Initial dislocation distributions in tungsten fibre-copper composites

Abstract

Etch-pit studies of composites consisting of small volume fractions of tungsten wires into which a copper matrix had been introduced by vacuum infiltration showed the dislocation density in the single crystal matrix to increase with volume fraction of fibre and to rise to high values toward the fibre-matrix interface. The dislocation distributions, which resulted from strains arising due to differential shrinkage, were interpreted in terms of a contribution, independent of fibre fraction, due to transverse strains which fall off with distance from the fibre and a second one due to axial strain which increases with fibre fraction but is invariant with distance from the fibre. Part of the axial adjustment is accomplished by interface shear.