Growth kinetics of β-Ti solid solution in reaction diffusion

Abstract

The growth kinetics of the β-Ti solid solution phases in several pure metal diffusion couples have been investigated. The layer growth of β-Ti solid solution phases is observed to obey the parabolic law, indicating that the rate controlling process is diffusion. The temperature dependence of the rate constant of the layer growth shows a linear relationship in the Arrhenius plots at higher temperatures. On the other hand, it deviates from the linearity at low temperatures. This deviation from the linearity is shown to be related to the variation of compositional range of the β-Ti solid solution with temperatures. Additionally, the activation energy for the layer growth is found to be equal to sum of the activation energy for interdiffusion and the formation enthalpy of β-Ti solid solution in the eutectoid temperature range.