Abstract
This paper concerns the effect of heat treatment on the toughness of metal fibre reinforced ceramic composite. Drawn fibres of 304 and 310 stainless steel have been used. Their response to heat treatment in air has been investigated, in terms of both oxidation kinetics and tensile properties. This has been correlated with measured fracture energies of composite containing these fibres, after similar heat treatments. As received, 304 fibres exhibit greater ductility and work of deformation than 310 fibres. However, severe heat treatments (up to 1170°C) cause 304 fibres to become oxidised and embrittled, whereas 310 fibres retain good strength and ductility. Composites subjected to these heat treatments become embrittled when they contain 304 fibres, but retain their toughness when reinforced with 310 fibres. These data are consistent with predictions from a previously published model of the fracture process, based on energy absorption being dominated by fibre pullout and/or fibre plasticity.
Acknowledgements
The authors are grateful for financial support from the Khazanah National Berhad, Malaysia. Technical support, and various samples, etc., have been provided by Fiberstone Ltd. The value of extensive technical discussions and interactions with L. W. Marston, who is based there, is also acknowledged. Relevant experimental work was carried out by Ms L. Gale and Mr R. Jones of Cambridge University. Assistance with certain technical aspects was provided by K. Roberts of the Materials Science Department in Cambridge.