Fabrication and plasma resistance of Y2O3 ceramics

Y2O3 granular powder was fabricated using a spray drying process from slurry prepared by mixing PVA binder, NaOH for pH control, PEG and milled Y2O3 powder. The Y2O3 specimen was sized to ∅14 mm and then sintered at 1650 °C. The decrease in particle size due to the milling process with attrition mill and granulation of milled powder promoted the densification of the Y2O3 specimen without cracks. The characteristics, microstructure, density and plasma resistance of the Y2O3 specimen were investigated as functions of the forming pressure and sintering time. The plasma resistance and the edge depth of the Y2O3 specimens were compared with those of Al2O3 and SiC specimens using a laser microscope. After a plasma etching test, the Al2O3 specimen showed a very high edge depth value and a severely etched morphology in laser microscope images. Upon increasing the sintering time, the Y2O3 specimens showed relatively high density and strong resistance compared with those of the Al2O3 and SiC specimens in the plasma etching test.