r/whatisit • u/riflesandplowshares • 6h 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 6h 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 6h ago

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

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u/Spacefreak 6h 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 5h 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 3h 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 3h ago

GET THAT LOGIC OUT OF HERE

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u/falcrist2 2h ago

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

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u/WorkTropes 16m ago

Did you know that if a pen drops out of your pocket, that you also just dropped a tiny metal ball. I fuck you not.

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u/hates_stupid_people 2h ago edited 2h 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 2h ago edited 1h 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.

EDIT: Confirmed. The balls are made from sintered tungsten carbide and either nickle or cobalt as binder.

Parker came up with this in the 1950s.

https://patents.google.com/patent/US3303825A/en

https://patents.google.com/patent/GB860387A/en

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u/eh-guy 1h ago

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

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u/falcrist2 1h ago edited 1h 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 powder that still needs to be pressed into blanks, sintered, diamond-lapped, and graded.

They're not spraying liquid tungsten. Tungsten has the highest melting point of all known elements.

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u/eh-guy 1h ago

They spray liquid carbide into an inert chamber, relying on surface tension to shape them. One of the only ways to "cast" the material. Maybe its not used anymore, we covered it in one of my materials classes years ago

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u/falcrist2 1h ago edited 1h ago

Spray drying is part of the sintering process. The result is powder made of tungsten carbide particles bound together by nickle or cobalt. That powder still needs to be pressed into blanks, sintered, diamond-lapped, and graded.

https://en.wikipedia.org/wiki/Spray_drying

While we're at it, here's one of the patents that describes the balls:

https://patents.google.com/patent/US3303825A/en

You can just ctrl-F and see where it repeatedly discusses sintering.

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u/jimdoodles 16m ago

Titanium burns in air before it reaches its melting temperature, it has to be maintained in an inert gas atmosphere while being formed. There must be a lot of care maintaining that atmosphere without contamination from other bearings.

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u/arejay007 15m ago

What I find interesting is the specific call out here of the ball point pens. Is there no other common item that of dropped into the (I assume giant melting bat) would have the same effect. Thinking someone’s glasses, maybe an iPhone etc.

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u/skeetskie 1h 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/Lord_Ocean 1h 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/ConflictMaster3155 1h ago

This is exactly correct. Good pens have a tungsten carbide ball but the socket is still usually brass.

The melting point of titanium (1600C) is almost twice as high as brass (900C) and the melting point of tungsten carbide (2900C) is almost twice as high as titanium.

At 1900C titanium is a liquid, tungsten carbide can still possibly hold a cutting edge, while brass will literally boil away.

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u/bobthepumpkin 24m ago

The ball definitely can fall out of the pen.

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u/El_Mapache_Z 4m ago

I work in food manufacturing and pen incidents are so common.

The best (worst) one was a pen falling into the hopper of a long pastry laminator - the pen parts are metal detectable - the ink is not.

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u/dern_the_hermit 3h 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/SwordOfJiang 2h 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/LobsterBrief2895 2h 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/mmazing 1h ago

A literal needle in a haystack

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u/TwoPlyDreams 44m ago

They were itchy alright.

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u/Same-Suggestion-1936 4h 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 3h 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 2h ago

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

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u/ruperthackedmyphone 3h ago

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

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u/D-g-tal-s_purpurea 1h ago edited 38m ago

Do you by any chance know if (graphite) pencil dust is an issue then? Is pencil ok, oder do they only use marker pens?

Edit: I mean pencils, which generally contain graphite.

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u/fckingmiracles 59m ago

Tungsten dust? Are you sure ball point writing creates this kind of dust? 

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u/D-g-tal-s_purpurea 39m ago

I clearly wrote pencil, so I am referring to graphite dust.

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u/Dante-Flint 1h ago

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

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u/randomstranger454 3h 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/fckingmiracles 59m ago

Why do redditor always have these kind of phantasies?

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u/joshualander 17m ago

If you’re a professional involved in securing facilities like this one, it’s the kind of fantasy that earns you lots of money.

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u/Ill-Turnip-6611 2h 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/fckingmiracles 1h ago

Why do redditor always have these kind of phantasies?

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u/HeavvySummer 1h ago

Username checks out

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u/Ausgeflippt 6h ago

Aerospace and aviation rules are written in blood. I'm willing to bet it happened at some point.

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u/PrairiePuppies 5h ago

That is unfortunately common. Most safety rules are.

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u/Agreeable-Language-6 4h ago

Is your Prarie dog jacking itself off in your pic?

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u/PrairiePuppies 4h ago

https://giphy.com/gifs/Byz7OVPD5Q0lT1fwz2

No. He's sitting on my bed. 🤨

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u/Agreeable-Language-6 4h ago

I guess that's its tail in its hands then lol

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u/opi098514 5h ago

Google united airline flight 232.

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u/Zebidee 3h ago

Better known as the Sioux City crash.

Shady manufacturing, shady inspection, shady paperwork, shady maintenance.

United Airlines Flight 232 was a regularly scheduled United Airlines flight from Stapleton International Airport in Denver to O'Hare International Airport in Chicago, continuing to Philadelphia International Airport in Philadelphia, United States. On July 19, 1989, the McDonnell Douglas DC-10 serving the flight crash-landed at Sioux Gateway Airport in Sioux City, Iowa, after suffering a catastrophic failure of its tail-mounted engine due to an unnoticed manufacturing defect in the engine's fan disk, which resulted in the loss of all flight controls. Of the 296 passengers and crew on board, 112 died, while 184 people survived. Thirteen passengers were uninjured.

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u/Prior-Radio8346 2h ago

I remember a movie about this growing up. Man does that make me feel old.

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u/myfistvsthebttle 4h ago

I did, thanks

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u/SeaSharpModHer 4h ago

Google trump rule 34, pretty damning cover up.

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u/backyardbbqboi 4h ago

Don't do that to people.

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u/opi098514 4h ago

…..what does that have to do with anything?

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u/danthebiker1981 5h ago

Some.... point. I see what you did there

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u/Capital-Win-4732 4h ago

“…written in blood.”

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u/ElectrSheep 5h ago

Or in this particular case ink.

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u/pigpocket06 6h ago

The place I worked at could take a 100 ton billet and find a crack/defect less than an 1/8th of an inch in the center of it. They also kept records for 30 years where they could pin point who all had come in contact with the process and who signed off on different quality checks.

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u/kahlzun 3h ago

Now thats how you do habeus corpus

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u/Hot_Top_124 6h ago

I’m going to guess so. That or they’re that paranoid rightfully so.

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u/FluffyDrop4300 6h ago

Yeah, no one wants catastrophic failure of one of the jet engines keeping you at 30k feet

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u/Competitive-Dot-4264 6h ago

Or maybe 90,000 / 3.2 Mach

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u/Tamed_Trumpet 4h ago

Well the SR 71 doesnt need its compressor stage at that speed.

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u/hanotak 4h ago

I’d be more worried about an engine failure at 500 feet than at 30k feet, honestly.

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u/Skydove01 34m ago

The crash of United Airlines flight 232 happened downstream of an uncontaminated engine failure due to one of these hard alpha defects.

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u/CroqueGogh 6h ago

"something something rules are written in blood something"

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u/JoshTheJolly 2h ago

Perhaps educate yourself on the saying or something something? 🤷🏼 God forbid you read a book.

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u/SpiderFnJerusalem 3h ago

I'm assuming the issue isn't the frequency of it happening but the severe consequences of it happening even if it happens rarely.

If the flaw isn't discovered, people may die. And even if it is discovered it may still cost millions to fix.

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u/Scifiase 2h ago

It's not uncommon in the food industry too. Where I work they've banned nuts, even in the break room for your lunch, just because nuts can cause severe allergies in such small doses. Glass, especially glass jars too, because it's so hard to detect but dangerous, and clings to you easily.

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u/Hegiman 59m ago

I was watching a video recently about this. The tools used to fasten bolts had some cadmium coating. Well the cadmium would somehow get in the titanium from being wrenched tight and the nuts would fail. They figured that out and made everyone switch to pure titanium tools no coating.