Session D40 - Poster Session I.
POSTER session, Monday afternoon, March 12
Exhibit Hall, Washington State Convention Center
We outline the earlier-developed master equation approach to configurational kinetics of non-equilibrium alloys and the kinetic tetrahedron cluster field method (KTCFM) and use them to study the kinetics of microstructural evolution under L1_2 and L1_0 type orderings in FCC alloys. We present the results of extensive simulations of A1\toL1_2 and A1\toL1_0 phase transformations after a quench of an alloy from the disordered A1 phase to the single-phase L1_2 or L1_0 state for a number of alloy models with both short-range and long-range interactions, including the cases of a significant deformational interaction due to the tetragonal distortions accompanying the L1_0 type ordering. The simulations reveal a number of peculiar features both in the transient microstructures and in the transformation kinetics, many of them agreeing well with experimental observations. We also present a Ginzburg-Landau-type theory describing the structure and orientations of antiphase boundaries in characteristic polytwin structures of alloys with L1_0 type ordering and compare the results with the experiment.