Thermodynamics properties of the surface layer from alloys of Ti—Cu and Zr—Cu systems

  
J.Naydich,
  

I. M. Frantsevich Institute for Problems of Materials Science of the NAS of Ukraine, Krzhizhanovsky str., 3, Kyiv, 03142, Ukraine
Adhesion of Melts and Brazing of Materials - Kiev: Frantsevich Institute for Problems of Materials Science NASU, 2007, Т.null, #40
http://www.materials.kiev.ua/article/198

Abstract

The surface tension and density of titanium—copper and zirconium—copper melts in temperature range from 1000 up to 12500С were measured. For the first approximately the linear dependences of surface tension isotherms of metal systems were established. The compression in alloys takes place. The melts are characterised by negative deviation from an ideal state. An adsorption and thermodynamic activity of components, composition of surface layer, Gibbs energy of solution formation and their excess values in surface layer and bulk of melts were calculated. The adsorption curve of copper for both melts has the slanting maximum. The composition of surface layer from a composition by bulk differs a little. The solutions, which one are formed in surface layer, have negative deviation from a Raoult’s law. In surface layer the Gibbs energy of solution formation and their excess values at all concentrations are negative. They are less than their values in bulk.