Optical Property of Non-stoichiometric Mg-Al Spinel Transparent Ceramics Prepared by Two-step Sintering Method

This paper reports the Mg-Al spinel transparent ceramics with four different non-stoichiometries fabricated by two step sintering method of combining vacuum sintering and hot isostatic pressing sintering,from the MgO·nAl2O3 powder.Transmittances in visible and infrared regions of the ceramics were analyzed.The results show that the ceramics with n of 1.3 and 1.5 have as high transmittance from ultra-violet region to infrared region as that of the stoichiometric ceramics.In contrast,the transmittance in the same sector of the ceramics with n of 1.8 is significantly lower.