Determination of activation energy for α + β ⇒ β transformation in Ti-6Al-4V alloy by dilatometry

Shah, Arman; Kulkarni, GT; Gopinathan, V.; Krishnan, R.

doi:10.1016/0956-716x(95)00170-z

Cited by 11 publications

(5 citation statements)

References 3 publications

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“…Thus, the total activation energy Q of the α + β → β transformation during the continuous heating process is 445.5 kJ•mol −1 , and the pre-exponential factor K0 of the Johnson-Mehl-Avrami (JMA) equation is 1.067 × 10 17 . The above results are in the same order of magnitude as the phase transformation activation energy of Ti-6Al-4V alloy measured by the electric resistance method during the continuous heating process [9]. 1 T β Figure 6.…”

Section: Phase Transformation Kinetics During the Heating Processsupporting

confidence: 67%

“…Thermal dilatometry is an effective method for analyzing the phase transformation kinetics of solid metal. Shah et al [9] studied the α + β → β phase transformation activation energy of Ti-6Al-4V by thermal dilatometry, and speculated that the diffusion of the stable element V from the β phase to the α phase determines the transformation speed. In addition, Ming et al [10], Katzarov et al [11] and Elmer et al [12] also described the effect of the V element on the phase transformation behavior of different types of titanium alloys.…”

Section: Introductionmentioning

confidence: 99%

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Study on Non-Isothermal Transformation of Ti-6Al-4V in Solution Heating Stage

Zou

et al. 2019

Metals

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In order to understand the non-isothermal transformation behavior of Ti-6Al-4V titanium alloy in the continuous heating stage of solution treatment, thermal dilatometry tests with heating rates of 0.1~0.8 °C/s were designed. The conversion between the expansion amount and the transformed volume fraction was realized by the lever principle, and the transformation characteristics of α + β → β were quantified based on the Kissinger-Akahira-Sunose (KAS) theory and the modified Johnson–Mehl–Avrami (JMA) model. The results show that the phase transformation kinetics curves present typical “S” patterns, and the element diffusion transformation controls the nucleation and growth of new grains during the transformation of α + β → β. The phase transformation interval gradually moves to high temperature regions with the increase of heating rates, and the phase transformation activation energy is 445.5 kJ·mol−1. The phase transformation process is divided into three stages according to the relationship between the Avrami exponent n and the transformed volume fraction fT. These three stages correspond to different stages of grain nucleation or growth.

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Section: Phase Transformation Kinetics During the Heating Processsupporting

confidence: 67%

Section: Introductionmentioning

confidence: 99%

Study on Non-Isothermal Transformation of Ti-6Al-4V in Solution Heating Stage

Zou

et al. 2019

Metals

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“…Based on the dilatometric experiments performed at different heating rates, the activation energy of the ␣ + ␤ → ␤ transformation can be obtained in ␣ + ␤ titanium alloy [21], which is related to T ␤ and heating rates H (K/s) as follows:…”

Section: Determination Of the Phase Transformation Fraction And Activmentioning

confidence: 99%

Phase transformation in TC21 alloy during continuous heating

Wang

Kou

Chang

et al. 2009

Journal of Alloys and Compounds

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“…The study of phase transformation kinetics in various heat treatment processes of titanium alloys is generally based on the thermal expansion method and Johnson-Mehl-Avrami (JMA) theoretical model. Shah [13] found that the activation energy of α + β → β transformation of TC4 alloy is close to the diffusion activation energy of vanadium from β to α by thermal expansion method. It was speculated that the diffusion of vanadium determined the transformation rate of α + β → β, and similar conclusions were also described in the studies of Ming [14], Katzarov [15] and Elmer [16].…”

Section: Introductionmentioning

confidence: 83%

Study on Transformation Mechanism and Kinetics of α’ Martensite in TC4 Alloy Isothermal Aging Process

et al. 2020

Crystals

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The law of microstructure evolution and transformation mechanism of the α′ martensite decomposition during 400–600 °C were studied by the isothermal dilatometry. The transformation process of α′ martensite was quantitatively characterized based on Johnson–Mehl–Avrami (JMA) model, and the microstructure evolution under different aging processes was observed and compared on Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM). The results showed that α′ → α + β is the elemental diffusion transformation, the position and shape of the precipitate gradually change with the holding time and temperature. The decomposition rate of α′ martensite was positively correlated with the aging temperature. The whole transformation process was divided into two stages based on the value of the Avrami exponent n, and the corresponding average values of the transformation activation energies Q are 46.1 kJ/mol and 116.8 kJ/mol, respectively. The calculated model had good agreement with the experimental data, and the transformation curve of α′ martensite with time and temperature during the isothermal aging at 400–600 °C was drawn.

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Determination of activation energy for α + β ⇒ β transformation in Ti-6Al-4V alloy by dilatometry

Cited by 11 publications

References 3 publications

Study on Non-Isothermal Transformation of Ti-6Al-4V in Solution Heating Stage

Study on Non-Isothermal Transformation of Ti-6Al-4V in Solution Heating Stage

Phase transformation in TC21 alloy during continuous heating

Study on Transformation Mechanism and Kinetics of α’ Martensite in TC4 Alloy Isothermal Aging Process

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