Bending 1/8 inch thick 7075-T6 aluminum


Results 1 to 7 of 7

Thread: Bending 1/8 inch thick 7075-T6 aluminum

  1. #1
    Registered
    Join Date
    May 2012
    Location
    United States
    Posts
    1
    Downloads
    0
    Uploads
    0

    Default Bending 1/8 inch thick 7075-T6 aluminum

    Hey all:

    I'm wondering what it will take to put a 2-3 inch curve in a 21 to 24-
    inch wide sheet if 1/8 inch thick 7075-T6 aluminum. I ask because I
    run a business making stage/film weapons out of 1/4 inch 7075 plate, and
    would like to be able to offer shields as well. Flat shields are
    fine, but curved shields are more user-friendly. I realize that 7075
    is not an alloy that is friendly to forming operations, but we're
    talking about a slight curve in a relatively large, thin piece. And yes, it must be 7075-T6 because I need to match the strength of the alloy I make my swords and axes out of. Softer alloys like 6061 just won't stand up to the beating that 7075 can dish out.

    Specifically, will a 20-ton shop press (with a shield-sized stamping
    mold attached, of course) do this job? I say 20 ton, because that's
    the smallest size press that will accommodate a work piece at least 21
    inches in width, and it's about what's in my price range.

    Ultimately, I'm hoping to make both square shields and dished rounds,
    but if these operations require heavy industrial rollers and spinners,
    then I'd rather not spend the dough on such a large press. Does anyone
    have any advice to give?

    Thanks,
    Nathan

    Similar Threads:


  2. #2
    Member
    Join Date
    Mar 2012
    Location
    USA
    Posts
    378
    Downloads
    0
    Uploads
    0

    Default

    I have no idea how well a press will work or if that size will do the job. I do know though that it will take less pressure if you buy the material annealed and heat treat it afterword. Also can bend it more without it cracking.



  3. #3
    Registered
    Join Date
    Jun 2011
    Location
    bavaria
    Posts
    282
    Downloads
    0
    Uploads
    0

    Default

    Eventually you can glow your sheet, to improve the bending properties. You should heat it until it sparkes a bit and then throw it into water.



  4. #4
    Registered
    Join Date
    Nov 2008
    Location
    usa
    Posts
    2
    Downloads
    0
    Uploads
    0

    Default

    Quote Originally Posted by brian257 View Post
    I have no idea how well a press will work or if that size will do the job. I do know though that it will take less pressure if you buy the material annealed and heat treat it afterword. Also can bend it more without it cracking.
    I agree. Heat treating to soft condition and forming is about the only way to form it in a press die. Otherwise the material will spring back off the tool. the only other machine that would form it would be a drop hammer, but tooling can be pricey. Good luck!



  5. #5
    Registered
    Join Date
    Dec 2012
    Location
    United States
    Posts
    10
    Downloads
    0
    Uploads
    0

    Default

    This may be a good excuse to buy an english wheel. It wouldn't be as fast, but it would be fun. And actually it would probably do a pretty quick job on aluminum.



  6. #6
    Registered
    Join Date
    Oct 2005
    Location
    Australia
    Posts
    2392
    Downloads
    0
    Uploads
    0

    Default

    Such a gentle bend with a really large radius like that should be no problem. Probably a sheet metal roller (like the ones with 3 rollers) is ideal for adding such a gentle curve. A car body shop might have one you can use.

    The dished round buckler etc will be harder to do and could be pressed, beaten, or maybe rolled on an english wheel by someone with enough skill.

    I've bent 1/8" aluminium sheet by hand (inserted in a phone book) over things like poles and round gas bottles, anything strong with some radius. It's a common thickness to bend by hand for motorcycle seats etc.

    Bending a 24" piece into a gentle shield curve by hand would be pretty easy, maybe sandwich it between a couple sheets of flexible plywood (to stop any chance of kinking) and then bend it over something large and curved, doing it a bit at a time.



  7. #7

    Default Re: Bending 1/8 inch thick 7075-T6 aluminum

    Old thread but this might help the OP or others trying to or wanting to do this.

    CAUTION! Be very careful doing this and always be behind a safe barrier when pressurising and whilst there is any pressure in the system in case something blows! Make sure nobody can walk in whilst pressurising, ensure it is done in done in a safe place that will stop any shrapnel from flying off in the event of a catastrophic failure, be smart about it! Compressed air can be bloody dangerous! Always wear PPE (safety glasses, hearing protection, etc)! If you have any doubts with what your doing and/or don't have a barrier to stand behind and/or don't have a SAFE place to do this in, DON'T ATTEMPT THIS!!! YOU TAKE FULL RESPONSIBILITY FOR ANYTHING THAT HAPPENS IF YOU ATTEMPT THIS!!! Don't try this at home! Be 100% sure you know what you are doing! If you are not 100% sure what to do, get someone who does! Safety! Safety! Safety!


    Get the 1/8 thick 7075 as 7075-0 (or T6 and anneal it to 7075-0). Get some 16mm thick (minimum) steel plate and cut a hole in it to the size and shape you want the shields to be. Ensure that these edges are smooth and free from any burrs etc, even round them off so they won't cut into the aluminium. With a second piece of 16mm thick plate, line them both up with the hole for the shield on top. Drill 16mm holes all the way around the cutout about 40mm apart and 30mm from the edge of the cutout through both 16mm sheets and then drill and tap a hole in the centre of the bottom plate so you can fit an air fitting underneath, carefully weld the fitting in place. Place the 7075 aluminium between the 16mm sheets and drill through the 7075 where the outer 16mm holes are so you can put bolts through them. Use minimum Grade 8.8 M16 bolts and tension them up bloody tight and to equal tensions.

    Now the dangerous part... Connect your air compressor to the air fitting you have installed underneath and have an adjustable inline pressure regulator with a release valve and accurate pressure gauge (configured: compressor, hose, adjustable regulator, release valve, pressure gauge, hose, fitting, workpiece) in the air line far enough away so you can adjust the pressure from a distance (preferably behind a thick polycarbonate screen or in a different room with a video monitor). Once everything has been checked thoroughly for tension, slowly start adding compressed air using the in line pressure regulator and watch as the aluminium starts to bulge up to the required shape. When you are happy with the shape, check what pressure you are at, note it, then release the pressure using the pressure release valve to release all the air in the system from the regulator to the work piece. It will spring back a little or a lot. If it's just a little then re pressurise it and add slightly more air pressure so it will spring back to your desired shape and note the pressure you went to. Depending on the radius you need, you may need to evenly heat the workpiece before/during pressurising, if you need to heat it, use some heatproof stainless braided air hose or copper pipe etc from from the fitting back about 2-3m or more (depending on how much heat you need) to a copper coil that is placed in a bucket of ice water and tap and weld in a second relieve valve on the lower plate next to the air in fitting under the workpiece. This is so you can release the hot air from there and not back through your gauges, regulator, etc. Using 1/8" 7075-0 you shouldn't need to heat the piece at all.

    Once your happy, undo all the bolts, pull the top "die" off and trim the piece to size. Once completed, temper or re temper the 7075-0 to T6.

    Again, CAUTION! Be very careful doing this and always be behind a safe barrier when pressurising and whilst there is any pressure in the system in case something blows! Make sure nobody can walk in whilst pressurising, ensure it is done in done in a safe place that will stop any shrapnel from flying off in the event of a catastrophic failure, be smart about it! Compressed air can be bloody dangerous! Always wear PPE (safety glasses, hearing protection, etc)! If you have any doubts with what your doing and/or don't have a barrier to stand behind and/or a SAFE place to do this in, DON'T ATTEMPT THIS!!! YOU TAKE FULL RESPONSIBILITY FOR ANYTHING THAT HAPPENS IF YOU ATTEMPT THIS!!! Don't try this at home! Be 100% sure you know what you are doing! If you are not 100% sure what to do, get someone who does! Safety! Safety! Safety!



Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  


About CNCzone.com

    We are the largest and most active discussion forum for manufacturing industry. The site is 100% free to join and use, so join today!

Follow us on


Our Brands

Bending 1/8 inch thick 7075-T6 aluminum

Bending 1/8 inch thick 7075-T6 aluminum