Cobalt-Base High-Temperature Alloys

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, [fleqn,10pt,legalpaper]{article} {amssymb} {amsfonts} {amsmath} {empty} {document} \({γ}^{{^}}\) {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, [fleqn,10pt,legalpaper]{article} {amssymb} {amsfonts} {amsmath} {empty} {document} \({γ}^{{^}}\) {document} Ir 3 (Al,W), with the L1 2 structure, which suggests that the Co-Ir-Al-W–base systems with [fleqn,10pt,legalpaper]{article} {amssymb} {amsfonts} {amsmath} {empty} {document} \({γ}+{γ}^{{^}}\) {document} (Co,Ir) 3 (Al,W) structures offer great promise as candidates for next-generation high-temperature materials.