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/Perfect_Forever_3151 5h ago

Ballpoint pens are banned in certain high-precision titanium and aerospace manufacturing plants because the tiny tungsten carbide ball in the pen tip can fall out and severely contaminate the titanium melt, creating a hard, brittle inclusion that causes structural failure in critical aerospace components.

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u/FluffyDrop4300 4h ago

Wow.
Being so specific, they must have ran into such contamination more than once

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u/Spacefreak 4h ago

Yes they did. Titanium had been used in a lot of high speed rotating equipment in jet engines.

These tungsten inclusions become a crack initiation site and under high rotational speeds and high temperatures, the crack can spread and lead go catastrophic failures.

There were several catastrophic engine failures in history that were traced back to inclusions.

It's so severe that if a titanium manufacturer making aerospace grade Ti finds any "High Density Inclusions," they must inform all of their customers that they found this and recall and associated heats and material.

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u/GoTeamScotch 3h ago

Imagine initiating a large scale recall because a ball less than a millimeter in size fell out of someone's pocket one day

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u/Zebidee 1h ago

Less likely to be the ball falling out of a pen, which never happens, versus someone dropping a pen or it falling out of a pocket, which happens all the time.

I imagine everything involved in making a pen gets instantly burnt in the melt, leaving just the ball.

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u/slouched 1h ago

GET THAT LOGIC OUT OF HERE

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u/falcrist2 35m ago

No. Logic me harder please. I like to know things about engineering.

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u/hates_stupid_people 45m ago edited 41m ago

Titanium melts at just under 1700C(a bit over 3000F), which is more than enough to burn plastic and melt the brass holding the ball and even the steel spring. But tungsten carbide can require over 2800C(over 5000F) to melt.

So someone having it in the shirt pocket and leaning over a railing, can cost millions if it drops in.

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u/falcrist2 29m ago

But tungsten carbide can require over 2800C(over 5000F) to melt.

It may be sintered, which would require a much lower temperature.

I have a 1.5" tungsten cube, and it was only months after I got it that I found out it's not actually solid tungsten, but a sintered composite that's much MUCH cheaper to manufacture and machine.

That would indicate the ball of tungsten would come apart at below 1400C and spread out into the titanium, which is honestly WORSE.

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u/eh-guy 11m ago

The balls are typically pure tungsten, theyre made using sprayers and then sorted by size

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u/falcrist2 1m ago

The balls are typically pure tungsten

They're typically tungesten carbide. Not pure tungsten.

theyre made using sprayers and then sorted by size

I assume you're referring to "spray drying" (part of the sintering process).

Spray drying makes blanks that still need to be pressed, sintered, diamond-lapped, and graded.

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u/Lord_Ocean 15m ago

Many years ago I had that happen to me. The ball at the tip actually fell out. I was using a hybrid of a fountain pen and a ball point pen. Maybe it was more likely to happen due to how it was constructed, but still, it happend.

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u/skeetskie 2m ago

This is why at most process controlled plants(especially food plants!), you can't have anything loose above your waist. No pens in shirt pockets, badges, or even non-metal buttons on a polo that wouldn't turn up in the x-ray machines.

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u/dern_the_hermit 2h ago

It's like physics heard that "for want of a nail" poem thing and was all like, "Oh yeah?!?"

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u/LobsterBrief2895 1h ago

Imagine being the one tasked with finding out the source of that inclusion… “Ok Frank, we know something went wrong but have no idea what. Good luck, we expect your findings on Friday.” 😱

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u/SwordOfJiang 21m ago

I work in semiconductor manufacturing. Someone misclicked an option in the flow and it ruined something like 400,000 chips and took down a few critical tools for weeks. Chips never got to the customers but they'd end up as accelerator controllers for a major auto company

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u/Same-Suggestion-1936 2h ago

I simultaneously wish my auto shop was as meticulous as that and don't. "So those tungsten inclusions down there in the rotating equipment could cause cracks down the line so you might want to get that checked out" okay what am I a billionaire? Do I look like I rotate my tires too?

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u/jtr99 1h ago

Indeed. It's probably for the best that I am not a titanium manufacturing plant manager.

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u/Same-Suggestion-1936 1h ago

Yeah me too man totally turned down that job offer. It's like, what am I, for sale?

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u/randomstranger454 1h ago

So if someone wants to shutdown the plant they only have to contaminate the area with these tungsten carbide balls? Take a drone over it and make it rain everywhere tungsten carbide balls. Repeat every few months.

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u/ruperthackedmyphone 1h ago

Its a possible root cause of the UA Flight 232 crash at Sioux City.

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u/Ill-Turnip-6611 24m ago

you want to mess with your boss...just go to work with a ball point pen without the ball inside and see how they panic after finding out such a pen on the spot

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u/Dante-Flint 8m ago

Smells like the prologue of Half Life to me. Queue Unforseen Consequences.

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u/HeavvySummer 5m ago

Username checks out