Abstract

AlN powder was prepared by the nitridation of metal Al in flowing NH₃. The effects of reaction temperature and the temperature gradient of the reaction zone on the nitridation of Al were investigated. Comparative analysis of products formed in different reaction zones and reaction temperatures suggested that the nitridation reaction of liquid Al particles in flowing NH₃ was through the following mechanisms: NH₃ dissociated into reactive nitrogen (N) and hydrogen (H) radicals at the surface of Al particles. N reacted with Al to form AlN, while H promoted the decomposition of NH₃, which provided enough energy for the dissociation of NH₃. All of the experimental results had been discussed on the basis of this model, which indicated high reaction temperature or positive temperature gradient was favorable for the nitridation of Al.

Author Keywords: Al; AlN; Nitridation; Powder preparation

Article Outline

1. Introduction

2. Thermodynamic considerations

3. Experimental procedure

3.1. Reactor design

3.2. Procedure

3.3. Characterization

4. Results and discussion

4.1. Effect of the temperature gradient

4.2. Effect of reaction temperature

4.3. Using nitrogen as the nitriding gas

4.4. Mechanism for the nitridation reaction of liquid Al particles by NH₃

5. Conclusion

References

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