International Seminar on Mechanics and Mechanisms of Solid-Solid Phase Transformations
J. Phys. IV France 06 (1996) C1-119-C1-128
Internal Mismatch Stresses in Nickel-Based Superalloys : A Finite Element ApproachA. Hazotte, A. Racine and S. Denis
Laboratoire de Science et Génie des Matériaux Métalliques, URA 159 du CNRS, Ecole des Mines, Parc de Saurupt, 54042 Nancy cedex, France
A three-dimensional finite element (F.E.) model is used to estimate the mismatch stresses at a microscopic scale in γ-γ' single-crystal nickel-based superalloys. F.E. calculations point out the specificity of stress/strain distributions in these alloys, in particular the fact that internal stresses concentrate in the connected γ matrix. The analysis of stress/strain fields and elastic energy evolution as a function of precipitate morphology and volume fraction allows to explain some atypical precipitate shape changes such as "splitting" during precipitation treatments or "raftening" during high temperature creep tests.
© EDP Sciences 1996