GB652234A - Improvements in or relating to fluxes for use in the treatment of light metals - Google Patents

Abstract

A flux, for the treatment of light metals, consists of at least two chlorides of the group consisting of alkali chlorides and alkaline earth chlorides, including magnesium, more than 25 per cent of the chlorides being barium chloride, together with a sufficient proportion of one or more inspissating agents, other than barium fluoride and strontium fluoride, to enable the flux to form a pasty viscous covering on the surface of the molten metal at 750 DEG C, the flux having a specific gravity of at least 2.2 at 800 DEG C. The barium chloride may be partly or wholly replaced by strontium chloride reckoning 1 per cent of strontium chloride equivalent to 0.7 per cent of barium chloride. A modification of the flux contains one or more of the fluorides and chlorides of barium and strontium and includes at least one of these fluorides, the total quantity of these salts being equivalent to more than 20 per cent barium chloride reckoning 1 per cent of barium chloride equivalent to 1.4 per cent of strontium chloride, 0.6 per cent barium fluoride or 1.6 per cent strontium fluoride, the flux containing also magnesium chloride, in amount at least stoichiometrically equivalent to the said fluorides, and one or more of the other chlorides of the alkali and alkaline earth metals and, if desired, one or more additional inspissating agents. The quantity of the inspissating agents, including the barium and/or strontium fluoride may be 13-43 per cent. The barium chloride and/or strontium chloride is preferably fused with the other chlorides used before being mixed with the inspissating agents. The flux may be used in the treatment of magnesium, magnesium base alloys, e.g. those containing zirconium and/or rare earth metals and aluminium base alloys containing magnesium. Specifications 511,137, 539,023, 539,024, 652,224, 652,226, 542,227 and 652,235 are referred to.