"Ed Huntress" wrote in message
...
On Sat, 2 Jan 2016 11:44:17 -0800 (PST), whit3rd
wrote:

On Sunday, August 16, 2015 at 11:05:10 PM UTC-7, Tom Gardner wrote:
On 8/16/2015 1:30 AM, Gunner Asch wrote:

I should mention that Ive turned rough pure silver rods into
bullets
on CNC lathes.

They dont cast well

I turn some also, they cut as nice as AL. They cast fine ... if
you
have the stuff.

Pure silver cannot be melted in an oxygen atmosphere, or it
cracks (due to dissolved gas release) on solidification. That's why
sterling silver contains copper- the alloy is better behaved.

Interestingly, some high-performance bearings, instead of Babbitt
metal,
have been made of silver. It may be hard, but it's apparently nice
and slippery.

This may not be what you're referring to, but steel roller bearings
used in gas turbines often are silver-plated. The purpose it
twofold:
it makes a superior bearing surface in normal operation (why, I
don't
know), and it offers some protection in case the oil supply is
temporarily blocked. Like cast iron or babbitt, it provides some
lubrication even when run dry.

--
Ed Huntress

http://www.enginehistory.org/NoShort...Crankshaft.pdf
pp 1-4, 1-5:
"Hobbs organized virtually the entire Pratt &
Whitney engineering staff to solve the problem.
Through much experimentation, hard work, and
perseverance, the team invented the lead-silver-indium
bearing that was so good it was even adopted by Pratt
& Whitney's rival, Curtiss-Wright."

The German scientists who analyzed a crashed engine misreported the
Indium as an impurity.

-jsw