Hot deformation and dynamic recrystallization of a near-beta titanium alloy in the β single phase region

A self-designed Ti-35421 (Ti-3Al-5Mo-4Cr-2Zr-1Fe wt%) titanium alloy is a new type of low-cost high strength titanium alloy. In order to understand the hot deformation behavior of Ti-35421 alloy, isothermal compression tests were carried out under a deformation temperature range of 750–930 °C with a strain rate range of 0.01–10 s−1 in this study. Electron backscatter diffraction (EBSD) was used to characterize the microstructure prior to and post hot deformation. The results show that the stress–strain curves have obvious yielding behavior at a high strain rate (>0.1 s−1). As the deformation temperature increases and the strain rate decreases, the α phase content gradually decreases in the α + β phase region. Meanwhile, spheroidization and precipitation of α phase are prone to occur in the α + β phase region. From the EBSD analysis, the volume fraction of recrystallized grains was very low, so dynamic recovery (DRV) is the dominant deformation mechanism of Ti-35421 alloy. In addition to DRV, Ti-35421 alloy is more likely to occur in continuous dynamic recrystallization (CDRX) than discontinuous dynamic recrystallization (DDRX).

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The strain rate sensitivity exponent and the strain hardening exponent of as-cast TC21 titanium alloy in β single-phase region

Materials Research Express ◽

10.1088/2053-1591/ab513f ◽

2019 ◽

Vol 6 (11) ◽

pp. 1165g1

Author(s):

Zhenwei Yue ◽

Yanchun Zhu ◽

Jiaxin Fan ◽

Zhucai Shao

Keyword(s):

Titanium Alloy ◽

Strain Rate ◽

Strain Hardening ◽

Strain Rate Sensitivity ◽

Single Phase ◽

Rate Sensitivity ◽

Phase Region ◽

Strain Hardening Exponent ◽

Single Phase Region

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Thermal Deformation Behavior of a New Metastable Beta Titanium Alloy

Materials Science Forum ◽

10.4028/www.scientific.net/msf.1035.32 ◽

2021 ◽

Vol 1035 ◽

pp. 32-38

Author(s):

Jing Li ◽

Xin Nan Wang ◽

Zhi Shou Zhu

Keyword(s):

Titanium Alloy ◽

Strain Rate ◽

Deformation Behavior ◽

Thermal Deformation ◽

Phase Region ◽

Hot Compression ◽

Beta Titanium Alloy ◽

Experimental Conditions ◽

Beta Titanium ◽

Metastable Beta

The thermal deformation behavior of a new metastable beta titanium alloy composed of Ti-Al-Mo-V-Nb-Cr was studied under different experimental conditions of varying temperatures (760°C~ 970°C) and strain rates (0.001s−1, 0.01s−1, 0.1s−1, 1s−1 and 10s−1) up to deformation amount of 60%. The hot compression experiments were completed on a Gleeble-3500 thermal analogue. The experimental results showed that the true stress of the Ti-Al-Mo-V-Nb-Cr titanium alloy decreased with increasing the temperature and decreasing the strain rate, the stress peaks and the steady-state stress values were higher with the decreasing of temperature at the same strain rate. The calculated values of the deformation activation energy were 187.87 kJ/mol in the two-phase region and 165.17kJ/mol in beta single-phase region. The corresponding constitutive equation was determined by the multiple linear regression calculation on the hot compression experimental data, on the base of Arrhenius equations.

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