Optimized shaping process for transparent spinel ceramic

Bulky transparent ceramic, especially spinel (MgAl2O 4), can be used for applications such as high-energy laser windows and lightweight armor. One of the traditional routes to manufacture transparent spinel plates includes the steps of material preparation, uniaxial pressing, cold isostatic pressing (CIP), de-bindering and hot isostatic pressing (HIP). When larger sizes are required, CIP can become one of the bottlenecks of the process chain. The paper shows, how an optimized uniaxial hydraulic pressing process with an evacuated mould allows to avoid the cold isostatic pressing completely. The process is described and the first results of the investigation of transparent spinel properties are discussed. This simplified process will allow to reduce the manufacturing costs for larger sized transparent spinel significantly and/or improve the production capacity.