Heat Treating of Aluminum Extrusions (6063, 6061, 6005 alloys)
Heat Treating of Aluminum Extrusions (6063, 6061, 6005 alloys)
(OP)
I work for an aluminum extruder and have been here for almost 3 years - not a long tenure here, but I have learned a lot and am not having some concerns about some of our practices. Coming from a materials engg. background, I am fairly familiar with aluminum heat treating, but here we have an in-house published spec. that shows much shorter heating cycles than I am used to. I brought it up to our extrusion manager and got the typical "that's just how we've always done it here" response and not much else. My concern is that we may not be meeting required properties for some of our customers, but am not sure how to go about making the right people aware of the situation without stepping on too many toes. I would like to know how common it is to undercut the heating time during aging like this at other companies - anyone have any thoughts?





RE: Heat Treating of Aluminum Extrusions (6063, 6061, 6005 alloys)
Coka
RE: Heat Treating of Aluminum Extrusions (6063, 6061, 6005 alloys)
RE: Heat Treating of Aluminum Extrusions (6063, 6061, 6005 alloys)
6063 as an example of an alloy with a lot of latitude.
The solution treatment can be done by controlling the extrusion temper and quenching from that temperature.
The precipitation treatment for tempers T5 and T52 are 400°F and 450°F for 1 Hr while the T6 treatment is 8 Hrs at 350°F. The alternate for T6 is 6 Hrs at 360°F.
6061(extruded) doesn’t have the latitude of 6063, but there is different heat treatment for plate, rolled or drawn, extruded, and forgings.
I don’t have data on 6005.
All these alloys have a general requirement of rapid heating to solution temperature and rapidly quenching to RT. The times at temperature are started when the metal temperature is within ± 10°F of the desired .
Make sure when you HT aluminum read the notes and general requirements.
RE: Heat Treating of Aluminum Extrusions (6063, 6061, 6005 alloys)
RE: Heat Treating of Aluminum Extrusions (6063, 6061, 6005 alloys)
Thanks to all for your responses so far!! (c:
RE: Heat Treating of Aluminum Extrusions (6063, 6061, 6005 alloys)
RE: Heat Treating of Aluminum Extrusions (6063, 6061, 6005 alloys)
Coka
RE: Heat Treating of Aluminum Extrusions (6063, 6061, 6005 alloys)
As I posted the parts can be solution treated fron the extrusion process. This is quite common for the 6063 material as stated.
RE: Heat Treating of Aluminum Extrusions (6063, 6061, 6005 alloys)
RE: Heat Treating of Aluminum Extrusions (6063, 6061, 6005 alloys)
After doing more research into this whole debacle, I found out we do have a solution HT on some alloys, but it's a forced air "quench" at the extrusion press rather than H2O. (Labeled acceptable in the ASM documentation.) Nearly everything we make also gets stretched (stress relieved) which is not called out as Tx51 anywhere in our in-house documentation that I can find (not sure if it's a big deal). Most everything also gets artificially aged at very close to the ASM spec. for time and temp. Now, though, my battle will be the "at temp." part of the procedure. At least it narrows the fight down to a more specific set of data that I can gather and provide as evidence of my concerns. Hopefully my words will not fall on deaf ears around here!
Again, thanks to all who posted, I have learned a lot from all of you AND from doing all this homework!
RE: Heat Treating of Aluminum Extrusions (6063, 6061, 6005 alloys)
6061 T4 T451X
6061 T6 T651X 300°F for 8 Hrs.
RE: Heat Treating of Aluminum Extrusions (6063, 6061, 6005 alloys)
RE: Heat Treating of Aluminum Extrusions (6063, 6061, 6005 alloys)
The following is an excerpt from the 2001 article:
"Cooling rate for this practice [TVP-meaning press quenching] is defined as the average temperature drop when subjected to a constant cooling system from initial extrudate temperature (exit temperature) to 400 F (204.4 C). Lower cooling rates may be used if supported by satisfactory documentary evidence that such lower rates yield mechanical properties complying with all specification requirements. This also applies to the die exit-quench entry time interval. Permitted quench media include, but are not limited to, water or water/glycol mixture in a standing wave, quench tank, spray, pressurized water jets, or as fog, air blast, or combinations of these."
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