Vacuum grade aluminium thicknesses, forging and porosity....
Vacuum grade aluminium thicknesses, forging and porosity....
(OP)
Can anyone clarify?
I am told that billet aluminium is supplied forged to a degree, and that each time the billet is forged, the aluminium loses its porosity.
I want to investigate fabricating a high vacumm vessel, (10E-9T) using aluminium and not sure whether to machine from solid or fabricate with individual panels. Because the chamber is 750 x750 x 2200mm my concern that the billet to manufacture this will not have been forged and have relatively higher porosity and potentially poor vacuum performance properties.
We use EN AW-6016 T6 for standard chambers at the moment.
Any help appreciated, Simon.
I am told that billet aluminium is supplied forged to a degree, and that each time the billet is forged, the aluminium loses its porosity.
I want to investigate fabricating a high vacumm vessel, (10E-9T) using aluminium and not sure whether to machine from solid or fabricate with individual panels. Because the chamber is 750 x750 x 2200mm my concern that the billet to manufacture this will not have been forged and have relatively higher porosity and potentially poor vacuum performance properties.
We use EN AW-6016 T6 for standard chambers at the moment.
Any help appreciated, Simon.





RE: Vacuum grade aluminium thicknesses, forging and porosity....
Regards,
Cory
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.
RE: Vacuum grade aluminium thicknesses, forging and porosity....
You said
"Any wrought Al alloy (sheet, plate, extrusion, forging) will be "pore-free" so that it could be used for vacuum applications".
What do you mean exactly ?
Are you saying that Al Alloy's are "pore-free", or are you saying they should be "pore-free".
To clarify my question as I know its a bit vague.
Q. Is their a guarantee of non-porosity in billet aluminium that has not had any work,like forging, done to it?
Cheers, Simon.
RE: Vacuum grade aluminium thicknesses, forging and porosity....
Regards,
Cory
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.
RE: Vacuum grade aluminium thicknesses, forging and porosity....
I am in discussion with the supplier. They have to talk to Russia, where the billet comes from.
However, we believe the billet is forged to size, and I am only assuming, this is done by taking smaller thickness plate/sheet and forging up. However I am awaiting answers to these questions.
Any more questions you can think of great.
Regards, Simon.