STRENGTH AND TOUGHNESS OF SLIP-CAST FUSED-SILICA COMPOSITES

The effects of fiber composition, size, and surface treatment on the m echanical behavior of slip-cast fused-silica composites were investiga ted. The ambient and 1000-degrees-C stiffness and strength, fracture t oughness, G(R)-curve behavior, and fiber-matrix interface bond strengt h were determined. Quantitative fractography and scanning electron mic roscopy were used to ascertain the mechanisms of toughening and streng thening. Composites with weak interface bonding exhibited good strengt h retention and rising G(R)-curve behavior. The fracture resistance wa s improved primarily through crack deflection.