Corrosion of steel under the defected coating studied by localized electrochemical impedance spectroscopy

Zhong, Cheng; Tang, Xu; Cheng, Y. Frank

doi:10.1016/j.electacta.2008.02.014

Cited by 101 publications

(48 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The high frequency semicircle was attributed to the impedance response from the coating, while the low frequency behavior was associated with the corrosion reaction occurring at the coating/substrate interface. 18 Therefore, the diameter of the high frequency semicircle is reflective of the degree of protection offered by the coating. Differently-treated surfaces exhibited differentlysized high-frequency semi-circles with sample #D showing the smallest semi-circle (least protective) and sample #A the largest semi-circle.…”

Section: Electrochemical Impedance Spectroscopymentioning

confidence: 99%

Electrochemical investigation of chromium oxide‐coated Ti‐6Al‐4V and Co‐Cr‐Mo alloy substrates

et al. 2011

View full text Add to dashboard Cite

Hard coatings for articulating surfaces of total joint replacements may improve the overall wear resistance. However, any coating approach must take account of changes in corrosion behavior. This preliminary assessment analyzes the corrosion kinetics, impedance and mechanical-electrochemical stability of 100 μm thick plasma sprayed chromium oxide (Cr₂O₃) coatings on bearing surfaces in comparison to the native alloy oxide films on Co-Cr-Mo and Ti-6Al-6V. Cyclic potentiodynamic polarization, electrochemical impedance spectroscopy, and mechanical abrasion under potentiostatic conditions were performed on coated and substrate surfaces in physiological saline. SEM analysis characterized the coating morphology. The results showed that the corrosion current density values of chromium oxide coatings (0.4-1.2 μA/cm²) were of the same order of magnitude as Ti-6Al-4V alloy. Mechanical abrasion did not increase corrosion rates of chromium oxide coatings but did for uncoated Co-Cr-Mo and Ti-6Al-4V. The impedance response of chromium oxide coatings was very different than Co-Cr-Mo and Ti-6Al-4V native oxides characterized by a defected coating model. More of a frequency-independent purely resistive response was seen in mid-frequency range for the coatings (CPE(coat) : 40-280 nF/cm² (rad/s)(1-α) , α: 0.67-0.83) whereas a more capacitive character is seen for Co-Cr-Mo and Ti-6Al-4V (CPE(ox) around 20 μF/cm² (rad/s)(1-α) , α around 0.9). Pores, interparticle gaps and incomplete fusion typical for thermal spray coatings were present in these oxides which could have influenced corrosion resistance. The coating microstructure could have allowed some fluid penetration. Overall, these coatings appear to have suitable corrosion properties for wear surfaces.

show abstract

Section: Electrochemical Impedance Spectroscopymentioning

confidence: 99%

Electrochemical investigation of chromium oxide‐coated Ti‐6Al‐4V and Co‐Cr‐Mo alloy substrates

et al. 2011

View full text Add to dashboard Cite

show abstract

“…Their equivalent circuits are proposed in Fig. 9c and d, respectively [19] and the fitting results are listed in Table 4. R s is solution resistance, C dl is double layer capacitance, R t is charge transfer resistance, CPE and R f are constant phase element and resistance of passive film on steel formed in aqueous solution.…”

Section: Phase Constituents Analyses and Hardness Profile Of Pec Treamentioning

confidence: 99%

Enhanced wear and corrosion resistance of plasma electrolytic carburized layer on T8 carbon steel

Wang

Zhang

et al. 2016

Materials Chemistry and Physics

View full text Add to dashboard Cite

h i g h l i g h t sElectron temperature in plasma electrolytic carburizing process is determined. Diffusion coefficient of carbon in PEC is higher than conventional carburizing. Wear and corrosion resistance of T8 steel are both improved after PEC treatment. Pitting corrosion of steel substrate is obviously suppressed by PEC treatment. t r a c tA hardening layer of 70 mm on T8 carbon steel was fabricated by plasma electrolytic carburizing (PEC) in glycerol solution at 380 V with 3 min treatment. The discharge process was characterized using optical emission spectroscopy (OES), and the electron temperature in plasma envelope was determined. Meanwhile, diffusion coefficient of carbon was calculated on the basis of carbon concentration profile. The tribological property of carburized steel under dry sliding against ZrO 2 ball was measured by a balldisc friction and wear tester. The corrosion behaviors were evaluated by potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). It was found that the carburized layer mainly contained a-Fe and Fe 3 C phases with maximum hardness of 620 HV. The PEC treatment significantly decreased the friction coefficient from 0.4 to 0.1. The wear rate of PEC treated steel was about 5.86 Â 10 À6 mm 3 /N$m, which was less than 1/4 of T8 steel substrate. After PEC treatment, the wear and corrosion resistance of T8 steel were improved. Particularly, the pitting corrosion of steel substrate was obviously suppressed.

show abstract

“…The two peaks were close to each other and appeared in the frequency range of 0.1 Hz to 1000 Hz. The high frequency peak is brought out by the electrochemical interaction at the coating/solution interface and low frequency peak is brought out by the electrochemical interaction at the coating/substrate interface [21].…”

Section: Electrochemical Impedance Spectroscopy Measurementsmentioning

confidence: 99%

“…Electrochemical impedance spectroscopy is a non destructive technique that has been used extensively to analyze the protective ability of coatings [21,22]. Equivalent circuit model analysis of impedance data provides reasonable estimates of the resistive and capacitive characteristics of the interface and the coating itself which are highly influenced by the heterogeneous character of the coating and the associated conductive paths.…”

Section: Introductionmentioning

confidence: 99%

Electrochemical investigation of chromium nanocarbide coated Ti–6Al–4V and Co–Cr–Mo alloy substrates

Swaminathan¹,

Zeng²,

Lawrynowicz³

et al. 2012

Electrochimica Acta

View full text Add to dashboard Cite

show abstract

Corrosion of steel under the defected coating studied by localized electrochemical impedance spectroscopy

Cited by 101 publications

References 12 publications

Electrochemical investigation of chromium oxide‐coated Ti‐6Al‐4V and Co‐Cr‐Mo alloy substrates

Electrochemical investigation of chromium oxide‐coated Ti‐6Al‐4V and Co‐Cr‐Mo alloy substrates

Enhanced wear and corrosion resistance of plasma electrolytic carburized layer on T8 carbon steel

Electrochemical investigation of chromium nanocarbide coated Ti–6Al–4V and Co–Cr–Mo alloy substrates

Contact Info

Product

Resources

About