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