Heat Treating Aluminum 6061-T6

[Linghunt]

Probably a simple question.

I'm looking to soften the 6061-T6 so I can do a crimping / forming operation.

My initial thought was to anneal the material and do forming before the aluminum ages back to a T4. I'm not interested in getting the material back to a T6 state for this application.

Should I do a "solution heat treatment" or an "annealing" process to soften up the aluminum.

Below is the process details that I have found in research. -John
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HEAT TREATMENT
Solution heat treat at 990°F for adequate time to allow for thorough heating and then water quenched. Precipitation hardening is done at 320°F for 18 hours and air cool, followed by 350°F for 8 hours and air cooled.
ANNEALING
Annealing should be done at 775°F for at 2 to 3 hours at temperature, followed by controlled cooling at 50°F per hour down to 500°F then air cooled.
AGING
The aging precipitation heat treatment is done at 350°F for 8 hours followed by air cooling. This produces the T6 temper.

 

[Greg Bernhardt]

Thanks for the post! Sorry you aren't generating responses at the moment. Do you have any further information, come to any new conclusions or is it possible to reword the post?

 

[Linghunt]

Complete now. I went with the 990F soak and then water quench. Forming of part worked great. I tried a part without treatment and was completely different.

Not sure exactly what happened to crystal structure, but worked out fine. Been adjusting size of part to to forming die to maximize quality of item.

ASIDE, I did put a large chunk of SS in Oven to set parts on, Figured the large thermal mass would help for faster soaks and more temp uniformity.

 

[Metallurgist]

Complete now. I went with the 990F soak and then water quench. Forming of part worked great. I tried a part without treatment and was completely different.

Not sure exactly what happened to crystal structure, but worked out fine. Been adjusting size of part to to forming die to maximize quality of item.

ASIDE, I did put a large chunk of SS in Oven to set parts on, Figured the large thermal mass would help for faster soaks and more temp uniformity.

Are you still interested to know how the Microstructure evolved?

 

[Linghunt]

Are you still interested to know how the Microstructure evolved?

Absolutely. Thanks in advance. Also the actual time for the material to go back to T4 as well and why it changes?

From data testing, seemed like it was about 3 days before material was not able to move in forming without cracking. Forming operation changed shape by about .015"

 

[Metallurgist]

Absolutely. Thanks in advance. Also the actual time for the material to go back to T4 as well and why it changes?

From data testing, seemed like it was about 3 days before material was not able to move in forming without cracking. Forming operation changed shape by about .015"

Knowing the strain rate is important. What is your forming operation? Due to the strain hardening of the material knowing the approximate total strain and strain rate will help. To get strain, I need to know the maximum change in dimensions. To know strain rate, I need to know the total time it takes to finish the operation.

 

[Linghunt]

Custom Circular dies, Time is like 1-2 seconds. OD of ring change is around .015"

Cutting off a ring for inspection, the soft ring forms around the diamond kurl pattern as expected. Picture worth a 1000 words, hopefully this will help.

http://linghunt.com/Pictures/LINGHUNTPHOTOS/POLE/2015-04-06 13.25.21.jpg

I have a hardness tester. I should do some measurements vs time to see the transition back to T4.

 

[Linghunt]

Knowing the strain rate is important. What is your forming operation? Due to the strain hardening of the material knowing the approximate total strain and strain rate will help. To get strain, I need to know the maximum change in dimensions. To know strain rate, I need to know the total time it takes to finish the operation.

Custom Circular dies, Time is like 1-2 seconds. OD of ring change is around .015"

Cutting off a ring for inspection, the soft ring forms around the diamond kurl pattern as expected. Picture worth a 1000 words, hopefully this will help.

http://linghunt.com/Pictures/LINGHUNTPHOTOS/POLE/2015-04-06 13.25.21.jpg

I have a hardness tester. I should do some measurements vs time to see the transition back to T4. [forgot to quote it so you would get notice]

 

[Metallurgist]

"

Cutting off a ring for inspection

"
Linghunt, I will post a few guessed micrographs for you next weekend. Since my passion is microstructure Informatics and offer it to various businesses, It will be interested in looking at your material after deformation. You mentioned that you will cut the ring for inspection, I can get some metallography done on the ring if you like (at no cost if I can post the micrograhs on my website for you and public to see). If you like the idea, I like to have a longitudinal slice of the deformed ring with the EDM cut along the diameter of the ring and the cut surface has the diameter of the ring the axis of the ring. This way, I can see the whole longitudinal section from radius=0 to radius= OD/2. The thickness of the slice can be ~1/8-1/4 inch. If you like the above suggestion, I can email you the shipping address and we can discuss more on the phone. If this suggestion does not work, I will have the standard expected microstructure based on the heat treatment you mentioned as promised next weekend.

 

[Linghunt]

"
"Linghunt, I will post a few guessed micrographs for you next weekend. I can email you the shipping address and we can discuss more on the phone. If this suggestion does not work, I will have the standard expected microstructure based on the heat treatment you mentioned as promised next weekend.

Let's talk, Standard microstructure for posting here should be fine. I would like to know more about your capability here and other areas... Possible referrals for you from myself and other engineers in my consulting network. We get involved in lots of many different types of jobs.

 

[Metallurgist]

Let's talk, Standard microstructure for posting here should be fine. I would like to know more about your capability here and other areas... Possible referrals for you from myself and other engineers in my consulting network. We get involved in lots of many different types of jobs.

I will be happy to talk. On the Microstructure Data generation side, you may find more information about my company from our website under services (www.ICMRL.net) for the Microstructure data analytics side and material behavior modeling including cloud based FE simulations, you will find more about my newly launched Microstructure Informatics Cloud (MiCloud on www.ICMRL.com). Please send an email to info@ICMRL.net with your name and phone number and I will get in touch with you to setup a quick phone call/webex. As for using our services to support your consultancy, MiCloud should be a good platform to fullfill many of your needs especially if we generate the data in my lab in Ohio. I look forward to our discussion!

 

[Linghunt]

I As for using our services to support your consultancy, MiCloud should be a good platform to fullfill many of your needs especially if we generate the data in my lab in Ohio. I look forward to our discussion!

I checked out your Web site. Looks like you might have capability to support thin film manufacturers in some capacity.

 

[Metallurgist]

I checked out your Web site. Looks like you might have capability to support thin film manufacturers in some capacity.

It depends about what you are looking for. We have a state of the art scanning electron microscope with various detectors that can capture high resolution data. Also, we have a specialized equipment for Laser Ultrasonic characterization. The more I know about your needs, the better I can suggest tools and solutions.