REACTION-BONDED 3-LAYER ALUMINA-BASED COMPOSITES WITH IMPROVED DAMAGERESISTANCE

Three-layer alumina-based composites with Al2O3-containing mullite as an outer layer and ZrO2-containing alumina as an inner layer were fabr icated by die-pressing and reaction-bonding. The strength of samples w ith Vickers indents made at loads up to 300 N was investigated. When c ompared to monolithic ceramics, three-layer composites exhibit excelle nt damage resistance due to compressive stresses in the outer layer. H ot isostatically pressed samples show a four-point bend strength of 80 0 MPa after indentation at 300 N.