The ternay alloy structure of the bismuth – indium – tin system

By means of X-ray structural analysis, it was established experimentally that the Bi26 In39 Sn35 alloy obtained at the cooling rate ≈102 K/s, includes three phase: e-phase BiIn, Bi3 In5, and g-phase Sn4ln. The phases form three structures with the volume parts determined by the random secant method as 0.54; 0.41, and 0.05, respectively. The structures are homogeneously distributed within the alloy volume. Using Х-ray spectroscopic microanalysis, the authors determined concentrations of the components in different regions of the alloy and demonstrated that light regions are associated with e-phase BiIn; grey regions represent BiIn and Bi3 In5 phases. Distribution of the maximal bisecants lmax in size groups for light regions has two maxima. The average bisecant lengths of random secants for the structures are no greater than 15 mm. Eutectic transformation at the final stage of crystallization is associated with the formation of the eutectic compound comprising the three phases (e-phase BiIn, Bi3 In5 and g-phase Sn4 In).