RESISTANCE WELDING OF ALUMINIUM

摘要

Electrodes used for spot welding of aluminium workpieces are improved by a combination of steps: a) A roughened surface is formed on the electrode tip, preferably to an average roughness depth of 12 to 30 microns. b) Also an artificial protective coating, e.g. a chromate-based coating or an anodic oxide film, is applied to the workpieces. c) Optionally the nugget diameter in the initial welding set-up is arranged to be not more than 15% greater than the minimum acceptable. Features a) and b) act synergistically to increase the service life of the electrodes, typically to more than 2000 welds.