M. Fukumoto, C. C. Lee, Y. Kouzaki, T. Yasui, Toyohashi University of Technology, Toyohashi, Japan; M. Yamada, Toyohashi University of Technology, Toyohashi, Aichi, Japan; K. Takahashi, Tosoh Corporation, Ayase, Japan
Aluminum nitride (AlN) is one of the attractive ceramics in respect of its excellent mechanical and electrical properties. In this study, AlN coatings were fabricated and the influence of primary powder was investigated by reactive RF (Radio Frequency) plasma spraying. Two different particle sizes of commercial Al powders and Al/AlN mixed powder were applied as the primary powder. The primary powder was injected in RF plasma, and sprayed particles were deposited onto quartz substrates. As the results, it was possible to fabricate thick and dense AlN coating with using smaller particle size of powder. However, many agglomerates were formed in the coatings. On the other hand, 50 wt% or above of AlN addition in the primary powder was effective to fabricate thick and dense coatings without formation of the agglomerates. Therefore, Al/AlN mixed powder with smaller particle size was useful for fabrication of AlN coatings by reactive RF plasma spraying.
Summary: Aluminum nitride coatings were fabricated and the influence of feedstock powder was investigated by reactive RF plasma spraying. The different particle sizes of Al powders and Al/AlN mixed powder were applied as the feedstock powders. The feedstock powders affected the nitridation and the porosity of the coatings.