A novel hydrostatic extrusion process utilising sacrificial Al billets has been developed to allow
the size reduction by deformation of samples of various cross-sectional shape (e.g. square, rectangular).
Cyclic deformation of a stack of sub-mm thick foils of magnetic and non-magnetic metals (Fe and Ag),
combining extrusion with cold-rolling, has been used to prepare nanoscaled multilayered structures. 6%
GMR was measured in the Fe/Ag multilayer system, after 4 deformation cycles, in the current-in-plane
geometry at 4K. Extrusion was also used to prepare micro-composite Sm/Fe structures which were
subsequently heat treated to form magnetostrictive SmFe2 rods with room temperature magnetostriction
values as large as -800ppm in the extrusion direction. ?? 2002 Elsevier Science B.V. All rights reserved.
