Elastic characteristics and fracture behaviour of materials in the system Al2O3+TiC at elevated temperatures

In the region between room temperature and 14000C the elastic constants, fracture values and flow-stress values of different compositions of the Al2O3+TiC system were determined. It was found that: 1. The elasticity modulus and shear modulus increase linearly with the TiC content. 2. Up to approximately 10500C the elastic constants decrease linearly with increasing temperature. 3. Additions of dispersed TiC lead to a uniform grain size distribution. 4. In the low temperature region the faults leading to cracks are about 50 times as large as the average grain size; this suggests the effect of thermal stresses on the occurrence of microcracks. 5. At temperatures above 9000C TiC deforms macroscopically. In the case of a high proportion of the 2nd phase the latter contributes, as a plastic substance, to stress reduction and thus to an increase of fracture stress in comparison to the single-phase material. (orig.)