GB652224A - Improvements in or relating to magnesium base alloys - Google Patents

Abstract

A process for the production of magnesium base alloys containing zirconium wherein a zirconium containing substance is reacted with molten magnesium in the absence of any appreciable quantity of zirconium alloying inhibitor elements, said substance comprising zirconium fluoride mixed or combined with one or more of the fluorides of lithium, barium, strontium, calcium and magnesium, which are so selected that the fluoride or fluorides both with and without the magnesium fluoride produced during alloying will be sufficiently fluid to facilitate easy mixing of the salts with the magnesium in order to permit the alloying of the zirconium with the magnesium at the temperature employed which may be for example below 850 DEG C, the mixture containing at least 5 per cent of zirconium. Zirconium fluoride is defined as a material containing at least 20 per cent of fluorine, at least 90 per cent of fluorine, oxygen and zirconium together and is substantially free from hydroxyl groups. Zirconium alloying inhibitor elements are those which form high melting point compounds with zirconium insoluble in magnesium. The substance preferably consists solely of the specified fluorides, but it may p contain also one or more chlorides or bromides of potassium, sodium, lithium, barium, strontium calcium and magnesium and reducible halides of elements which do not inhibit alloying of zirconium. The substance may contain not more than 2 per cent of lithium, if any, and fluorides of at least three metals other than zirconium and lithium. The substance may be used in the form of prefused lumps. Alloying may be carried out by pouring molten magnesium on to the substance which is in the form of prefused lumps or a fused bath. Specifications 511,137, 511,482, 533,264, 539,023, 549,024, 652,223 and 26438/39 (as open to inspection under Sect 91), are referred to.