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, gamma' Co3(Al,W), which precipitates in the disordered gamma face-centered cubic cobalt matrix with high coherency and with high melting points. We also identified a ternary compound, gamma' Ir3(Al,W), with the L1(2) structure, which suggests that the Co-Ir-Al-W-base systems with gamma+gamma' (Co,Ir)3(Al,W) structures offer great promise as candidates for next-generation high-temperature materials.
Sato
J
J
Department of Materials Science, Graduate School of Engineering, Tohoku University, Sendai 980-8579, Japan.
Omori
T
T
Oikawa
K
K
Ohnuma
I
I
Kainuma
R
R
Ishida
K
K