Electrochemical noise analysis of cavitation erosion corrosion resistance of NbC nanocrystalline coating in a 3.5 wt% NaCl solution

SURFACE & COATINGS TECHNOLOGY

卷:415

Article

Peng, Shuang¹  Xu, Jiang¹  Li, Zhengyang²  Jiang, Shuyun³  Xie, Zong-Han⁴  Munroe, Paul⁵ 

[1] Nanjing Univ Aeronaut & Astronaut, Dept Mat Sci & Engn, 29 Yudao St, Nanjing 210016, Peoples R China

[2] Chinese Acad Sci, Inst Mech, Beijing 100190, Peoples R China

[3] Southeast Univ, Dept Mech Engn, 2 Si Pai Lou, Nanjing 210096, Peoples R China

[4] Univ Adelaide, Sch Mech Engn, Adelaide, SA 5005, Australia

[5] Univ New South Wales, Sch Mat Sci & Engn, Sydney, NSW 2052, Australia

关键词: NbC nanocrystalline coating;    Cavitation erosion-corrosion;    Electrochemical noise;    Cyclic polarization;   

DOI  :  10.1016/j.surfcoat.2021.127133

来源: Elsevier

【 摘 要 】

To combat cavitation erosion-corrosion damage inflicted upon mechanical components in marine applications, NbC nanocrystalline coatings were synthesized by a double cathode glow discharge assisted reactive sputtering method. The coating comprised equiaxed B1-NaCl-type NbC grains with an average grain size of similar to 10 nm and a strong NbC (200)-oriented texture by TEM observation. The electrochemical response of the coating exposed to a 3.5 wt% NaCl solution with and without the influence of cavitation was monitored by electrochemical noise (EN) measurements, in addition to open circuit potential and cyclic polarization. To differentiate the cavitation erosion-corrosion resistance between the NbC coating and a reference Ti-6Al-4V alloy substrate, the EN data were further evaluated, based on a series of analyses, including frequency domain, time-domain, shot noise and wavelet transform. For the Ti-6Al-4V alloy, with increasing output power, the noise resistance (R-n) and slope (k values) of potential and current power spectral density (PSD) decreased, and the average charge in each corrosion event (q) and the total energy of d series crystals increased markedly at the output power levels above 400 W, indicative of a high propensity of pitting corrosion for this alloy. Conversely, the R-n and k values for the NbC coating were found to be almost independent of the output power, and the charge of the corrosion event and the total energy of the d series crystals were much lower than that of the Ti-6Al-4V alloy. The findings garnered from analyzing the EN signals is in accord with what were uncovered from examining the eroded surface morphologies, suggesting that the EN method might offer a reliable and effective tool to probe the cavitation erosion-corrosion behavior in developing durable material.

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