@inproceedings{7d239173191545258c6da5c64c1e19af,
title = "Effect of Nb Alloying Addition on Local Phase Transformation at Microtwin Boundaries in Nickel-Based Superalloys",
abstract = "This work investigates two nominally similar polycrystalline alloys, with a subtle difference in Nb content, intended to elucidate its effect on local phase transformation strengthening during high temperature creep. Tests were conducted at 750 °C and 600 MPa to target the creep regime dominated by superlattice intrinsic and extrinsic stacking faults, as well as microtwinning. Alloy A, with higher Nb and lower Al, was found to be superior in creep strength to Alloy B, with lower Nb and higher Al, as well as previously investigated ME3 and LSHR. Atomic resolution scanning transmission electron microscopy and energy-dispersive spectroscopy found that this increased creep strength was due to a novel local phase transformation occurring along microtwin boundary interfaces as a result of the Nb increase. Complementary density functional theory calculations helped to confirm that this was χ phase formation. It is hypothesized that this transformation was the cause of the increased creep strength exhibited by Alloy A.",
keywords = "Creep, HAADF, Local phase transformation, Microtwin, STEM",
author = "Egan, \{A. J.\} and Y. Rao and Viswanathan, \{G. B.\} and Smith, \{T. M.\} and M. Ghazisaeidi and S. Tin and Mills, \{M. J.\}",
note = "Publisher Copyright: {\textcopyright} 2020, The Minerals, Metals \& Materials Society.; 14th International Symposium on Superalloys, Superalloys 2021 ; Conference date: 12-09-2021 Through 16-09-2021",
year = "2020",
doi = "10.1007/978-3-030-51834-9\_62",
language = "English (US)",
isbn = "9783030518332",
series = "Minerals, Metals and Materials Series",
publisher = "Springer Science and Business Media Deutschland GmbH",
pages = "640--650",
editor = "Sammy Tin and Mark Hardy and Justin Clews and Jonathan Cormier and Qiang Feng and John Marcin and Chris O'Brien and Akane Suzuki",
booktitle = "Superalloys 2020 - Proceedings of the 14th International Symposium on Superalloys",
address = "Germany",
}