annealing copper

To: tesla-at-poodle.pupman-dot-com
Subject: annealing copper
From: Tesla List <storey-at-stic-dot-net>
Date: Fri, 25 Apr 1997 08:08:51 -0500
Approved: tesla-at-stic-dot-net

Subject:  annealing copper
  Date:   Fri, 25 Apr 97 04:33:03 UT
  From:   "William Noble" <William_B_Noble-at-msn-dot-com>
    To:   "Tesla List" <tesla-at-poodle.pupman-dot-com>

aaargh, I can't stand it.  Let me post this once more and then I'll
quit.  You 
do not have to let copper cool slowly after annealing it, it makes no 
difference.  prove this yourself.  Workharden a piece of copper wire -
smack 
it with a hammer or bend it a lot or something,  Cut it in half so you
have 2 
work hardened pieces.  Heat them both up to cherry red - use the stove
if you 
wish.  Drop one immediately into water while it is cherry red.  Let the
other 
one cool as slowly as you care.  When they are both cool, flex each one
and 
see if you can tell the difference.

There is a physical (as in metallic latice) reason why an iron carbon
mixture 
(called steel) reacts differently when you quench it - it has to do with
the 
phase transition of the metal - I don't remember all the names from way
back 
when - there's martensite and austinite and some other name - when you
quench 
iron the metal ends up with regions of different "phases" - e.g.
different 
crystal packing, and that sets up internal stresses and makes it hard. 
Copper 
does not have this phenomena.

ok, I'll shut up on this now, I just hate to see incorrect information
on a 
list like this where everyone is so careful about what they say.