Microstructure and mechanical properties of barium aluminosilicate glass-ceramic matrix composites reinforced with SiC whiskers

BAS glass-ceramic composites reinforced with different volume fractions (0, 10, 20, 30, 40 vol%) of SiC whiskers were successfully fabricated by a hot -pressing method. The microstructure, whisker/matrix interface structure, p hase constitution and mechanical properties of the composites have been sys tematically studied by means of SEM, TEM, XRD techniques as well as three-p oint bending tests. It was demonstrated that the incorporation of SiC whisk ers could significantly increase the flexural strength and fracture toughne ss of BAS glass-ceramic matrixes. The celsian seeds can effectively promote the hexacelsian-to-celsian transformation in BaAl2Si2O8. The active Al2O3 added to the BAS matrix obviously reduced the amount of SiO2 in the matrix and formed needle-like mullite. The high temperature strengths of the compo sites were also investigated. (C) 2001 Kluwer Academic Publishers.