Sintering Behavior of Aluminum Nitride Doped with Y2O3

The aim of this study was to investigate the sinterability of a commercial AIN powder doped with Y 2 O 3 . It was done by sintering several samples with different compositions in a graphite furnace using a nitrogen atmosphere. The effect of the sintering temperature (between 1500 and 1700 °C) was studied by isochronal heat treatments whilst its kinetics was studied by isothermal sintering treatments at 1600 °C for different times. Sintered samples were characterised by density measurements, secondary electron image analysis and energy dispersive spectroscopy in SEM, to investigate their microstructural evolution. Pure AIN samples showed low sinterability in both series of experiments, reaching maximum relative densities of approximately 60%, when they were sintered at 1600 °C for 8 h and 1700 °C for 1 h. Additions of Y 2 O 3 promoted the densification of AlN. However, the range of sintering temperatures utilised in this work was not enough to produce high density ceramics. The samples doped with Y 2 O 3 presented lower weight loss than pure AIN samples.