Enhancement of the electrochemical behavior for Cu–70Zr alloy by grain refinement

A 20 μm thick nanocrystalline (NC) Cu–70Zr film has been fabricated by direct current magnetron sputtering (DCMS). The NC film, with a mean grain size of 10–20 nm, has a composition identical to that of the conventional coarse-grained alloy. The electrochemical corrosion behavior of the NC film and the coarse-grained alloy in the hydrochloric acid solution was investigated by using potentiodynamic and potentiostatic polarization techniques. The results showed that the NC Cu–70Zr film had a lower corrosion rate and an increased localized corrosion resistance than that of the cast one. Compared with the microcrystalline Cu–70Zr alloy, the enhanced corrosion resistance was closely related to the homogeneous element distribution in the nanocrystalline Cu–70Zr film.