elastic stress fields generated by ion-implanted helium layers on changes in carbon steel microstructure

Microstructure and phase composition of iron-based alloys with 0.1 to 0.7% carbon are studied upon irradiation of the latter by α-particles followed by annealing at temperatures higher than those of the polymorphic α-γ-transformation. This treatment is shown to bring about irreversible phase and structural changes of the ferrite-pearlite structural components and grain size resulting in a higher microhardness in the areas saturated with helium. Based on calculations by the theory of elasticity of stress fields generated by the implanted helium atoms, it is shown that these microstructural changes are caused by deformations induced by helium present in the region of α-particle deceleration. Nuclear Physics Institute of the National Nuclear Center, the Republic of Kazakhstan. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 6, pp. 14–18, June, 1999.     

Thermally Induced Processes of Intermetalloid Phase Formation in Laminar Systems Fe–Sn

Hyperfine Interactions - Phase transformations at series of thermal annealings in a laminar system of Sn–Fe–Sn were investigated by means of Mössbauer spectroscopy. Sequence and...