FLUX FOR SOLDERING AND WELDING ALUMINUM

摘要

PURPOSE: To realize a flux for Al brazing or welding which is suitable for spray-application by specifying a content which comprises a composition of boron-containing potassium fluoroaluminate. CONSTITUTION: A composition of boron-containing potassium fluoroaluminate which has 1/(3-5) Al/F atomic ratio, 1/(<1.25) Al/Ca atomic ratio and >=0.05 wt.% boron content is comprised. The flux contains particles of boron-containing potassium fluoroaluminate slag with boron content at least 0.05 wt.% of the slag. At least 90 wt.% of the particles has <75μparticle size. The flux is painted on a work-piece by a brush or by a trowel in the form of a paste containing a small portion of water, or is spray-applied to it in the form of an aqueous dispersion of the flux.