Novel Silicate Matrices for Fibre Reinforced Ceramics

The use of the glass ceramic route to fabricate ceramic fibre reinforced ceramic matrix composites allows fabrication temperatures to be lowered. This avoids unnecessary fibre degradation, whilst retaining the 'in-situ' reacted carbon rich interfacial layer which is required for good mechanical properties. Work has been carried out on two systems, the magnesium aluminosilicate and calcium aluminosilicate ternary systems. Compositions were selected to further lower the processing temperature and to promote either cordierite or anorthite as the major phase. Minor phases allow tailoring of the matrix thermal expansion to be above, below or equal to mat of the fibre. The effects of processing upon the mechanical properties of the composite have been investigated for both as produced and thermally aged composites. Microstructural characterization has mainly been carried out using SEM and XRD. Interface characterization, structure and constitution has been carried out using TEM and light element EDS.