Dissimilar Metals/Sintering

By KPI Date 11-13-2001 18:02

We're having difficulty welding copper to bronze with wire fed mig and argon shielding. The welds seem strong enough, but the copper becomes brittle and breaks. COuld we be getting some type of hydrogem embrittlement? Would annealing or passivating help? Should we just try brazing instead?

Thanks.

By G.S.Crisi (****)

Date 11-13-2001 18:30

If I were you, I'd use the good old oxyacetilene welding, provided there's nothing to preclude it. I'd also use a bronze rod and the good old borax as deoxidizer. Oxyacetilene (gas) welding was invented a century ago, exactly to weld copper and copper alloys. Back in my days of erector engineer I've use it countless times with excellent results. We shouldn't think that a method is no good just because it's old, as we shouldn't think that a method is marvelous just because is bright new. As a matter of fact, old methods still in use have had the chance of being tested much more and for a longer time than the bright new ones.
Giovanni S. Crisi
Sao Paulo - Brazil

By George-kh (**)

Date 11-14-2001 22:00

Dear KPI
What kind of copper and bronze have you welded? What has been your filler metal? How much has been your welding amperage and voltage? And what kind of metal transfer, spray or short circuiting, have you used?