  A filamentary composite elaborated by cold drawing was processed by High
Pressure Torsion (HPT). The nanostructure resulting from this severe plastic
deformation (SPD) was investigated thanks to scanning electron microscopy,
transmission electron microscopy, X-ray diffraction and 3D atom probe. Although
the mutual solubility of Cu and Fe is extremely low at room temperature in
equilibrium conditions, it is shown that nanoscaled Fe clusters dissolve in the
Cu matrix. The non-equilibrium copper supersaturated solid solutions contain up
to 20at.% Fe. The driving force of the dissolution is attributed to capillary
pressures and mechanisms which could enhanced the atomic mobility during HPT
are discussed. We conclude that the interdiffusion is the result of a dramatic
increase of the vacancy concentration during SPD.
