Hello, I apologize in advance if this is the wrong place to ask this question, but I could not find any vacuum related forums. I am currently designing a thermal evaporation or PVD chamber that needs to reach a temperature of 600C and vacuum of 10^-7 torr. I originally planned on using a combination of Viton O-orings and Metal to Metal seals(CONFLAT)for the chamber but I am now considering using flexible graphite gaskets. The reasons for this are numerous, and have to due with the fact that graphite can withstand far greater temperatures and can seal micro cracks without the complexity of traditional metal to metal seals. My only issue is I have yet to find any literature regarding their use in vacuum systems and I have only seen information on it's use in aerospace and nuclear applications.

Am I just spit-balling here or is there some potential in this idea? Any suggestions in the right direction would be appreciated.