Resistance Welding Copper: Problematic, Practical Joining Advice

Summary for resistance welding copper Discussion

Resistance welding issue on copper metal with dull nickel plating and tin plating: Divahar S asked whether a tin top-coat, dull nickel under-coat, and copper base metal is a good system for resistance welding and asked for the reason. James Watts replied that the combination is problematic because the three metals have very different melting points, so small temperature changes can create many different alloys in the melt zone. He noted that while such a stack may be used somewhere, he had never heard of welding copper in this way. Instead, he said brazing is common, with solder used for lower strength and silver solder for higher strength joints. The practical takeaway is that resistance welding may not be the best joining method for this layered copper/nickel/tin system, and alternative joining methods should be considered.