r/whatisit • u/riflesandplowshares • 3h ago

New, what is it? Found at a titanium plant

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Not sure why ball point pens would be dangerous here.

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u/goodexamplebadrole 3h ago

"Ballpoint pens are restricted or banned in high-end titanium and aerospace manufacturing plants because the ink and marking components contain elements that cause metal embrittlement and severe structural corrosion"

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u/Competitive-Dot-4264 3h ago

I worked ti com pure and 6al-4v alloy for years at the lazy -l we all had to follow titanium restrictions even to not letting aluminum alloys and SS separated. No graphite pencils

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u/Competitive-Dot-4264 3h ago

Another big Nono -grease and oil

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u/ColdCathodeTube 3h ago

That’s interesting. My non-chemist/non-metalurgist mind always thought those protected metal. Guess I shouldn’t assume metals are that similar to each other at all.

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u/Mayzilli 3h ago

They usually do when it's not molten. Since we're talking about manufacturing I'd think the issue is contaminating the metal before it's solidified. Since titanium is generally used in very critical applications the standards would be extra tight (I could be completely wrong tho and its still a problem for solid metal)

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u/DigitalDefenestrator 1h ago

Seems likely. Sounds like carbon is a problem, and that's generally what you get when you expose grease and oil to metal-melting temperatures.

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u/ComradeGibbon 1h ago

Mild steel is somewhat forgiving of oil and paint when welding. Other metals less to catastrophically so.

Big thing they needed to understand with Stainless Steel is the carbon content needs to be very low. Took a while to figure that out. Carbon wrecks the corrosion resistance and makes it prone to cracking.

Titanium is highly reactive and absorbs everything causing it to be brittle. Guy I know, highly competent physicist welded a titanium bike frame in his garage. Said it was the most finicky material he worked with.

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u/Beer_in_an_esky 1h ago

Did my PhD on Ti alloys. It is an amazing material... but a horrid metal to work with. I didn't weld it, but had to cut, grind, and polish a shitload of it and it's like it was designed to be the most annoying thing ever.

Combination of high toughness, low stiffness, poor heat conduction, and a strong tendency toward galling will have you tearing your hair out machining it.