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holiday
15th Nov 2020, 06:59 AM
Hi everyone, I'm a new member.

About 7 years ago, I purchased some small copper sheets online. They are about 3/32" thick by 2" x 3". I've made a few things with them over the years.

I read about the dangers of process BeCu alloys and as a hobbyist, I was not aware of this metal. I have no way of contacting the seller at this point to find out what the alloy of copper I have could be.

I've been over on some other metal working forums asking this question. Looks like some of you may be in this forum as well, but I'm asking here to cast a wider net. :?

Is there a way to distinguish "normal" copper from BeCu alloys? The copper that I have is fairly hard to start with, but it can get very soft if hot quenched annealed. I'm attaching some pics of one of the sections with the blue film over it. The copper has patinaed a little bit, being that its 7 years in my possession at this point.

Thanks.

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BobL
15th Nov 2020, 10:24 AM
The only way to be sure of identification is using something like a specialised XRF analysis device/instrument - a standard XRF unit won't pick it up..
However, given it goes very soft on annealing it's unlikely it's Be-Cu. Only a few very unusual forms of Be-Cu are as soft as regular Cu.
Being in sheet form this doesn't help you but apparently when machined Be-Cu doesn't gall anywhere near as much.

Even if it is Be-Cu what do you plan to do with it?
Handling even with bare hands is not a problem and even if it's just being folded, cut or drilled is should also not present a problem. It only becomes a problem in a vapour or dust form such as when sanded or brazed where it can be breathed in. If you need to sand it use wet sanding.

Given you have such small amounts even if you were to dry sand it, if you have an extraction/ventilation system that vents dust outside your work area the dilution effect should take care of it. Its not like you're going to end up making a lot of dust.

If you are going to use a mask you will need to use a P3 mask. Mask use can be problematic, once the mask is used several times it should be disposed of and not repeatedly reused in case it gets damaged.

holiday
16th Nov 2020, 09:27 AM
The only way to be sure of identification is using something like a specialised XRF analysis device/instrument - a standard XRF unit won't pick it up..
However, given it goes very soft on annealing it's unlikely it's Be-Cu. Only a few very unusual forms of Be-Cu are as soft as regular Cu.
Being in sheet form this doesn't help you but apparently when machined Be-Cu doesn't gall anywhere near as much.

Even if it is Be-Cu what do you plan to do with it?
Handling even with bare hands is not a problem and even if it's just being folded, cut or drilled is should also not present a problem. It only becomes a problem in a vapour or dust form such as when sanded or brazed where it can be breathed in. If you need to sand it use wet sanding.

Given you have such small amounts even if you were to dry sand it, if you have an extraction/ventilation system that vents dust outside your work area the dilution effect should take care of it. Its not like you're going to end up making a lot of dust.

If you are going to use a mask you will need to use a P3 mask. Mask use can be problematic, once the mask is used several times it should be disposed of and not repeatedly reused in case it gets damaged.

Hey BobL, thanks for your insight on this. As far as what I'm doing with this copper, I've made a few keychains and also some knife handles from it. I have done some minimal shaping of the cut out pieces on my small belt sander, but yes, I do wear a particulate respirator style mask.

Part of my fear (perhaps paranoia) is that if this is Be-Cu and I give these items away as gifts someone could become sick from them. Maybe far fetched, esp seeing as I couldn't see them sanding the implements I would gift them.

I have not suffered any known ill effects from working with this material, even after getting the shavings all over my bare hands on several occasions. Not sure if this makes a difference, but I am in the USA, and I'm almost 100% sure the seller on ebay who I got it from was also a US seller. Would the blue film and the thickness be any indicator of alloy? It seems like most 99.99% pure copper plate offered for sale here via eBay has this thin blue film.

Its frustrating that I have no way of looking back to 2013 to see the original listing or know who the vendor was. Ebay only lets you go back 3 years now, and paypal is similar. I also unfortunately deleted most of my emails from prior to 2014 that might provided a clue as to the seller.

Holiday