Effect of mechanical activation of electroexplosive Al ₂ O ₃ nanopowder on the characteristics of sintered ceramics

Aluminum oxide‐based materials exhibit significant potential for application in the aerospace industry, advanced manufacturing technologies, the automotive industry, power engineering, and other fields. However, the inherent brittleness of aluminum oxide limits its broader application. Therefore, an ongoing search is underway for methods to produce corundum ceramics with high mechanical properties, including the use of Al 2 O 3 nanopowders. This paper is the first to investigate the production of corundum ceramics using Al 2 O 3 nanopowder obtained by electric explosion of wire. The effect of mechanical activation of the nanopowder on characteristics of the sintered samples is appreciated. It is found that pre‐treatment of the nanopowder in a high‐speed planetary ball mill within 2 min facilitates the compaction of sintered ceramics up to a density of 3.85 g/cm 3 , which is 96% of the theoretical density. The highest strength under radial compression of the ceramic samples is achieved with a crystallite size of about 46 nm. A general relationship between the strength and mechanical activation time is similar to the Hall–Petch relationship.