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Digby and others,

There is a structural phase change that occurs with no change in volume of the
unit cell. You can find this on the phase diagram for brass, make sure to get
the right alloy. I think it was 80/20 for the typical musical instrument.
There is not a correstponding transition for pure silver, so this shouldn't
work for pure silver. When instruments are crafted from silver, the metal used
is not pure silver. At the time I was interested in all this, I could not find
the phase diagram for sterling silver. If I recall, the unit cell for brass
changes from orthorhombic to rhombic, with no change in unit cell volume. There
was a definate INCREASE in the stress in the crystal structure as determined
with a diamond anvil test. This is where you press a diamond point into and
deform the material. The shape left behind (does it exactly match the point, do
the walls buckle in, etc.) tells you something about the residual stress in the
material.

Sam

Stuewer David wrote:

Digby Willard wrote:

So what's the difference if it ends up at the same temperature it started
at?

Responding to the message of Wed, 12 May 1999 09:50:14 -0400
from Sam Sampere <sampere@SUHEP.PHY.SYR.EDU>:

You don't play it when it's cold, you let it warm up first!!



I've kind of been lurking on this question, but I've been tempted to ask the
same question that Digby asked. What >is< the difference if the instrument
ends up at the same temp it started at? It seems (obviously) that the very
structure of the instrument would have to change permanently if the
performance is to be changed by simply dipping it in liquid hydrogen.

By no means am I saying that this >doesn't< happen; it's just not something
that I'd expect.

Dave Stuewer
Shawano (WI) HS



--
Sam Sampere
Syracuse University
Department of Physics
Syracuse, NY 13244
315-443-5999