Oxide fibres in a nickel-base matrix—do they degrade or become stronger?

Abstract

The fibre/matrix interface in fibrous composites with brittle fibres can play a synergetic role in developing creep resistance of the composites. Increasing the interface strength, which is accompanied with a better fibre/matrix contact, results firstly in a decrease in the fibre critical length, which enhances the fibre strength as a result of the scale effect, and secondly in an increase in the characteristic fibre strength as a result of the healing of defects on the fibre surface. Such behaviour of the fibres is the most important argument in favour of producing heat-resistant metal matrix composites with high interface strength. An additional argument is the stability of such an interface under variable loading. It is shown that oxide fibres in Ni-base matrices can be sufficiently strong to provide Ni-base composites with high creep resistance up to a temperature of at least 1150°C.