# Impact of Heat Treatment on the Mechanical Properties and Fracture Morphology of Ti555211 Alloy

## TL;DR

This paper examines how different heat treatments affect the strength and toughness of a titanium alloy, finding that a specific treatment balances high strength and ductility.

## Contribution

The study identifies an optimal heat treatment process for Ti555211 alloy that achieves high strength and ductility.

## Key findings

- β-annealing retains high strength but shows no ductility or yield strength.
- Double annealing increases elongation to ~54% but reduces strength.
- Solid-solution and aging treatment balances high strength (1404 MPa) and ductility (11% elongation).

## Abstract

Heat treatment is important for optimizing the strength performance and improving the toughness of titanium alloys. In this study, we investigated the impact of three heat treatment methods (β-annealing, double annealing, and solid-solution and aging treatment) on the mechanical properties and fracture morphology of Ti555211 titanium alloy. The results show that after β-annealing treatment, the alloy retains a high strength, while showing almost no ductility, and no yield strength. The alloy after double annealing has a high elongation rate (~54%) and lower strength. After solid-solution and aging heat treatment, the alloy was able to retain both high strength and a certain degree of ductility. The optimal heat-treatment process is solid-solution treatment at 820 °C/2 h and aging at 560 °C/12 h, which results in a maximum tensile strength of 1404 MPa and an elongation rate of 11%.