Small angle neutron scattering from polycrystalline Cu-2 at% Co aged and dynamically deformed

(Received 30 October 1991, revised 28 February 1992, accepted 3 March 1992)

Abstract
The unmixing of polycrystalline Cu-2 at% Co alloy water quenched then aged at 650 °C was followed by small angle neutron scattering and transmission electron microscopy. The two-dimensional scattering patterns were analyzed with a two-phase model which leads to the time evolution of the size, number density and interdistance of the spherical precipitates enriched in Co. During ageing, the precipitates partially lose coherency and their magnetic state evolves from ferromagnetic to paramagnetic stability. Each state was shown to be stable down to 10 K. Samples aged for 3 and 120 h were subsequently deformed at 20 °C by dynamic compression to different strains. From a comparison of the SANS recorded on three faces (perpendicular, parallel and to 45° of the compression axis) and with the help of TEM observations, qualitative information was obtained concerning the deformation modes of the precipitates.