RESUMO
In this study, green walnut husk (GWH) extract was explored as a cost-effective (waste-agricultural) and eco-friendly inhibitor to increase the corrosion resistance of carbon steel in a 1 M HCl solution. Electrochemical impedance spectroscopy, weight change, and potentiodynamic polarization (PDP) tests were utilized to examine the electrochemical behavior of steel substrates with and without the inhibitor. Atomic force microscopy (AFM), field emission scanning microscopy, Fourier-transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD) were performed to analyze corroded surface structures with and without the inhibitor. This inhibitor was found to be 27-82 % efficient in increasing the corrosion resistance of the steel substrates. When the temperature of the solution was increased from 303 to 323 K, the retardation coefficient decreased due to the physical adsorption of GWH molecules on the surface. The results indicated that GWH acted as a mixed inhibitor, and its adsorption on the surface followed the Langmuir model. AFM measurements showed that the roughness of corroded surfaces decreased by approximately 22 % when the GWH concentration was at its optimum level of 400 ppm. Thermodynamic studies displayed a decrease in the corrosion reaction's activation energy of about 25 %. FTIR and XRD patterns of corroded surfaces represented that hydrated iron chloride was the dominant corrosion product. Furthermore, the results provided insight into the GWH adsorption mechanism.
RESUMO
Since, nowadays, utilizing the eco-friendly and economic corrosion inhibitors in various industries is a challenge, in this research, the corrosion behavior of carbon steel in the HCl solution by the addition of the extract of Oestrus ovis larvae as a novel bio-inhibitor has been evaluated. The electrochemical tests plus the gravimetric investigations were performed to study the corrosion property of steel substrates in various concentrations of bio-inhibitor (0.25-3 g/L). Different methods such as grazing incidence X-ray diffraction, field emission scanning electron microscopy (FESEM), and atomic force spectroscopy (AFM), were utilized to detect the chemical composition and morphology of corroded surfaces. Results of the Tafel polarization showed that the inhibition efficiency was about 57-86% with the highest value at the inhibitor concentration of 1 g/L. Electrochemical impedance spectroscopy results indicated that with the specified concentration of bio-inhibitor the electrochemical properties of samples changed based on the suggested electrical circuit. Results showed that the adsorption isotherm of the inhibitor was the Langmuir model with the cathodic-anodic performance. Both FESEM and AFM images demonstrated that the intensity of deterioration and the roughness of corroded surfaces reduced significantly at the optimum concentration of inhibitor (1 g/L). The inhibition mechanism was proposed based on experimental results.
RESUMO
This dataset describes the tribological properties of aluminum-silicon alloys when reinforced with two types of nanoparticles: silica and clay. Moreover, two types of aluminum-silicon alloys were chosen as matrices. These alloys are used in the piston and cylinder-head parts of an automobile engine part. The percentage of nanoparticles was about 1 wt. %. All specimens were developed through the stir casting method. The range of casting temperature was about 700-850 °C. Stirring times for aluminum alloy melts were 2 and 4 min. Ageing heat treatment was also applied for some specimens after the casting process. The Vickers hardness instrument, a pin-on-disk tribometer, and compression test were utilized to collect the data. In addition, to analyze data, a Design-Expert software was used. The data contain hardness, wear rate, friction coefficient, and compression elastic module for aluminum-silicon alloy specimens.
