Magnesium gadolinium alloys

This invention relates to gadolinium-containing magnesium alloys, particularly those which possess high strength combined with corrosion resistance, and an optimised balance of strength and ductility. The described alloys consist of 2.0 to 5.0, preferably 2.3 to 4.6, at% in total of gadolinium and at least one of soluble heavy lanthanides and yttrium, wherein the ration of the aggregate amount of soluble heavy lanthanides and yttrium to the amount of gadolinium is between 1.25:1 and 1.75:1, and preferably approximately 1.5:1, from 0 up to 0.3 at% of zirconium, preferably at least 0.03 at%, optionally with zinc, wherein when zinc is present the amount of zinc is such that the ratio of the weight of zinc to the weight of zirconium is preferably less than 2:1, and more preferably less than 0.75:1, all other lanthanides, viz. lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium and ytterbium in an aggregate amount of less than at 0.2 at%, and preferably less than 0.1 at%, the balance being m