Hirokazu Tahara
Department of Mechanical Engineering, Faculty of Engineering Science, Osaka University Toyonaka, Osaka 560, Japan
Yoichi Kagaya
Department of Mechanical Engineering, Faculty of Engineering Science, Osaka University Toyonaka, Osaka 560, Japan
Takao Yoshikawa
Department of Mechanical Engineering, Faculty of Engineering Science, Osaka University Toyonaka, Osaka 560, Japan
For applications of quasi-steady magneto-plasma-dynamic (MPD) arcjet generators to ceramic coatings, an MPD arcjet generator with a cathode covered with a ceramic material was developed. The front velocities of ablated Al atoms inferred with a streak camera were much higher than velocities of 200-500 m/s for conventional plasma torches. This is effective for deposition of rigid films adhering strongly to substrate surfaces. The MPD plasma spraying showed that a dense uniform ceramic film with above 1200 Vickers hardness was deposited. Further-more, from the XPS spectra the peak area ratio of Si/Al for the coating almost equaled that for the raw ceramic material, and the valence numbers of Al and Si did not change.