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

KALEMTAŞ A., TOPATEŞ G., Oezcoban H., MANDAL H., Kara F., Janssen R.

JOURNAL OF THE EUROPEAN CERAMIC SOCIETY, cilt.33, sa.9, ss.1507-1515, 2013 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 33 Sayı: 9
  • Basım Tarihi: 2013
  • Doi Numarası: 10.1016/j.jeurceramsoc.2012.10.036
  • Dergi Adı: JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Sayfa Sayıları: ss.1507-1515
  • Anahtar Kelimeler: Porous beta-Si3N4, 4-Point bending strength, Fracture toughness, Microstructural evolution, SILICON-NITRIDE CERAMICS, PHASE-TRANSFORMATION, FRACTURE-TOUGHNESS, HIGH-STRENGTH, SI3N4, MICROSTRUCTURE, BEHAVIOR, ND, RE
  • Anadolu Üniversitesi Adresli: Evet

Özet

In this study, porous beta-Si3N4 ceramics containing limited amount of Sm2O3 and CaO as sintering aids were produced by addition of potato starch (10 and 20 vol.%) and partial sintering. Two different Si3N4 powders, alpha- and beta-, were used as starting materials. Scanning electron microscopy investigations revealed that development of elongated beta-Si3N4 grains were much more pronounced when alpha-Si3N4 starting powder was used. Even though porosity values of the compositions prepared by using alpha-Si3N4 (similar to 57.0-58.4%) is significantly higher than the samples produced by beta-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. (C) 2012 Elsevier Ltd. All rights reserved.