Corrosion protection of AISI 316 stainless steel by ALD alumina/titania nanometric coatings

Abstract

Stainless steels are used today in a wide range of applications as a result of their combination of high corrosion resistance and good mechanical properties. In some applications, for example, temporary contact biomedical devices or solar water heaters, corrosion resistance may need further improvement, and surface coatings may be applied for enhanced protection. In this study, AISI 316 stainless steel samples with two different standard industrial finishes were coated using atomic layer deposition (ALD) of Al 2 O 3 /TiO 2 layers. The morphology, composition and corrosion protection was then investigated using different techniques. Atomic force microscopy (AFM) and scanning electron microscopy (SEM) were used to obtain a morphological characterization of coatings and substrates. Glow discharge optical emission spectrometry (GDOES) was used to obtain an in-depth profile of composition. Polarization curves in a 0.2 M NaCl solution were used to evaluate the corrosion protection given by the coatings. The deposited ALD layers were found to be almost flawless. The measured RMS roughness values were compared before and after the ALD, and were around 50 and 370 nm for the two samples. GDOES profiles were strongly influenced by the roughness of the substrate. The corrosion protection obtained on AISI 316 stainless steel by the application of nanometric coatings proved to be very effective in reducing the passive region current density from 10 À7 to less than 10 À9 A/cm 2 and increasing the passive region potential interval from 0.8 to 1.3 V before breakdown.

Atomic layer deposition: state-of-the-art and research/industrial perspectives

“…It is very interesting to note that corrosion studies of coatings prepared by ALD-based technologies using electrochemical techniques are recent and the major part of these studies are on coatings obtained by thermal-ALD technology; only three are dedicated to coatings prepared by PVD + ALD (Marin et al, 2011;Shan et al, 2008a) and PEALE (Potts et al, 2011). In the past decade, several studies were conducted on the potential use of ALD for the corrosion protection of different metal alloys mainly using salt-spray tests and/or potentiodynamic polarization (PP) and electrochemical impedance spectroscopy (EIS) techniques in aggressive solutions.…”

“…A totally equivalent Table 1 Time-line of ALE/ALD technologies, coating development and properties. D í az et al, 2011a,b;Hoivik et al, 2003;Marin, Lanzutti, Guzman, & Fedrizzi, 2011;Shan, Hou, & Choy, 2008a,b;Tripp et al, 2006;Lu, Wang, Zang, & Li, 2007;Wang et al, 2010a,b. a Atomic layer evaporation.…”

“…The protective properties of ALD oxide layers were also investigated at the preliminary level, for the Brought to you by | Western University Authenticated Download Date | 6/10/15 3:54 PM protection of microelectromechanical devices (Hoivik et al, 2003;Tripp et al, 2006), nanodiamonds (Lu et al, 2007) against oxidation, magnesium alloys against wear and cavitation (Wang et al, 2010a,b), stainless steel (D í az et al, 2011b;Marin et al, 2011), and carbon steel (D í az et al, 2011a) against corrosion.…”

Manufacturing, Microstructure and Corrosion Resistance of Electrophoretically Deposited SiO2 and Ni/SiO2 Coatings On X2CrNiMo17–12–2 Steel

“…In the literature such methods as plasma detonation technique [10], arc-ion plating [11], sol-gel deposition [12][13], chemical conversion layers of cerium [14] and chromium [15], chemical vapor deposition (CVD) [16], high-velocity oxy-fuel spray [17], plasma-nitriding [18], atomic layer deposition (ALD) [19,20] and electrophoretic deposition (EPD) [21] are reported. Between them, EPD is a very promising method that allows deposition of high-quality coatings of various materials at room temperature in comparatively short time.…”

Influence of Surface Modification on Properties of Stainless Steel Used for Implants / Wpływ Modyfikacji Powierzchni Na Właściwości Stali Nierdzewnej Stosowanej Na Implanty

“…In 2007, Shan et al [19] used TiO 2 ALD layers to protect an undefined stainless steel, obtaining only a limited effect. In 2011, Marin et al [20], Diaz et al [21] and Potts et al [22] clearly showed that the residual porosity of ALD layers decreases increasing the thickness of the layer, thus improving the protection of the substrate. In most cases [20][21][22] the nanometric ALD layers clearly showed a corrosion protection similar, if not superior to conventional protective techniques and thicker coatings, even if common industrial tests (salt spray) performed on Plasma Enhanced ALD by Potts et al [22] clearly showed a time-limited corrosion protection.…”