I posted this issue to physicsforums, where there were some helpful suggestions & links.
I think the final answer is that the natural oxide layer _is_ present, but it only takes a few volts potential difference for the insulation to break down & conduct. You did mention earlier "If your voltage...
Thanks for the link.
It's an interesting paper, but I don't know how much it applies.
They're intentionally growing thin aluminum oxide layers from Aluminum Nitride (on a silicon substrate) under controlled lab conditions.
I don't know if their 'lab purity' oxide compares in any way to oxide...
What is 'high enough voltage' to overcome a typical (natural air-sourced) thickness of aluminum oxide?
I know anodized aluminum is essentially a 'thick' (up to 100s of microns) oxide coating, but as the oxide layer is also porous they also apply a sealer, which can also impact continuity. I did...
Thanks for responding, Tug. I've seen your responses to similar questions on eng-tips.
We are already planning on applying electroless nickel plating on one of the key components.
The 'messy conductive grease' will be used to help assembly with a (conductive) o-ring (for pressure seal) &...
I'm using aluminum alloy (6061-T6 sheet at the moment) to construct a chassis for mechanical support of an assembly. This chassis also serves as part of an EMI mitigation system (RF, GHz range), so I need to ensure electrical continuity between the chassis and other components of the system. I...
