Bridging stresses and R-curves in ceramic/metal composites

• Published in: Journal of the European Ceramic Society Vol. 20; no. 13; pp. 2261 - 2273
• Main Authors: Raddatz, O, Schneider, G.A, Mackens, W, Voß, H, Claussen, N
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.01.2000; Elsevier
• Subjects: Al 2O 3/Al; Applied sciences; Bridging stresses; Building materials. Ceramics. Glasses; Ceramic industries; Chemical industry and chemicals; Composites; Exact sciences and technology; Metallic inclusions; Metals. Metallurgy; Other composite materials with one or more metallic components; Powder metallurgy. Composite materials; Production techniques; R-curves; Structural ceramics; Technical ceramics; Toughness and toughening; Bridging stresses; R-curves; Composites; Toughness and toughening; Metallic inclusions; Al 2O 3/Al; Aluminum fiber; Fiber reinforced material; Mechanical properties; Aluminium; Review; Modeling; Crack propagation resistance; Oxide ceramics; Composite material; Structural ceramic; Interpenetrating network; Crack opening displacement; Metal fiber; Crack bridging; Mechanical stress; Alumina
• ISSN: 0955-2219; 1873-619X
• DOI: 10.1016/S0955-2219(00)00065-0

Incorporation of metal into brittle ceramics results in an increase in fracture toughness, which can lead to an increase in strength, reliability and thermal shock resistance of the composite compared to monolithic ceramics. The basic material specific property, which controls the enhancement of the mechanical properties, is the bridging stress relation of the metal reinforcements. This relation was calculated from measured profiles of loaded cracks (COD) for fiber reinforced model composites and interpenetrating network composites in the system Al 2O 3/Al. Results are compared with directly measured bridging stress relations for the model materials. The bridging relations are further used to model the R-curve behavior of the composites which are compared with experimentally measured ones. Limitations of the applied procedure are discussed as well as the influence of specimen geometry and flaw size.