Statistical description of thermoreversible chemical bonding in metallic alloys

¹ Institute of Metallurgy of Ural Division of Russian Academy of Sciences, Amudsena str. 101, 620016 Russia
² Ural State Pedagogical University, pr. Kosmonavtov 26, Yekaterinburg, 620017 Russia

^a e-mail: rrylcev@mail.ru

Abstract

A general statistical model, developed in our previous works for describing network-forming systems, have applied to study of metallic alloys with chemical bonding. The model is based on the representation of the partition function for all possible configurations of a thermoreversible network in the form of a functional integral over a scalar field. The main object of our investigation was the solution of free atoms A, B and the elements of chemical short-range order with the stoichiometry A₂B that could form thermoreversible chemical bonds. The thermodynamic and structural properties of this system is analyzed. It is revealed that at some temperatures and concentrations, geometry percolation of the network of chemical bonds and thus a sol-gel transition may take place. The critical percolation line is plotted in common with phase diagram. Three different scenarios of sol-gel transition is considered in light of competition between gelation and phase separation phenomena.