how to remove bend in material AL6061 T6

[heavenly]

Hi Freinds
We are asked for maching of size 600 X 400 x 9mm thick
AL60616T Grade,
To face need to me machined with flattnes 50microns,
problem is after machining,component getiing bend upto 1mm
any process to remove bend

Thax in before

John

 

[bklauba]

Removing the bend, i.e., the distortion that took place upon releasing the plate from your machine tool, might be difficult. Yes, it could be cold-straightened, but with confidence that the part will hold 50 microns (pretty tight), well, good luck.

Prevention of the "bend", i.e., minimizing the distortion, can be accomplished in a number of ways. Here are some:

- Depending how much stock is removed, break up the machining into two portions: A rough machining, and a final machining. Between the two machining operations, RELEASE THE PLATE from clamping, allow it find its new equilibrium (which might take some time), and carefully set it up again for machining, being VERY careful to not deflect in during the setup. Noncontact sensors that can go down to your 50 micron tolerance would be preferred method. If you bend it during in the setup, this bend will manifest itself upon being released.

- If these ideas are already incorporated in your machining, consider using vibratory stress relief to deaden the perhaps "live" aluminum plate. This part is somewhat small for the VSR Process, but, if fixtured and using the right equipment, it could be done, with no change in the tempered condition. The vibration treatment might need to be done both before and after rough machining, and, with the right equipment, you can tell if the treatment was effective by the change in resonance pattern the plate exhibits.

BK

 

[Frederick]

Cryogenic treatment will also tend to stabilyze the plate before machining.

 

[heavenly]

Hi Bklauba & Frederick,
Thanx for messages & we started trying with chemical milling,to remove bend

thanx once again

John

 

[twinny]

you must skim very small amount from first face
to break skin of ally.
Turn over and take deeper cut.
Turn over again and cut to finish size.
A vacuum chuck helps a lot!

It is I appreciate a ball ache but this method works.

regards