Mechanical characterization of highly porous β-Si3N4 ceramics fabricated via partial sintering & starch addition

In this study, porous β-Si3N4 ceramics containing limited amount of Sm2O3 and CaO as sintering aids were produced by addition of potato starch (10 and 20vol.%) and partial sintering. Two different Si3N4 powders, α- and β-, were used as starting materials. Scanning electron microscopy investigations revealed that development of elongated β-Si3N4 grains were much more pronounced when α-Si3N4 starting powder was used. Even though porosity values of the compositions prepared by using α-Si3N4 (∼57.0-58.4%) is significantly higher than the samples produced by β-Si3N4 (42.6%), no significant change was observed for the bending strength, fracture toughness and Weibull modulus. This indicates that microstructural features have a significant contribution to the mechanical properties of the porous materials in terms of bending strength and fracture toughness. © 2012 Elsevier Ltd.

Subjects

4-Point bending strength

Fracture toughness

Microstructural evolution

Porous β-Si N 3 4

DDC Class

540: Chemie

600: Technik

620: Ingenieurwissenschaften

More Funding Information

Foundation for Scientific Research Projects of Anadolu University (Project number: 090229)

International Research Fellowship Programme

Scientific and Technological Research Council of Turkey

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Mechanical characterization of highly porous β-Si3N4 ceramics fabricated via partial sintering & starch addition