Stratification of In–Bi Melts in Glass Capillaries

The stratification of binary metal melts in glass capillaries was studied over the whole concentration range of the indium–bismuth system. The results of stratification were correlated with the form of the state diagram and other physicochemical properties of the melts, especially with the isobaric heat capacity. The value of the achieved difference in the concentrations of the components along the capillary height is related to the balance between the clusters (units) of pure components and their chemical compounds presented in the state diagram of the binary system. The depth of stratification of the melts in the field of chemical compounds is much smaller than in the "eutectic zones" of the diagram. The intermetallic compounds In_nBi_m retained their stability when overheated above the liquidus line by at least 300°C. The results of our study of stratification in capillaries are characterized by high sensitivity with respect to the density of the clusters located directly in the metal melts and are structure-sensitive, due to which they may be recommended for use as one of the physicochemical techniques for investigating the structure of liquid metal alloys.