Development of microstructure in hot isostatically pressed MgO·Al2O3 spinel

Fine-grained MgO·Al2O3 spinel was formed by hot isostatic pressing (HIP) using a titanium container. The cold isostatically pressed green bodies were subjected to heat treatment in air prior to HIP at different temperatures. The resulting microstructures were characterized by scanning and transmission electron microscopy and related to process parameters. It was possible by this route to elaborate almost dense spinel with the fine-grained microstructure required for superplastic behaviour. Compressive creep test has given a clear indication of the potential of this material to be superplastically deformed.