A Phase Decomposition-calculation of γ'-phase Precipitation Hardening Nickel-base Superalloys and Its Applicationto the Estimation of Alloy Properties

Abstract

A program to calculate both the molar fractions and compositions of γ-and γ'-phases for a given average composition of γ'-phase precipitation hardening nickel-base superalloy is developed. The main procedure of the calculation consists of the formulation of both the γ-phase composition and Al concentration of γ'-phase as functions of γ'-phase composition.
Microstructural and mechanical properties of the various commercial alloys can be well described through the parameters such as the values of average electron-vacancy number by PHACOMP, γ' fraction, and γ'-phase composition which are calculated by the above program.