Discussion Overview
The discussion revolves around the suitability of using aluminium 2007 alloy for a part in an oil diffusion vacuum pump, specifically concerning the potential outgassing of copper and lead during the vacuum process. Participants explore the implications of using this alloy compared to other aluminium alloys like 6061 or 6082, as well as the challenges associated with thermal expansion in vacuum environments.
Discussion Character
- Technical explanation
- Debate/contested
- Experimental/applied
Main Points Raised
- One participant expresses concern about the outgassing of copper and lead from the aluminium 2007 alloy during the vacuum process.
- Another participant suggests that the aluminium surface will have an oxide layer and may contain moisture, recommending a bake-out process and possibly using getters or electron beams to clean the surface.
- A different viewpoint emphasizes the challenges of thermal expansion in aluminium, noting that large dimension changes with temperature could complicate the operation of the diffusion pump.
- The original poster clarifies that they must use aluminium due to machining limitations and inquires about the differences between using 2007 versus 6061 or 6082 alloys.
- It is mentioned that the aluminium will only be used for the jets, while the main body of the pump will be made of stainless steel.
Areas of Agreement / Disagreement
Participants express differing views on the implications of using aluminium 2007 versus other alloys, as well as the potential outgassing issues. The discussion remains unresolved regarding the specific risks associated with the alloy choice and the best practices for mitigating outgassing.
Contextual Notes
There are limitations regarding the assumptions about outgassing behavior and the specific conditions under which the vacuum pump will operate. The discussion does not resolve the technical uncertainties related to the materials involved.