ULTRASONIC SOL-GEL PROCESSING OF ALUMINOBOROSILICATE GLASS AND ITS COMPOSITE WITH CARBON-FIBER REINFORCEMENT

An ultrasonic sol/gel technique has been used to process aluminoborosilicate glass and its composite with carbon fiber reinforcement. In this new technique, ultrasonic energy is used in place of alcohol solvent. Gel time is easily controlled by varying the amount of ultrasonic energy and the resulting gel also exhibits less shrinkage during the densification process. The sonogel-based composite has lower flexural strengths than the alcogel and has close values between the measured moduli, while still retaining the same fracture toughness. Micromechanical analysis produces higher values; however, it is suspected that the in situ modulus of matrix is lower than the value used in the analysis.