TY - JOUR
T1 - High-temperature deformation mechanisms in a polycrystalline nickel-base superalloy studied by neutron diffraction and electron microscopy
AU - Francis, Elisabeth M.
AU - Grant, Benedict M.B.
AU - Quinta da Fonseca, João
AU - Phillips, Patrick J.
AU - Mills, Michael J.
AU - Daymond, Mark R.
AU - Preuss, Michael
PY - 2014/8/1
Y1 - 2014/8/1
N2 - To study the effect of γ′ precipitate size on the deformation behaviour of a polycrystalline nickel-based superalloy, model microstructures with a unimodal γ′ size distribution were developed and subjected to loading experiments at 750 °C. Neutron diffraction measurements were carried out during loading to record the elastic lattice strain response of the γ and γ′ phase. A two-site elasto-plastic self-consistent model (EPSC) assisted in the interpretation of the elastic lattice strain response. In addition, the microstructures of the deformed specimens were analysed by (scanning) transmission electron microscopy (STEM). Excellent agreement was found between the EPSC and STEM results regarding a joint deformation of the γ and γ′ phase in the fine γ′ microstructures and for low plastic strains in the medium γ′ microstructures. With increasing γ′ size and increasing degree of plastic deformation, both experimental methodologies revealed a tendency of the two phases to deform independently. © 2014 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.
AB - To study the effect of γ′ precipitate size on the deformation behaviour of a polycrystalline nickel-based superalloy, model microstructures with a unimodal γ′ size distribution were developed and subjected to loading experiments at 750 °C. Neutron diffraction measurements were carried out during loading to record the elastic lattice strain response of the γ and γ′ phase. A two-site elasto-plastic self-consistent model (EPSC) assisted in the interpretation of the elastic lattice strain response. In addition, the microstructures of the deformed specimens were analysed by (scanning) transmission electron microscopy (STEM). Excellent agreement was found between the EPSC and STEM results regarding a joint deformation of the γ and γ′ phase in the fine γ′ microstructures and for low plastic strains in the medium γ′ microstructures. With increasing γ′ size and increasing degree of plastic deformation, both experimental methodologies revealed a tendency of the two phases to deform independently. © 2014 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.
KW - Elasto-plastic self-consistent (EPSC) model
KW - High-temperature deformation
KW - Neutron diffraction
KW - Nickel-base superalloy
KW - Transmission electron microscopy
U2 - 10.1016/j.actamat.2014.04.028
DO - 10.1016/j.actamat.2014.04.028
M3 - Article
SN - 1359-6454
VL - 74
SP - 18
EP - 29
JO - Acta Materialia
JF - Acta Materialia
IS - 1
ER -