Corrosion behavior of novel imitation-gold copper alloy with rare earth in 3.5% NaCl solution: Fid-Bau Portal

Corrosion behavior of novel imitation-gold copper alloy with rare earth in 3.5% NaCl solution

Chen, J.L. / Li, Z. / Zhu, A.Y. / Luo, L.Y. / Liang, J.

Highlights ► The design alloy has better anti-tarnish property than that of H7211 alloy during salt-spray test. ► The corrosion rate of design alloy is much lower than that of H7211 alloy as immersed in NaCl solution. ► In the low frequency region, the capacitive behavior normally faded and diffusion process had a key role. ► In the medium frequency region, the Bode pattern showed a capacitive behavior.

Abstract A novel imitation-gold copper alloy with rare earth was designed and prepared. The corrosion behavior of the alloy immersed in 3.5% NaCl solution and its anti-tarnish property in the salt spray for different days has been studied. The designed alloy (CuZnAlNiMeRe) has more excellent anti-tarnish property and lower corrosion rate than those of currency coinage materials of H7211 alloy (used in China). A uniform and compact of corrosion film has been formed after the designed alloy immersed in 3.5% NaCl solution. The corrosion current densities I corr of the alloy decreased while the polarization resistance R p increased with time. The capacitance of the corrosion product film C film of the alloy decreased while the charge transfer resistance R ct. The Warburg diffusion impedance WR and the resistance of the equivalent circuit R increased with time.