DEVELOPMENT OF A MICROSTRUCTURAL METHODOLOGY TO ESTABLISH STRUCTURE/PROPERTY RELATIONS OF REFRACTORIES AND FIRST RESULTS FOR MAGNESIA-SPINEL MATERIALS

摘要

The prediction of the thermomechanical behaviour of refractories is quite difficult to achieve because of the heterogeneous character and the complex microstructure of such materials. This study aims at elaborating refractory model materials with simplified microstructure in order to investigate the relations existing between microstructure and thermomechanical properties. Elastic properties of two different types of composites are determined at room temperature and compared to an analytical model. The first considered material is a glass/alumina composite which presents very simplified microstructure and the second one is a magnesia/spinel composite which exhibits much more complex microstructure (microcracks) since it is thermally damaged. Further investigations at high temperature have been carried out on these magnesia/spinel composites in order to better understand their thermal history and the influence of the spinel content (and spinel size) on the induced thermal damage.