scholarly journals The Influence of Microstructure on the Passive Layer Chemistry and Corrosion Resistance for Some Titanium-Based Alloys

Materials ◽  
2019 ◽  
Vol 12 (8) ◽  
pp. 1233 ◽  
Author(s):  
Nader El-Bagoury ◽  
Sameh I. Ahmed ◽  
Ola Ahmed Abu Ali ◽  
Shimaa El-Hadad ◽  
Ahmed M. Fallatah ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Pitting Corrosion ◽  
Photoelectron Spectroscopy ◽  
Volume Fraction ◽  
Electrochemical Impedance ◽  
Passive Layer ◽  
Layer Growth ◽  
Uniform Corrosion ◽  
Cyclic Polarization ◽  
X Ray

The effect of microstructure and chemistry on the kinetics of passive layer growth and passivity breakdown of some Ti-based alloys, namely Ti-6Al-4V, Ti-6Al-7Nb and TC21 alloys, was studied. The rate of pitting corrosion was evaluated using cyclic polarization measurements. Chronoamperometry was applied to assess the passive layer growth kinetics and breakdown. Microstructure influence on the uniform corrosion rate of these alloys was also investigated employing dynamic electrochemical impedance spectroscopy (DEIS). Corrosion studies were performed in 0.9% NaCl solution at 37 °C, and the obtained results were compared with ultrapure Ti (99.99%). The different phases of the microstructure were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Chemical composition and chemistry of the corroded surfaces were studied using X-ray photoelectron spectroscopy (XPS) analysis. For all studied alloys, the microstructure consisted of α matrix, which was strengthened by β phase. The highest and the lowest values of the β phase’s volume fraction were recorded for TC21 and Ti-Al-Nb alloys, respectively. The susceptibility of the investigated alloys toward pitting corrosion was enhanced following the sequence: Ti-6Al-7Nb < Ti-6Al-4V << TC21. Ti-6Al-7Nb alloy recorded the lowest pitting corrosion resistance (Rpit) among studied alloys, approaching that of pure Ti. The obvious changes in the microstructure of these alloys, together with XPS findings, were adopted to interpret the pronounced variation in the corrosion behavior of these materials.

scholarly journals Exploring the Influence of the Microstructure on the Passive Layer Chemistry and Breakdown for Some Titanium-Based Alloys in Normal Saline Solution

2019 ◽  
Author(s):  
Nader El-Bagoury ◽  
Sameh Ibrahim ◽  
Ola Ahmed Abu Ali ◽  
Shimaa El-Hadad ◽  
Ahmed M. Fallatah ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Corrosion Rate ◽  
Pitting Corrosion ◽  
Volume Fraction ◽  
Electrochemical Impedance ◽  
Beta Phase ◽  
Passive Layer ◽  
Layer Growth ◽  
Uniform Corrosion ◽  
X Ray

The effect of microstructure and chemistry of passive films on the kinetics of passive layer growth and passivity breakdown of some Ti-based alloys, namely Ti-6Al-4V, Ti-6Al-7Nb and TC21 alloys was studied. The rate of pitting corrosion was evaluated using cyclic polarization measurements. Chronoamperometry was applied to assess the passive layer growth kinetics and breakdown. Microstructure influence on the uniform corrosion rate of these alloys was also investigated employing Tafel extrapolation and dynamic electrochemical impedance spectroscopy. Corrosion studies were performed in 0.9% NaCl solution at 37 oC, and the obtained results were compared with ultrapure Ti (99.99%). The different phases of the microstructure were characterized by X-ray diffraction and scanning electron microscopy. Chemical composition and chemistry of the corroded surfaces were studied using X-ray photoelectron analysis. For all studied alloys, the microstructure consisted of &alpha; matrix, which was strengthened by &beta; phase. The highest and the lowest values of the &beta; phase&rsquo;s volume fraction were recorded for TC21 and Ti-Al-Nb alloys, respectively. The uniform corrosion rate and pitting corrosion resistance (Rpit) of the studied alloys were enhanced following the sequence: Ti-6Al-7Nb &lt; Ti-6Al-4V &lt;&lt; TC21. The corrosion resistance of Ti-Al-Nb alloy approached that of pure Ti. The obvious changes in the microstructure of these alloys, together with XPS findings, were adopted to interpret the pronounced variation in their corrosion rates.

Role of chromium in anomalous behaviour of the passive layer in Ni-Cr-Mo alloys in 1M HCl solution

CORROSION ◽  
10.5006/3767 ◽  
2022 ◽  
Author(s):  
Malvika Karri ◽  
Amit Verma ◽  
J.B. Singh ◽  
Sunil Kumar Bonagani ◽  
U.K. Goutam
Keyword(s):  
Corrosion Resistance ◽  
Electrochemical Impedance ◽  
Corrosion Behaviour ◽  
Underlying Mechanism ◽  
Passive Layer ◽  
X Ray ◽  
Superior Corrosion Resistance ◽  
Hcl Solution ◽  
Cr2o3 Layer

This work seeks to understand the underlying mechanism involved in passivity of Ni-Cr-Mo alloys in a less concentrated HCl solution (1M) by systematically varying contents of Cr and Mo solutes in model Ni-Cr-Mo alloys. Corrosion behaviour was evaluated based on potentiodynamic polarisation tests carried out in conjunction with electrochemical impedance and x-ray photoelectron spectroscopies of passive films that formed on alloys during their exposure to the HCl solution. Results have shown that an increase in Mo alone is not sufficient to improve the corrosion resistance of the alloys at lower concentrations of HCl. Optimum concentrations of Cr and Mo solutes have been found to be in the vicinity of ~17 wt.% Cr and ~19 wt.% Mo for superior corrosion resistance of the alloys. This was attributed to the protection of the Cr2O3 layer as a consequence of the enrichment of Mo6+ ions in the passive film in 1M HCl solution.

MICROSTRUCTURE AND ELECTROCHEMICAL PROPERTIES OF Ni–B/GO ULTRASONIC-ASSISTED COMPOSITE COATINGS

2019 ◽  
Vol 26 (10) ◽  
pp. 1950080
Author(s):  
JIBO JIANG ◽  
HAOTIAN CHEN ◽  
LIYING ZHU ◽  
YAOXIN SUN ◽  
WEI QIAN ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Photoelectron Spectroscopy ◽  
Electrochemical Impedance ◽  
Composite Coatings ◽  
Ultrasonic Field ◽  
Protective Material ◽  
X Ray ◽  
Electrochemical Tests ◽  
Ultrasonic Assisted ◽  
Corrosive Environments

Graphene oxide (GO) sheet and ultrasonic field (UF) were successfully employed to produce Ni–B/GO and UF–Ni–B/GO composite coatings on Q235 mild steel by electroless plating. The composite coatings’ structure and surface morphology were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), Raman spectroscopy and X-ray photoelectron spectroscopy (XPS). Results showed that GO was successfully co-deposited in the Ni–B alloy. Moreover, UF–Ni–B/GO composite coatings have smoother surface and thicker cross-section than others. The microhardness and corrosion resistance of the sample coatings were determined using Vickers hardness tests, Tafel electrochemical tests and electrochemical impedance measurements (EIS) in 3.5[Formula: see text]wt.% NaCl solution to receive the effect of GO and ultrasonic. The findings indicated that UF–Ni–B/GO exhibited optimum hardness (856[Formula: see text]HV) and enhanced corrosion resistance (6.38 [Formula: see text][Formula: see text] over the Ni–B and Ni–B/GO coatings. Due to these interesting properties of the coating, it could be used as a protective material in the automotive and aerospace industries for parts of machines that were manipulated in high temperature and corrosive environments.

scholarly journals Composition and Performance of Nanostructured Zirconium Titanium Conversion Coating on Aluminum-Magnesium Alloys

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Sheng-xue Yu ◽  
Rui-jun Zhang ◽  
Yong-fu Tang ◽  
Yan-ling Ma ◽  
Wen-chao Du
Keyword(s):  
Corrosion Resistance ◽  
Salt Solution ◽  
Photoelectron Spectroscopy ◽  
Electrochemical Impedance ◽  
Impedance Spectrum ◽  
Conversion Coating ◽  
Mg Alloy ◽  
Electrochemical Impedance Spectrum ◽  
X Ray ◽  
Titanium Salt

Nanostructured conversion coating of Al-Mg alloy was obtained via the surface treatment with zirconium titanium salt solution at 25°C for 10 min. The zirconium titanium salt solution is composed of tannic acid 1.00 g·L−1, K2ZrF60.75 g·L−1, NaF 1.25 g·L−1, MgSO41.0 g/L, and tetra-n-butyl titanate (TBT) 0.08 g·L−1. X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared spectrum (FT-IR) were used to characterize the composition and structure of the obtained conversion coating. The morphology of the conversion coating was obtained by atomic force microscopy (AFM) and scanning electron microscopy (SEM). Results exhibit that the zirconium titanium salt conversion coating of Al-Mg alloy contains Ti, Zr, Al, F, O, Mg, C, Na, and so on. The conversion coating with nm level thickness is smooth, uniform, and compact. Corrosion resistance of conversion coating was evaluated in the 3.5 wt.% NaCl electrolyte through polarization curves and electrochemical impedance spectrum (EIS). Self-corrosion current density on the nanostructured conversion coating of Al-Mg alloy is9.7×10-8A·cm-2, which is only 2% of that on the untreated aluminum-magnesium alloy. This result indicates that the corrosion resistance of the conversion coating is improved markedly after chemical conversion treatment.

scholarly journals Enhanced Corrosion Resistance of SiCp/ 2009 Al by Cerium and Lanthanum Conversion Treatment

2018 ◽  
Vol 778 ◽  
pp. 251-255
Author(s):  
Irfan Aziz ◽  
Qi Zhang
Keyword(s):  
Corrosion Resistance ◽  
Photoelectron Spectroscopy ◽  
Electrochemical Impedance ◽  
Localized Corrosion ◽  
Al Alloy ◽  
Unreinforced Alloy ◽  
Maximum Increase ◽  
X Ray ◽  
Eds Analysis ◽  
Polarization Studies

The present study investigates the effect of lanthanide chlorides conversion coatings on the corrosion response of the 2009 Al alloy and SiCp reinforced 2009 Al MMCs. Electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization studies showed that the localized corrosion resistance increased after treatments with solutions having various combinations of CeCl3.7H2O and LaCl3.7H2O, with maximum increase noticed for 5000ppm CeCl3.7H2O. It was found that the protection degree effect obtained under similar coating conditions for 25 vol.% SiCp/2009 Al was relatively higher than 15vol.% SiCp/ 2009 Al MMC, but both of them were less than that of the unreinforced alloy. Scanning electron microscopy (SEM) accompanied with energy dispersive spectroscopy (EDS) analysis revealed the deposition of Ce and/ or La oxides/ hydroxides on cathodic intermetallics/ SiCp and the existence of crevices at the SiCp/ matrix interfaces. X-ray photoelectron spectroscopy (XPS) results indicated that Ce was incorporated as Ce3+ and Ce4+ species in the coatings.

scholarly journals Preparation and Anti-Corrosive Properties of Waterborne Epoxy Composite Coating Containing Graphene Oxide Grafted with Sodium Tripolyphosphate

Coatings ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 307 ◽  
Author(s):  
Na Wang ◽  
Xu Yin ◽  
Jing Zhang ◽  
Huiying Gao ◽  
Xinlin Diao ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Graphene Oxide ◽  
Photoelectron Spectroscopy ◽  
Electrochemical Impedance ◽  
Sodium Tripolyphosphate ◽  
Salt Spray ◽  
Salt Spray Test ◽  
Coated Sample ◽  
X Ray ◽  
Waterborne Epoxy

In this paper, graphene oxide (GO) was grafted with sodium tripolyphosphate (STP) to achieve a new anti-corrosive pigment (STG) with homogenous dispersion in waterborne epoxy (EP). The results obtained from Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM) and X-ray Diffraction (XRD) revealed that STP was successfully combined with GO by chemical bonding. The corrosion resistance of EP, GO/EP and STG/EP coatings on carbon steel substrates was investigated via electrochemical impedance spectroscopy (EIS) and salt spray test. The EIS results showed that the impedance value of coating with 0.7 wt.% STG reached 1.019 × 109 Ω∙cm2, which was considerably higher than that of neat waterborne EP coatings. Salt spray test results revealed once again that STG (0.7 wt.%)/EP coating had superior corrosion resistance. Besides, the STG (0.7 wt.%)/EP coated sample showed the highest adhesion strength between coating and substrate.

scholarly journals Graphene Oxide Decorated with Titanium Nanoparticles to Reinforce the Anti-Corrosion Performance of Epoxy Coating

Coatings ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 129 ◽  
Author(s):  
Heng Yuan ◽  
Fugang Qi ◽  
Nie Zhao ◽  
Pengying Wan ◽  
Biao Zhang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Corrosion Resistance ◽  
Graphene Oxide ◽  
Composite Materials ◽  
Photoelectron Spectroscopy ◽  
Electrochemical Impedance ◽  
Salt Spray ◽  
Corrosion Mechanism ◽  
X Ray ◽  
Ti Particles

Graphene oxide–titanium (GO-Ti) composite materials were fabricated using GO as a precursor and then anchoring nano titanium (Nano-Ti) particles on GO sheets with the help of a silane coupling agent. Then, the coating samples were prepared by dispersing GO, Nano-Ti particles, and GO-Ti in an epoxy resin at a low weight fraction of 1 wt %. The GO-Ti composites were investigated by X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The dispersibility and anti-corrosion mechanism of the coatings were studied by sedimentation experiments, electrochemical impedance spectroscopy (EIS), SEM, and salt spray tests. The mechanical properties of the coatings were analyzed by friction and wear tests. The results showed that the Nano-Ti particles were successfully loaded on the GO surface by chemical bonds, which made GO-Ti composites exhibit better dispersibility in the epoxy than GO. Compared with Nano-Ti particles and GO, the GO-Ti composite exhibited significant advantages in improving the corrosion resistance of epoxy coatings at the same contents, which was attributed to the excellent dispersibility, inherent corrosion resistance, and sheet structure. Among the different proportions of composite materials, the GO-Ti (2:1) material exhibited the best dispersibility and corrosion resistance. In addition, the composite material also greatly improved the wear resistance of the coating.

scholarly journals Effect of cerium content on the corrosion characteristics of Al-Co-Ce amorphous alloy solution

2019 ◽  
Author(s):  
L.M. Zhang ◽  
S.D. Zhang ◽  
A.L. Ma ◽  
A.J. Umoh ◽  
H.X. Hu ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Amorphous Alloy ◽  
Photoelectron Spectroscopy ◽  
Amorphous Alloys ◽  
Open Circuit ◽  
Nacl Solution ◽  
Cyclic Polarization ◽  
X Ray ◽  
Cerium Content ◽  
Ce Content

The effect of cerium content on the corrosion behavior of Al-Co-Ce amorphous alloys in 0.6 M NaCl solution was investigated by cyclic polarization,Mott-Schottky and X-ray photoelectron spectroscopy techniques. Results indicated that the open circuit potential of Al-Co-Ce amorphous alloysdisplayed a decreased tendency with the increase in Ce content, and the amorphous alloy with 4 at.% Ce presented both the lowest passive currentdensity and donor density indicating the best corrosion resistance while adding excess Ce led to the reduced corrosion resistance of Al-Co-Ce alloys.Furthermore, it was found that a low Ce content is beneficial to the formation of a more protective passive film on Al-Co-Ce amorphous alloys, and thecorrosion inhibition reactions of Al-Co-Ce alloys in 0.6 M NaCl solution were changed with the increase in Ce content and the detailed reasons werediscussed.

MICROSTRUCTURE AND PROPERTIES OF THE Ni–B AND Ni–B–Ce ULTRASONIC-ASSISTED ELECTROLESS COATINGS

2018 ◽  
Vol 25 (06) ◽  
pp. 1950006 ◽  
Author(s):  
WEI QIAN ◽  
HAOTIAN CHEN ◽  
CHENQI FENG ◽  
LIYING ZHU ◽  
HUANMING WEI ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Photoelectron Spectroscopy ◽  
Inductively Coupled Plasma ◽  
Electrochemical Impedance ◽  
Low Carbon Steel ◽  
Amorphous Structure ◽  
Low Carbon ◽  
X Ray ◽  
Inductively Coupled ◽  
Hardness Tester

We successfully obtained Ni–B and Ni–B–Ce coatings with and without sonication on low-carbon steel (Q235) through electroless plating with the deposition time of 60[Formula: see text]min. The surface morphology and elemental composition of the coatings were evaluated by scanning electron microscopy (SEM) and inductively coupled plasma (ICP). The 11[Formula: see text][Formula: see text]m thick sonicated Ni–B–Ce (Son-Ni–B–Ce) coating is uniform with the composition of Ni 87.1%, B 6.2% and Ce 6.6%. X-ray diffraction (XRD) measurements implied a typical broaden peak around 44∘, considered as amorphous structure which was confirmed by selected area electron diffraction pattern (SAED). Atomic force microscopy (AFM) showed a typical circular pit of Ni–B–Ce coating and Son-Ni–B–Ce coating. X-ray photoelectron spectroscopy (XPS) revealed the chemical status of coating components. The mechanical and corrosion resistance properties were determined by Vickers hardness tester, potentiodynamic polarization (Tafel) and electrochemical impedance spectroscopy (EIS) in 3.5[Formula: see text]wt. % NaCl solution. As a result, the Son-Ni–B–Ce coating revealed the optimum hardness (956[Formula: see text]HV), minimum roughness [Formula: see text] (92.38[Formula: see text]nm) and excellent corrosion resistance (3.65[Formula: see text][Formula: see text]Acm[Formula: see text] among all coatings.

scholarly journals ZrN-ZrOxNy vs ZrO2-ZrOxNy coatings deposited via unbalanced DC magnetron sputtering

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Gloria I. Cubillos ◽  
Eduard Romero ◽  
Adriana Umaña-Perez
Keyword(s):  
Corrosion Resistance ◽  
Magnetron Sputtering ◽  
Photoelectron Spectroscopy ◽  
Bone Cells ◽  
Electrochemical Impedance ◽  
Dc Magnetron Sputtering ◽  
X Ray ◽  
Composition Structure ◽  
Mouse Osteoblast ◽  
Steel Substrates

AbstractZrN-ZrO$${ }_{x}$$ x N$${ }_{y}$$ y and ZrO$${ }_{2}$$ 2 -ZrO$${ }_{x}$$ x N$${ }_{y}$$ y coatings were deposited on 316L stainless steel substrates via the unbalanced DC magnetron sputtering technique in order to improve their corrosion resistance and evaluate their possible use as a coating biocompatible with bone cells. The composition, structure, morphology, and corrosion resistance were studied by sum means of x-ray photoelectron spectroscopy (XPS), x-Ray diffraction (XRD), scanning electron microscopy (SEM), and atomic force microscopy (AFM). The corrosion resistance was evaluated in 3.5 wt.% NaCl using potentiodynamic polarization (PL) and electrochemical impedance techniques (EIS). The ZrN-ZrO$${ }_{x}$$ x N$${ }_{y}$$ y and ZrO$${ }_{2}$$ 2 -ZrO$${ }_{x}$$ x N$${ }_{y}$$ y coatings exhibited barrier-type protection of the substrate against corrosion. The growth of mouse osteoblast cells was evaluated in the coating that exhibited the greatest resistance to corrosion, ZrO$${ }_{2}$$ 2 -ZrO$${ }_{x}$$ x N$${ }_{y}$$ y , finding that the cell viability was maintained, so this material can be considered to be a candidate for use in osteosynthesis processes.

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