Pressureless sintering of translucent MgO ceramics

MgO nanocrystalline powders were synthesized via a wet precipitation process. X-ray diffraction analysis of the heat-treated precursor powders shows that a crystalline MgO phase forms at similar to 500 degrees C. Translucent MgO ceramics were prepared by pressureless sintering the nanocrystalline MgO powders at 1400 degrees C for 2 h under ambient atmosphere. The as-sintered MgO ceramics have a relative density of 98.1% with an average hardness of 6.8 GPa. Scanning electron microscope characterization revealed that the translucent MgO ceramics have an average grain size of similar to 6 mu m. (c) 2008 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.