Application of the adiabatic remelt model to the solidification of undercooled iron-cobalt alloys.

摘要

Control of the grain size is integral to reducing the cobalt fraction of iron-cobalt alloys. Using high-speed imagery and non-contact temperature sensing, it is possible to determine solidification growth velocities as a function of undercooling and phase. LKT theory can be used to model this relationship to determine an effective heat capacity of stable phase growth into pre-existing metastable solid.;Growth of the stable phase into pre-existing solid occurs rapidly before slowly reaching equilibrium. The volume of rapid solidification requires remelting the pre-existing solid. The thickness of this region can be calculated using the Adiabatic Remelt (AR) Model or Microstructural Limit (ML) Theory. Both methods require the effective heat capacity calculated by LKT theory. Use of ML Theory generates an upper limit to the rapid solidification region thickness. As the predicted thickness using the AR Model is less than this limit, it is physically validated.