Composite Oxide Fibres Grown by Internal Crystallisation Method

Abstract

The internal crystallisation method (ICM) allows producing bundles containing hundreds and thousands of the fibres of a limited length. It is shown in the present paper that ICM can be used to produce fibres composed of a sapphire matrix and inclusions of calcium hexaaluminate. The fabrication of such composite fibres is described in the present paper. An effect of the calcium hexaaluminate inclusions in sapphire fibres is evaluated by testing model composites with brittle molybdenum matrices. The critical stress intensity factors of composite-fibre/molybdenum-matrix specimens are higher than those of specimens reinforced with sapphire fibres. The model specimens reveal non-linear stress/strain behaviour. The results of this work show the effectiveness of composite fibres as a reinforcement for brittle matrices.

Keywords

• ceramic fibre
• composites
• mechanical testing
• fracture toughness
• microstructure
• internal crystallisation method