N.A. Tomilin

Тhе physicochemical analysis is a more fruitful method for creating new alloys. It describes alloys and its physical properties using two types of diagrams  constitution diagram and diagram «thermodynamic equilibrium factor - property» (particularly, the «content - property» diagram). These diagrams are the base for the development of materials with given characteristics. The development of precision materials usually is based on experimental results. The amount of experimental investigations may be reduced by using theoretical calculations and known correlations between the physical properties. The knowledge of constitution diagrams data enables a qualitative evaluation of a change of characteristics. It also enables a quantitative analysis of a range of characteristics. For example, the known for pure metals correlation between the melting point and coefficient of thermal expansion may be used for calculation of thermal expansion of alloys. The thermal expansion coefficients for alloys of double systems (Ag  Pd, Pd  Au, Ag  Au, Cu  Ni, Nb  Mo, Nb  V, Cr  Mo, Nb  Ta, Mo  Ta) were calculated using the constitution diagrams data. These calculations demonstrate safe approximation with experimental results. Using the constitution diagrams data for calculation is very effective for development of precision materials with physical properties the experimental investigations of which are very labour-intensive. For example, such property is components saturated vapor pressure in alloys. The method of calculating these pressure was proposed using constitution diagrams data and taking into account the chemical and phase content. This method was successfully tested for creating of amalgams Hg-Bi-Sn-Pb with certain vapor mercury pressure for the fluorescent mercury low pressure lamps.