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The results of studies of the structures of rapidly solidified foils of alloys of the Sn – Zn system with a low content of alloying elements (up to ~1,5 wt.%), alloys of near-eutectic compositions, as well as alloys with an alloying element content of 20 – 95 wt.% are presented. In rapidly solidified alloys containing 1,5 wt. % Sn and 1,2 wt. % Zn, supersaturated solid solutions are formed, which decompose according to the mechanism of formation and growth of nuclei of a new phase at room temperature. Alloys (4,4 – 15 wt.% Zn) after rapidly solidification are supercooled and supersaturated with both components, and experience spinodal decomposition followed by the formation of supersaturated solid solutions based on Sn and Zn, which decompose at room temperature. In all other alloys, a two-phase structure is formed from solid solutions based on Sn and Zn. It was found that as the crystallization front moves from the surface of the contacting foil layer with the surface of the mold, the Sn particles coarsen and the specific surface of the interface decreases. It has been established that rapidly solidified foils have a microcrystalline grain structure, with an increase in the concentration of alloying elements, a tendency to a decrease in grain size is observed.

The results are presenred of a study of the microstructure of rapidly solidified foil of the eutectic alloy Sn — 8,8 wt.% Zn A and B surfaces, microstructure parameters are determined. The texture of the precipitates of tin and zinc solid solutions in the foil was studied, and the pole densities of the diffraction lines of these phases are presented. The effect is studied of ultrafast cooling on the distribution of misorientation angles of neighboring and randomly selected grains for surface foil layers in contact with surfaces A and B.

Specific features of silicon carbide layer formation with the structure (polytype) different from the SiC-substrate structure (polytype) are considered. Simple theoretical foundations of the nonstoichiometric character, impurities, C- and Si-faces effect on the heteropolytype epitaxy (HPE) of silicon carbide are proposed. By means of Harrison’s bond orbital model it is shown that the adsorption possibility for the C-face is much greater than for the Si-face. Within the scopes of the earlier proposed models (D-model and vacancy model) it is demonstrated that the presence of impurities changes characteristic lifetimes of the HPE process and the transition layer widths: impurities which enforce the interpolytype transition decrease corresponding life-time constants and the transition layer widths. For interpretation of the polytype stripes existence within the transition layer, the model of specific spinodal decomposition taking into account vacancy concentrations variations in both SiC sublattices is used.