Mechanical properties of magnesia-spinel composites

Aksel C., Rand B., Riley F. L., Warren P. D.

Journal of the European Ceramic Society, cilt.22, sa.5, ss.745-754, 2002 (SCI-Expanded) identifier identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 22 Sayı: 5
  • Basım Tarihi: 2002
  • Doi Numarası: 10.1016/s0955-2219(01)00373-9
  • Dergi Adı: Journal of the European Ceramic Society
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Sayfa Sayıları: ss.745-754
  • Anahtar Kelimeler: fracture toughness, magnesite refractories, MgAl2O4, MgO, modulus, refractories, residual stress, spinel, strength, thermal expansion, PARTICLE-SIZE, FRACTURE, CERAMICS, BEHAVIOR, ENERGIES, MGAL2O4, OXIDE
  • Anadolu Üniversitesi Adresli: Evet

Özet

A set of dense magnesia-magnesium aluminate spinel composites has been prepared by hot-pressing magnesia powder using 0 to 30 wt.% of spinel powder of mean particle size 3, 11 and 22 μm. Bend stength, modulus, and fracture toughness, have been measured. Strength and modulus decrease with increasing spinel content, and for a given loading, spinel particle size, as a result of microcracking caused by thermal expansion mismatch between the magnesia matrix grains and the spinel particles, the effects of which may be intensified by recrystallization of spinel. Fracture is predominantly transgranular for the pure magnesia, and intergranular for the composite materials. Possible reasons for the differences in behaviour between this system and the SiC-Al2O3 system with a similar thermal expansion mismatch are examined. © 2002 Elsevier Science Ltd. All rights reserved.