TY - JOUR
T1 - Influence of microstructure on local intra- and intergranular deformations during creep of a nickel-based superalloy at 700°C
AU - Thibault, Kevin
AU - Locq, Didier
AU - Caron, Pierre
AU - Boivin, Denis
AU - Renollet, Yves
AU - Bréchet, Yves
PY - 2013/12/20
Y1 - 2013/12/20
N2 - Several microstructural parameters of the NR6 nickel-based superalloy were varied by applying four heat treatment procedures. Tensile creep tests were performed in air at 700. °C and 700. MPa on specimens exhibiting different grain sizes, strengthening γ' precipitate sizes and distributions and grain boundary morphologies. Flat creep specimens were instrumented thanks to a dedicated microextensometry technique to analyze the local intra- and intergranular deformations after tensile creep under vacuum at 700. °C. Tertiary γ' precipitate dissolution, grain boundary serration and larger grain size reduce grain boundary sliding contribution to overall strain. These effects are attributed to the promotion of Orowan by-passing instead of shearing of the γ' strengthening particles by matrix dislocations, increase of grain boundary resistance or decrease of grain boundary fraction. Relationships between local deformations and macroscopic creep behavior have been evidenced.
AB - Several microstructural parameters of the NR6 nickel-based superalloy were varied by applying four heat treatment procedures. Tensile creep tests were performed in air at 700. °C and 700. MPa on specimens exhibiting different grain sizes, strengthening γ' precipitate sizes and distributions and grain boundary morphologies. Flat creep specimens were instrumented thanks to a dedicated microextensometry technique to analyze the local intra- and intergranular deformations after tensile creep under vacuum at 700. °C. Tertiary γ' precipitate dissolution, grain boundary serration and larger grain size reduce grain boundary sliding contribution to overall strain. These effects are attributed to the promotion of Orowan by-passing instead of shearing of the γ' strengthening particles by matrix dislocations, increase of grain boundary resistance or decrease of grain boundary fraction. Relationships between local deformations and macroscopic creep behavior have been evidenced.
KW - Creep
KW - Grain boundary sliding
KW - Local deformation
KW - Microextensometry
KW - Microstructure
KW - Nickel-based superalloy
UR - http://www.scopus.com/inward/record.url?scp=84884630940&partnerID=8YFLogxK
U2 - 10.1016/j.msea.2013.09.015
DO - 10.1016/j.msea.2013.09.015
M3 - Article
AN - SCOPUS:84884630940
SN - 0921-5093
VL - 588
SP - 14
EP - 21
JO - Materials Science and Engineering A: Structural Materials: Properties, Microstructure and Processing
JF - Materials Science and Engineering A: Structural Materials: Properties, Microstructure and Processing
ER -