Dual-Array Nano Configuration for High-Performance Metastable β Titanium Alloys.

Area of Science:

• Materials Science
• Metallurgy
• Mechanical Engineering

Background:

• High-temperature failures in metallic components necessitate understanding strength-ductility trade-offs.
• Developing advanced titanium alloys for elevated temperature applications is crucial.

Purpose of the Study:

• Investigate the mechanical properties of a specific metastable beta titanium alloy at high temperatures.
• Elucidate the microstructural evolution and mechanisms responsible for superior performance.

Main Methods:

• Mechanical testing of a metastable beta titanium alloy (Ti-15.1Mo-3.1Nb-2.77Al-0.21Si) at 500 °C.
• Microstructural analysis focusing on phase transformation and nano-phase formation.
• Investigating dislocation slip and thermal activation effects.

Main Results:

• The alloy achieved an ultimate tensile strength of 863 MPa and 78.3% elongation at 500 °C.
• Observed continuous and strong work hardening rate (2000-3100 MPa).
• Identified dual-array nano configuration of alpha phase (≈68% density, ≈10 nm width) driven by dislocation slip and thermal activation.

Conclusions:

• Hierarchical microstructural evolutions, including phase transformation and dual-array nano alpha grains, contribute to excellent high-temperature mechanical properties.
• Dynamic nano alpha precipitation with unique dual-array configurations offers new avenues for high-performance metastable titanium alloys.
• Findings provide insights for designing titanium alloys for extreme temperature environments.