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My Tungsten Cube (2019)

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Re: My Tungsten Cube (2019)

#221

Post by skyfaller »

Animats wrote: post #203

You can get cubes of most of the solids in the periodic table here.[1] Some are very expensive, but available. [1] https://luciteria.com/metal-cubes

What's not 100% clear to me, after reading through some descriptions, is which metal cubes I could handle semi-regularly without damaging them (iron? will it rust?) or endangering myself (lead? how likely is handling it to poison me?).

It seems to me that the point of buying a cube of some metal is to feel its weight and texture, to see it respond to light. If you're just going to keep it in a capsule and never take it out, you could just have a photo or video of the metal.

What elements can you hold in your hand without either you or the element taking damage?

Re: My Tungsten Cube (2019)

#222

Post by science4sail »

falcrist wrote: post #214
markus_zhang wrote: post #148

This reminds me of Bill Gates who owns a small amount of every chemical element.

I had to look this up. It seems he has a periodic table with lots of little cubbyholes with pictures and items representing the element, but not every element is actually there. It's hard to find a good source for details about this display, but he has cubbyholes for all of the lanthanides and actinides, so there must be some that don't have the actual element being represented.

Yeah, I imagine that it'd be hard to get ahold of some technetium or astatine

Re: My Tungsten Cube (2019)

#223

Post by jfk13 »

skyfaller wrote: post #221
Animats wrote: post #203

You can get cubes of most of the solids in the periodic table here.[1] Some are very expensive, but available. [1] https://luciteria.com/metal-cubes

What's not 100% clear to me, after reading through some descriptions, is which metal cubes I could handle semi-regularly without damaging them (iron? will it rust?) or endangering myself (lead? how likely is handling it to poison me?). It seems to me that the point of buying a cube of some metal is to feel its weight and texture, to see it respond to light. If you're just going to keep it in a capsule and never take…

In case you haven't seen it, https://englishatlc.files.wordpress.com/2016/03/randall-munr...

Re: My Tungsten Cube (2019)

#224

Post by TeMPOraL »

mensetmanusman wrote: post #58
_caw wrote: post #33

> I struggled a lot with deciding to buy a cube. It felt wrong to spend so much money on a featureless hunk of metal. When I bought my cube, I used it as an exercise to fight back against my frugality. But it wasn't meant to be: it was delivered to the wrong address and I received a full refund. Then my neighbor delivered it to me.

The cube thwarted your attempts at frugality, so that it could spend time with you alone.

A perfect Companion Cube.

Re: My Tungsten Cube (2019)

#225

Post by jacquesm »

kragen wrote: post #217
jacquesm wrote: post #198

Earlier quoted context omitted.

Per unit of mass yes, but there is rather a lot of mass for a given volume. And those are relatively slow processes when it comes to dealing with surfaces. Perpendicular cuts should be a lot quicker (you only have to separate the two sides, in theory one slice of atoms would be enough but in practice you'll end up with some minimal cutting radius). Fascinating processes by the way, and the precision that you can reac…

Hmm, I thought ECM and tap-disintegrating EDM (which is not very precise and does use a huge amount of power, unlike, say, wire EDM) had pretty astonishingly huge MRRs? I think the density ratio for tungsten and steel (19:8, just over 2:1) is actually more even than the atomic mass ratio (23:7, just over 3:1). So I'd think that even on a volume-per-coulomb basis ECM would cut tungsten faster, assuming comparable fara…

No, but if I had a machine like that here I'd definitely give that a work out because this is an interesting question that I normally would not have considered.

That's a question worth settling, from memory the speed is not so much a function of the material as it is of the current density that you can achieve with the gear you have. Thousands of Amps will get you some pretty good speeds, on the order of a cubic cm of material removed per minute for a 25KW machine.

I also wonder what would happen if you tried to plasma cut it, that should work as well.

If there is one thing I really miss from life in Canada then it was the fully equipped machine shop, that was such a great thing to have. You could go from idea to a pretty decent physical implementation fast than you could have ever mail ordered the parts and there is so much satisfaction in working metal. The plasma torch I had there was a relatively small one (12 KW) but it still cut anything an everything I ever threw at it with pretty impressive speed. But I never tried it on Tungsten. Missed chance! I suspect it wouldn't work all that well because Tungsten isn't the best conductor and probably would backsplatter all over the place from the compressed air dispersing the metal that would melt rather than evaporate so you get a puddle rather than a stream of gas.

Re: My Tungsten Cube (2019)

#226

Post by TeMPOraL »

tyingq wrote: post #163
mbreese wrote: post #123

Earlier quoted context omitted.

To save people some time clicking through... A 10mm cube of Iridium weighs ~21.9g. And from this source, costs $9000. From the same source, a single gram is only $275. This means that due to the difficulty in working with this very dense metal, the cost of turning the Iridium into a cube is nearly $3000 (on top of the ~$6000 for the metal itself)!

Osmium would be heavier still (22.59 grams/cc), and a relative bargain at $1275 for the 10mm cube at the same source. Not polished/shiny though.

And, as divbzero's Quora link points out, it's going to kill you by oxidizing into a toxin when exposed to open air.

Re: My Tungsten Cube (2019)

#227

Post by User23 »

fraa-orolo wrote: post #173
fywacro wrote: post #145

Earlier quoted context omitted.

FYI, tungsten carbide (tungsten + carbon) is a different substance from the pure metal tungsten... They have very different physical properties. But I do appreciate your story about tungsten carbide, too :-)

> FYI I'd wager they're fully aware of the differences between tungsten carbide and pure tungsten, having done a doctorate about it.

The FYI might be poor phrasing, but GP is right that many people confuse the two. This isn't helped by many sellers of novelty "tungsten" online selling tungsten carbide and mentioning it in the fine print, if at all.

Re: My Tungsten Cube (2019)

#228

Post by HarryHirsch »

paulgerhardt wrote: post #170
fywacro wrote: post #145

Earlier quoted context omitted.

FYI, tungsten carbide (tungsten + carbon) is a different substance from the pure metal tungsten... They have very different physical properties. But I do appreciate your story about tungsten carbide, too :-)

If anyone knows where to get a tungsten cube I would be interested. I’ve wanted one since reading this post a few years ago but every vendor usually sells alloys.

Can't blame them for selling alloy. Pure tungsten is extremely brittle and virtually unmachineable. So they'll sell you nickel alloy, because you can work that to tolerance. No powder metallurgy required.

Re: My Tungsten Cube (2019)

#229

Post by learc83 »

jacquesm wrote: post #196
learc83 wrote: post #181

Earlier quoted context omitted.

EMTs aren't amputating your finger either. You'd go to the ER and they'd call the surgeon. They'd also know that you can crack a tungsten ring, so they wouldn't need to do that in the first place.

If your finger is broken it will swell up so fast you may not even be able to get to the ring with something that can crack it. This is not something that I would risk for any price.

Just confirmed with my wife (ER doctor) that there is no situation where an EMT amputates your finger because they can’t get a ring off.

Re: My Tungsten Cube (2019)

#230

Post by thaumasiotes »

MgB2 wrote: post #129

I used to work with tungsten carbide cubes during my PhD thesis. They're used in multianvil high-pressure synthesis. With the right setup you can reach almost 20 GPa of pressure. Not as much as with diamond anvil cells, but you have more reasonable sample sizes (a few milligrams). And thats still like the pressure pretty deep into Earth's mantle. I also used the opportunity to snap a neat picture of a polished WC cub…

> They have the mean tendecy to explode into super sharp pieces when you're not expecting it, so wear goggles.

This seems understated. Shouldn't you also wear armor?

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