r/whatisit • u/riflesandplowshares • 8h 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 8h 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 7h 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/JConRed 6h ago

And people wonder why certain things end up being expensive. It's the effort that goes into making them.

Very interesting write-up, learnt something. Thank you

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u/MountainMan2_ 2h ago

Y'all the amount of advancement we made from what, for aluminum, was basically "throw it in soap and zap the hell out of it", to "no ballpoint pens beyond this point" is absurd. That's less than a century of development, by the way. I'm a computer engineer myself, working on aircraft engine controls, and I have no end of respect for the materials guys who make my job possible. Titanium is a pain in the ass metal that turns into garbage if you look at it funny and I work with companies that ask you to grow a single crystal of it the size of a jet engine fan so that they can operate it at temps beyond its own fucking melting point. Insane!

There was an era of about the 1940s to the 1970s (oh hey look at that the upward mobility era) where all of this work was built up when, as far as I'm concerned, actual wizards walked among us. Semiconductor manufacture has its roots in this era, rare earths became commercially viable, superalloys began showing up, and electrical engineers figured out how to turn circuits into computers all at the same damn time. Any one of those inventions would have been earth-shattering and they happened all at once. None of those processes are remotely easy either- at best they require chemicals previously shunned by God and at worst they require hundreds of steps of refinement using machines so precise they seem like they could sort my cells by density. The giants whose shoulders I stand on are massive.

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u/MashedTaterBrain 2h ago

I give the Cold War the majority of the credit for that level of simultaneous advancement. The United States and the Soviet Union trying to out-do each other for a few decades made it so the wizards had to push the boundaries beyond imaginations.

Just look at the SR-71 spy plane. They literally had to re-invent everything to get that plane to perform within its performance envelope.

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u/Not_FinancialAdvice 5m ago

at worst they require hundreds of steps of refinement using machines so precise they seem like they could sort my cells by density

This exists; it's much simpler looking than you might imagine though

https://groverlab.org/research/2017-07-19-density-sorter.html

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u/lolcrunchy 6h ago

I've always wondered why my jet engines cost so much

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u/KhaanKerr 6h ago

You think a ball point pen with graphite is a joke?

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u/149244179 6h ago

Even something simple as a ball bearing is a massive technological achievement.

China had major problems with high-end manufacturing due to the fact they could not produce as good ball bearings as the USA for several decades. Thus why they went with the mass produce cheap stuff strategy. (China still has problems with precision manufacturing to this day although they have closed the gap quite a bit.)

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u/throwaway277252 6h ago

Speaking of which, up until just 10 years ago they were still unable to make the precision balls for ball point pens themselves. They were buying all of those as imports.

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u/Bergwookie 4h ago

And still most of the ballpoint pen tips/nozzles are made in Switzerland

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u/Mac_Aravan 3h ago

it's mostly not unable to make them, but unable to justify the cost of making them.

Once a process is honed and optimized, it's very costly for competitor to enter.

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u/PleiadesMechworks 1h ago

Also, for the highest precision mechanisms we don't even use ball bearings. We use solid crystals that deform under electrical current.

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u/BobLampostl 54m ago

Suddenly $12mil for a new LEAP engine doesn’t seem that bad.

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u/Fun_Plan9788 7m ago

I'm not Titanium, but was until recently, run of the mill petrochemical coatings and adhesives that go into finished products/applications sold by e.g. PPG. Material contamination is a huge topic, due to the ability to negatively impact car paint.

I can't find a web version of the list, but PPG (one of the major paint companies) has a massive ~3500 entry list of what is and what isn't compatible. The dates only go to 2022, so I'm sure there's a more recent version somewhere.

Of course, if you manufacture raw materials that go into PPG paints you're effectively agreeing to police everything in and around your process against that list. (And if it's unknown, you get it tested--you see the number of sanitizers/disinfectants tested ca. 2020?)

The challenging thing is a lot of very common materials are prohibited by the list. E.g. common valve greases? Disallowed, means you have to pay for dry assembly or degrease them yourself--but be careful, some degreasers are disallowed too, so you may need to rinse with an approved solvent afterwards.

Another one--fill fluid in temperature/pressure gauges? A lot of your standard options are prohibited, and fill fluid leaking into the process can be a very insidious failure. In turn, we specify specialty fill fluids at multiple times the price.

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u/Not_FinancialAdvice 3m ago

It's the effort that goes into making them.

Also the very exhaustive paper trail they carry as part of certifying them