Effect of grain size on corrosion electrochemical behavior of Cu-20Ag-30Cr alloy in HCl solution

Cu-20Ag-30Cr alloy powders with different grain size were prepared by mechanical alloying through controlling ball-milling time and afterwards coarse-grained and nanocrystalline bulk alloys were prepared by hot-pressing method.The corrosion electrochemical behavior of coarse-grained and nanocrystalline bulk Cu-20Ag-30Cr alloy in HCl solution were studied by means of PARM273Aand M5210electrochemical synthesis test system through potentiodynamic polarization method and electrochemical impedance spectroscopy(EIS)technique.Results show that the corrosion current densities of two alloys increase gradually,corrosion potentials move to the negative direction,and charge transfer resistance decrease gradually with the increase of HCl concentrations.The corrosion current densities of nanocrystalline Cu-20Ag-30Cr alloy increases and corrosion rates become fast as compared with the corresponding coarse-grained Cu-20Ag-30Cr alloy in HCl solution with the same concentrations.Thus,the corrosion resistances of Cu-20Ag-30Cr alloy fall off when the grain size is refined.