Effect of urea on synthesis of aluminum nitride powders from aluminum nitrate and glucose
(1. State Key Laboratory for Powder Metallurgy,
Central South University, Changsha 410083, China;
2. School of Materials Science and Engineering,
University of Science and Technology Beijing, Beijing 100083, China)
Central South University, Changsha 410083, China;
2. School of Materials Science and Engineering,
University of Science and Technology Beijing, Beijing 100083, China)
Abstract: AlN powders were synthesized by carbothermal reduction method from aluminum nitrate and glucose. The effect of urea on the preparation and nitridation of the precursors was studied. It is found that urea can affect the morphology and composition of the precursor as well as the nitridation process. During the nitridation process of the precursor prepared without urea, α-Al2O3 and AlON are detected and a high temperature(1600℃) is needed for a complete conversion. While for the precursor prepared with urea, a complete conversion is got at a relatively low temperature(1400℃) and AlN is synthesized directly from γ-Al2O3, with no sign of the formation of α-Al2O3 and AlON. AlN powders synthesized from the precursor prepared without urea agglomerate badly, while the powders synthesized from the precursor prepared with urea are soft aggregates of fine particle, which can be easily dispersed.
Key words: aluminum nitride; urea; precursor; carbothermal reduction