摘要 |
A method for repairing and joining aluminum alloy articles and structures, such as heat exchangers for use in automotive applications. The method utilizes a flux-coated soldering rod (10) that is used to deliver a solder alloy (12) and a flux compound to a region to be repaired. The flux compound has a higher melting temperature than the solder alloy (12), and is present as a coating (14) that sufficiently thermally insulates the alloy (12) to cause the flux compound and the solder alloy (12) to melt nearly simultaneously during the soldering operation. The solder alloy (12) is preferably a zinc-aluminum alloy, while the flux coating (14) preferably contains a cesium-aluminum flux compound such as potassium cesium tetrafluoroaluminate, dispersed in an adhesive binder that will readily volatilize or cleanly burn off during the soldering operation. The flux compound and binder form a hard coating (14) that tenaciously adheres to the solder alloy (12) and thermally insulates the solder alloy (12) until the flux compound melts during the soldering operation. By controlling the relative amounts of preferred flux compounds and binders, the flux coating (14) remains protective and thermal-insulating on the alloy (12) until melting of the flux compound begins.
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