Preparation and Characterization of Fiber-Reinforced Aluminum Phosphate/Silica Composites with Interpenetrating Phase Structures

Glass fiber-reinforced aluminum phosphate (AP)/silica composites were prepared by hydrolyzing tetraethylorthosilicate (TEOS) in AP binder. The composites were hot pressed and cured at a temperature range between 140°C and 200°C with Al2O3 as a curing agent. Microstructures of the prepared composites were examined using scanning electron microscopy. Flexural properties of the composites were investigated by a three-point bending test. It was found that the flexural strength of the prepared composites was significantly increased when appropriate concentrations of TEOS were used for hydrolysis. A microstructure study demonstrated that the improvement in flexural strength was due to the formation of an interpenetrating network structure between the two inorganic phases.