scholarly journals Urea as a complexing agent for selective removal of Ta and Cu in sodium carbonate based alumina CMP slurry

2021 ◽  
pp. 49-49
Author(s):  
Arpita Shukla ◽  
Victoria Selvam ◽  
Manivannan Ramachandran
Keyword(s):  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Sodium Carbonate ◽  
Corrosion Potential ◽  
Electrochemical Impedance ◽  
Removal Rate ◽  
Chemical Mechanical Planarization ◽  
Corrosion Current ◽  
Complexing Agent ◽  
Downward Pressure

This work reports urea as a promising complexing agent in sodium carbonate (Na2CO3) based alumina slurry for chemical mechanical planarization (CMP) of tantalum (Ta) and copper (Cu). Ta and Cu were polished using Na2CO3 (1 wt.%) with alumina (2 wt.%) in the presence and absence of urea. The effect of slurry pH, urea concentration, applied downward pressure and platen rotational speed were deliberated and the outcomes were conveyed. Prior to the addition of urea, Ta removal rate (RR) was observed to enhance with pH from acidic to alkaline having maximum RR at pH 11. However, Cu RR decreases with increasing pH with minimum RR at pH 11. With the addition of urea in the slurry, Cu to Ta removal rate selectivity of nearly 1:1 is encountered at pH 11. The addition of urea boosts the Ta RR and suppresses Cu RR at the same time at 11 pH, as it adsorbs on the metal surface. Potentiodynamic polarization was conducted to determine the corrosion current (Icorr) and the corrosion potential (Ecorr). The electrochemical impedance spectroscopy (EIS) of both the metals was carried out in the proposed formulation and the obtained outcomes were elaborated.

Electrochemical Characteristics of Al-Based Coating on Magnesium Alloy Fabricated by Supersonic Particles Deposition

2013 ◽  
Vol 756-759 ◽  
pp. 85-88
Author(s):  
Xiao Ming Wang ◽  
Sheng Zhu ◽  
Qing Chang ◽  
Guo Feng Han
Keyword(s):  
Electrochemical Impedance Spectroscopy ◽  
Magnesium Alloy ◽  
Impedance Spectroscopy ◽  
Current Density ◽  
Corrosion Current Density ◽  
Corrosion Potential ◽  
Electrochemical Impedance ◽  
Corrosion Current ◽  
Electrochemical Characteristics ◽  
Order Of Magnitude

Al-based coating on ZM5 magnesium alloy was prepared by Supersonic Particles Deposition (SPD). Electrochemical working station was utilized to test polarization curve, corrosion potential and electrochemical impedance spectroscopy etc. The results indicted that corrosion potential of Al-Si coating was about-767.6mV, much higher than that of ZM5 Mg-substrate; And corrosion current density of the coating sample decreased three order of magnitude than that of the uncoated. Compared to Mg-substrate, the radius of capacitive impedance arc of the coating enlarged and impedance modulus improved two order of magnitude.

scholarly journals Protection of Carbon Steel Rebars by Epoxy Coating with Smart Environmentally Friendly Microcapsules

Coatings ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 113
Author(s):  
Jacob Ress ◽  
Ulises Martin ◽  
Juan Bosch ◽  
David M. Bastidas
Keyword(s):  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Corrosion Protection ◽  
Corrosion Potential ◽  
Electrochemical Impedance ◽  
Pore Solution ◽  
Control Sample ◽  
Chloride Ions ◽  
Epoxy Coating ◽  
Transfer Resistance

The protection of mild steel by modified epoxy coating containing colophony microencapsulated corrosion inhibitors was investigated in this study. The corrosion behavior of these epoxy coatings containing colophony microcapsules was studied by electrochemical analysis using cyclic potentiodynamic polarization and electrochemical impedance spectroscopy. The microcapsule coating showed decreased corrosion current densities of 2.75 × 10−8 and 3.21 × 10−8 A/cm2 along with corrosion potential values of 0.349 and 0.392 VSCE for simulated concrete pore solution and deionized water with 3.5 wt.% NaCl, respectively, indicating improved corrosion protection in both alkaline and neutral pH. Electrochemical impedance spectroscopy analysis also showed charge transfer resistance values over one order of magnitude higher than the control sample, corroborating the electrochemical corrosion potential and current density testing results. Overall, the use of colophony microcapsules showed improved corrosion protection in simulated concrete pore solution and DI water solutions containing chloride ions.

scholarly journals Efficiency of Organic Corrosion Inhibitors Derived from Thai-Bael Fruit Extract for Preventing Corrosion in Carbon Steels

2020 ◽  
Vol 32 (8) ◽  
pp. 2043-2050
Author(s):  
Phattarasuda Manantapong ◽  
Nattanon Chaipunya ◽  
Suttipong Wannapaiboon ◽  
Prae Chirawatkul ◽  
Worawat Wattanathana ◽  
...  
Keyword(s):  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Steel Surface ◽  
Electrochemical Impedance ◽  
Protective Layer ◽  
Corrosion Current ◽  
Carbon Steels ◽  
Fruit Extract ◽  
Polarization Measurements ◽  
Hcl Solution

The inhibiting action of Thai-bael fruit extract at room temperature on hot-rolled steel in 1M HCl solution was studied. The chemical functional groups of the green inhibitors were characterized by Fourier-transformed infrared spectroscopy. The electrochemical activities of steel surface were investigated through linear polarization measurements, electrochemical impedance spectroscopy, surface assessment techniques based on optical microscopy and X-ray absorption spectroscopy. Electrochemical testing samples have been prepared in the form of square plates with the size 1 × 1 cm2. The organic corrosion inhibitor extract from Thai-bael fruit has shown the smallest corrosion current density (Icorr) of 114.8 μA cm-2 and corrosion potential (Ecorr) of -424.6 mV, compared with standard Ag/AgCl electrode potential. In comparison, similar tests in the bare HCl solutions yielded Icorr = 882.4 mA cm-2 and Ecorr = -445.8 mV. The mixed-type corrosion inhibiting behaviour was evidenced in the results of the polarization measurements. Electrochemical impedance spectroscopy reveals that the resistance to charge transfer due to the presence of the extracts has been increased by about four times that of the same test on the bare HCl solution, indicating the formation of a protective layer. The adsorption of the organic molecules near the steel-electrolyte interface is evident in the decreasing double-layer capacitance with the enhancing concentration levels of the extract. This latter finding supports the displacement of the water molecules by means of the adsorption of the inhibitors on the steel surface. The optical images of steel surface before and after being immersed in HCl solution also showed pieces of evidence of corrosion retardation. XANES study as well as the linear combination fitting revealed that the samples immersed in HCl solutions with Thai-bael fruit extract possess less Fe3+ compositions. All tendencies across the four examinations indicate that Thai-bael fruit extract could potentially inhibit the corrosion reaction of steel electrodes in the acidic solution.

Effects of Additives in KOH Based Electrolytes on Cu ECMP

2007 ◽  
Vol 991 ◽  
Author(s):  
Tae-Young Kwon ◽  
In-Kwon Kim ◽  
Jin-Goo Park
Keyword(s):  
Citric Acid ◽  
Applied Voltage ◽  
Counter Electrode ◽  
Corrosion Potential ◽  
Removal Rate ◽  
Chemical Mechanical Planarization ◽  
Corrosion Current ◽  
Dynamic State ◽  
Static State ◽  
Potentiodynamic Curves

ABSTRACTThe purpose of this study was to characterize KOH based electrolytes and effects of additives on electro-chemical mechanical planarization. The electrochemical mechanical polisher was made to measure the potentiodynamic curve and removal rate of Cu. The potentiodynamic curves were measured in static and dynamic states in investigated electrolytes using a potentiostat. Cu disk of 2 inch was used as a working electrode and Pt electroplated platen was used as a counter electrode. KOH was used as the electrolyte. H2O2 and citric acid were used as additives for the ECMP of Cu. In static and dynamic potentiodynamic measurements, the corrosion potential decreased and corrosion current increased as a function of KOH concentration. In dynamic state, different potentiodynamic curve was obtained when compared to the static state. The current density did not decrease in passivation region by mechanical polishing effect. The static etch and removal rate were measured as function of KOH concentration and applied voltage. In ECMP system, polishing was performed at 30 rpm and 1 psi. The removal rate was about 60 nm/min at 0.3 V when 5 wt% KOH was used. Also, the effect of additive was investigated in KOH based electrolyte on removal rates. As a result, The removal rate was increased to 350 nm/min when 5wt% KOH, 5vol% H2O2, 0.3 M citric acid were used.

Effect of Manganese Ions on Corrosion Inhibition of PANI for Mild Steel in 0.5 M H2SO4

2011 ◽  
Vol 415-417 ◽  
pp. 174-177
Author(s):  
Yu Qiu Huo ◽  
Ling Bai
Keyword(s):  
Cyclic Voltammetry ◽  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Mild Steel ◽  
Corrosion Inhibition ◽  
Corrosion Potential ◽  
Electrochemical Impedance ◽  
Steel Substrate ◽  
Manganese Ions ◽  
Mild Steel Substrate

Manganese ions doped Pani films were prepared by using a cyclic voltammetry technique on mild steel substrate. Corrosion resistances performances of them in 0.5 M H2SO4 solution were obtained by using electrochemical impedance spectroscopy (EIS), polarization curve, and SEM method. The results showed that manganese ions doped Pani particles became smaller and tighter, the resistance reduced, and the corrosion potential rose than Pani in H2SO4 solution.

scholarly journals Clays valorization as corrosion inhibitors for E400 reinforcing steel

2016 ◽  
Vol 27 (1) ◽  
pp. 28-35
Author(s):  
Diadioly Gassama ◽  
Modou Fall ◽  
Ismaïla Yade ◽  
Serigne Massamba Seck ◽  
Mababa Diagne ◽  
...  
Keyword(s):  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Corrosion Inhibitors ◽  
Corrosion Potential ◽  
Electrochemical Impedance ◽  
Constructional Steel ◽  
Polarization Curves ◽  
Nacl Solution ◽  
Protection Efficiency ◽  
Maximum Content

Abstract The behavior of E400 steel, a constructional steel widely used in Senegal, was studied in aqueous NaCl solution in the presence of two types of clay: volcanic tuffs, and sedimentary montmorillonite. The protection efficiency of these compounds were electrochemically assessed (corrosion potential variation curves, polarization curves and electrochemical impedance spectroscopy) at various inhibitor contents. The results obtained showed that these inhibitors present an inhibitory efficacy of about 70% for an optimal concentration of 0.60% for the tuffs and 62% for a maximum content of 0.50% for montmorillonite.

Study on the Corrosion Behavior of Two Kinds of Tubing at Different Temperatures

2011 ◽  
Vol 314-316 ◽  
pp. 1335-1341
Author(s):  
Xue Hui Zhao ◽  
Yan Han ◽  
Fa Gen Li ◽  
Zhen Quan Bai ◽  
Bin Wei
Keyword(s):  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Corrosion Behavior ◽  
Corrosion Potential ◽  
Electrochemical Impedance ◽  
Xrd Analysis ◽  
Tafel Polarization ◽  
Corrosion Rates ◽  
Two Samples ◽  
Different Temperatures

Aimed at the problem of sulfur-resistant corrosion in environment with carbon dioxide(CO2)and trace amounts of hydrogen sulfide (H2S), Tafel polarization curves and electrochemical impedance spectroscopy techniques were employed to study the electrochemistry corrosion behavior of two kinds of 80S(A and B) at different temperatures. The methods of weight-loss，scanning electron microscope and X-ray diffraction (XRD) analysis were used to study on the corrosion behavior of the sulfur-resistant tubes, including electrochemical impedance spectroscopy , average corrosion rates and the corrosion morphologies. The results showed that the corrosion potential and corrosion rates (CR) of two samples were different with the changing of the test temperatures. With the increase of the temperature, the corrosion potential decreased, and the corrosion rates increased, but decreased at 120°C. The corrosion-resistant of A80S was slightly superior to the B80S. The serious pitting corrosion and the maximum average CR occurred at 90°C. The XRD analysis suggested that the main corrosion products were FeS.

Electrochemical Studies of the Corrosion of Pure Fe, Ni and Cr in Molten (Li,Na,K)F

2014 ◽  
Vol 33 (3) ◽  
pp. 269-276
Author(s):  
Y.X. Xu ◽  
Y.L. Wang ◽  
C.L. Zeng
Keyword(s):  
Electrochemical Impedance Spectroscopy ◽  
Corrosion Current Density ◽  
Corrosion Potential ◽  
Electrochemical Impedance ◽  
Corrosion Current ◽  
Molten Salt Reactor ◽  
Electrochemical Studies ◽  
Warburg Impedance ◽  
Order Of Magnitude ◽  
Molten Fluorides

AbstractThe corrosion of structural materials is a great challenge for the applications of a molten salt reactor using molten fluorides. In this paper, electrochemical behavior of pure Fe, Ni and Cr has been investigated in molten (Li,Na,K)F at 973 K by potentiodynamic polarization and electrochemical impedance spectroscopy. The experimental results indicated that three metals are all in active state at the corrosion potential, with an increase in the corrosion potential by the following order: Cr, Fe, Ni. The free corrosion current density of Ni is more than one order of magnitude lower than that of Fe and Cr. A Warburg impedance was observed in the impedance plots for the corrosion of Cr, but not for Ni and Fe. Ni is the most stable metal, then Fe and Cr, and the corrosion of Cr is controlled by the diffusion of oxidants in the melt.

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