LOCAL STRAIN CONTOURS AROUND INCLUSIONS IN WIRE-DRAWN CU W COMPOSITES/

Composite samples are produced by casting copper around a long, single -fibre inclusion of tungsten. Samples are subsequently wire-drawn to r educe the grain size. Using high energy X-ray diffraction, the spatial distribution of residual lattice strains is mapped, showing large str ain gradients between the sample surface and fibre-matrix interface in samples with different thermal histories. The large strain gradients are primarily attributed to inhomogeneous deformation caused by the pr esence of the fibre during drawing. Distinct non-linearities in the st rain gradients are attributed to the development of strong radial text ure variations, and annealing at 300 degrees C is found to significant ly reduce the magnitude of the strain gradients. (C) 1997 Published by Elsevier Science Limited.