Substructure and texture evolution and flow behavior of TA15 titanium alloy compressed in the alpha+beta two-phase field

To investigate the flow stress, microstructure, and usability of TA15 titanium alloy, isothermal compression was tested at 1073–1223 K and strain rates of 10, 1, 0.1, 0.01, and 0.001 s−1, and strain of 0.9. The impact of strain and temperature on thermal deformation was investigated through the exponent-type Zener–Hollomon equation. Based on the influence of various material constants (including α, n, Q, and lnA) on the TA15 titanium alloy, the strain effect was included in the constitutive equation considering strain compensation, which is presented in this paper. The validity of the proposed constitutive equation was verified through the correlation coefficient (R) and the average absolute relative error (AARE), the values of which were 0.9929% and 6.85%, respectively. Research results demonstrated that the strain-based constitutive equation realizes consistency between the calculated flow stress and the measured stress of TA15 titanium alloy at high temperatures.

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Effects of strain state and slip mode on the texture evolution of a near-α TA15 titanium alloy during hot deformation based on crystal plasticity method

Journal of Material Science and Technology ◽

10.1016/j.jmst.2019.07.051 ◽

2020 ◽

Vol 38 ◽

pp. 125-134 ◽

Cited By ~ 4

Author(s):

Jie Zhao ◽

Liangxing Lv ◽

Kehuan Wang ◽

Gang Liu

Keyword(s):

Titanium Alloy ◽

Crystal Plasticity ◽

Hot Deformation ◽

Strain State ◽

Texture Evolution ◽

Slip Mode ◽

Ta15 Titanium Alloy

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Primary Alpha Grain Coarsening Behavior of Ti-6Al-2Zr-1Mo-1V Alloy in the Alpha + Beta Two-Phase Field

Journal of Materials Engineering and Performance ◽

10.1007/s11665-013-0537-8 ◽

2013 ◽

Vol 22 (9) ◽

pp. 2557-2566 ◽

Cited By ~ 11

Author(s):

C. Wu ◽

H. Yang ◽

H. W. Li ◽

G. B. Yang

Keyword(s):

Phase Field ◽

Two Phase ◽

Grain Coarsening ◽

Primary Alpha ◽

Coarsening Behavior ◽

Alpha Beta

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Recovery and Recrystallization during Thermo-Mechanical Processing of Ti-6.5Al-1.5Zr-3.5Mo-0.3Si Alloy

Materials Science Forum ◽

10.4028/www.scientific.net/msf.783-786.549 ◽

2014 ◽

Vol 783-786 ◽

pp. 549-555

Author(s):

Hui Qin Chen ◽

Xiao Dong Zhao ◽

Yue Sheng Chai ◽

Chun Xiao Cao

Keyword(s):

Grain Size ◽

Kinetic Model ◽

Dynamic Recrystallization ◽

Grain Boundaries ◽

Phase Field ◽

Single Phase ◽

Strain Rates ◽

Mechanical Processing ◽

Two Phase ◽

Alpha Beta

In this investigation, microstructure evolution of Ti-6.5Al-3.5Mo-1.5Zr-0.3Si alloy during thermo-mechanical processing at temperatures in beta single-phase and alpha+beta two-phase fields was studied. Microstructure analyses indicate that: (1) in the beta single-phase field, dynamic recovery accompanied by geometric dynamic recrystallization at large strains takes place dominantly within elongated large prior beta grains with serrate grain boundaries during deformation at higher temperatures and lower strain rates; and discontinuous dynamic recrystallization occurs along elongated small prior beta grain boundaries during deformation at lower temperatures and higher strain rates. During discontinuous dynamic recrystallization, recrystallized grain size is a function of Zener–Hollomon parameter, and a modified Avrami recrystallized kinetic model was established. (2) In the alpha+beta two-phase field, the globularization process is a thermally activated process controlled by parameters of temperature and strain rate. A modified Avrami globularized kinetic model was established. The primary alpha grain size is a function of Z on a ln-ln scale.

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Characterization of precipitates of Ti3Al in a titanium alloy

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100167500 ◽

1996 ◽

Vol 54 ◽

pp. 1008-1009

Author(s):

X.D. Zhang ◽

J.M.K. Wiezorek ◽

D.J. Evanst ◽

H.L. Fraser

Keyword(s):

Titanium Alloy ◽

High Temperature ◽

Aircraft Engine ◽

Alpha Phase ◽

Microstructural Stability ◽

Beta Titanium Alloy ◽

Two Phase ◽

Beta Titanium ◽

Alpha Beta

A two phase alpha-beta titanium alloy, Ti-6Al-2Mo-2Cr-2Sn-2Zr-0.2Si (Ti-6-22-22S), has recently been reconsidered as a high temperature material for aircraft engine applications. This alloy exhibits specific strength and fracture toughness superior to those of Ti-6A1-4V. However, similar to other alpha-beta titanium alloys, microstructural stability is one of the major concerns regarding industrial application of Ti-6-22-22S, since changes of the microstructure during long term high temperature exposure significantly affect the performance of components. Two types of precipitates have been observed in Ti-6-22-22S alloys, namely silicides and alpha 2-Ti3Al. The presence of intermetallic precipitates, such as alpha 2-Ti3Al, in the parent alpha matrix has been reported to result in brittle behaviour of the alpha-beta alloys due to the formation of intense planar slip bands. The present paper presents results of the characterization of intermetallic alpha2-Ti3Al precipitates in the alpha phase by methods of scanning and transmission electron microscopy (SEM and TEM respectively).

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Dynamic Recrystallization Behavior of TA15 Titanium Alloy under Isothermal Compression during Hot Deformation

Advances in Materials Science and Engineering ◽

10.1155/2014/413143 ◽

2014 ◽

Vol 2014 ◽

pp. 1-9 ◽

Cited By ~ 7

Author(s):

Yuanxin Luo ◽

Yuqing Heng ◽

Yongqin Wang ◽

Xingchun Yan

Keyword(s):

Titanium Alloy ◽

Dynamic Recrystallization ◽

Dimensionless Parameter ◽

Volume Fraction ◽

Phase Region ◽

Two Phase ◽

Ta15 Titanium Alloy ◽

Dynamic Recrystallization Behavior ◽

Series Of Experiments ◽

Sine Equation

In order to improve the understanding of the dynamic recrystallization (DRX) behaviors of TA15 titanium alloy (Ti-6Al-2Zr-1Mo-1V), a series of experiments were conducted on a TMTS thermal simulator at temperatures of 1173 K, 1203 K, 1223 K, and 1273 K with the strain rates of 0.005 s−1, 0.05 s−1, 0.5 s−1, and 1 s−1. By the regression analysis for conventional hyperbolic sine equation, the activation energy of DRX inα+βtwo-phase region isQS=588.7 Kg/moland inβregion isQD=225.8 Kg/mol, and a dimensionless parameter controlling the stored energy was determined asZ/A=ε˙exp(588.7×103)/RT/6.69×1026inα+βtwo-phase region and asZ/A=ε˙exp(225.8×103)/RT/5.13×1011inβregion. The DRX behaviors of TA15 titanium alloy were proposed on the strength of the experiment results. Finally, the theoretical prediction results of DRX volume fraction were shown to be in agreement with experimental observations.

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