Abstract
Transparent alumina compacts were fabricated by using spark plasma sintering method A commercial alumina powders with two different grain sizes were used as raw powder The average grain size of TM-DAR and AA02 powders were lOOnm and 230nm,respectively From results of in-line transmittance measurements, TM-DAR compacts sintered at 1423K and 1473K showed more than 60% of the in-line transmittance In contrast, AA02 compacts sintered at 1423K showed about 47% of the in-line transmittance In TEM observation of TM-DAR compacts sintered at 1423K and 1523K, dense microstructures without pores were observed On the other hand, it was found that AA02 compacts sintered at 1523K contained pores in the grain and line defects, while abnormal grain growth was locally observation in AA02 compacts sintered at 1423K These results indicated that the transparent alumina compacts was strongly affected by the particle size of raw powder, and the compact with dense microstructure showed high transmittance
