Magnesium alloys which possess good processability and/or ductility while retaining good resistance to corrosion and/or degradation comprising Y: 0-10% by weight, Nd: 0-5% by weight, wherein the total of Y+Nd is at least 0.05% by weight, one or more heavy rare earths selected from Ho, Lu, Tm and Tb in a total amount of above 0.5% and no more than 5.5% by weight, Gd: 0-3.0% by weight, and Sm: 0-0.2% by weight. The alloy optionally includes one or more of: Dy: 0-8% by weight； Zr: 0-1.2% by weight； Al: 0-7.5% by weight； Zn and/or Mn: 0-2% by weight in total； Sc: 0-15% by weight； In: 0-15% by weight； Ca: 0-3% by weight； Er up to 5.5% by weight, provided that the total of Er, Ho, Lu, Tm and Tb is no more than 5.5% by weight； and one or more rare earths and heavy rare earths other than Y, Nd, Ho, Lu, Tm, Tb, Dy, Gd and Er in a total amount of up to 0.5% by weight； the balance being magnesium and incidental impurities up to a total of 0.3% by weight.
