Effect of sintering atmospheres on the densification behavior of CuO ceramics

In this study, the effect of oxygen partial pressure on the densification and the resultant microstructure change of CuO were examined. When CuO green bodies were heated up to 1100 °C for sintering in air, denser CuO samples were obtained than the samples sintered in oxygen. When the samples were kept at 1100 °C for a prolonged period of time, however, the densification of the sample in oxygen was accelerated whereas that of the sample in air was hindered. This is attributed to the phase transformation from CuO to Cu₂O which accompanies oxygen release during sintering in air. On the basis of the results, dense CuO samples could be obtained by switching the sintering atmosphere from air to oxygen at the suitable stage so that oxygen release by reduction could be suppressed.