Corrosion Resistance and Tensile Property of Al-Coated Mg-Li Alloy Produced by Hot Extrusion

Abstract

Al-coated Mg-Li alloy rods and plates having a homogeneous coating layer of 180μm in thickness have been produced by hot extrusion of Mg-Li alloy billets together with Al disks. The Al-coated Mg-Li alloy exhibits an excellent corrosion resistance in a weight-loss test with a 0.5 mass% HCl aqueous solution, and it has been revealed by a potentiometric corrosion test with a 3 mass% NaCl aqueous solution that the Al-coated Mg-Li alloy has the same electric potential as that of pure Al. Al-coated Mg-Li alloy sheets produced by hot forging of the extruded plates exhibits good elongation of 22 %, 40 % and 130 % at room temperature, 200 °C and 300 °C, respectively.