SPINEL SINTERED BODY, METHOD FOR PRODUCING THE SAME, TRANSPARENT SUBSTRATE, AND LIQUID CRYSTAL PROJECTOR
摘要
Disclosed is a spinel sintered body having a composition of MgO nAl<SUB>2</SUB>O<SUB>3</SUB> (1.05 = n = 1.30), while containing 20 ppm or less of Si element. Also disclosed is a method for producing such a spinel sintered body. This production method comprises a step for forming a molded body from a spinel powder having an Si element content of not more than 50 ppm and a purity of not less than 99.5% by mass, a first sintering step for forming a sintered body having a density of not less than 95% by sintering the molded body at 1500-1700°C in a vacuum, and a second sintering step for press-heating the sintered body at 1600-1800°C.
