Abstract
Hypo stoichiometric Fe-Pd binary alloys (35-45 at% Pd) were severely deformed (>90%)
and subsequently aged to induce concomitant recrystallization, precipitation, and ordering. This
thermomechanical processing strategy was articulated by Hornbogen [1] over thirty years ago. The
resulting exchange-coupled ferromagnets contain ferrite precipitates and a complex metastable twophase
lamellar transformation product comprised of ordered L10 and a metastable FCC phase. The
later duplex microconstituent is suggested to form in conjunction with a so-called pseudospinodal
reaction [2] involving emerging cubic and tetragonal phases, whereby phase separation and ordering
result from continuous changes in composition and a reduction in symmetry, cubic to tetragonal.
The deformation texture of the parent austenite is substantially retained in the transformation
product, resulting in anisotropy of the magnetic properties as determined by magnetometry (VSM).
This paper presents electron microscopy results elucidating the crystallography and morphology of
the phase mixtures including HREM. Magnetic field annealing is also included as a branch of our
thermomechanical processing strategy, and we discuss the influence of the external fields on
recrystallization, precipitation, and ordering. This work was performed in cooperation with ORNL
and the NHMFL and is supported by the NSF – DMR.
