Microstructure and mechanical properties of SiC platelet reinforced BaOAl(2)O(3)2SiO(2) (BAS) composites

BaOAl(2)O(3)2SiO(2) (BAS) glass-ceramic powders were prepared by sol-gel te chnique. SIC platelet reinforced BAS glass-ceramic matrix composites with h igh density and uniform microstructure were fabricated by hot-pressing. The effect of additional crystalline seeds on hexagonal to monoclinic phase tr ansformation of Barium aluminosilicate was studied. The effects of SIC plat elet content on the microstructure and mechanical properties of the composi tes were also investigated. The results showed that the flexural strength a nd fracture toughness of the BAS glass-ceramic matrix composites can be eff ectively improved by the addition of silicon carbide platelets. The main to ughening mechanism was crack deflection, platelets' pull-out and bridging. The increased value of flexural strength is contributed to the load transit ion from the matrix to SIC platelets. (C) 2000 Elsevier Science Ltd and Tec hna S.r.l. All rights reserved.