On the electrochemical dealloying of Mg–Cu alloys in a NaCl aqueous solution

The dealloying of rapidly solidified Mg–Cu alloys in a 0.2 M NaCl aqueous solution has been investigated using electrochemical measurements. The results show that nanoporous copper can be fabricated by electrochemical dealloying of the Mg–Cu alloys in the NaCl solution. The electrochemical activities of the Mg–Cu alloys are related to both alloy composition and phase constitution. The critical potentials of biphasic Mg–Cu alloys are determined by the less noble Mg2Cu phase, rather than being in proportional to the contents of constitutive phases or elements. Furthermore, the dealloying of Mg2Cu has a promoting effect on that of the MgCu2 phase.

Research highlights► Nanoporous copper can be fabricated by electrochemical dealloying of Mg–Cu alloys. ► Phase constitution markedly affects electrochemical activities of Mg–Cu alloys. ► The critical potentials of biphasic Mg–Cu alloys are determined by Mg2Cu. ► The dealloying of Mg2Cu has a promoting effect on that of MgCu2.