Fabrication and Characterization of Optically Translucent Glass Matrix Composites

Besides the well-known requirement of matching thermomechanical properties of fibre and matrix in composite materials to realize effective reinforcement mechanisms, in the present composites also the refractive index of fibre and matrix must be matched to achieve optical translucency. Moreover the optimisation of the fibre matrix interface in order to prevent the forming of any reaction phases between matrix and fibre during processing plays an essential role. In the present composites Nextel 440™ fibres were coated with oxidic (TiO2, SnO2) and non-oxidic (BN) layers by thermal CVD. First results have shown that thin (30 nm) TiO2 coatings on Nextel 440™ fibres do not significantly influence the transmission of visible light in comparison to analogous composites without fibre coating. No fiber debonding and pull out was detected for both oxidic coatings. Composites made using fibres with BN interface, on the other hand, proved to have effective reinforcement mechanisms, including fibre pull-out effect.