PREDICTION THERMO-PHYSICAL CHARACTERISTICS HEAT-RESISTANT NICKEL ALLOYS DIRECTIONAL CRYSTALLIZATION

Abstract

The thermodynamic processes of phase separation are modeled, which significantly affect the temperature characteristics of heat-resistant nickel alloys of directional solidification. Using an empirical approach, new ratios of elements Kg¢ and Kg have been obtained for the first time, which take into account the combined effect of alloying elements on the temperature of multicomponent compositions of cast heat-resistant alloys. The calculated values of the critical temperatures for the Ni-6Al-9Co-8W-4Re-4Ta-1.5Nb-1Mo-0.15C system (ZhS32-VI, ZhS32B-VI, and ZhS32E-VI alloys) are in good agreement with the experimental ones. The dependences of the Kg ratio on the alloying system are constructed, and the effect of alloying on the liquidus temperature of alloys is investigated. The ratios of the content of alloying elements and regression models that can be used to predict the width of the temperature range of crystallization and the optimal temperature of homogenization for a particular alloy are presented.