Need help: Apollo Cold Welding Mitigation

Movybuf1979

New Member
I am currently debating with someone on a different platform and he brought up the phenomenon "cold welding." I must admit that I had never heard of that before, so I have been reading about it for a while now. I have been trying to find any documentation that NASA employed some kind of mitigation techniques to avoid moving parts being fused together. From what I imagine, the lander had only a few moving parts, but I am curious if anyone knows if they did anything to prevent cold welding. I am also curious about the cameras. The shutter on an SLR 35MM camera is a moving part, and most likely made of aluminum, but I can't find any information about it. It seems as if aluminum is rather prone to cold welding. I am guessing they used a lubricant on the moving parts of the camera, but I don't know if there is a place to find that information.

Any help would be awesome. This denier I am writing back and forth with is bringing up topics I have never looked into before, so I am happy to learn new things as I am doing my research. I don't know why I subject myself to the torture of dealing with this stuff, but every once in a while I get to learn about something new.
 

Mendel

Senior Member.
Derek from Veritasium has made a video about that topic, it seems that "...cold welding is not as big of a problem as scientists originally thought it was".

Source: https://www.youtube.com/watch?v=Y2nQ8isf55s
From the subtitles transcript (via downsub):

You see, in space if two metals come into contact they can actually fuse together without the need for heat or melting of either piece. And the reason for this is due to the fundamental structure of metals which is a little bit like this candy bar in that they contain a lattice of positively charged ions, like the peanuts embedded in a sea of freely moving negative electrons like the caramel. Now here on earth the surface layers of a metal react with the oxygen in the atmosphere to create a protective oxide layer and this actually prevents two pieces of metal from joining together. But in space this oxide layer can be worn away like if two pieces of metal aren't sliding over each other as in hinges and then the bare pieces of metal with a little bit of force or impact can actually fuse together so the electrons from one piece of metal can flow into the other. In this business, as Richard Feinmann put it, the atoms have no way of knowing that they're in different pieces.

This obviously has huge implications for the construction and maintenance of spacecraft like the International Space Station.
So why don't we hear about more disasters like this happening in space all the time? I mean, why isn't the ISS already a big welded mess?
Well, the truth is the cold welding is not as big of a problem as scientists originally thought it was.

I mean, experiments on the ground in vacuum chambers and in space have shown that perfectly clean metal surfaces when pressed together in the absence of atmosphere will weld together. But in practice the metals that are used in spacecraft are never that clean, I mean, they have those oxide layers on them, not to mention other contaminants, dirt and grease, and it would take a long time for all of those things to be eliminated so that bare metal touches in space.
[..]

A 2009 report by the European Space Agency recommended three main ways to reduce the risks of cold welding.
Number one - where possible use plastics or ceramics to avoid sliding metal on metal contacts.
Second, if you have to use metal and metal try to use two different metals, maybe two different metal alloys because that reduces the risks of those metals melding together.
And third, use durable coatings that resists wear to avoid bare metal on metal contact.
Content from External Source
From the video description:

ESA cold welding recommendations:
http://esmat.esa.int/Publications/Published_papers/STM-279.pdf
Content from External Source
 
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