Fracture behavior of centrifugally cast multilayer alumina/alumina composites

摘要: Increased fracture toughness in brittle materials can be achieved by incorporating weak (porous) interfaces (1,2). These improvements have been attributed to energy absorption through crack deflection and frictional bridging along the weaker (1). While improved properties are attractive for thermal structure ceramic components, difficulties producing a specific degree of interfacial porosity wide range ceramics limited application this approach. Studies investigating influence interlayers composites (1–10) examined systems ranging from tape cast multilayered alternating fully dense porous (7) plates bonded with thermoplastic adhesives (8–9). During flexural loading, cracks typically deflect interfaces, giving rise step-wise drop loaddisplacement behavior rather than catastrophic failure typical non-deflecting materials. Residual stress distributions within layered also produce similar behavior, where layers tensile compressive states due expansion mismatch promote bifurcation (10). Advances centrifugal consolidation colloidal suspensions (11–14) made technique an alternative composites. Tailored microstructures that either flocculated (11) inhibit particle segregation or dispersed (12–14) allow differences size density. This paper summarizes initial results on alumina alumina/agglomerated produced consolidation.