Presentation Information
[3F11]Evaluation of vacuum firing effect on sutainless steel and titanium from vacuum and surface point of view
*JUNICHIRO KAMIYA1 (1. Japan Atomic Energy Agency)
The effect of the vacuum firing on the stainless steel and titanium has been evaluated from the vacuum and surface point of view. As the results of the buildup test, the vacuum-fired stainless steel and titanium vacuum chambers showed lower outgassing than the non-vacuum-fired chambers. Especially the hydrogen outgassing was well reduced in the vacuum-fired chamber. The TDS and XPS analysis were performed to evaluate the vacuum firing effect from the surface point of view. These results support the outgassing reduction mechanism of the vacuum firing on the stainless steel that the hydrogen is reduced from the bulk due to the diffusion to the vacuum phase and the surface metal oxides are reformed as a diffusion barrier. For the titanium, the surface oxide layer was once removed by the vacuum firing and the thnner oxide layer was reformed in the titanium case. Thus the it is possible that the vacuum fired titanium chamber easily have the getter funcution by the baking.