Mechanical properties of alumina fiber/glass matrix composites with and without a tin dioxide interface

Alumina+zirconia (PRD-166) and Saphikon fibers reinforced glass matrix composites with and without a SnO2 interphase were prepared by slurry infiltration and their mechanical characteristics were evaluated. Longitudinal bend strength increased with volume fraction of fibers in both PRD-166/glass and PRD-166/SnO2/glass matrix composites. PRD-166/glass matrix composites failed in a brittle manner whereas PRD-166/SnO2/glass matrix composites exhibited non-planar failure with crack deflection and fiber bridging as major toughening mechanisms. Saphikon/SnO2/glass matrix composites failed in a tough manner with extensive fiber pullout. The difference in the failure mode between PRD-166/SnO2/glass and Saphikon/SnO2/glass matrix composites was due to fiber roughness. The toughness of PRD-166/SnO2/glass matrix composites was due to crack deflection, fiber bridging, partial fiber debonding and some fiber pullout. Major toughening mechanisms in Saphikon/SnO2/glass matrix composites were fiber debonding and fiber pullout with minor contributions due to crack deflection and fiber bridging.