Phase composition, microstructure and microhardness of alloy In–Sn, obtained by rapid crystallization

Abstract

The results of studying of the structure and properties of the In – 42 at.% Sn alloy in the form of foil obtained by the method of rapid solidification with a cooling rate of the melt of at least 10⁵ K/s are presented. X-ray diffraction analysis showed that the phase composition of the alloy corresponds to the equilibrium state diagram. Foils consist of an InSn₄ compound (γ-phase) and an In₃Sn compound (β-phase). The grain structure of foil was studied by electron backscatter diffraction technique. It is established that the foil have a microcrystalline structure. The parameters of the microstructure are determined by the method of random linear secants: the volume fraction of the phases, average chord length of the random linear secant on the inclusions of each phase, the specific surface of the interface. Microstructure and distribution of components was also studied for both foil surfaces. The texture of both phases of the polycrystalline foils was studied by the method of inverse pole figures. It is established that the initial foils of the investigated alloy are in an unstable state. It is shown that an increase in the microhardness of the alloy during aging and annealing caused by change in the parameters of the grain structure.