Papers by Author: Bing Liang Liang

Abstract: The influence of Nb2O5 and La2O3 on the phase and microstructure evaluation and mechanical properties of composite ceramics sintered with 2.45 GHz microwave energy was investigated. The results showed that Nb2O5 could densify the pure alumina with a lower sintering temperature and a short sintering time. Nb2O5 reacted with Al2O3 to form AlNbO4 completely and the amount of AlNbO4 increased with the increasing content of Nb2O5, distributing at the Al2O3 grain boundaries. The specimen doped with 10 Vol.% Nb2O5 sintered at 1500 °C exhibited plenty of columnar grains with draw ratio about 1:3. La2O3 reacted with Al2O3 to form LaAl11O18 completely, the specimen doped with 10 Vol.% and 15 Vol.% La2O3 sintered at 1500 °C exhibited plenty of columnar grains with draw ratio about 1:4. The existence of columnar grains enhanced the microhardness and fracture toughness of composite ceramics.

Abstract: The influences of Nb₂O₅ on the phase, microstructure and hydrochloric acid corrosion behaviors of Nb₂O₅-Al₂O₃ ceramics sintered with 2.45 GHz microwave energy were investigated. The results showed that Nb2O5 reacted completely with Al₂O₃ to form AlNbO₄ and densified the pure Al₂O₃ at a lower sintering temperature and in a short sintering time. Nb₂O₅-Al₂O₃ ceramic samples were corroded in diverse concentration hydrochloric acid for different time. Weight loss rate of Nb₂O₅-Al₂O₃ ceramic rose dramatically when the corrosion time was not longer than 4 h, and it increased slowly beyond 24 h. After Nb₂O₅-Al₂O₃ ceramic samples were corroded for 1 h, pitting corrosion was observed by scanning electric microscope, which was consistent with the analysis results of the scanning Kelvin Probe.

Abstract: The influence of Nb2O5 on the phase and microstructure evaluation and mechanical properties of Nb2O5-Al2O3 ceramics sintered with 2.45 GHz microwave energy was investigated. The results showed that Nb2O5 could densify the pure alumina with a lower sintering temperature and a short sintering time. Nb2O5 reacted with Al2O3 to form AlNbO4 completely and the amount of AlNbO4 increased with the increasing content of Nb2O5, distributing at the Al2O3 grain boundaries. The specimen doped with 10 vol.% Nb2O5 sintered at 1500 °C exhibited plenty of columnar grains with draw ratio about 1:3. The existence of columnar grains enhanced the microhardness and fracture toughness of Nb2O5-Al2O3 ceramics.