Determination of γ-γ' lattice misfit in a single-crystal nickel-based superalloy using convergent beam electron diffraction aided by finite element calculations

G Brunetti; A Settefrati; A Hazotte; S Denis; J-J Fundenberger; A Tidu; E Bouzy

doi:10.1016/j.micron.2011.10.009

Determination of γ-γ' lattice misfit in a single-crystal nickel-based superalloy using convergent beam electron diffraction aided by finite element calculations

Micron. 2012 Feb;43(2-3):396-406. doi: 10.1016/j.micron.2011.10.009. Epub 2011 Oct 13.

Authors

G Brunetti¹, A Settefrati, A Hazotte, S Denis, J-J Fundenberger, A Tidu, E Bouzy

Affiliation

¹ Laboratoire d'Etude des Microstructures et de Mécanique des Matériaux (CNRS - UMR 7239), Ile du Saulcy, F-57045 Metz Cedex 01, France.

PMID: 22055767
DOI: 10.1016/j.micron.2011.10.009

Abstract

In single-crystal nickel-based superalloys, the lattice mismatch associated with interface coherency between γ matrix and γ' precipitates has a strong influence on mechanical properties. The unconstrained lattice misfit in a single-crystal of the MC2 nickel-based superalloy is determined using convergent beam electron diffraction measurements and finite element calculations. The apparent lattice parameters of both constrained phases are obtained in thin foils, using a new multi-pattern approach, which allows for unambiguous determination of all the lattice parameters considering the real symmetry of the strained crystals. Finite element calculations are used to establish relations between the constrained and unconstrained lattice parameters, with the stress relaxation resulting from the thin foil geometry taken into account.