Neutron diffraction study of the deformation behaviour of deformation processed copper–chromium composites

The tensile behaviour of a co-deformed Cu–10vol.% Cr composite has been studied. The composite was produced from cast Cu–Cr by hot forging and then cold swaging to a reduction of 95.6% in order to attain a fibrous reinforcing microstructure. Tensile testing in situ on a neutron diffractometer has allowed the evolution of axial and transverse elastic strains in each phase to be monitored as a function of applied stress. The results show that contrary to expectation, inelastic load transfer occurs from the Cr to the Cu matrix. The measured elastic strains are compared with an Eshelby type model and the retained misfit between the phases calculated. Since damage of the fibres, even near the fracture surface was limited, it is inferred that load transfer to the matrix occurs by the greater relative plastic straining of the reinforcement.