A self-optimized Ti alloy with superior mechanical properties at wide temperature range

Conventional alloy design methods often rely on trial-and-error approaches, resulting in significant computational costs and resource consumption. To circumvent these limitations, we adopted a "self-optimizing" strategy by directly extracting the chemical composition of the single-phase region from a pre-designed alloy. Applying this method to a low-density Ti-Al-Si-Y system, we developed a novel single-phase α-Ti alloy, Ti85Al12Si3, through two rounds of self-optimization. The resulting alloy exhibits compositional homogeneity and superior mechanical performance. Specifically, it displays a room-temperature compressive strength of ~1.7 GPa with ~35% strain to fracture. At 600 °C, it significantly outperforms the conventional Ti4822 alloy, maintaining a tensile strength of ~582 MPa and ~10% elongation. These enhanced properties are attributed to the supersaturated solid-solution structure, which provides high lattice strength and multiple slip systems. This study validates the efficiency of the self-optimization strategy for designing high-performance Ti alloys.