TY - GEN
T1 - Morphology change of γ′ precipitates in γ/γ′ two-phase microstructure in Co-based superalloys by higher-order alloying
AU - Tanaka, Katsushi
AU - Ooshima, Masahiro
AU - Okamoto, Norihiko L.
AU - Kishida, Kyosuke
AU - Inui, Haruyuki
N1 - Funding Information:
A part of this work was supported by the Grant-in-Aid for Scientific Research (B) from the Ministry of Education, Culture, Sports, Science and Technology (MEXT), Japan, by the Global COE (Center of Excellence) Program of the International Center for Integrated Research and Advanced Education in Materials Science from MEXT, Japan.
PY - 2011
Y1 - 2011
N2 - Changes in the morphology of γ′ precipitates in a γ/γ′ two-phase microstructure in Co-based superalloys, which occur through higher-order alloying, have been investigated. The shape of γ′ precipitates changes from a cuboid to an irregularly rounded shape when the Ta content increases to 4 at.%. The irregular shape of the γ′ precipitates changes to cuboid again upon further alloying with 2 at.% Mo. Changes in the morphology of γ′ precipitates are closely related to variations in the lattice misfit between γ and γ′ phases upon alloying. A lattice misfit increases with an increase in Ta content, which makes γ/γ′ interfaces incoherent when the lattice misfit exceeds a critical value. On the contrary, the lattice misfit decreases upon alloying with Mo. Changes in the lattice misfit upon alloying are well explained through the partition behavior of alloying elements and their atomic volume.
AB - Changes in the morphology of γ′ precipitates in a γ/γ′ two-phase microstructure in Co-based superalloys, which occur through higher-order alloying, have been investigated. The shape of γ′ precipitates changes from a cuboid to an irregularly rounded shape when the Ta content increases to 4 at.%. The irregular shape of the γ′ precipitates changes to cuboid again upon further alloying with 2 at.% Mo. Changes in the morphology of γ′ precipitates are closely related to variations in the lattice misfit between γ and γ′ phases upon alloying. A lattice misfit increases with an increase in Ta content, which makes γ/γ′ interfaces incoherent when the lattice misfit exceeds a critical value. On the contrary, the lattice misfit decreases upon alloying with Mo. Changes in the lattice misfit upon alloying are well explained through the partition behavior of alloying elements and their atomic volume.
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U2 - 10.1557/opl.2011.191
DO - 10.1557/opl.2011.191
M3 - Conference contribution
AN - SCOPUS:80053188411
SN - 9781605112725
T3 - Materials Research Society Symposium Proceedings
SP - 423
EP - 428
BT - Intermetallic-Based Alloys for Structural and Functional Applications
T2 - 2010 MRS Fall Meeting
Y2 - 29 November 2010 through 3 December 2010
ER -