摘要
Effects of CuO on constrained sintering of a polycrystalline TiO <sub>2</sub> ceramics have been investigated. The densification temperature of TiO <sub>2</sub> is reduced from 1100-1200°C for pure TiO <sub>2</sub> to 900°C with the presence of 0.5-3 mol% CuO under free sintering. For the samples with 1 mol% CuO, the constrained densification is slowed down, but a high sintered density of >95% at 950°C, which is close to that sintered freely, is still obtained. The above results are caused by the formation of CuO-rich film at the grain boundaries, which reduces grain-boundary energy and enhances grain-boundary migration kinetics of TiO <sub>2</sub> . To confirm the above findings, molecular dynamics simulation, at which the ratio of grain boundary energy of TiO <sub>2</sub> between with and without CuO agrees well with that obtained experimentally, is conducted.