High-temperature-resistant cobalt-base superalloy
View Patent ↗A cobalt-base superalloy chemical composition is disclosed which includes, in % by weight: 25-28 W; 3-8 Al; 0.5-6 Ta; 0-3 Mo; 0.01-0.2 C; 0.01-0.1 Hf; 0.001 -0.05 B; 0.01-0.1 Si; and remainder Co and unavoidable impurities. This superalloy can be strengthened by γ′ dispersions and further dispersion mechanisms. Exemplary compositions can provide good oxidation properties and improved strength values at high temperatures.
1. A cobalt-base superalloy chemical composition consisting of:
25-28% by weight W;
3-8% by weight Al;
0.5-6% by weight Ta;
0-3% by weight Mo;
0.01-0.2% by weight C;
0.01-0.1% by weight Hf;
0.001-0.05% by weight B;
0.01-0.1% by weight Si; and
remainder Co and unavoidable impurities; and
wherein the superalloy has a microstructure including a γ-phase matrix and a γ′-phase dispersed in the matrix,
wherein the γ-phase matrix comprises a face centered cubic γ-Co phase, and
wherein the γ′-phase comprises Co 3 (Al,W) stabilized by Ta.
2. A gas turbine component containing a cobalt-base superalloy chemical composition consisting of:
25-28% by weight W;
3-8% by weight Al;
0.5-6% by weight Ta;
0-3% by weight Mo;
0.01-0.2% by weight C;
0.01-0.1% by weight Hf;
0.001-0.05% by weight B;
0.01-0.1% by weight Si; and
remainder Co and unavoidable impurities; and
wherein the superalloy has a microstructure including a γ-phase matrix and a Γ′-phase dispersed in the matrix,
wherein the γ-phase matrix comprises a face centered cubic γ-Co phase, and
wherein the γ′-phase comprises Co 3 (Al,W) stabilized by Ta.
3. A cobalt-base superalloy formed as a single-crystal, the superalloy chemical composition consisting of:
26% by weight W;
3.4% by weight Al;
5.1% by weight Ta;
0.02% by weight C;
0.02% by weight Hf;
0.002% by weight B;
0.01% by weight Si; and
remainder Co and unavoidable impurities.
4. A cobalt-base superalloy, wherein the chemical composition consists of:
26% by weight W;
3.4% by weight Al;
5.1% by weight Ta;
0.2% by weight C;
0.1% by weight Hf;
0.05% by weight B;
0.1% by weight Si; and
remainder Co and unavoidable impurities; and
wherein the superalloy has a microstructure including a γ-phase matrix and a γ′-phase dispersed in the matrix,
wherein the γ-phase matrix comprises a face centered cubic γ-Co phase, and
wherein the γ′-phase comprises Co 3 (Al,W) stabilized by Ta.