welding copper to aluminum is it possible?

[lasertech502]

I would like to know if it is possible to weld copper and aluminum together using a laser. If so please share the secret. The laser being used is a 4000 watt direct diode laser. Also, would it be easier or possible to use a filler like brass, and weld the copper to brass then the brass to aluminum.
Thanks.

 

[Niekie]

I do not know much about laser welding, but I have joined Cu to Al before, as follows:

1) Silver solder a "butter layer" onto the Cu.
2) Weld, using Al filler, the Al to the Silver solder.

This may form the basis of a welding procedure for yourself.

Regards
Niekie Jooste

 

[EnglishMuffin]

I don't know much about laser welding either. I do remember hearing that laser welding copper is supposed to be difficult because of its high reflectivity. However, here is a site with a reference to someone who has done it.

http://www.ilt.fhg.de/eng/jb00-s51.html

It mentions brittle, intermetallic phases developing in the joint zone, but they managed to overcome that.

One of the best ways to weld Al to Cu is friction welding -but that's probably no help.