CMSX-4 is a second-generation single-crystal nickel-based superalloy. Through aging heat treatments, the characteristics of γ’ precipitates, including their size, volume fraction, and morphology, can be controlled in this alloy. Therefore, the main goal of this research is to investigate the effect of aging temperatures (800-1140 ℃) and times (1-24 h) on the kinetics of γ’ precipitate formation and growth. As the aging temperature increases, the morphology changes from an irregular shape to a cubic one. The most regular cubic morphology is observed at 900 ℃, compared to other temperatures. Due to the competition between diffusion and matrix supersaturation, the volume fraction of precipitates initially increases and then decreases with increasing temperature and time. Kinetic studies of γ’ precipitate growth and formation using the Johnson-Mehl-Avrami method show that the rate of transformation and growth of γ’ precipitates increases with increasing aging temperature. The average value for the Avrami exponent (n) is approximately 4 in the temperature range of 835-900 ℃, which indicates regular and cubic growth of γ’ precipitates within this temperature range. Based on this model, a TTP diagram was plotted for CMSX-4, which shows that the nose of the TTP curve, indicating the optimal temperature and time conditions for γ’ phase formation, is obtained at approximately 850 °C.
Rabbani Fard, S. , seifollahi, M. , Abbasi, S. M. and aKhondzadeh, A. (2024). Investigation of γ' Precipitates Growth Kinetics in CMSX-4 Based on the Johnson-Mehl-Avrami Model. Progress in Engineering Thermodynamics and Kinetics, 1(2), -. doi: 10.22075/jpetk.2025.36480.1023
MLA
Rabbani Fard, S. , , seifollahi, M. , , Abbasi, S. M. , and aKhondzadeh, A. . "Investigation of γ' Precipitates Growth Kinetics in CMSX-4 Based on the Johnson-Mehl-Avrami Model", Progress in Engineering Thermodynamics and Kinetics, 1, 2, 2024, -. doi: 10.22075/jpetk.2025.36480.1023
HARVARD
Rabbani Fard, S., seifollahi, M., Abbasi, S. M., aKhondzadeh, A. (2024). 'Investigation of γ' Precipitates Growth Kinetics in CMSX-4 Based on the Johnson-Mehl-Avrami Model', Progress in Engineering Thermodynamics and Kinetics, 1(2), pp. -. doi: 10.22075/jpetk.2025.36480.1023
CHICAGO
S. Rabbani Fard , M. seifollahi , S. M. Abbasi and A. aKhondzadeh, "Investigation of γ' Precipitates Growth Kinetics in CMSX-4 Based on the Johnson-Mehl-Avrami Model," Progress in Engineering Thermodynamics and Kinetics, 1 2 (2024): -, doi: 10.22075/jpetk.2025.36480.1023
VANCOUVER
Rabbani Fard, S., seifollahi, M., Abbasi, S. M., aKhondzadeh, A. Investigation of γ' Precipitates Growth Kinetics in CMSX-4 Based on the Johnson-Mehl-Avrami Model. Progress in Engineering Thermodynamics and Kinetics, 2024; 1(2): -. doi: 10.22075/jpetk.2025.36480.1023
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