PSI - Issue 71

Ritik K. Nakhate et al. / Procedia Structural Integrity 71 (2025) 357–363

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stability (Nayak et al., 2020).

Fig. 4. (a) Potentiodynamic polarization curves and (b-d) Electrochemical impedance plots of coatings deposited at different plasma power and expose to 3.5% NaCl solution. (b) Nyquist plot, (c) Bode impedance plot, (d) Bode phase angle plot.

Raman spectroscopy was also utilized to analyze different forms of iron-based rust produced during corrosion. Fig. 5 reveals the presence of iron oxide and oxyhydroxide phases like lepidocrocite (γ - FeOOH), maghemite (γ -Fe 2 O 3 ), and akageneite (β -FeOOH); while maghemite remains stable, lepidocrocite and akageneite are prone to rapid deterioration in saline conditions, with a higher proportion of γ - FeOOH and β -FeOOH phases contributing to enhanced corrosion resistance (Kumar et al., 2019; Fuente et al., 2016).

Fig. 5 . Raman spectra of coating displaying characteristic peaks of various oxide and hydroxides phases.

4. Conclusion Fe-based amorphous/ nanocrystalline coatings were developed using atmospheric plasma spraying. Variations in