X-ray topography study of deformed composites obtained by directional solidification of Al-Cu-Co alloy

Fibre-reinforced composites were produced by the modification of the static horizontal Bridgman method. The single-crystalline composite matrix consisted of the tetragonal T phase (Al72Cu27Co1). Decagonal quasi-crystal D phase (Al64Cu20Co16) was the reinforcement in the form of fibres parallel to the solidification direction. These fibres were surrounded by the tetragonal Θ phase (Al66Cu31Co3). The composite specimens in the shape of plates were studied by tensile tests and X-ray topography. The specimens deformed up to rupture and, from the X-ray topographs, the dependence of the composite structure defects on deformation was examined. It was found that the rupture of specimens is related to low-angle boundaries created during deformation. The influence of defects on the strength of the composites is discussed. (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)