Enhanced microstructural stability of γ/γ′-strengthened Co-Ti-Mo-based alloys through Al additions

We studied the microstructural stability and high-temperature mechanical properties of γ/γ′ Co-Ti-Mo-based alloys of varying compositions (Co-12Ti-4Mo, Co-12Ti-4Mo-2Al, Co-12Ti-4Mo-4Al, Co-10Ti-4Mo-2Al, and Co-8Ti-4Mo-4Al (at.%)) using electron microscopy and density functional theory. The Co-12Ti-4Mo alloy underwent discontinuous precipitation into FCC (γ) and D019 (χ) phases after aging at 800°C for 500 h while the Co-12Ti-4Mo-4Al alloy...