Alumina-chopped fibres as reinforcements for glass-ceramic materials

The paper reports a preliminary study about alumina short fibres (20 mass-%) and particulate reinforced glass-ceramic matrix composites. The fabrication techniques used are: a) preparation of pellet containing randomly distributed fibres and particulate, by wet mixing, cold pressing and sintering of the dried powders; b) tape casting. The nature of the matrix was investigated in order to obtain good interfacial properties; a new calcium and magnesium aluminosilicate (CMAS) glass ceramic formulation is proposed. The sintering behaviour of composites was studied at different temperatures, ranging from 800 to 1000°C, using scanning electron microscopy (SEM) and X-ray diffraction analysis (XRD). The evaluation of linear shrinkage and density was sufficient to define the best sintering conditions, while SEM and XRD indicated the nature of matrix/fibre interface's.