{gamma}{prime} precipitate splitting in nickel-based superalloys: A 3-D finite element analysis
- Ecole des Mines de Nancy (France). Laboratoire de Science et Genie des Materiaux Metalliques
A coherent precipitate can encounter successive shape changes while increasing in size during either coarsening (at constant volume fraction) or growth (at increasing volume fraction). This phenomenon has been widely studied in the case of {gamma}-{gamma}{prime} nickel-based superalloys. It has been unambiguously related to the existence of internal stresses resulting from the small lattice discrepancy between {gamma} matrix and {gamma}{prime} precipitates. Sphere-to-cube and cube-to-plate shape transitions have been reported, together with a phenomenon sometimes called reverse coarsening, which is the splitting of a single cuboidal precipitate into a pair of plates (a doublet), a group of eight cuboids (an octet) or chaplets of cuboids aligned along the <111> crystallographic directions. With regard to the wide range of morphologies reported in the literature, it appears that the shape evolution strongly depends on the alloy composition and on the heat treatment parameters. In the present paper, the authors utilize a 3-D finite element approach to estimate the internal elastic energy associated with coherent {gamma}{prime} precipitates of different shapes.
- OSTI ID:
- 194937
- Journal Information:
- Scripta Materialia, Journal Name: Scripta Materialia Journal Issue: 4 Vol. 34; ISSN 1359-6462; ISSN XZ503X
- Country of Publication:
- United States
- Language:
- English
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