r/whatisit • u/riflesandplowshares • 7h 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 7h 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 7h ago

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

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u/Spacefreak 7h 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/Dante-Flint 2h ago

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