Plastic deformation properties of the orthorhombic complex metallic alloy phase Al 13Co 4

Abstract

Plastic deformation experiments were performed on single crystals of the orthorhombic Al 13Co 4 complex metallic alloy phase. The material was compression tested in a temperature range between 873 and 1073 K at a strain rate of 10 −5 s −1. The stress–strain curves show a pronounced yield-point effect followed by a regime of weak work hardening. Incremental tests, i.e. stress-relaxation tests and temperature changes, were conducted in order to determine thermodynamic activation parameters of the deformation process. After deformation the samples exhibit localised zones of inhomogeneous deformation. Microstructural investigations by means of transmission electron microscopy reveal a high density of dislocation with [010] Burgers vector terminating (001) planar defects. Contrast-extinction experiments show that the Burgers vectors of dislocations as well as the displacement vectors of the planar defects are parallel to the [010] direction. The basic mechanism of plastic deformation is dislocation glide on (001) planes.