Subject: Re: Hardening Copper

From: [email-masked] (Bruce Johnson)
Date: Wed, 4 May 1994 12:42:00

In article <[email-masked]> [email-masked] (James Foster x2912) writes:
>From: [email-masked] (James Foster x2912)
>Subject: Re: Hardening Copper
>Date: Tue, 3 May 1994 22:51:28 GMT

>In article <[email-masked]>, [email-masked] (Doug Blain)
>writes:
>|>   I have been making a copper collar for a sword and have just finished
>|> brazing the ends together. Since it was hammered out a lot, to remove work
>|> hardening I softened it up several times by heating to red hot and
>|> quenching in water. Now I would like to toughen it up again but obviously
>|> I cannot work harden it. How does one temper copper (or silver)? 
>|> 

>Out of curiousity, do many other people not associate "temper" with
>hardening?  Though I know the definition can mean to either soften or harden
>I always think of a tempering treatment after hardening to achieve a
>lower hardness.

     I always thought the object of 'tempering' was to 'relax' the crystal 
structure of the metal so that some of the qualities desired from the 
hardening process, ie: toughness, ability to hold an edge, were retained, 
while minimizing the undesireable effects, ie: brittleness.  Also, when I was 
working jewelry, using silver, copper and brass, we were taught that there was 
no way to harden the metal other than workhardening.  You can make a wire 
spring from sterling silver by forming it from stock through a die, but then 
you had to be really careful when bending it because it could break, or 
heating it, which would anneal it, making it lose its springiness.

   Slightly related question...why do you want the collar hard again?  

	Bruce Johnson
	The University of Arizona

	This place...have an OPINION????

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1994
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From: [email-masked] (Charles B. Vincent)
Subject: Re: 1994 NAMES exhibition
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Alan Frisbie ([email-masked]) wrote:
: In article <[email-masked]>, 
: [email-masked] (Ron Ginger) writes:

: Does anyone have any experience with "exotic" materials like
: titanium?   Does it work harden?   What would I have to watch
: out for in this kind of application?   Where can I get it in
: small quantities (4" x 4" x 0.1" sheets)?

    My brother in law used to work in the Advanced Materials Lab at LTV,
and worked with titanium quite a bit.  I remember him telling me it
couldn't be worked with normal bits, but required some rather expensive
cobalt ones. I don't remember the percentage of cobalt.   I will call him
tonight and find out more.  I'll also see if he knows of any sources.

---

From: [email-masked] (John Kopf, X6305)
Date: 5 May 1994 19:20:10 GMT

In article [email-masked], [email-masked] (Doug Blain) writes:
>   <stuff deleted>
> I cannot work harden it. How does one temper copper (or silver)? 

BEAT ON IT!!  (Hardness of copper caused by dislocations in the metal, caused
by "work-hardening", and removed by heating...It MAY be possible to re-introduce
these by pounding LIGHTLY, so the work doesn't deform appreciably, but that's
pushing it -- if it were wire, you could do it by twisting.)

JK

---

From: [email-masked] (Will Fischer)
Date: Thu, 5 May 1994 21:47:50 GMT

Doug Blain ([email-masked]) wrote:
:   I have been making a copper collar for a sword and have just finished
: brazing the ends together. Since it was hammered out a lot, to remove work
: hardening I softened it up several times by heating to red hot and
: quenching in water. Now I would like to toughen it up again but obviously
: I cannot work harden it. How does one temper copper (or silver)? 

I believe annealling copper increases its hardness slightly (which is
why you quench after heating to remove work-hardening), but other than
that, you're out of luck.  Iron is unique among the common metals in
having alloys which can be quench-hardened.

Terminology:  as has been mentioned, though "temper" is often used as a
general term for heat-treating steel, technically speaking, you first
"harden" (i.e. by quenching), then "temper" by re-heating to relieve
stress, reduce brittleness, slightly decreasing hardness in the
process.

Quote:	"I tempered the tools just like you showed me, but they turned
	out soft as butter!"

	"Did ya _harden_ 'em first?"

	"No... Oh! _I_ see."

________________________________________________________________________
Will Fischer				[email-masked]

Department of Biology			voice1	812-855-7773
Indiana University			voice2	812-333-2433
Bloomington, Indiana 47405 USA

---

From: [email-masked] (Barry Workman)
Date: Fri, 6 May 1994 06:13:55 GMT

[email-masked] (James Foster x2912) writes:

>In article <[email-masked]>, [email-masked] (Doug Blain) writes:

>That aside, I don't think that copper or its alloys heat harden very much
>at all.  They do work harden as you found out.  

Copper, silver, and gold can be toughened, but not hardened by adding
sodium cloride to the melt when casting the metals but I don't think
it will work like case hardening.

Humm, red hot and quench usually hardens as I recall.  Heating to orange
and air cooling softens.  Heat to orange/yellow, quench, heat to cherry
and air cools tempers.  Hardened metal is brittle tempered metal is 
tough.
-- 
    - Barry Workman

---

From: [email-masked] (Will Fischer)
Date: Sat, 7 May 1994 07:43:34 GMT

Barry Workman ([email-masked]) wrote:
[snip]
: Humm, red hot and quench usually hardens as I recall.  Heating to orange
: and air cooling softens.  Heat to orange/yellow, quench, heat to cherry
: and air cools tempers.  Hardened metal is brittle tempered metal is 
: tough.

The above is a nice summary, but it ONLY applies to steels.
Non-ferrous pure metals and alloys have different crystal structures,
and respond differently to heat treatments (brass, for example, is
_softer_ when quenched from a red heat than it is when air-cooled).

I, too, am curious why the original poster wants to harden the collar,
anyhow.
________________________________________________________________________

---

From: [email-masked] (WAYNE A. BAUGHMAN)
Date: 4 May 1994 12:44:12 GMT

Hmmm . . . I used to make hand-made trumpets, which meant working with
brass and copper, so I'll give you my best approach.  Copper and brass
both harden with working and soften by anealing, i.e., heating red-hot
then allowing to cool, as you know.  What I would suggest is that you
simply figure a more creative way to work the piece in order to obtain
the desired hardness.  This could be accomplished by expanding and
drawing the piece several times.  I used to draw copper and brass tubes
through both steel and lead dies at various stages in the manufacturing
process, which certainly hardened them!  Making a sword sounds like fun.

------------------------------------------------------------------------------
Wayne A. Baughman             | "Delusive fortune hears the incessant call,
George Mason University USA   |  They mount, they shine, evaporate, and fall."
Tel: 703.993.3706/703.573.2023|                           - Sam. Johnson
email: [email-masked]   |
------------------------------------------------------------------------------

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From: [email-masked] (RICHARD ALLAN JOHNSON)
Date: Fri, 6 May 1994 18:21:13 GMT

>at all.  They do work harden as you found out.  
	I beleive that the second gentleman is right and themper is 
correctly used as a term for softening after a hardening stage.  
	As for the first question I think (perhaps some materials engineer 
can tell me if I'm wrong) that certain copper alloys can be age hardened.  
If I remember right you heat the object and then quench it.  Then you heat 
again at a lower temperature for a few minutes to a few hours and quench 
again.  Good luck.  
	Why do you want the collars harder.  I have seen plenty of 200-500 
year old swords with copper collars and I doubt they are hradened.
	Rick

---

From: [email-masked] (Russ Kepler)
Date: Sun, 8 May 1994 15:08:11 GMT

In article <[email-masked]>,
>and air cools tempers.  Hardened metal is brittle tempered metal is 

Copper is backwards from steel, softening in a quench and hardening in
an air cool.  Kinda strange.  I've already sent what I have on hardening
copper (what little there is) to the author of the original note.

-- 
Russ Kepler posting from home  [email-masked]

                      Please don't feed the Engineers