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

Abstract 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 grains with an average grain size of ~10 nm and strong (200)-oriented texture TEM observation. electrochemical response the exposed to 3.5 wt% NaCl solution without influence was monitored noise (EN) measurements, addition open circuit potential cyclic polarization. differentiate resistance between reference Ti-6Al-4V alloy substrate, EN data further evaluated, based on series analyses, including frequency domain, time-domain, shot wavelet transform. For alloy, increasing output power, (Rn) slope (k values) current power spectral density (PSD) decreased, charge each corrosion event (q) total energy d crystals increased markedly at levels above 400 W, indicative high propensity pitting for this alloy. Conversely, Rn k values found be almost independent much lower than that findings garnered from analyzing signals is accord what uncovered examining eroded surface morphologies, suggesting method might offer reliable effective tool probe behavior developing durable material.