Transparent polycrystalline MgAl2O4 spinel with submicron grains, by low temperature sintering

Transparent, polycrystalline MgAl2O4 ceramics have been fabricated by sintering optimized-configuration, powder compacts formed from a material prepared by flame spray pyrolysis. Transparent parts (80% light transmission at 2 mm thickness) could be obtained after pressureless sintering in air at 1280°C/3 h, followed by hot isostatic pressing at 1320°C/3 h/200 MPa. The average grain size was 0.45 μm. Such materials exhibit property combinations suitable for transparent armor applications.