Accelerated discovery of oxidation resistant CoNi-base γ/γ' alloys with high L12 solvus and low density

TitleAccelerated discovery of oxidation resistant CoNi-base γ/γ' alloys with high L12 solvus and low density
Publication TypeJournal Article
Year of Publication2020
AuthorsStewart CA, Murray SP, Suzuki A, Pollock TM, Levi CG
JournalMaterials and Design
Volume189
Pagination1–12
ISSN18734197
KeywordsAlloy design, Cobalt-base superalloys, Combinatorial synthesis, Oxidation, Superalloys
Abstract

A systematic and accelerated methodology for alloy design is demonstrated by combining combinatorial synthesis, high-throughput oxide scale characterization, computational density functional theory, and CALPHAD database calculations. By applying this strategy to the senary Co-Ni-W-Al-Cr-Ta material system, a novel γ/γ' alloy exhibiting a superior combination of properties has been identified. Properties include a γ' solvus near 1200 °C, continuous α-Al2O3 scale formation after 1 h in air at 1100 °C, and comparable density to 2nd-generation commercial Ni-base superalloys. This novel alloy SB-CoNi-10 has a nominal composition of 39.8Co – 36.5Ni – 13.2Al – 1.0W – 6.0Cr – 3.5Ta at.%, and its properties are compared with other recently studied Co-, CoNi-, and Ni-base γ/γ' alloys.

DOI10.1016/j.matdes.2019.108445