Pitting behavior of Ti-15-3 titanium alloy with different surface in salt spray studied using electrochemical noise

Autor: Longfei Xie, Wenlong Zhou, Shiwen Zou
Jazyk: angličtina
Rok vydání: 2021
Předmět:
Zdroj: Journal of Materials Research and Technology, Vol 14, Iss , Pp 2865-2883 (2021)
Druh dokumentu: article
ISSN: 2238-7854
DOI: 10.1016/j.jmrt.2021.08.072
Popis: Ti-15-3 titanium alloy has been widely used as a connecting material for aerospace structural parts. However, the non-uniform pitting caused by salt spray corrosion and the limitations of the conventional electrochemical techniques in predicting localized corrosion seriously prevent the practical application of Ti-15-3 alloy. Herein, the electrochemical noise based on discrete wavelet transform and Hilbert-Huang transform is employed for studying pitting corrosion of both the untreated and polished Ti-15-3 alloy under different neutral salt spray time. Combining with the further analysis of the electrochemical impedance spectroscopy, a complementary evaluation is used to analyze the effect of surface roughness on pitting corrosion behaviors of Ti-15-3 alloy systematically. It is found that pitting forms of both surface roughness electrodes exposed to different salt spray time are successfully distinguished, and the polished Ti-15-3 alloy shows better corrosion resistance. Microstructural characterization confirms the inferences from electrochemical noise analyses, the results indicate that the smooth surface of the polished Ti-15-3 alloy is less vulnerable to the coexistence of metastable pitting and the growth of stable pitting, and effectively improves the resistance to pitting corrosion of Ti-15-3 alloy. Furthermore, a possible mechanism for the triggering of pitting corrosion of Ti-15-3 alloy with different roughness in salt spray environment is proposed. This work will provide significant insights for rational design of Ti-15-3 alloy used in the tropical ocean facilities to avoid the attack of pitting corrosion.
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