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Re: Aluminum Tempers
Re: Aluminum Tempers -- ericbaker	Post Reply	Top of thread	Forum

Posted by: adyonel ® 11/22/2005, 05:45:16 Author Profile Mail author Edit

Yes Eric, it is the same temper for all conditions Ady

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Re: Aluminum Tempers
Re: Aluminum Tempers -- ericbaker	Post Reply	Top of thread	Forum

Posted by: DDHiggins ® 11/21/2005, 23:28:28 Author Profile Mail author Edit

I am sorry, I have no response, only another question on the same topic. I am with a small start-up company in southern California that needs a steady supply of 10 foot long aluminum tubes (2" OD, .065" wall thickness, 6061 T6 aluminum) with a 7 inch radius bend through approximately 60 degrees of arc. We believe that this bend can be done cold on a hydraulic mandrel bender provided the tubing is bent soon after the tubing is extruded and before it acquires its T6 temper. Our problem is we can find no one who can tell us how rapidly the extruded tube acquires its temper. What is the temper of T6 6061 immediately after it leaves the extruder, and how rapidly does it cure? Where can we get technical advice on this? The tubing manufacturers we have contacted are not much help. Also, where can we get info on the relative strenght of T6 and T4. We might be able to live with T4, and it is easier to bend cold.

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Re: Aluminum Tempers
Re: Re: Aluminum Tempers -- DDHiggins	Post Reply	Top of thread	Forum

Posted by: david04883 ® 12/14/2005, 12:40:34 Author Profile Mail author Edit

yo, "Also, where can we get info on the relative strenght of T6 and T4. We might be able to live with T4, and it is easier to bend cold." You can find this in the relevent specification. BS EN 755:Aluminium and aluminium alloys. Extruded rod/bar, tube and profiles. Mechanical properties. That's the bristish standard, i'm not familiar with the ASTM. If you're having trouble bemding the pipe, The easiest thing to do would be to buy in tube in less 'high tensile' condition, i.e 'o' , then bend it, then get it heat treated to the T6 temper. Having re-read your post, i'm a bit confused - you say you can "cold" bend before aquiring the temper without re-heating. If thats what you mean, it's simply not possible. cheers, David

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Re: Aluminum Tempers
Re: Re: Aluminum Tempers -- david04883	Post Reply	Top of thread	Forum

Posted by: ddhiggins ® 12/14/2005, 13:05:52 Author Profile Mail author Edit

Thanks for your reply, David. It's easy to tell that I'm not an engineer. Our objective is to end up with the 6061 .065 wall 2" OD tubes with the 6" radius bend in them over a 39 degree arc with a temper that will allow them to be used as an outrigger spar connecting two hulls similar to a small Hobie Cat. The mandrel bending shop THINKS theat they can make the bend cold if we give them a T4 tube; they say they have to heat the tube (aneal?) if it is T6. The manufacturer or extruder of the tube says the tube they make comes out of the extruder as a T4. If we order T6, they take the T4 and heat treat it to make it a T6. I have been told that when the T4 tube is heat treatet to make it T6, it comes out of the heat treatment process as a T4+ and gradually acquires the T6 temper over the next few days or weeks (or months?). This, I was told by the bender, is why he has been able to cold bend some T6 (presumably it was delivered a short time after the T6 heat treatment)but had difficulty cold bending other T6 stock. IF the T4 can be bent cold, and IF the T4 is strong enough to use as an outrigger spar, then using T4 is the least costly solution for us as we avoid the heat treating step. If the T4 is not strong enough, OR if we can't bend it cold, then we probably should try to order something softer than T4 from the extruder, then bend it, and then heat treat it to T6. Am I understanding all this correctly and drawing the right conclusion? Dave

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Re: Aluminum Tempers
Re: Re: Aluminum Tempers -- ddhiggins	Post Reply	Top of thread	Forum

Posted by: david04883 ® 12/16/2005, 12:45:16 Author Profile Mail author Edit

"I have been told that when the T4 tube is heat treatet to make it T6, it comes out of the heat treatment process as a T4+ and gradually acquires the T6 temper over the next few days or weeks (or months?"........Never heard of this before, (and don't believe it!) "IF the T4 can be bent cold, and IF the T4 is strong enough to use as an outrigger spar, then using T4 is the least costly solution for us as we avoid the heat treating step. If the T4 is not strong enough, OR if we can't bend it cold, then we probably should try to order something softer than T4 from the extruder, then bend it, and then heat treat it to T6" Yes, I think that's the best solution. cheers david

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Re: Aluminum Tempers
Re: Re: Aluminum Tempers -- david04883	Post Reply	Top of thread	Forum

Posted by: liquid-steel ® 12/26/2005, 01:19:38 Author Profile Mail author Edit

sorry, by reading this discussion on the above subject I was thinking that some of you might be able give a feedback to my queries in casing issue: i have right now in my company. we are trying to develop a foundry shop in order to cast high chrome alloy into grinding media ball (Cr: 13-18%, C: 1.8-3.2%). we are setting up green sand mold arrangement and induction melting. we have planned also to cast products of stainless steel, Al, Brass and cast iron at the time there wouldnt be high chrome casting (i.e. in the idle time). Some engineers are protesting that the arrangement for high chrome alloy is not suitable for casting other metals. they indicated that the sand used for high chrome alloy will no more be suitable for other castings. Well some engineers commented that somehow things could be managed. Could I please have some thoughtful discussion here about this so I might be able to clear myself. Thanks. haS

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