Thermal shock parameters [R, R ''' and R ''''] of magnesia-spinel composites

Aksel C., Warren P.

JOURNAL OF THE EUROPEAN CERAMIC SOCIETY, vol.23, no.2, pp.301-308, 2003 (SCI-Expanded) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 23 Issue: 2
  • Publication Date: 2003
  • Doi Number: 10.1016/s0955-2219(02)00178-4
  • Journal Name: JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.301-308
  • Keywords: composites, mechanical properties, MgAl2O4, MgO, microcracking, thermal shock damage resistance (R ''' and R '''') parameters, thermal stress resistance (R) parameter, STRESS RESISTANCE, FRACTURE, CERAMICS
  • Anadolu University Affiliated: No

Abstract

Thermal shock parameters (R, R'" and R"") have been calculated using measured strength and modulus values for model magnesia-spinel composite materials. The R'" and R"" parameters vary with both spinel content (0-30%) and spinel particle size (3-22 mu-m). In general, the larger the spinel content, the higher the values of R'" and R"". It is predicted that the coarsest (22 mu-m) spinel provides a significant improvement in resistance to thermal shock damage through maximised difficulty of crack propagation, with a maximum at approximately 20% addition. These predictions were also matched by thermal shock testing. After quenching from 1000 degreesC, the 20% 22 mu-m spinel composite had a retained strength approximately 4.5 times higher than that for similarly quenched pure magnesia. (C) 2002 Elsevier Science Ltd. All rights reserved.