Corrosion behavior of equal-channel-angular-pressed pure magnesium in NaCl aqueous solution

Effect of microstructure change on corrosion behavior of equal-channel-angular-pressed (ECAPed) pure Mg was investigated. The ECAPed sample after 6 passes obtained finer grains (50-100 mu m) compared with as-cast one (800-1500 mu m). The strain-induced grain refinement with more crystalline defects weakened corrosion resistance of pure Mg, resulting in more and deeper pits after in-situ corrosion, higher mass-loss rate immersed in NaCl solution, larger I-corr values in polarization curves and lower fitted R-t values in EIS plots. However, the enhanced initial OCP values indicate better weather resistance. Furthermore, corrosion improvement can be expected by reducing defects via subsequent annealing. (c) 2009 Published by Elsevier Ltd.