Kinetics of face-centered cubic (FCC) phase evolution in equiatomic AlCoCrFeNi alloy has been studied in this work, measuring the phase fraction from X-ray diffraction (XRD). As-cast alloy showed a body-centered cubic (BCC)+B2 structure. Heat treatments performed at different temperatures showed the formation up-to 30 to 35 pct FCC phase between 1073 K and 1373 K. A systematic decrease in hardness from 540 to 390 HV₁₀ with increase in temperature suggested an increase in the FCC volume fraction. Kinetics of FCC evolution were analyzed using the Johnson–Mehl–Avrami–Kolmogorov equation and Arrhenius law to calculate the activation energy for the phase transformation. Furthermore, a time-temperature-transformation diagram was constructed from the isothermal transformation studies. Detailed microstructural investigation suggests faster kinetics of FCC phase formation near dendritic boundaries compared to interdendritic regions. The Kurdjumov–Sachs orientation relationship between FCC and BCC phases suggested a coherent interface between these phases. Results of the present study pave the way to decide on heat treatment practices in AlCoCrFeNi alloy.

在这项工作中，研究了等原子AlCoCrFeNi合金中面心立方（FCC）相演化的动力学，并测量了X射线衍射（XRD）的相分数。铸态合金显示出体心立方（BCC）+ B2结构。在不同温度下进行的热处理显示，在1073 K和1373 K之间，高达30至35 pct的FCC相形成。硬度从540 HV降低至390 HV ₁₀温度升高提示FCC体积分数增加。使用Johnson-Mehl-Avrami-Kolmogorov方程和Arrhenius定律分析了FCC演化的动力学，以计算相变的活化能。此外，根据等温转变研究建立了时间-温度-转变图。详细的微观结构研究表明，与树突间区域相比，FCC相在树突边界附近形成的动力学更快。FCC和BCC相之间的Kurdjumov-Sachs取向关系表明，这些相之间具有连贯的界面。本研究结果为决定AlCoCrFeNi合金的热处理方式铺平了道路。