February 16, 201214 yr Copper is different, it will be soft after annealing regardless of air cooling or quenching. How hard copper will be after annealing (hard, half hard, dead soft) depends on how hot you get it. I think there has been a slight misunderstanding about copper returning to hard if air cooled. Some (but not all) non-ferrous metals do need to be quenched to soften them (Silver need to be held at temp over time, then quenched). If you let them air cool (4 hours?) then they would still be hard, but the original question was about copper.
June 7, 20169 yr Traditionally it is work hardened. Note that there is a reason that steel has supplanted copper for tool manufacture...
June 7, 20169 yr Work hardening is the only way--hammering, stretching, rolling, etc. Beryllium copper alloys are precipitation hardening, and can be heat treated for higher hardness. 600°F-750°F for 1-2.5 hours depending on which alloy, and requirements needed.
June 8, 20169 yr Lay a speaker on it's back and lay your pieces on it with a bunch of coins. Play loud window rattling music. Given time it'll harden copper alloys nicely. Frosty The Lucky.
June 9, 20169 yr On 08/06/2016 at 6:20 AM, Frosty said: Lay a speaker on it's back and lay your pieces on it with a bunch of coins. Play loud window rattling music. Given time it'll harden copper alloys nicely. Frosty The Lucky. Won't this 100% mess up my speakers ?
June 10, 20169 yr Leave the covers on the speakers, you don't want stuff rattling around on the cones. Don't turn them to destroy my speakers volume. Another way is to put them in a box or metal bucket in the trunk of your car and do some gravel road driving. Stop when they're hard enough. Frosty The Lucky.
June 10, 20169 yr I have a dirt road that leads to my house, so the car thing sounds good. Thanks, Michael.
June 10, 20169 yr Shot peening will do it too. Anything that impacts the surface, stretches it, rolls it, or otherwise works it will harden it.
July 8, 20178 yr 1 hour ago, tanvir said: How can I harden 98.97% copper with Zr and Cr as trace elements Permanently submerge it in a bath of liquid nitrogen. Oh, did you want a practical solution? Well, you'll have to tell us how big a piece, what it's to be used for, what kind of stress and wear it will be subjected to, and so on.
July 8, 20178 yr Work hardening; including ultrasonic hardening; some thermal methods; depends on what you are trying to do.
July 10, 20178 yr Wallnut shell blasting won't remove material though an ultrasonic cleaner might do it for you. Frosty The Lucky.
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