[TheForge] amorphous steel

[Hochewa at aol.com]

To All,
Amorphous metals, metallic glasses have been around for 20 years or so.  The 
lack of structure come from the extremely rapid cooling rate from the melt.  
They are usually cast as ribbons a few thousandths thick and a fairly limited 
number of inches wide.  They all contain Boron and some combination of rare 
earth elements of which Yttrium is not.  They are not cheap!  Allied Chemical has 
their plant in Orange, Texas and their products are called "Met-glas".  One 
of the big uses is in high performance transformer cores because they do not 
have those pesky grain boundaries to interfere with the magnetic field.  Another 
use is brazing foils.  They can cast the foils to thickness in alloys that 
they can't process by normal thermo-mechanical methods.
The metallic glasses have very good flexural and tensile properties but to 
not respond well to mechanical deformation, impact or flaws.  Heating does cause 
recrystallization and what ever desirable properties they had from the 
amorphous structure go away.

Hochewa