Effect of Alloying Mg on Corrosion Resistance of Cu at High Temperature

Effect of Mg alloying in Cu with pretreatments on corrosion behavior of Cu was studied, which was compared with that of a CuAl alloy. It was found that, at under oxygen pressure of , although the corrosion resistance of CuMg alloy was evidently improved in comparison with that of pure Cu, it was worse than that of CuAl alloy. Three possible reasons were: (i) Cu atoms were incorporated into the MgO surface layer. (ii) Fissures were produced in MgO layer. (iii) The adherence of MgO surface layer on Cu was poor. The first one could be due to formation of a new intermetallic phase of on the surface of Cu sample during the formation of MgO surface layers, while the latter two were attributed to low Pilling-Bedworth ratio of Mg-O system smaller than 1.