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Ultrasonic cavitation as way to create impossible alloys? Answered

I played around with ultrasonics now for a while and noticed that when it comes to certain things then logic seems no longer to apply.
In the normal household you might find some ultrasonic cleaner and that's about it.
A few people might have some distance measuring device or sensor array somewhere.
As far as the normal human is concerned that is more than enough ;)

Playing with certain metals like Bismuth or Gallium is not only but also a nice way to create nice alloys that you can play with even more.
Take a portable and simple hydrogen supply as an example.
Just make an alloy with lots of aluminium and a small amount of gallium.
Cut it into strips, blocks or grind into a powder if you dare.
Either way you just add water in a sealed container and get lots of pure hydrogen.
The waste product is aluminium oxide, which has additional uses.
The gallium itself is not affected by the reaction and can be reused many times.
However, with some metals things are just different.
As you might know it is hard to impossible to create certain alloys and other wouldn't make any sense.
For example an alloy made from Calcium and iron...
One of the big problems with alloys is that you need to have both metals in a molten form, then mix them properly and hope it turns out as planned.
And well, if the metals in question just on't want to combine we cheat by using slats as a flux for example or by blowing hydrogen through the molten mix to act as a sacrificial binder until the metal cools down.

Through ultrasonic cavitation we can not only clean surface, the same effect also destroys cells as the power from the implosion and the intense heat is more than what a cell can handle.
There are even tests now to determine how safe and effective it would be to sterilise hospital equippment.
A few seconds in an ultrasonic bath would safe the hours in the autoclave...
On an industrial scale ultrasonic vibrations are used to weld plastic parts - like the head and tail lights on modern cars or just sealed plastic housings of any kind.
With all this in mind my experiments with ultrasonic soldering made me wonder...

Science papers state that that for example ceramics are not actually soldered.
Appearently it is again hydrogen bonds provided by the ceramic or trapped air inside that provide the means to stick permantly.
There is also an effect based on the implosion of the cavitation bubble.
Here the solder literally is shot at well aboce ultrsonic speeds onto the surface of the ceramic.
Together with the vacuum effect the solder is then pushed into the tiniest of cracks and cavities.
Surface tension and other effects finally prevent the solder from just flowing off like it would do if we use just heat.
What it means is that there is no real soldering at all happening.
In reality it is like millions of big hydraulic presses would push the molten metal onto the surface.

Going back to the fun of Gallium with Aluminium....
Aluminium does not really go to well with steel.
And gallium does not that good with steel either.
Melting an Aluminium-gallium alloy is quite simple.
With an excess of Gallium in the mix it should be possible to add fine steel powder (steel, not iron!).
Of course it would neither mix well nor really melt at these low temperatures.
With ultrasoic cavitation however we could force the stuff to not only mix but also create the same effect as used by ultrasonic soldering.
The additional metals and minerals in a steel alloy should hopefully prevent any unwanted reactions in the final step...
If the steel powder is ine enough then the assimilation of the steel into the aluminium-gallium mix would result in the breakdown of the steel.
Once cooled and hard again the big question what would happen if we let water attack it?
In theory all aluminium would react to form aluminium oxide and aluminium hydroxide.
The gallium again would not be affected and as it is also bound to the steel should form a nice gallium-steel alloy.
But what hapens to the voids where the aluminium was???

The alloy would either be only affected on the surface or through cavitation and time all aluminium would be transformed.
In the best scenario we would get a steel-gallium sponge where the voids are filled with alumium oxide.
Forging such a mix could result in a ceramic steel..... !?? ;)

Imagine a safe...
There is always forceful ways to get in.
Like drilling or using a big angle grinder.
The pro might use a magnesium torch rod though....
The common approach to improve penetration resistance is by filling a space between the outside and inside walls of a safe.
Whatever you can imagine that is nightmare for your tools can be used, like thick glass plates, hardened steel bits, carbide studs, concrete with glass fibres....
But even diamond tipped tools would already struggle if the steel itself would contain high amounts of a hard ceramic like aluminium oxide.
The remaining gallium would also cause very high friction and through this heat - which these tools really can't stand unless you can provide water cooling as well.
With the right balance of aluminium and gallium most of the original properties the steel had can be preserved.

Just and idea though....


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