Flux for brazing aluminium and method of employing the same.

摘要

In the brazing of aluminium a flux composed of a mixture of alkali metal fluoaluminates, with or without admixed AIF<Sub>3</Sub>, is employed. The flux has a composition of AIF<Sub>3</Sub> about 53-62%. KF about 35-44% and LiF about 2-7%, in terms of simple compounds. The flux has a liquidus temperature in the range of 490°-560°C depending on its actual composition. The flux is of particular utility when brazing aluminium containing 0.4-2% magnesium and/or having a low solidus temperature and is preferably employed in an atmosphere of a dry, inert gas.