Elevated Temperature Mechanical Characteristics and Fracture Behavior of a Novel Beta Titanium Alloy

Abstract

In the present work, the elevated-temperature deformation characteristics and microstructural evolution of a Ti-5V-5Mo-5Cr-4Al alloy in solution-treatment conditions were studied under a tensile load at temperatures in the range of 25 to 550 °C and strain rates between 0.001 and 0.1 s−1. The results obtained indicated that, essentially, dynamic recovery (DRV) was the dominant softening mechanism in the case of the regimes considered. An analysis based on transmission electron microscopy (TEM) and the assessment of the mechanical behavior of the solution-heat-treated Ti-5V-5Mo-5Cr-4Al alloy revealed that dynamic precipitation (DPN) only took place at a strain rate of 0.001 s−1 and at temperatures of 450 °C and 500 °C. Void coalescence occurred upon an increase in the deformation temperature and a decrease in the strain rate due to a higher rate of diffusion and the provision of sufficient time for growth, respectively. The results obtained in the present study pave the way for the robust processing of this novel β titanium alloy. Depending on the deformation parameters, the deformation characteristics can be governed by either DRV (at moderate temperatures) or DPN (at moderate temperatures and at low rates of deformation).

Keywords

• Ti-5V-5Mo-5Cr-4Al alloy
• beta titanium
• elevated temperature
• mechanical behavior
• dynamic recovery
• dynamic precipitation