Mechanical Properties and Oxidation Behavior of Al2O3-AlN-TiN Composites

The study examines the effect which the composition of hot‐pressed electroconductive ceramics has on their structure, mechanical properties, and oxidation behavior, for ceramics of the type AIN–Al2O3–42 wt% TiN, differing in the AIN/Al2O3 ratio. The results are physico‐mechanical property data, including density, hardness, strength, fracture toughness, and wear resistance. A correlation was found between the wear resistance and fracture toughness. The analysis of oxidation products revealed the formation of α‐Al2O3 and rutile in the temperature range from 600° to 1100°C and aluminum titanate above 1200°C. The spallation of the oxide layer caused low oxidation resistance of Al2O3‐rich composites above 1250°C. The oxidation of composites was compared with the oxidation of pure TiN. The relationship is discussed between material properties, composition, phases, and processing parameters.