Metal heals itself.... (1 Viewer)

[Uncle Gizmo]

My dad told me that he fractured a piece of cast iron.

He said he placed the broken pieces together and it healed it's self....

Now I see this:-

Cracked Piece of Metal Heals Itself in Experiment That Stuns Scientists

File this under 'That's not supposed to happen!': Scientists observed a metal healing itself, something never seen before.

www.sciencealert.com

 

[The_Doc_Man]

Definitely interesting. In the article there was a hint that the "healing" might occur at the nano level if the crystalline aspect of the metal has remained intact. (I.e. surface has not been befouled.) That would make sense, because at the nano level, the crystals form a lattice, but at the edges of the lattice, the atoms are exposed on one side. If you put to such lattices together, the forces that held them together as a crystal would still be available to bring them back together as a crystal.

 

[AccessBlaster]

It would bring tears to my eyes if I ever cracked my cast iron

 

[Cotswold]

In all practical situations cast iron cannot be repaired. Some try to weld it with CI rods that supposedly work but don't.
Depending upon the section you can drill and tap, then plate the pieces together but the repair usually looks a mess.
It is also likely that it will unable to perform its original function after repair. Just weigh it is is the advice.
Cast iron is good in compression situations and doesn't rust. Which is why you will see examples hundreds of years old.

Mild steel needs protection from the atmosphere in order not to sacrifice, or rust. If you have any steelwork, then make
sure it is fully covered by paint. Mild steel can be galnanised in a hot dipping process which even in coastal situations
the zinc coating may well not sacrifice for around 20 years and show the metal underneath. Unless you paint galvanised
steel soon after it was dipped and remove the grease removed with a mild acid followed by an etching primer. You will
never afterwards successfully paint it. At inland locations galvanised protection may last a lifetime. It is pointless and
is simply wasting money having steel inside buildings galvanised.