The analysis of hot deformation behaviour of low-cost α+β Ti-6Al-0.4V-1.2Fe alloys

Abstract

The low-cost Ti-6Al-0.4V-1.2Fe alloy was subjected to isothermal compression experiments on the Gleeble 3800, and the deformation temperature was 775°C∼975°C and the strain rate was 0.01 s⁻¹∼10 s⁻¹. Based on the experimental data on thermal deformation, the microstructure evolution was studied and the constitutive equation was developed. The experimental results show that the flow stress increased with increasing deformation temperature and with the increase of the strain rate; the optimal deformation temperature of Ti-6Al-0.4V-1.2Fe alloy is 820°C∼950°C, and the strain rate is 0.01 s⁻¹∼0.32 s⁻¹; During hot deformation, the primary softening mechanism of this alloy is continuous dynamic recrystallisation. Compared with Ti-6Al-4V, the Ti-6Al-0.4V-1.2Fe alloy has better hot workability and better plasticity.

Highlights

1. A newly low-cost Ti-6Al-0.4V-1.2Fe alloy was designed based on the K_β stability coefficient method, and the β stability coefficient was the same as that of Ti-6Al-4V.

2. A study on the microstructure evolution in the process of hot deformation between Ti-6Al-0.4V-1.2Fe and Ti-6Al-4V alloys.

3. A study on microstructure evolution and hot working process of a newly low-cost Ti-6Al-0.4V-1.2Fe alloy.

KEYWORDS:

• Titanium alloy
• hot deformation
• constitutive equation
• microstructure evolution

Disclosure statement

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

CRediT authorship contribution statement

Guilin Wan did the experiment, analysed the data and wrote the paper. Zhihao Ren, Guoqing Dai, Yanhua Guo were responsible for the alloy preparation and analysed the data. Zhonggang Sun, Hui Chang conceived the idea, and designed the experiment. All the authors discussed the result, revised the paper, and approved the final version.

Prime novelty statement

The microstructure evolution and hot working process of a new low-cost Ti-6Al-0.4V-1.2Fe alloy were studied. The comparison and analysis of Ti-6Al-0.4V-1.2Fe alloy and Ti-6Al-4V alloy, as well as the influence of Fe/V interaction on the deformation behaviour, microstructure evolution and mechanism of the alloy are also made. Then the optimal processing range of the new alloy is determined by the hot working diagram.

Data availability

The raw/processed data required to reproduce these findings cannot be shared at this time due to legal or ethical reasons.

Additional information

Funding

The authors acknowledge is supported by the National Key Research and Development Program of China [2020YFB2008301, 2020YFB2008303], the National Natural Science Foundation of China [No. 52001163, No. 52075237], Taizhou Science and Technology Project [No. TG202125] and Aeronautical Science Foundation of China [202000360T4-0001].