DENSIFICATION BEHAVIOUR OF CuO-DOPED Al₂O₃ CERAMICS

The effects of doping small amounts of CuO up to 1 wt% on the densification behaviour of alumina (Al₂O₃) ceramics were investigated. The pellets were sintered in air at temperatures ranging from 1400°C to 1600°C, at a furnace ramp rate of 10°C/min. and soaking time of 2 hours. Sintered samples were characterised to determine phases present, bulk density, hardness and grain size. It has been found that all the doped samples exhibited higher bulk density (> 3.85 Mgm^-3) compared to the undoped samples. X-ray diffraction analysis revealed that only α-Al₂O₃ were present in the structure regardless of sintering temperature or CuO doping. The hardness of the undoped Al₂O₃ samples were lower than the CuO-doped material when sintered below 1550°C. However, maximum hardness of 21 GPa was measured for the undoped ceramics when sintered at 1600°C. Copper oxide doping is one economical way of improving the densification of Al₂O₃ without significantly affecting hardness.