화학공학소재연구정보센터
Thin Solid Films, Vol.545, 194-199, 2013
Diagnostic of corrosion-erosion evolution for [Hf-Nitrides/V-Nitrides]n structures
HfN/VN multilayered systems were grown on 4140 steel substrates with the aim to improve their electrochemical behavior. The multilayered coatings were grown via reactive r.f. magnetron sputtering technique by systematically varying the bilayer period (Lambda) and the bilayer number (n) while maintaining constant the total coating thickness (similar to 1.2 mu m). The coatings were characterized by X-ray diffraction (XRD), and electron microscopy. The electrochemical properties were studied by Electrochemical Impedance Spectroscopy and Tafel curves. XRD results showed preferential growth in the face-centered cubic (111) crystal structure for [HfN/VN](n) multilayered coatings. The maximum corrosion resistance was obtained for coatings with (Lambda) equal to 15 nm, corresponding to bilayer n = 80. Polarization resistance and corrosion rate was around 112.19 k Omega cm(2) and 0.094*10(-3) mmy respectively; moreover, these multilayered system showed a decrease of 80% on mass loss due to the corrosive-erosive process, in relation to multilayered systems with n = 1 and Lambda = 1200. HfN/VNmultilayers have been designed and deposited on Si (100) and AISI 4140 steel substrates with bilayer periods (Lambda) in a broad range, from nanometers to hundreds of nanometers to study the microstructural evolution and electrochemical progress with decreasing bilayer thickness. (C) 2013 Elsevier B. V. All rights reserved.