# Dual‐Array Nano Configuration for High‐Performance Metastable β Titanium Alloys

## TL;DR

A new titanium alloy design achieves high strength and ductility at high temperatures through a unique nanostructure formed by dislocation and phase interactions.

## Contribution

A novel dislocation-phase coupling mechanism enables dynamic microstructure control in metastable titanium alloys.

## Key findings

- The alloy achieves 863 MPa ultimate tensile strength and 78.3% elongation at 500°C.
- Dual-array nano α grains form through interlaced and parallel configurations.
- Phase-field simulations and strain mapping validate the new mechanism.

## Abstract

Catastrophic failures in engineering metallics frequently occur at high temperatures. A fundamental understanding of plastic deformation and the mechanisms governing the strength‐ductility trade‐off is essential for developing titanium alloys exhibiting superior properties at elevated temperatures. Herein, a metastable β titanium alloy (Ti‐15.1Mo‐3.1Nb‐2.77Al‐0.21Si, wt.%) exhibits unexpected mechanical properties, including an ultimate tensile strength of 863 MPa and a total elongation of 78.3% at 500 °C, accompanied by a continuous and strong work hardening rate (2000–3100 MPa). Dislocation slip and heating play pivotal roles in interlaced parallel α nucleation, and thermal activation promotes interlaced α nucleation. Finally, the dual‐array nano configuration of dense (≈68%) and thin (≈10 nm in width) α phase forms. Hierarchical microstructural evolutions, including β to α phase transformation, nano α grains with dual‐array configurations (interleaved and parallel), and dislocation interaction, contribute to the excellent mechanical properties. These findings reveal that dynamic nano α precipitation with unique dual‐array nano configurations can unveil new prospects for the development of high‐performance metastable titanium alloys at elevated temperatures.

This work resolves a fundamental paradox in metastable alloys by establishing a novel dislocation‐phase coupling mechanism, enabling dynamic microstructure control for simultaneous thermal stability and deformability. Geometrically ordered α‐nanograins achieve unprecedented 500°C strength‐ductility synergy (863 MPa UTS, 78.3% elongation). Validated by phase‐field simulations and atomic‐scale strain mapping, this paradigm shift offers universal principles for defect‐engineered materials, surpassing aerospace titanium benchmarks.