Affiliation:
1. National Kaohsiung University of Science and Technology
Abstract
The synthesis of aluminum nitride (AlN) powders is traditionally completed through a thermal nitridation process, in which the reacting aluminum powders are combined with nitrogen at high temperatures with a long reaction time (usually several hours). Moreover, the occurrence of agglomeration within the melting Al particles results in a poor dispersibility of AlN powders, with a low efficiency of nitridation. In this study, an atmosphere-pressure microwave plasma preceded the rapid gas-gas synthesis process. In the reactor, the gaseous aluminum chloride (AlCl3) reactant was fed at different positions (R1, R2, R3) to react with nitrogen at various reaction temperatures (690~1150°C) to rapidly produce AlN nano powders (in several seconds). The process was operated at a total flow rate of 13 slm with NH3 gas content of 0 or 0.77% and an applied power of 1200/1400 W. Results showed that the high purity and dispersibility of AlN powders were found at a AlCl3 feeding position closer to the resonant cavity of the reactor (R3, 1150°C). The AlN particle size was in the range of 25-50 nm. The experiments indicated that the gas-gas reaction for rapidly synthesizing AlN nanopowders can be successfully carried out via an AlCl3-N2 plasma-chemical approach.
Publisher
Trans Tech Publications, Ltd.
Subject
Mechanical Engineering,Mechanics of Materials,General Materials Science
Reference20 articles.
1. C. Sangural, Y. Kinemuchi, T. Suzuki, W. Jiang, K. Yatsui, Synthesis of nanosize powders of aluminum nitride by pulsed wire discharge, Jpn. J. Appl. Phys. 40 (2001) 1070-1072.
2. G. Selvaduray, L. Sheet, "Aluminum nitride: review of synthesis methods, Mater. Sci. Tech. Ser. 9 (1993) 463-473.
3. R. Fu, H. Zhou, L. Chen, Y. Wu, Synthesis of aluminum nitride fibres from aluminum silicate fibres by carbothermal reduction method, J. Mater. Sci. 34 (1999) 3605-3608.
4. M. Radwan, M. Bahgat, A modified direct nitridation method for formation of nano-AlN whiskers", J. Mater. Process. Tech. 181 (2007) 99-105.
5. C.N. Lin, C.Y. Hsieh, S.L. Chung, J. Cheng, D.K. Agrawal, Combustion synthesis of AlN powder and its sintering properties, Allerton Press Inc. 13 (2004) 93-106.