Investigations on the influence of surface mechanical attrition treatment on the corrosion behaviour of friction stir welded NiTi shape memory alloy

• Published in: Surface & coatings technology 2020-11, Vol.402, p.126495, Article 126495
• Main Authors: Prabu, S.S. Mani, Perugu, Chandra S., Jangde, Ashutosh, Madhu, H.C., Manikandan, M., Joshi, Manoj D., Hosmani, Santosh S., Kumar, P. Ajay, Kailas, Satish V., Palani, I.A.
• Format: Article
• Language: English
• Subjects: Corrosion; Corrosion rate; Corrosion resistance; Electrochemical impedance spectroscopy; Friction; Friction stir welding; Intermetallic compounds; Nickel base alloys; Nickel titanides; Shape memory alloy; Shape memory alloys; Surface mechanical attrition
• ISSN: 0257-8972; 1879-3347
• DOI: 10.1016/j.surfcoat.2020.126495

The surface mechanical attrition treatment (SMAT) was applied to friction stir welded NiTi shape memory alloy (SMA) as a post welding treatment to improve the corrosion properties of the weld. The influence of SMAT on corrosion behaviour of friction stir welded NiTi alloy was studied by employing electrochemical impedance spectroscopy and potentiodynamic polarization tests. The SMAT process has improved the corrosion properties of the welded NiTi alloy. Notably, the 1 h SMAT has shown the lowest corrosion rates and its oxide layer exhibited the highest resistance. The 1.15 h SMAT sample has exhibited a noblest breakdown potential of 1331 mV among other samples. •SMAT has been applied to welded NiTi alloy to improve the corrosion behaviour.•Influence of duration of SMAT on the corrosion behaviour has been explored.•SMAT performed for 1 h has shown very high resistance to corrosion.