Welded aluminum water cooling

[roddypiper]

Hello,
I have just taken responsibility for a new production line and they currently have a weld process where we weld a top piece of aluminum to an aluminum can. Inside the can, and about 1.5 cm away from the joint is a plastic seal. It is very important that we do not melt the plastic seal, so we immediatly immerse the part in water to just below the weld bead.
I would like to know, can the water cooling cause cracks to form in the weld bead? Does the material condition change during the quench?
Do you know of any other ways to immediatly cool the part to prevent the plastic seal from melting.

Thanks

 

[unclesyd]

What are the Aluminum alloys?

 

[roddypiper]

The material is 6061, F temper aluminum alloy with min 28.5 ksi 0.2% Y.S.

 

[sherwood]

i would think that cooling after would cause the joint to weaken, there are products that absorb heat, they are sometimes used on chrome when it needs to be welded without discoloring the chrome, try this

http://www.classicsandcustoms.com/eastwood/products/1937.asp

its used to keep heat to a minimum. hope this helps, Patrick