Globularization of Two-Phase Titanium Alloy during Deformation at 600 and 800°C

2012 ◽  
Vol 715-716 ◽  
pp. 854-859
Author(s):  
Sergey V. Zherebtsov ◽  
Maria A. Murzinova ◽  
Gennady A. Salishchev
Keyword(s):  
Titanium Alloy ◽  
Deformation Temperature ◽  
Dynamic Recovery ◽  
Flow Direction ◽  
Metal Flow ◽  
Lamellar Microstructure ◽  
Dislocation Slip ◽  
Two Phase ◽  
Lower Temperature ◽  
Kinetics Of

Microstructure evolution and mechanical behavior of alpha/beta Ti-6Al-4V titanium alloy with initial α-colony microstructure during uniaxial compression at 600 and 800°C to a height strain of 70% were studied. It was shown that decrease in deformation temperature considerably influences on the kinetics of globularization of a lamellar microstructure. At the lower temperature stages of strengthening and softening extend that associates with inhibition of globularization. Deformation at 600°C is also associated with a smaller fraction of high-angle boundaries during deformation, smaller fraction of globular grains, increased contribution of shear deformation and more intensive rotation of α-lamellae towards the metal flow direction. In contrast to 800°C, the rate of thinning of α-lamellae at the lower temperature is noticeably higher. The results obtained are related to the change of the type of dislocation slip in α-lamellae due to inhibition of dynamic recovery with decreasing deformation temperature.

scholarly journals Thermo-cycling impact upon velocity choice of titanium alloy super-plastic flow

2019 ◽  
Vol 2019 (10) ◽  
pp. 19-25
Author(s):  
Владимир Гадалов ◽  
Vladimir Gadalov ◽  
Ирина Ворначева ◽  
Irina Vornacheva ◽  
Александр Филонович ◽  
...  
Keyword(s):  
Plastic Deformation ◽  
Titanium Alloy ◽  
Plastic Flow ◽  
Temperature Interval ◽  
Deformation Temperature ◽  
Processing Time ◽  
Phase State ◽  
Two Phase ◽  
Deformation State ◽  
Super Plastic

The modes of the thermo-cyclical deformation of pseudo-α alloys having the super-plastic deformation state under isothermal conditions at temperatures in the field of two-phase state are investigated. The modes for preliminary thermo-processing influencing processing characteristics of VT20 and OT$ alloys, that is, increasing a deformation temperature interval and decreasing processing time are determined.

Interphase distribution of 2-furylethylenes

1985 ◽  
Vol 50 (8) ◽  
pp. 1642-1647 ◽  
Author(s):  
Štefan Baláž ◽  
Anton Kuchár ◽  
Ernest Šturdík ◽  
Michal Rosenberg ◽  
Ladislav Štibrányi ◽  
...  
Keyword(s):  
Partition Coefficient ◽  
Partition Coefficients ◽  
Transport Rate ◽  
Phase System ◽  
Two Phase ◽  
Interphase Distribution ◽  
Distribution Kinetics ◽  
System 1 ◽  
Kinetics Of

The distribution kinetics of 35 2-furylethylene derivatives in two-phase system 1-octanol-water was investigated. The transport rate parameters in direction water-1-octanol (l1) and backwards (l2) are partition coefficient P = l1/l2 dependent according to equations l1 = logP - log(βP + 1) + const., l2 = -log(βP + 1) + const., const. = -5.600, β = 0.261. Importance of this finding for assesment of distribution of compounds under investigation in biosystems and also the suitability of the presented method for determination of partition coefficients are discussed.

β Grain Growth Kinetics of a New Metastable β Titanium Alloy

2013 ◽  
Vol 747-748 ◽  
pp. 844-849 ◽  
Author(s):  
Yue Fei ◽  
Xin Nan Wang ◽  
Zhi Shou Zhu ◽  
Jun Li ◽  
Guo Qiang Shang ◽  
...  
Keyword(s):  
Titanium Alloy ◽  
Grain Growth ◽  
Kinetic Equations ◽  
Type Equation ◽  
Growth Exponent ◽  
Solution Treated ◽  
Growth Activation ◽  
Grain Growth Kinetics ◽  
Kinetics Of ◽  
Strength And Ductility

Ti-Mo-Nb-Cr-Al-Fe-Si alloy is a new metastable β titanium alloy with excellent combination of strength and ductility. The β grain-growth exponent and the activation energies for β grain growth for the investigated alloy at specified temperature were computed by the kinetic equations and the Arrhenius-type equation. The rate of β grain growth decreases with elongating solution treated time and increases with the increasing solution-treated temperature. The β grain-growth exponents, n, are 0.461, 0.464 and 0.469 at 1113, 1133 and 1153K, respectively. The β grain growth activation energy is determined to be 274 KJ/mol.

scholarly journals Recognition of hydrogen isotopomers by an open-cage fullerene

2013 ◽  
Vol 371 (1998) ◽  
pp. 20110629 ◽  
Author(s):  
Yasujiro Murata ◽  
Shih-Ching Chuang ◽  
Fumiyuki Tanabe ◽  
Michihisa Murata ◽  
Koichi Komatsu
Keyword(s):  
Equilibrium Constants ◽  
Equilibrium Mixture ◽  
Size Difference ◽  
Binding Affinities ◽  
Kinetic Isotope ◽  
Molecular Sizes ◽  
Lower Temperature ◽  
Kinetics Of ◽  
Pressure Hydrogen

We present our study on the recognition of hydrogen isotopes by an open-cage fullerene through determination of binding affinity of isotopes H 2 /HD/D 2 with the open-cage fullerene and comparison of their relative molecular sizes through kinetic-isotope-release experiments. We took advantage of isotope H 2 /D 2 exchange that generated an equilibrium mixture of H 2 /HD/D 2 in a stainless steel autoclave to conduct high-pressure hydrogen insertion into an open-cage fullerene. The equilibrium constants of three isotopes with the open-cage fullerene were determined at various pressures and temperatures. Our results show a higher equilibrium constant for HD into open-cage fullerene than the other two isotopomers, which is consistent with its dipolar nature. D 2 molecule generally binds stronger than H 2 because of its heavier mass; however, the affinity for H 2 becomes larger than D 2 at lower temperature, when size effect becomes dominant. We further investigated the kinetics of H 2 /HD/D 2 release from open-cage fullerene, proving their relative escaping rates. D 2 was found to be the smallest and H 2 the largest molecule. This notion has not only supported the observed inversion of relative binding affinities between H 2 and D 2 , but also demonstrated that comparison of size difference of single molecules through non-convalent kinetic-isotope effect was applicable.

scholarly journals Dynamic Softening Mechanisms and Microstructure Evolution of TB18 Titanium Alloy during Uniaxial Hot Deformation

Metals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 789
Author(s):  
Qiang Fu ◽  
Wuhua Yuan ◽  
Wei Xiang
Keyword(s):  
Titanium Alloy ◽  
Dynamic Recovery ◽  
True Strain ◽  
Hot Workability ◽  
Compression Tests ◽  
Phase Zone ◽  
Β Phase ◽  
Stability And Instability ◽  
Dynamic Softening ◽  
Transus Temperature

In this study, isothermal compression tests of TB18 titanium alloy were conducted using a Gleeble 3800 thermomechanical simulator for temperatures ranging from 650 to 880 °C and strain rates ranging from 0.001 to 10 s−1, with a constant height reduction of 60%, to investigate the dynamic softening mechanisms and hot workability of TB18 alloy. The results showed that the flow stress significantly decreased with an increasing deformation temperature and decreasing strain rate, which was affected by the competition between work hardening and dynamic softening. The hyperbolic sine Arrhenius-type constitutive equation was established, and the deformation activation energy was calculated to be 303.91 kJ·mol−1 in the (α + β) phase zone and 212.813 kJ·mol−1 in the β phase zone. The processing map constructed at a true strain of 0.9 exhibited stability and instability regions under the tested deformation conditions. The microstructure characteristics demonstrated that in the stability region, the dominant restoration and flow-softening mechanisms were the dynamic recovery of β phase and dynamic globularization of α grains below transus temperature, as well as the dynamic recovery and continuous dynamic recrystallization of β grains above transus temperature. In the instability region, the dynamic softening mechanism was flow localization in the form of a shear band and a deformation band caused by adiabatic heating.

scholarly journals Hot Deformation Behavior and Processing Maps of a New Ti-6Al-2Nb-2Zr-0.4B Titanium Alloy

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2456
Author(s):  
Zhijun Yang ◽  
Weixin Yu ◽  
Shaoting Lang ◽  
Junyi Wei ◽  
Guanglong Wang ◽  
...  
Keyword(s):  
Titanium Alloy ◽  
Flow Stress ◽  
Constitutive Equation ◽  
Deformation Mechanism ◽  
Power Dissipation ◽  
Hot Deformation ◽  
Dissipation Rate ◽  
Dynamic Recovery ◽  
Processing Maps ◽  
Temperature Range

The hot deformation behaviors of a new Ti-6Al-2Nb-2Zr-0.4B titanium alloy in the strain rate range 0.01–10.0 s−1 and temperature range 850–1060 °C were evaluated using hot compressing testing on a Gleeble-3800 simulator at 60% of deformation degree. The flow stress characteristics of the alloy were analyzed according to the true stress–strain curve. The constitutive equation was established to describe the change of deformation temperature and flow stress with strain rate. The thermal deformation activation energy Q was equal to 551.7 kJ/mol. The constitutive equation was ε ˙=e54.41[sinh (0.01σ)]2.35exp(−551.7/RT). On the basis of the dynamic material model and the instability criterion, the processing maps were established at the strain of 0.5. The experimental results revealed that in the (α + β) region deformation, the power dissipation rate reached 53% in the range of 0.01–0.05 s−1 and temperature range of 920–980 °C, and the deformation mechanism was dynamic recovery. In the β region deformation, the power dissipation rate reached 48% in the range of 0.01–0.1 s−1 and temperature range of 1010–1040 °C, and the deformation mechanism involved dynamic recovery and dynamic recrystallization.

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