LI Zhen, LEI Muyun, WANG Lidi

(Bright Crystals Technology Inc., Beijing 100018, China)

Abstract:A series of enhanced transparent magnesia-alumina (MgO·nAl2O3) ceramics were prepared by sol-gel method, hot press and hot isostatic press (HP/HIP) technique. The effects of "n" on the powder phase composition, optical property and flexural strength of transparent ceramics were investigated. When n=1.5, 2, and 4, MgO·nAl2O3 powder can still be in pure spinel phase. The flexural strength of MgO·1.5Al2O3 is improved greatly from 152MPa (MgO·Al2O3) to 215MPa (MgO·1.5Al2O3) by a growth rate of 40%, while Mid-IR transmittances of MgO·1.5 Al2O3 and stoichiometric magnesia-alumina spinel (MgAl2O4, MgO·Al2O3) are evenly matched.

Key words:magnesia-alumina spinel; transparent ceramics; enhancement; Mid-IR; flexural strength