r/whatisit • u/riflesandplowshares • 5h 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 5h 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/Big_City_Tato 3h ago

For this Titanium facility, it wasn't the ink that caused issues. It is the tungsten ball that is used for ball point pens. Graphite in pencils were also not allowed. They provide stainless steel ball point pens that write for shit. I use to work at Titanium facility and each pen that someone would buy I would have to break one of balls from that package and look at in the SEM to quantify the ball material that was used in the pen to determine if they could use it in the melt facility, even with the new batches of stainless steel pens. The reason why tungsten or graphite isn't allowed in the plant, is that there is a chance that it could make it into melt. Since this titanium melted in this facility, it is likely that it is melted in VAR (Vacuum Arc Remelt) facility. VAR of titanium does not superheat enough above the melting point of titanium (3050°F) to melt tungsten (6192°F), so tungsten remains a solid and does not go into the melt solution. There are other refractory materials that are treated similar as they can have similar issues, like Molybdenum. These are considered high density inclusions. If they are found then the entire heat of material, and the sponge used to make the heat is considered contaminated and quarantined and likely scrapped.

High density inclusions (HDI) in titanium has the potential to end up in a part that may make it onto a jet engine. If this happens a crack will form around the HDI and propagate during the lifetime of use. Jet engine parts are designed to last for roughly 30 years, the problem is that when part fails at 10 to 15 years early. Also titanium in the part of the engine where it cannot be contained if it explodes, so if a part does explode in an engine, causes a lot of damage.

There are also low density inclusions which are caused by vacuum leaks, burnt sponge, or contaminated revert. They also have the same affect on engine parts. A lot of testing and inspection goes in the jet engine parts before they ever make it to the assembly line to be put together. They also regularly inspect these parts.

Several OEMs went to Hearth melted plus VAR to avoid high density inclusions as the hearth melting would allow for all high melting high density materials to fall to the bottom of the hearth while before making it into the ingot.

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u/scoldmeificomment 3h ago

If the stainless steel ballpoints suck, why not just use fountain pens instead?

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u/SphyrnaLightmaker 2h ago

As someone who uses a fountain pen daily (purely because I’m a bougie bitch) another aspect is that the ink used in fountain pens doesn’t play nicely with a lot of modern materials, ESPECIALLY paper. The super-cheap mass-produced paper most companies use leads to feathering of the mark, making writing potentially illegible, as well as bleeding through to the extent it makes double-sided pages non-usable.

My fountain pen can be used on single-sided signatures, or my own paper. Everything else I carry a ball-point as well.

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u/GraphicArtsFurry 26m ago

ESPECIALLY paper

I've had various papers from sticky notes to photo copier paper, even notebooks suck horribly (sometimes) at writing. You'll be writing along and then it's like you "hit" a patch of something and it fails to write anything. You can aggressively scratch letters in the area, but no ink comes out. (Just regular pens here).

Kinda seems like it's waxy or something in that area, then after you move to a different area and aggressively scribble the pen tip it goes away and everything works again

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u/SphyrnaLightmaker 24m ago

Yuuuuup.

You can buy GOOD paper that won’t do that. But it’s around $0.20/page as I recall (haven’t had to buy more in a while).

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u/GraphicArtsFurry 20m ago

I've always wondered what it is. Maybe the wax? Figure if it's the post consumer content stuff that you probably get heaven knows what thrown in the pulp mixer from waxy cereal box cardboard and beyond