LIU Yaxin ^{1, 2, 3}, ZHOU Jianmin ¹, XIA Changrong ^{1, 2}

(1. Energy Materials Center, Anhui Estone Materials Technology Co. Ltd, Hefei 230088, Anhui, China; 2. Department of Materials Science and Engineering, The University of Science and Technology of China, Hefei 230026, Anhui, China;3. Nano Science and Technology Institute, The University of Science and Technology of China, Suzhou 215123, Jiangsu, China)

Abstract:With the rapid development of microelectronics and semiconductor technology, heat dissipation function of device materials has attracted more and more attention in recent years. As one of the promise heat dissipation materials, AlN possesses excellent properties, especially high thermal conductivity. A new process combining sol-gel transformation and polymerization reaction was developed to prepare AlN nanoparticles. With melamine, formaldehyde and boehmite sol as the starting materials, a boehmite-MF composite gel was formed. In this composite, the organic polymer and the inorganic boehmite gel network interacted, so that the carbon source (melamine resin) and aluminum source (boehmite) were mixed homogeneously. Moreover, the composite system inhibited the growth of the aluminum source, hindered the phase transition of alumina, promoted the nitridation reaction to start from the γ-Al₂O₃ directly, and completed nitridation to AlN eventually at 1300 °C, leading to particles with an average size of less than 30 nm. The activation energy of the carbothermal reduction-nitridation reaction of the system is only 126 kJ•mol^-1, which is much lower than that (360 kJ•mol^-1) of the traditional solid-phase method. Therefore, the simultaneous sol-gel and polymerization process effectively enhanced the reaction.

Key words: AlN; nano-powder; gelation-polymerization; boehmite; Melamine resin