Corrosion Inhibition of Carbon Steel in hydrochloric acid medium using Gliclazide drug

  • Tab. 4: Thermodynamic variables for the dissolution of CS in 1 M HCl in the nonexistence and existence of varied doses measurements of investigated drug
    Tab. 4: Thermodynamic variables for the dissolution of CS in 1 M HCl in the nonexistence and existence of varied doses measurements of investigated drug
The role of Gliclazide as corrosion drugs for CS in 1 M HCl have been studied by using weight loss (WL), Hydrogen evaluation (HE), potentiodynamic polarization (PP), electrochemical impedance spectroscopy (EIS) and Electrochemical frequency modulation (EFM) techniques. Weight loss (WL) studied at various temperatures between (25 – 45oC) but Hydrogen evaluation (HE), Open circuit potential (EOCP) and all electrochemical studied at 25oC and seen that the gliclazide studied are mixed type drug. The effect of temperature on corrosion inhibition, the activation and the thermodynamic of adsorption parameters were determinate. Electrochemical impedance was utilizing to examine the inhibition of corrosion and the mechanism. The existence of the Gliclazide in the solution rise the charge transfer resistance and reducing the capacitance of the double layer. The adsorption of the Gliclazide on the surface of CS was found to obey with Langmuir adsorption isotherm and discussed the thermodynamic parameters (ΔGo, ΔHo and ΔSo) that were determinate. The morphology of inhibition of Gliclazide on CS surface was analyzed by scanning electron microscope (SEM) technology, energy dispersive X-ray spectroscopy (EDX) and atomic force microscopy (AFM), all examine techniques illustrate the formation of thin film from Gliclazide inhibitor adsorbed on the metal surface.It was found the adsorption process is spontaneous and increases, with increasing of inhibition efficiency.


    

New generation of acid Zn-Ni electrolyte for barrel application (Part 2)

  • Fig. 20: ALSV of galvanostatically deposited Zn-Ni coating. Deposition was done from Zinni® 220 and the conventional acid Zn-Ni electrolyte with 0.1 A/dm2 (a) and 0.7 A/dm2 (b) at 35 °C with rotation speed of the RDE of 1000 rpm. The ALSV was done in metal ion free electrolyte at 35 °C with 1000 rpm and potential scan rate of 10 mV/s
    Fig. 20: ALSV of galvanostatically deposited Zn-Ni coating. Deposition was done from Zinni® 220 and the conventional acid Zn-Ni electrolyte with 0.1 A/dm2 (a) and 0.7 A/dm2 (b) at 35 °C with rotation speed of the RDE of 1000 rpm. The ALSV was done in metal ion free electrolyte at 35 °C with 1000 rpm and potential scan rate of 10 mV/s

The demand for Zinc Nickel coatings continuously increases in the automotive industry. Especially interesting are zinc nickel alloys with a nickel incorporation of 12–16 %, due to their high corrosion protection as well as superior wear and heat resistance as compared to pure zinc and other zinc alloy coatings.
Despite many advantages of acid Zn-Ni electrolytes there are still some areas of application, like barrel plating or plating of complex-shaped parts, believed to be reserved for alkaline processes. In this paper zinc nickel coatings deposited from ammonium and boric acid-free acid zinc nickel electrolytes, with improved throwing power for rack and barrel applications are investigated. Their corrosion resistance, ductility and hardness will be presented. Moreover, their texture and morphology will be investigated using SEM, XRD and FIB methods. In the end thickness distribution and Ni-incorporation will be presented and compared to alkaline systems.


    

Corrosion protection of 6061 Al-15 Vol. Pct. SiC(p) composite using a biopolymer- An electrochemical approach

The influence of biopolymer starch as corrosion inhibitor on 6061 Al-15 vol. pct. SiC(p) composite in 0.05M hydrochloric acid was studied by potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS) technique. The surface morphology was studied using SEM, EDX, AFM and XRD techniques. The results showed that the inhibition efficiency of starch increased with increasing inhibitor concentrations and also with increase in temperatures. Starch acted as a mixed inhibitor and underwent chemical adsorption following Langmuir adsorption isotherm.