Cobalt-Base High-Temperature Alloys

Abstract

We have identified cobalt-base superalloys showing a high-temperature strength greater than those of conventional nickel-base superalloys. The cobalt-base alloys are strengthened by a ternary compound with the L1 ₂ structure, \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \({\gamma}^{{^\prime}}\) \end{document} Co ₃ (Al,W), which precipitates in the disordered γ face-centered cubic cobalt matrix with high coherency and with high melting points. We also identified a ternary compound, \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \({\gamma}^{{^\prime}}\) \end{document} Ir ₃ (Al,W), with the L1 ₂ structure, which suggests that the Co-Ir-Al-W–base systems with \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \({\gamma}+{\gamma}^{{^\prime}}\) \end{document} (Co,Ir) ₃ (Al,W) structures offer great promise as candidates for next-generation high-temperature materials.