Interplay Between Thermodynamic and Kinetic Factors in the Formation of Metastable Phases

研究了四种合金体系，以比较亚稳相的形成与相关的热力学和动力学模型。选择了两种生成热为负的三元体系；这些都受到液体快速淬火速率的限制。观察到的亚稳相的形成与基于连续冷却结晶动力学模型的理论预测进行了比较。研究了两种具有正生成热的二元非混相合金体系，试图通过溅射或机械合金化制备亚稳相。根据各自的自由能及其随温度变化的建模，计划对这些双星系统进行相预测。

Four alloy systems are examined in order to compare the formation of metastable phases with related thermodynamic and kinetic modeling. Two ternary systems are selected that display negative heats of formation; these are subjected to a schedule of rapid quench rates from the liquid. Observed metastable phases that form are compared with theoretical predictions based on a model of continuous cooling crystallization kinetics. Two binary immiscible alloy systems with positive heats of formation are included in the research in an attempt to produce metastable phases by sputtering or mechanical alloying. Phase predictions based on modeling of the respective free energies and their changes with temperature are planned for these binary systems.