Microstructure and Mechanical properties of Bi27In38Sn35 produced by Rapid Solidification

Abstract

Investigations into the microstructure of Bi 27In38Sn35 alloy have shown that an increase in the melt cooling rate from 10 2 to 105 K/s leads to a change in the solidi fication mechanism. At a melt cooling rate of 10 2 K/s, we observe consecutive solidification of the dendrites of the Sn 4In phase, and then that of BiIn and BiIn 2 phases in the interdendritic space. Bi 27In38Sn35 foil produced by rapid solidi fication consists of BiIn, BiIn 2, and Sn 4In phases forming a lace-like structure. The foil ′s chemical composition determined by X-ray spectral analysis was constant in thickness. Alloy foil phase grains have a microcrystalline structure and texture. The aging of rapidly solidi fied foil at room temperature causes size enlargement in phase and grain precipitations, which determines the change in its physical properties. Foil aging causes an increase in microhardness and affects tensile deformation: there is consolidation of rapidly solidified alloy at the initial stage of deformation and a reduction in its plasticity.