Member
Joined 2003
I have been working on 1" ribbons for several months using 6.5 micron foil in the protypes. The problem with this foil is that I can't hold a close enough width tolerance (.004 or so) while slitting a 6' length.
I located a very small roll of 1" by 5 micron precision slit foil (exactly what I ultimately want to use) and have been hoarding it for the final ribbons...which were finished yesterday.
New problem. This foil is either treated differently, or a different alloy such that it seems very brittle and has a tendency to break during pleating.
Does anyone have any suggestions on how I might go about annealing the 5 micron foil?
I located a very small roll of 1" by 5 micron precision slit foil (exactly what I ultimately want to use) and have been hoarding it for the final ribbons...which were finished yesterday.
New problem. This foil is either treated differently, or a different alloy such that it seems very brittle and has a tendency to break during pleating.
Does anyone have any suggestions on how I might go about annealing the 5 micron foil?
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I have heat treated AL, but much thicker than the one you are using, 1/8".
AL will be treated to zero temper after heating in oven at 700-800 F, after through heating, turn off oven. DO NOT open the oven door. Then let it cool in the oven.
AL will age and harden just being out in the air.
Hope this help.
AL will be treated to zero temper after heating in oven at 700-800 F, after through heating, turn off oven. DO NOT open the oven door. Then let it cool in the oven.
AL will age and harden just being out in the air.
Hope this help.
Cryo Treatment
If you are interested I would be happy to cryo treat your aluminum ribbon material no charge. Also I know of some folks who have found that a fine dimple patternis superior to the usual krinkle or fold technique most folks use. this makes the ribbon more rigid while keeping more of the conductor in the linear gap.
Send me an email if you are interested in the cryo offer. Best regards Moray James.
If you are interested I would be happy to cryo treat your aluminum ribbon material no charge. Also I know of some folks who have found that a fine dimple patternis superior to the usual krinkle or fold technique most folks use. this makes the ribbon more rigid while keeping more of the conductor in the linear gap.
Send me an email if you are interested in the cryo offer. Best regards Moray James.
The only way to anneal or heat treat (most of the time people wants harder, but can be softer too) is to heat the metal in a control fashion and let it cool, some cool in control fashion, some in atmospere.
I have never read or heard of cryo treating to anneal metal. Believe me, I have read the a lot of books on heat treating.
However, I can not argue as how good the sound after cryo treatment due to lack of experience.
I have never read or heard of cryo treating to anneal metal. Believe me, I have read the a lot of books on heat treating.
However, I can not argue as how good the sound after cryo treatment due to lack of experience.
And I don't knoww much about annealing, actually but that won't stop me from commenting!
I agree that the only way I know of to anneal or harden aluminum is heating it.
Yet you gengis, are saying that cryo is going to harden it, without heat..
I don't see that Moray says that it will anneal the aluminum.
He says that it will improve the flex characteristics of the metal and sound better. I don't know what that means, and I don't know if it will or not. If anything I'm of the sceptical persuation
I also know that some metals are softened by slow cooling, some by fast quenching-right?
I thought that fast quenching hardened ferrous metals and softened non ferrous.
Anyway - why not try annealing,
If slow cooling doesn't work try fast....
then liquid nitrogen on a sample.
I agree that the only way I know of to anneal or harden aluminum is heating it.
Yet you gengis, are saying that cryo is going to harden it, without heat..
I don't see that Moray says that it will anneal the aluminum.
He says that it will improve the flex characteristics of the metal and sound better. I don't know what that means, and I don't know if it will or not. If anything I'm of the sceptical persuation
I also know that some metals are softened by slow cooling, some by fast quenching-right?
I thought that fast quenching hardened ferrous metals and softened non ferrous.
Anyway - why not try annealing,
If slow cooling doesn't work try fast....
then liquid nitrogen on a sample.
Member
Joined 2003
Thanks guys. A little reading indicates that, depending on the alloy, a temperature between 500-900 degrees F is required. Heating is followed by, again depending on alloy, a slow cooldown, fast cooling, or instant/quenching.
Since I don't know which alloy I'm working with, I'm gonna sacrifice some foil to the oven gods!
Paul
Since I don't know which alloy I'm working with, I'm gonna sacrifice some foil to the oven gods!
Paul
The hardening mechanism in Aluminum is not the same as in Iron.
In carbon steels, you take the metal up in temperature until you get austenite, then you quench to get martensite. Martensite is very hard and very brittle due to the carbon atomns being squeesed into teh crystals and making them misshapen. Then you temper the steel and the carbon comes out of the crystals and makes little graphite inclusions in the iron as well as carbides. The iron crystals are in a more stable form and the iron gets more malleable.
In aluminum, you bring the metal up to the solution temperature and quench it rapidly. In this state it is a soft homogenous lump of metal with alloying metals more or less uniformly distrubuted. "Aging" the metal (typically at a few hundred degrees) causes the alloying agents to come out of solution. They tend to go to places where there are errors in teh crystalline structure. These errors are what allow slip and deformation in the metal. By precipitating out near these locations, the alloting agents lock the error down and make the metal resist deformation.
Pure single crystals have interesting properties which make them very strong, tough and resistant to chemical attack and stress relaxation in many cases. High performance jet and steam turbines use single crystal blades.
I believe cryo treatment may be useful for relieving residual stress, but many of the magic properties associated with it are high end myth. I don't believe it will do much unless the ribbon has residual stress such that it warps.....
In carbon steels, you take the metal up in temperature until you get austenite, then you quench to get martensite. Martensite is very hard and very brittle due to the carbon atomns being squeesed into teh crystals and making them misshapen. Then you temper the steel and the carbon comes out of the crystals and makes little graphite inclusions in the iron as well as carbides. The iron crystals are in a more stable form and the iron gets more malleable.
In aluminum, you bring the metal up to the solution temperature and quench it rapidly. In this state it is a soft homogenous lump of metal with alloying metals more or less uniformly distrubuted. "Aging" the metal (typically at a few hundred degrees) causes the alloying agents to come out of solution. They tend to go to places where there are errors in teh crystalline structure. These errors are what allow slip and deformation in the metal. By precipitating out near these locations, the alloting agents lock the error down and make the metal resist deformation.
Pure single crystals have interesting properties which make them very strong, tough and resistant to chemical attack and stress relaxation in many cases. High performance jet and steam turbines use single crystal blades.
I believe cryo treatment may be useful for relieving residual stress, but many of the magic properties associated with it are high end myth. I don't believe it will do much unless the ribbon has residual stress such that it warps.....
Cryo has me curious. Its claims seem to be the opposite of what simplistic Arrhenius considerations would predict. And I've annealed a lot of materials (glass, metals, and plastics), but always with a heat soak folowed by a gradual cooling.
I'm all ears, so to speak, if it actually does something. Moray, are there any mechanical measurements that repeatably show an effect of cryo? Flex modulus, for example?
I'm all ears, so to speak, if it actually does something. Moray, are there any mechanical measurements that repeatably show an effect of cryo? Flex modulus, for example?
Member
Joined 2003
I was trying to solve the wrong problem!
After observing the "breakage" under magnification, the foil was actually being cut, or chopped, by the edges of the 64 pitch spur gear stock I'm using for pleating. Polished the edges of the gears with compound and a buffing wheel...problem solved!
Amazing how delicate this stuff is. 6.5 microns, no problem. 5 microns, problem!
After observing the "breakage" under magnification, the foil was actually being cut, or chopped, by the edges of the 64 pitch spur gear stock I'm using for pleating. Polished the edges of the gears with compound and a buffing wheel...problem solved!
Amazing how delicate this stuff is. 6.5 microns, no problem. 5 microns, problem!
An externally hosted image should be here but it was not working when we last tested it.
lost post
I posted the other day but have not seen it come up. SY there are lots of documents on line. Industry does not spend this kind of money if the benefits are not there. While I would be happy to see a search done myself I just do not have the time to do one. I am spread as thin as I can go. The proof is in the pudding.
I can understand Paul being very protective of his 5 micron foil. So Paul send me enough of your thicker foil to do a couple of ribbons and I will treat that. Give it a listen and if you like it send me some of the thin foil no charge just cover the mail.
SY your preamp looks cool send me a couple of ECC88's or E88CC's or your favotite 6dj8 and I will treat them for you. But be fore warned it is a very slippery track on which you will be treading and you will want to cryo everything sooner or later. The only opinions that count are your own. Best regards Moray James.
I posted the other day but have not seen it come up. SY there are lots of documents on line. Industry does not spend this kind of money if the benefits are not there. While I would be happy to see a search done myself I just do not have the time to do one. I am spread as thin as I can go. The proof is in the pudding.
I can understand Paul being very protective of his 5 micron foil. So Paul send me enough of your thicker foil to do a couple of ribbons and I will treat that. Give it a listen and if you like it send me some of the thin foil no charge just cover the mail.
SY your preamp looks cool send me a couple of ECC88's or E88CC's or your favotite 6dj8 and I will treat them for you. But be fore warned it is a very slippery track on which you will be treading and you will want to cryo everything sooner or later. The only opinions that count are your own. Best regards Moray James.
Hi Paul W.
Firstly I think your ribbon hybrid is a very elegant solution. Hope it sounds as good as it looks. Re annealing aluminium, I quote from Australian Model Engineering mag. A reader successfully heat treats the metal by firstly applying some common white soap to an area of the metal, heat until the soap goes brown and immediately plunge in to cold water. How you do this with foil I am not sure, maybe do the entire roll as a billet. Keep in mind that non ferrous metals usually work harden, so after pleating it may be brittle again.
Cheers, Builder Bob
Firstly I think your ribbon hybrid is a very elegant solution. Hope it sounds as good as it looks. Re annealing aluminium, I quote from Australian Model Engineering mag. A reader successfully heat treats the metal by firstly applying some common white soap to an area of the metal, heat until the soap goes brown and immediately plunge in to cold water. How you do this with foil I am not sure, maybe do the entire roll as a billet. Keep in mind that non ferrous metals usually work harden, so after pleating it may be brittle again.
Cheers, Builder Bob
Cryo Treatment
Noob: I would be happy to treat some foil for you as long as you cover the post in both directions. I would however like to see you do a direct A/B between a set of treated ribbons and a non treated set. If you would be willing to do that and to post your results that would be great. If you can aneal your foil first I think that would be useful. You can contact me directly at moraydot jamesat3webdot com. Regards Moray James.
Noob: I would be happy to treat some foil for you as long as you cover the post in both directions. I would however like to see you do a direct A/B between a set of treated ribbons and a non treated set. If you would be willing to do that and to post your results that would be great. If you can aneal your foil first I think that would be useful. You can contact me directly at moraydot jamesat3webdot com. Regards Moray James.
Re: Cryo Treatment
I would need to find some foil then... I'm only going to have 6-10 inches of 5 micron... I can send you some 12 micron to cryo... and I will test with and without it...
but I would also like my 5 micron cryo'd... but if I'm testing that can wait till after I'm done with testing if that's ok with you
email sent
moray james said:
I would need to find some foil then... I'm only going to have 6-10 inches of 5 micron... I can send you some 12 micron to cryo... and I will test with and without it...
but I would also like my 5 micron cryo'd... but if I'm testing that can wait till after I'm done with testing if that's ok with you
email sent
I have a few questions and need your help. Firstly, can the cryo method be applied to copper foil? second, should I crease the ribbon before cryo treatment or cryo first and then fold it later. third, should I use more heat treatment with high temperature? Or just cryo is enough.