engleski

Influence of Mn on the corrosion behavior of CuAlMn alloy in NaCl solution

The corrosion behavior of different CuAlMn shape memory alloys (Cu-12%Al-4%Mn, Cu-12.3%Al-5.2%-Mn and Cu-12%Al-6%Mn) in 0.9% NaCl solution at pH = 7.4 and T = 37°C was investigated using open circuit potential measurements, polarization and electrochemical impedance spectroscopy methods. It has been found that the corrosion resistance of the tested samples at open circuit potential increases with increasing Mn content in the alloy, i.e. growing in the order of: Cu-12%Al-4% Mn < Cu- 12.3%Al-5.2%Mn < Cu-12%Al-6% Mn. Namely, the corrosion current decreases in same order, while the polarization resistance and the resistance, thickness and compactness of the surface oxide layer increase. However, at high anodic potentials (E > 0.1 V), the corrosion rate increases with Mn content in the alloy, and light microscopy investigations reveal pits on the surface of Cu- 12.3%Al-5.2%-Mn and Cu-12%Al- 6%Mn alloys, while Cu-12%Al-4%Mn surface is almost clear of any corrosion damage.

shape memory alloys ; CuAlMn alloy ; corrosion ; polarization ; electrochemical methods

nije evidentirano