PROGNOSTIC SEMI-EMPIRICAL CALCULATION OF THE THERMOPHYSICAL PROPERTIES OF GOLD-SILICON ALLOYS BASED ON COMPONENT DATA

Abstract

The discovery of a chaotic spatial distribution (while maintaining short-range order) of atoms in a gold-silicon alloy marked the beginning of not only the intensive development of technological methods for producing amorphous alloys and their widespread practical application, but also the theoretical study of disordered systems. The wide range of amorphous alloys and the uniqueness of their thermophysical characteristics require a preliminary assessment of the alloys' properties in order to reduce material, energy, and economic costs. Over time or with increasing temperature, an amorphous metal alloy undergoes a crystallization process. This process leads to the formation of a well-ordered distribution of atoms in space, resulting in the restoration of long-range order. Due to the thermal and temporal instability of such alloys, there are problems of both determining the temperature dependencies of thermal and other physical properties, as well as the coefficients of kinetic equations. In this work, the use of a two-phase locally-equilibrium region model and empirical approximating functions is proposed to describe the thermo-physical characteristics of gold-silicon alloys. The application of this model is based on the fact that, according to Prigogine's principle, thermodynamic equilibrium is established much faster in small local regions than in a massive sample as a whole. It has been established that the theoretical description is adequate to the experimental data arrays for gold and silicon. The calculations were performed using continuous approximating functions, which can be used to solve other thermal problems. The continuous functions obtained within the framework of the model allow us to describe such features of the temperature curves of thermophysical properties as jumps, peaks, and pits. Their appearance is associated with the occurrence of structural and polymorphic transformations, as well as phase transitions of the first and second kinds, in the systems. The thermal properties of the alloys are calculated using the component mixing rule. It is shown that the properties of alloys are located in temperature bands limited by the temperature dependencies of the components, and inherit the properties of the constituent elements. Additional theoretical studies conducted on other amorphous alloys demonstrated the possibility of sup-pressing the inheritance effect through the interaction of the alloy components. The presence of points of indistinguishability of the values of thermal conductivity and thermal diffusivity of components and alloys of any composition is established.