Grain structure of Ni3Fe alloy

The grain structure of aN ₃Fe polycrystal is studied by means of optical metallography taking into account the type of grain boundaries. Grains with random boundaries having special boundaries on the inside are revealed. Grains are classified by the presence and position of special boundaries. The energy of different types of grain boundaries is estimated. Tomsk State University of Architecture and Building. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 11, pp. 34–42, November 1999.     

Change in the crystallographic structure of grain boundaries in an order-disorder phase transition in Ni3Fe alloy

Electron diffraction microscopy and metallography are used to investigate the crystallographic structure of grain boundaries in Ni₃Fe alloy with short-range and long-range atomic order. It is found that the fraction of special boundaries in alloys with short-range and long-range order is 0.3–0.4. Heat treatment, which leads to ordering, causes a reorientation of some of the grains with boundaries of a general type, boundary migration, and also faceting of some of the boundaries of general type.Tomsk Engineering-Construction Institute. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 7, pp. 3–10, July, 1992.     

Distribution of slip tracks in single crystals of Ni3Fe alloy

The results of an experimental investigation of the distribution of slip tracks in a primary system in single crystals of Ni₃Fe alloy, oriented for a single slip, are presented. Investigations were carried out over a range of scales which differed by three orders of magnitude. Histograms of the distances between slip tracks at different scale levels are constructed. Self-similar track distributions in the primary slip system over the range of scales investigated are established. Tomsk State Architectural-Construction University. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 4, pp. 51–56, April, 1998.     

Evolution of slip-line pattern during straining in polycrystalline Ni3Fe alloy

An electron microscope study is made of the evolution of the slip-line pattern during straining to the breaking point in polycrystalline Ni₃Fe alloy in the disordered and ordered states.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 11, pp. 24–29, November, 1979.It is our pleasant duty to thank Professor L. E. Popov and Assistant Professor V. F. Esipenko for their constant assistance and useful discussions throughout the work.     

Thermally activated deformation processes in monocrystals of an ordered Ni3Fe alloy

The temperature dependence of the flow stresses of monocrystals of an ordered Ni₃Fe alloy is studied. The mechanisms determining the temperature dependence are deduced from experiments on the variation of the deformation temperature and stress relaxation. A theoretical estimate is given for the contribution of the thermal component of the flow stresses, and is found to be in good agreement with experiment.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 5, pp. 86–91, 1979.     

Order-disorder phase transition in Ni4W alloy

The order-disorder phase transition in Ni₄W alloy with a D1 _a superlattice was studied experimentally by x-ray structural analysis and theoretically by the Green function method. An experimental temperature dependence was obtained for the equilibrium parameter of long-range order for Ni₄W alloy. It was established that the order-disorder phase transition in the alloy is a first-order transition; the transition occurs through the two-phase region D1_a + A1. The Green function technique, with account for the pair-correlation functions, was used to describe the order-disorder transition for the D1 _a superlattice. The theoretical temperature dependence obtained for the equilibrium parameter of long-range order is in satisfactory agreement with the experimental curve.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 4, pp. 92–97, April, 1978.     

Influence of grain size on strain hardening of orderable Ni3Fe alloy

An experimental study was made of the strain hardening of the Ni₃Fe alloy in disordered and ordered states as a function of the grain size. An analysis of the stress-strain diagrams was made using the Hall-Petch equation allowing for the contributions of the density of statistically stored dislocations _s and the density of geometrically expected dislocations _g to the total dislocation density .Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 2, pp. 33–37, February, 1981.     

Temperature-induced metamagnetic transition in ErCo3: influence of Fe and Ni substitutions for Co

The phenomenon of a temperature-induced itinerant metamagnetism in ErCo₃ (at 65 K) was investigated with respect to small substitutions of Fe and Ni for Co. Five percent of Fe or Ni substitutions change the transition temperature to 170 or 25 K, respectively. The transition is accompanied by a large magneto-volume effect, ΔV/V reaches ∼0.5%, which allowed to relate the thermal expansion data with the magnetic state of the d-electrons. The change of the magnetic characteristics with substitutions is mainly ascribed to the shift of the position of the Fermi level in the hybridised d-electron energy band.     

Discontinuous deformation of Ni3Fe alloy single crystals in various states of atomic order

The conditions conducive to discontinuous deformation of alloy single crystals in various states of order were studied in experiments. An equation defining the minimum temperature for deformation discontinuities to develop was obtained. The possible reasons for the influence of order upon discontinuous deformation were analyzed.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 12, pp. 65–71, December, 1977.     

Impurities in Ni3Fe magnetic alloys

The theoretical—in terms of the classical theory of ordering—and the experimental—with neutron diffraction analysis—investigations of the influence of the third component impurities on structural and magnetic ordering of Ni₃ Fe alloys have been carried out. Comparison of theoretical results with the experimental data, revealing the effect of the third component impurities of W, Mo, Cr and Mn atoms on the degree of atomic ordering and magnetization in Ni₃ Fe binary alloys, on order-disorder and Curie temperatures, and on the interrelation between atomic and magnetic ordering phenomena, shows good qualitative agreement between theory and experiments for all the systems chosen.     

Change of superdislocation splitting with strain in single crystals of the Ni3Fe ordered alloy

The method of transmission electron microscopy is used to study the dislocation structure in single crystals of the Ni ₃ Fe ordered alloy for different degrees of strain. The [1812], [011], [111] and [001] single crystal orientations are examined. The superdislocation splitting (r) is measured for different degrees of strain, distributions of r are constructed, and their average values 〈r〉 are estimated. The 〈r〉-ε curves are constructed. With the use of the experimental r values, the effective energy of antiphase boundaries ζ* is estimated. __________ Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 1, pp. 51–56, January, 2006.     

Effect of plastic deformation on phase transitions in a Ti50Ni47Fe3 alloy

The results of x-ray structural studies of the effect of previous plastic deformation by rolling on the occurrence of phase transitions in a TiNi(Fe) alloy are presented in the present work. The temperature dependences of the Bragg reflection intensities and half-widths and the dependence of the rhombic angle in the R phase with various degrees of deformation were obtained. Analysis of the results found gave the following rules. Plastic deformation substantially shifts the characteristic temperatures of the martensitic transitions (MT) R-B19′ and B19′-B19″, increases the temperature range of the transformation and can result in a “stepwise” transformation. It was observed that deformation weakly affects the temperature T_R for the B2-R transformation. Tomsk State Architecture and Construction Academy. V. D. Kuznetsov Siberian Physicotechical Institute at Tomsk University. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 7, pp. 11–20, July, 1996.     

Thickness dependence of magnetization in FeNi invar alloy film

The thickness dependence of magnetization of FeNi Invar alloy films was observed by means of small angle Lorentz electron diffraction. A remarkable reduction of magnetization at room temperature was observed for films with thickness below 400 Å. This may be ascribable to the instability of the ferromagnetic state in Fe-Ni Invar alloys.     

Influence of Ni on Cu precipitation in Fe Cu Ni ternary alloy by an atomic study

The early aging Cu precipitations in Fe-3%Cu and Fe-3%Cu-4%Ni ternary alloys are investigated by molecular dynamics （MD） simulations. The results show that the average size of Cu clusters in Fe-3%Cu-4%Ni alloy is larger than that in Fe-3%Cu alloy. The diffusion of Cu is accelerated by Ni according to the mean square displacement （MSD）. Furthermore, the whole formation process of Cu-rich clusters is analyzed in detail, and it is found that the presence of Ni promotes small Cu-rich clusters to be combined into big ones. Ni atoms prefer to stay at the combination positions of small clusters energetically due to a large number of the first nearest neighbor Cu-Ni interactions, which is verified by first-principles calculations based on density functional theory （DFT）.     

Thermally activated mechanisms of plastic deformation of single crystals of the disordered alloy Ni3Fe

On the basis of experiments on the variation of temperatures in the process of deformation and relaxation of stresses, we make an analysis of the temperature dependence of the yield stresses of single crystals of the disordered alloy Ni₃Fe and of the nature of the processes determining it.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 7, pp. 109–113, July, 1978.     

PES study of amorphous alloy Fe40Ni40P20

The electron structure of amorphous Fe₄₀NI₄₀P₂₀ has been investigated before and after annealing by XPS and UPS (HeI, HeII). It is shown that the spectra of UPS were modified obviously by various degree of annealing. Composition and chemical states of the components on the surface of the sample are also presented and the effect of structural ordering on the density of states (DOS) of the valence band is discussed.     

Field-induced phase transition in Fe3BO6

The temperature dependence of the field-induced phase transition in Fe₃BO₆ has been measured in fields up to 14.7 T. The experimental value for the anisotropy is compared with the calculated result for the dipole-dipole energy.