Preparation and characterization of BAS reinforced with SiC platelets

BAS glass-ceramic powders were prepared by sol-gel processing. SiC platelet s reinforced BAS glass-ceramic matrix composites with high density and unif orm microstructure could be made using hot-pressing method. The related pro cessing parameters were studied in this work, including effects of addition al seed on transformation from H to M of barium aluminosilicate. DTA method was used to determine exact time to press mixture powders during hot-press ing for the purpose of effective densification. Microstructure and mechanic al properties of the composites were investigated by mean of SEM, XRD and T EM techniques as well as three points bending test and single edge notched beam measurement. The results showed that the flexural strength and fractur e toughness value of the BAS glass-ceramic matrix composites could be effec tively improved by the addition of the SiC platelets. But the relative dens ities of composites were slightly decreased. The main toughening mechanism is crack deflection, platelets' pull-out and bridging. The increased value of flexural strength is contributed to the load transition effect from matr ix to SiC platelets.