Suchergebnisse

The paper presents a study of the processes of mutual diffusion in the binary system Fe - Ni (obtained by the electrocondensation of nickel and iron powders) by the method of X-ray energy dispersive spectroscopy, as well as the processes of thermal and electrical conductivity in the temperature range of 5-300 K. Well-separated regions of almost pure iron and nickel were revealed . The nickel content, estimated by the concentration dependence of the mutual diffusion coefficient, which determines the kinetics of the process of homogenization of the electroconsolidated sample of the Fe - Ni composite, was ~ 70 at. %. The value of the mutual diffusion coefficient of the electroconsolidated Fe - Ni composite is significantly higher than that of an alloy of a similar composition, which is probably the result of the influence of SPS technology (pressure and current in one direction during consolidation), as well as a significant contribution of grain boundary diffusion mass transfer in the composite. It was established that the electrical and thermal conductivity of the electroconsolidated sample is significantly higher than that of samples of the same composition obtained by melting. It was found that the temperature dependence of the electrical resistance of the electroconsolidated sample in the studied interval of 5-300 K is due to the scattering of electrons on defects and on phonons, and the scattering of electrons on phonons can be approximated with high accuracy by the Bloch-Gruneisen-Wilson ratio. The paper shows that the experimental data on the temperature dependence of the effective electrical resistance and thermal conductivity in the range 4.2-300 K of the electroconsolidated Fe0.50Ni0.50 composite are within the Hashin-Shtrikman limits for the conductivities of a three-phase system. The components of the system are pure Fe and Ni, and the intergranular medium in the form of an alloy with an average composition close to Fe0.50Ni0.50 is considered as the third phase.