Effect of heat treatment on corrosion properties of CuAlNi shape memory alloy

Scientific paper - Original scientific paper

• Author: Ladislav Vrsalović
• Author: Ivana Ivanić
• Author: Stjepan Kožuh
• Author: Senka Gudić
• Author: Borut Kosec
• Author: Mirko Gojić
• Author's institution: University of Split; Faculty of Chemistry and Technology
• Author's institution: University of Zagreb; Faculty of Metallurgy
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Metallurgy
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Chemical Engineering

Abstract (english)

The effect of heat treatment on corrosion properties of CuAlNi shape memory alloy was investigated in 0.9% NaCl solution at pH 7.4 and 37 °C by open circuit potential measurements, polarisation techniques, and electrochemical impedance spectroscopy. Investigations were performed on CuAlNi alloy samples in as-cast state and after heat treatment procedure containing annealing at 850, 885 and 920 °C followed by water quenching. Electrochemical impedance measurement results indicate that heat treatment of CuAlNi alloy leads to the increase in charge transfer resistance and surface layer resistance and the decrease in values of capacitance of the double and surface layers, indicating higher corrosion resistance compared with the as-cast CuAlNi alloy. The increase in polarisation resistance and the decrease in corrosion current density of heat-treated CuAlNi alloy also suggest beneficial influence of heat treatment on corrosion resistance of CuAlNi alloy. Optical microscopy, SEM/EDX and XRD analysis of samples surface after polarisation measurements show the occurrence of pitting corrosion on the electrode surfaces, with the existence of CuCl2, AlCl3 and Cu2Cl(OH)3 compounds as the surface corrosion products.

• Keywords (english): CuAlNi alloy; corrosion; polarization; electrochemical methods; SEM
• Language: english
• Publication type: Scientific paper - Original scientific paper
• Publication status: Published
• Peer review: Peer review - international
• Publication version: Published version
• Journal title: Transactions of nonferrous metals society of china
• Numbering: vol. 28, no. 6, pp. 1149-1156
• p-ISSN: 1003-6326
• URN:NBN: urn:nbn:hr:115:294082
• Publication: 2018
• Document URL: http://bib.irb.hr/945796
• Type of resource: Text
• Access conditions: Open access
• Created on: 2019-07-02 10:41:48