Preparation of Translucent Magmesium Oxide Ceramics

Abstract

Translucent magnesium oxide (MgO) ceramics were prepared by combined sintering technique of first step sintering and hot isostatic pressing (HIP) after compacting at 100 MPa. The first step sintering was carried out by pressureless sintering in nitrogen atmosphere, vacuum sintering and hot pressing in vacuum. Both of the pressureless sintering and vacuum sintering were carried out at 1600 °C for 60 min. Hot pressing was carried at 1500 and 1700 °C for 30 min in vacuum. Following the primary sintering, HIP was carried out at 1800 °C for 120 min under 180 MPa. The optimum condition to fabricate translucent MgO, was HIP after hot pressing at 1500 °C for 30 min. Specimen of 2.5 mm thickness had in-line transmittance of 3 to 8 % in visible region.