Influence of Stoichiometry on Fracture Behaviour of Magnesium Aluminate Spinels at 1200 deg. C

摘要

The mechanical behaviour at 1200 deg. C of one stoich- iometric and two alumina rich polycrystalline magnesium aluminate spinels is studied. Similar microstructures have been obtained for both spinel compositions. Lattice parameters have been deter- mined and related to the solid solution stoichiom- etry for all materials. Microstructures have been characterized by scanning electron microscopy. Fracture toughness measurements at 1200 deg. C as a Function of strain rate and observations of polished And fracture surfaces have been performed.