don't tread on me

How to harden copper

39 posts in this topic

Copper will work harden a little bit if you hammer on it, bend it or work it an a lot of ways..you will be able to tell if it is working as it will crack. Then it needs to be softened, heat til it shows a little color and cool with water.
Basically copper and a lot of other non ferrous metals do not harden in the way we think of doing it to ferrous metals.

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Copper doesn't harden by heating and quenching the way steel does. It has the exact opposite effect. The only way I know of is to work harden or cold work i. e. hammering, shot blasting, etc. What are you trying to do? A brief description would be helpful to further narrow down a method that works for your use.

Scott

Edit: Rich beat me to it :D

Edited by Dodge

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ISTR an ultrasonic method of hardening of copper. It never gets to the hardness of a good alloy of steel with a proper heat treat though.

What are you trying to do? There may be other ways to getting what you want!

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I know that there is a way to harden copper with heat and quenching, You use some kind of brine but I don't know what kind of brine you would use. And as to what I am doing I am tring to save my Dad some money by rehardening some copper parts out of an electrical discanect.

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I would like to read wot you find about about the heat and brine procedure. Keep us posted.

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If it's pure copper I have strong doubts about that.

Note DIY stuff in electrical systems usually voids ones insurance allowing the insurance company to not pay on a possible electrical fire. This may be a "pennywise pound foolish" situation . (It also opens you up to horrendous liability in the future.)

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The only way to "harden" copper that I know of through heat treatment is oxide embrittlement. Basically the copper is heated in an abundance of oxygen, and the oxides penetrate deeply into the metal, hardening it some, but making it break easily. There is no "undo" to it other than melting it back down. The oxide forms inclusions that make the metal move less well. This is a serious problem in electrical components, and causes batches to be rejected if metal suffering from this problem is used.

Copper is work hardened, heat annealed. It is a "normal" metal, quite unlike steel (and thank goodness steel is quite abnormal.

Replace the parts with new, use the old copper to make something pretty or cash it in.

Phil

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just google ultrasonic hardening of copper

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Copper is normally work hardened, but some alloys can be precipitation hardened. That is , heated to a specific temp, and held for a specific amount of time. I ran across this at work while were reviewing some cracking issues we had with an electrical contact that we make.

Heating copper, and quenching it will soften it, no matter how you quench it.

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http://www.keytometals.com/Article71.htm

You'll need to know which alloy your Dad salvaged out of those disconnects. Also, if you plan on him re-installing this copper in the same or similar application, I suggest you first look up electrical code requirements. They insist he use only equipment "listed for the purpose."

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There are all kinds of wacky copper alloys out there. A company near here speciallizes in copper alloys. One is an iron-copper. One of the hardest to work coppers I ever dealt with.

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I skimmed through that article and found that most of it dealt with brasses and bronzes and not pure copper so it gets down to the fact that you need to know if you have a bronze or a brass to see how to re-harden it but there just doesn't seem to be a way to harden pure copper except to work harden it. Ifing it was me and how I feel about electricity I most likely just buy a new part. That electricity stuff will fry your brain quicker than jungle juice!!

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I skimmed through that article and found that most of it dealt with brasses and bronzes and not pure copper so it gets down to the fact that you need to know if you have a bronze or a brass to see how to re-harden it but there just doesn't seem to be a way to harden pure copper except to work harden it. Ifing it was me and how I feel about electricity I most likely just buy a new part. That electricity stuff will fry your brain quicker than jungle juice!!


My Dad is an electiction and I am his aprentice! I now it can cook you!

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if its pure copper it can be work hardened to a certain point (after being annealed) but no more, well not much if any more than it'l naturally harden over time without working it.
Say after annealing, leave it a good 4 or so hours and the copper will be back to its original state

J

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Say after annealing, leave it a good 4 or so hours and the copper will be back to its original state

J


What will leaving it for 4 hours do?

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I'd say so, it'l naturally harden as much as it's going to without going to extraordinary lengths to get it essentially too brittle with chemicals and stuff

Also, any curvature or shape in the copper will help its strength, it'l harden just the same

Just had a thought - how long it'l take to harden may depend on the thickness of the copper, I'd say up to 4hrs for copper up to perhaps 1.5mm thick

May have to experiment a little, tell us how it goes!

J

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Are you saying that 4 hours after annealing it will be hard again? So, how come I can buy hard, half-hard and annealed copper?

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well you've got me there, but when ever ive worked with copper, annealed it then had to do some other odd job or come back the next day i'd have to re-anneal it because it's hard again.
Also, ive never seen options to buy different hardnesses of copper, only different compositions or alloys

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From COPPER.ORG:


Types of Copper and Properties

The copper most commonly used for sheet and strip applications complies with ASTM B370. It consists of 99.9 percent copper, and is available in six tempers designated by ASTM B370 as: 060 (soft), H00 (cold rolled), H01 (cold rolled, high yield), H02 (half hard), H03 (three quarter hard), and H04 (hard).

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Don't worry, it's not a matter of submitting. The great thing about these forums is we can discuss opinions, experiences, sources etc. Hopefully, by doing so, we can all learn something.

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Don't worry, it's not a matter of submitting. The great thing about these forums is we can discuss opinions, experiences, sources etc. Hopefully, by doing so, we can all learn something.


True dat!

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