General > General Technical Chat

What is this metal?

(1/8) > >>

Refrigerator:
Found this weird chunk of metal in the garage, no idea what metal it is.
All i know is that some 15 years ago when me and my brother were kids he told me that you rub this metal on the bench grinder stone to clean it.
But i doubt that's true.  ;D
The metal is non magnetic and feels quite dense. The structure is very crystalline and it's very brittle, the crystals are huge and very long.
It seems very resistant to tarnishing, this piece is many years old but despite dirt still has shiny spots where it was broken long ago.
I tried breaking a piece off with pliers but it seems the metal is quite hard and breaking a piece off is not that easy.
Once i managed to knock a corner off it revealed some very shiny metal underneath.
It leaves me wondering what metal or alloy of metals this is, my closest guess would be bismuth but i'm not sure.
I have not yet tried melting the metal.
Any guesses?  :)

Robert Smith Eco Warrior:
Interesting.  :-//

Andy Watson:
Could be many things! If it is a "wheel dressing stick" it will be a composite of a very hard material, e.g. tungsten carbide or even diamond, sintered into a solid block. Norten make a proprietry stick that has a grey-ish appearance - sintered boron carbide - look up "Norbide wheel dresser".

Zero999:
Are you sure it's a metal? Did you measure the electrical resistance? Does it read near zero, when measured with a DVM set to Ohms? Note you might need to stab it quite hard with probes, to break the oxide layer.

T3sl4co1l:
Can you get an idea of specific gravity (weigh it, weigh its water displacement)?  Does it dissolve in HCl or H2SO4?  NaOH solution?  And if so, what color is the solution?

The long crystals resemble either a cross section from the Van Arkel–De Boer process, or condensed/sublimated material.  I suppose it could be directionally solidified and fractured too.

Tim

Navigation

[0] Message Index

[#] Next page