GB822451A - Improvements in or relating to the production of magnesium base alloys - Google Patents

Abstract

Manganese and zirconium are simultaneously introduced into magnesium-base alloys by means of a salt mixture consisting of at least 5% by weight of MnCl2 and/or MnF2 and at least 5% of ZrCl4 together with at least one of the chlorides of the alkali and alkaline earth metals in amount at least 25% by weight of the mixture, the amount of ZrCl4 being 1 to 4 times the weight of MnCl2 and 1.3 to 5.4 times the weight of MnF2. The mixture may also contain ZrF4. If a fluoride is present an amount of MgCl2 is included at least stoichiometrically equivalent to the fluoride. The salt mixture preferably contains:-ZrCl4 33-45%, MnCl2 33-12%, KCl 33-45%, BaCl2 0-20%. The mixture may be used to form a master alloy which may consist of (1) a matrix phase of magnesium or of magnesium alloyed with one or more permissible elements, e.g. 30-70% of the alloy, (2) metallic particles containing manganese and zirconium embedded in the matrix, e.g. 20-60% of the alloy, (3) a salt phase mainly of MgCl2 with at least one alkali metal chloride, e.g. 1-20% of the alloy. The production of alloys containing also thorium or rare earth metals is referred to and examples of alloys produced are Th 3.5%, Zn 2.25%, Zr 0.47%, Mn 0.17%, Mg the remainder; Th 3.5%, Zn 2.25%, Zr 0.51%, Mn 0.18%, Mg the remainder; Th 3.5%, Zn 2.25%, Zr 0.63%, Mn 0.16%, Mg the remainder. Specifications 511,137, 759,411, 806,103 and 806,104 are referred to.