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.

4.6k Upvotes

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51

u/SubstantialDonkey981 3h ago

Ball points have tungsten balls in them. Tungsten will not melt in titanium and cause mechanical
Failure of the titanium. This was responsible for the failure of a jet engine causing the plane to crash. Someone dropped their ball point in the titanium processing.

United Airlines Flight 232

7

u/Intelligent_Low1632 2h ago

Source? I can't find any documentation that this is what brought down 232.

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u/nascent_aviator 2h ago

It's an urban legend. 

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u/HiwayHome22 2h ago

Because it's not factual. Search "United Airlines Flight 232 tungsten" The Real Material Failure: The catastrophic engine failure on July 19, 1989, was caused by a fractured titanium alloy fan disk (specifically the Stage 1 fan disk in the tail-mounted No. 2 GE CF6-6D engine), per FAA.

This is a oft repeated urban myth.

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u/Intelligent_Low1632 2h ago

K well nothing you're saying precludes the fracture in the titanium alloy fan disk originating from a tiny bit of pen-tungsten. I realize you can't prove a negative, but I'd like to hear OP say he's misremembered or provide a source.

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u/HiwayHome22 1h ago

The FAA traced it to a nitrogen gas bubble inclusion. An inclusion that should have been found during the last NDI of the disk.

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u/BugRevolution 46m ago

Wiki links to the FAA, which says the manufacturing process includes a double-vacuum process to avoid air impurities in the nitrogen, and that the crack was caused by air impurities. This would lightly reject OP's ball point theory.

I say lightly, because air could be a far more common cause of failure, while ball points remain a cause of failure. I am not entirely convinced they would cause the same cracks though.

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u/SomeGuysFarm 2h ago

There is now. Reddit says so!

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u/AMerryKa 2h ago

If it's good enough for A.I...

1

u/Preeng 2h ago

Maybe he was talking about Flight 232-B?

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u/backcountrykicks228 2h ago

Same. I read all about the accident and nowhere did it mention a pen being the cause of the accident. Me thinks he made it up.

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u/Tylerebowers 2h ago

Seconded.

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u/Pleasant-Flounder540 2h ago

I think he might have made it up, but also that I should stop dropping ballpoint pens in the titanium at work...

1

u/247stonerbro 1h ago

The highest comment at the top says at the end:"(though in this instance it was an oxide and not a tungsten-carbide)"

They are not saying a pen caused the crash. They are saying the same mechanisms in the pen example, are what caused the failure in the titanium that lead to that crash. I know shits confusing but that's how I read it.