Superfast densification of oxide ceramics by spark plasma sintering

The SPS (Spark Plasma Sintering) Process is a new materials synthesis procussing techllology recently developed by Sumitomo Coal Mining Co.Ltd.. Japan. Some oxides such as Al2O3, Y-TZP,YAG, Al2O3-ZrO2 and Mullite were successfully superfast densified by SPS under the conditions of heating rate as high as 600℃/min, no keeping time at the sintering temperatures above 1200℃,and thed fast cooling to 600℃ within 3 minutes. The superfast sintering samples show high densities, fine inicrostructures and excellent mechanical properties. The fracture toughness K1c of 20mol% Al2O3-ZrO2 (3Y) samples sinterse by SPS at 1250℃ for 2 min is higher than 6MPa.m1/2.The reaction sintering of ZrO2- mullitc could be completed by SPS at 1530℃ for 3 min.