Microstructure and mechanical properties of SiC platelet reinforced BaOAl2O32SiO2 (BAS) composites

BaOAl(2)O(3)2SiO(2) (BAS) glass-ceramic powders were prepared by sol-gel technique. SIC platelet reinforced BAS glass-ceramic matrix composites with high density and uniform microstructure were fabricated by hot-pressing. The effect of additional crystalline seeds on hexagonal to monoclinic phase transformation of Barium aluminosilicate was studied. The effects of SIC platelet content on the microstructure and mechanical properties of the composites were also investigated. The results showed that the flexural strength and fracture toughness of the BAS glass-ceramic matrix composites can be effectively improved by the addition of silicon carbide platelets. The main toughening mechanism was crack deflection, platelets' pull-out and bridging. The increased value of flexural strength is contributed to the load transition from the matrix to SIC platelets. (C) 2000 Elsevier Science Ltd and Techna S.r.l. All rights reserved.