THE THERMODINAMICS AND SURFACE PROPERTIES OF LIQUID Co-Si ALLOYS

Thermophysical properties of liquid Co-Si alloys are interesting for composite materials production. However, despite the importance of these properties, the determination of their thermophysical properties is lacking due to the experimental difficulties related to high melting temperatures as well as due to the high reactivity of these alloys with crucible materials. The energetics of mixing in liquid Co-Si system has been analyzed through the study of the concentration dependence of various thermodynamic, surface (surface tension and surface composition) and structural properties (concentration fluctuations in the long-wavelength limit and chemical short-range order parameter) in the framework of the Compound Formation Model (CFM) and Quasi Chemical Approximation for regular solutions (QCA). The surface tension of a few Co-Si liquid alloys has been measured as a function of temperature above the corresponding liquidus temperatures. The results obtained were discussed with respect to both, temperature and concentration, and subsequently were compared with the aforementioned thermodynamic models.