PECULIARITIES OF PHYSICOCHEMICAL PHASE-ANALYSIS OF MODERN HIGH-TEMPERATURE NICKEL-ALLOYS

A method is proposed for estimating the chemical inhomogeneity of the gamma'-phase and the electrolytes for its realization. The method includes separation of the gamma'-phase into the fractions gamma1' and gamma2' which differ from each other by composition and morphology. It has been demonstrated that the chemical composition of the fractions and their ratio in the alloy are determined by the segregation characteristics of the metal, rate and method of solidification, heat treatment, and some other factors. High-temperature stresses enhance phase transformation in the alloy and promote the formation of a less stable gamma2'-fraction and Me6C carbide at slip planes, especially in the zone of destruction of the metal. A correlation between carbide transformations and variation of the chemical composition of fractions of the gamma'-phase has been found.