Kinetics of the martensitic transition in In-Tl alloys

Abstract

The kinetics of the martensitic transition in In-Tl alloys has been studied by x-ray- and neutron-diffraction methods. A characteristic waiting time appears at fixed temperature above ${\mathit{M}}_{\mathit{s}}$, the normal martensitic phase transition start temperature. A similar waiting time is also seen for inverse phase transitions. A peculiar temperature ${\mathit{T}}_{\mathit{p}}$, which is above ${\mathit{M}}_{\mathit{s}}$, but below ${\mathit{T}}_0$, is found to exist. The time development of x-ray-diffraction patterns shows a very different behavior whether the temperature is above ${\mathit{T}}_{\mathit{p}}$ or below ${\mathit{T}}_{\mathit{p}}$. It is found that ideal nucleation and growth take place between ${\mathit{T}}_{\mathit{p}}$ and ${\mathit{T}}_0$. Between ${\mathit{T}}_{\mathit{p}}$ and ${\mathit{M}}_{\mathit{s}}$, the kinetics of the phase transition is more complicated. In order to understand the kinetics of the phase transition, the temperature-dependent waiting time curve in In-Tl alloys is calculated using the Roitburd method [A. L. Roitburd, Mater. Sci. Eng. A127, 229 (1990)] and is found to be in good agreement with experimental results.