Ceramic Fibre/Glass Matrix Composites with Outstanding Mechanical Performance

摘要

The performance of most engineering ceramics, when used under conditions of stress, is limited by their tensile strength. The introduction of fibers into a ceramic matrix offers the possibility of a significant increase in fracture energy associated with the fibrous nature of the fracture. Samples were prepared with unidirectional fiber reinforcement. Particular attention was given to good fiber alignment, even glass distribution during impregnation and winding, and to time/temperature/pressure cycle in the hot pressing stage so as to fully optimize the mechanical properties. The work of fracture was estimated from the area under the stress/strain curves and from notched impact testing. It should be noted in addition that unlike in many other brittle matrix systems there was no evidence of significant, permanent, matrix cracking except at stresses very near the ultimate failure stress. This effect and the very high work of fracture both suggest that the interfacial shear strength between fiber and matrix is very high, but not so high that the fiber is completely bonded to the matrix.