O.S.I. Fayomi

Chemical interaction, interfacial effect and the microstructural characterization of the induced zinc-aluminum-Solanum tuberosum in chloride solution on mild steel

In this study, we report the effect of Solanum tuberosum (ST) as a strong additive on the morphological interaction, wear, and hardness properties of electroplated zinc coating in chloride bath solutions. The structural and the mechanical behavior of the Zn–Al–ST coating were studied and compared with the properties of Zn coatings. Characterization of the electrodeposited coatings were carried out using scanning electron microscopy, energy dispersive spectrometer, AFM, and X-ray diffraction techniques. The adhesion between the coatings and substrate was examined mechanically using hardness and wear techniques. From the results, amorphous Zn–Al–ST coatings were effectively obtained by electrodeposition using direct current. The coating morphology was revealed to be reliant on the bath composition containing strong leveling additives. From all indications, ST content contribute to a strong interfacial surface effect leading to crack-free and better morphology, good hardness properties, and improved wear resistance due to the precipitation of Zn2Si and Zn7Al2Si3. Hence, addition of ST is beneficial for the structural strengthening, hardness, and wear resistance properties of such coatings.

Anti-corrosion Properties and Structural Characteristics of Fabricated Ternary Coatings

In this paper deposition of zinc (Zn)-cobalt (Co) particles and the titanium IV oxide composite (TiO2) by electrodeposition in a single electrolyte bath was studied. Zinc coatings modified with cobalt and titanium IV oxide incorporation were produced using optimized process parameters. Morphological and microstructural properties of the fabricated coatings were characterized by an X-ray diffractometer (XRD) and a scanning electron microscope equipped with energy dispersive spectrometer (SEM/EDS). Mechanical characteristics of the coatings were evaluated by a high impact diamond-based Dura Scan micro hardness tester. The corrosion resistance properties were determined with the VA 669 PG STAT 101 using the linear potentiodynamic polarization method. As a result, it was found that the deposition of admixed Zn-Co submicron sized TiO2 composite particles was successful. A better interfacial interaction was found to exist between the based particulate and the composite. Structural comparison of the deposited coatings with SEM, optical microscope and atomic force microscope images revealed that the homogenous grain structure was formed. Corrosion resistance increased significantly and, in addition, a better micromechanical behavior of the coatings wasattained by changing the parameters and content of Co and TiO2 particulates.

The Inhibitory Effect and Adsorption Mechanism of Roasted Elaeis guineensis as Green Inhibitor on the Corrosion Processof Extruded AA6063 Al-Mg-Si Alloy in Simulated Solution

The green roasted Elaeis guineensis oil was tested as a natural inhibitor for Al-Mg-Si in simulated 3.5 % sodium chloride solution by linear potentiodynamic polarization and gravimetric method in the inhibited concentration variation between 5 % and 15 %. SEM/EDX studies were used to examine the surface morphology of the corrosion process and adsorption corrosion product that retards the degradation activities. From the experimental result, the adsorption of surface active compounds at the metal surface proved to create an organic protective film leading to efficient corrosion inhibition. The inhibitory effect significantly improved with about 98 % efficiency and the adsorption of Elaeis guineensis surfactants extract was found to follow the Langmuir adsorption isotherm.

Aluminum Silicon Carbide Particulate Metal Matrix Composite Development Via Stir Casting Processing

In this paper, conventional simple methods of producing MMC with attained properties through the dispersion of silicon carbide in the matrix are investigated. To achieve these objectives a two-step mixing method of stir casting technique was employed. Aluminum (99.66 %C.P) and SiC (320 and 1200 grits) were chosen as matrix and reinforcement materials respectively. Experiments were conducted by varying the weight fraction of SiC for 2.5 %, 5.0 %, 7.5 % and 10 %. The result indicated that the stir casting method was quite successful to obtain uniform dispersion of reinforcement in the matrix. This was evident by the improvement of properties of composites over the base metal. Reinforced Aluminum Silicon Carbide (ASC) showed an increase in Young’s modulus (E) and hardness above the unreinforced case and marginal reduction of electrical conductivity was recorded for the composites. The silicon carbide of 1200 grits (3 μm) showed increased Young’s modulus (E) and hardness of 1517.6 Mpa and 26.1 Hv values at 7.5% volume fraction silicon carbide; when compared with the silicon carbide 320 grit (29 μm). Also; the electrical conductivity properties of the two grit sizes of the silicon carbides were less than the base metal for all the volume fractions of silicon carbide.

Hybrid effect of an in situ multilayer Zn–ZnO–Cr2O3 electrodeposited nanocomposite coatings for extended application

ABSTRACT Multifunctional composite coatings of Zn−ZnO−Cr2O3 were deposited electrolytically on prepared carbon mild steel (CS) from Zn electrolyte, having Zn2+ ions and uniformly dispersed nano ZnO−Cr2O3 particulates. The corrosion resistance characteristics of the deposited coatings were evaluated using the linear polarization measurement method in 3.65% NaCl. The microstructural properties of the produced multilayered coatings were evaluated by scanning electron microscope (SEM) equipped with an energy dispersive spectrometer (EDS), x-ray diffraction (XRD), and atomic force microscope (AFM). Thermal deformations were observed after 4 h at 250°C and the mechanical response of the coated samples was investigated using a diamond-based Dura Scan microhardness tester and a MTR-300dry abrasive wear tester. From the results, a significant improvement in the corrosion performance of coatings was observed with bath containing less than 2 g/L. The microhardness, thermal stability, and anti-wear properties of Zn−ZnO−Cr2O3 shows improved performance against Zn−ZnO coating matrixes, which was attributed to dispersive strengthening effect and grain induced effect of the ZnO/Cr2O3 particulate.

Properties of Tic/Tib Modified Zn–Tic/Tib Ceramic Composite Coating on Mild Steel

Researches in the area of zinc coatings on steel are rather unending because of the unique properties and the very low cost that it offers. In this study, an attempt to develop a compact and structurally modified coating that will work against chemical and mechanical deterioration with the help of Zn–Tic/Tib was studied. Scanning electron microscope and atomic force microscope were used to study the surface morphology, the topography, and the surface adherence properties of the coatings. Micro-hardness of the deposited substrate, the electrochemical behavior and the corrosion properties of the deposits were investigated by means of high impact diamond Dura scan micro-hardness tester and gravimetric method. From the results, the deposition of Zn–Tic/Tib composite particles showed good protection against corrosion and also improved the hardness values. Hence, Zn–Tic/Tib alloy coating on mild steel can be used to improve the properties of mild steel.

Effect of load on the wear behaviour of polypropylene/carbonized bone ash particulate composite

Abstract The effect of applied load on the wear behaviour of polymer matrix composites produced using carbonized bone particles (CBp) as reinforcement has been studied. The addition of the CBp ranges from 5 to 20 wt% in the polypropylene matrix. The composites were produced by compounding and compressive moulding. The wear test was conducted by varying the applied load from 5 to 15 N. Microstructures of the worn surface were assessed with high resolution scanning electron microscopy (HRSEM/EDS). The wear rate increased with increases in applied load from 5 to 15 N and decreased with increasing in CBp from 0 to 15 wt%. The work has established that carbonized bone can be use in increasing the wear resistance of polypropylene composites.

Study of Al2O3/SiC particle loading on the microstructural strengthening characteristics of Zn–Al2O3–SiC matrix composite coating

Abstract In this paper, the microstructure, and mechanical performance of Zn–Al2O3–SiC film co-deposited on mild steel substrate were produced by electrodeposition method. The structural characteristic of the composite coating was analyzed by scanning electron microscope (SEM) equipped with energy dispersive spectrometer (EDS), X-ray diffraction (XRD) and atomic force microscope (AFM). Mechanical examination was done using durascan hardness tester. The result showed that the influence of individual particle loading greatly alter the structural properties and hardness behavior. The increase in hardness is attributed to the perfect homogeneity and characteristics of the particulate which led to the formation of uniform distribution, coherent and interfacial precipitation within the zinc lattice.

Effect of Avogadro Oil as Corrosion Inhibitor of Thermally Pre-aged Al-Si-Mg Alloy in Sodium Chloride Solution

The corrosion inhibition of thermally pre-aged Aluminium-Silicon-Magnesium (Al-Si-Mg) alloy in 3.5 % NaCl solution with natural Avogadro oil of varying concentrations has been studied using linear polarization techniques. From the results obtained, the corrosion rate decreased with an increase in Avogadro oil concentration. An inhibitor efficiency of 46.7, 58 and 71 % were obtained at 1.5, 3.0, 4.5 g/v Avogadro oil addition in a 3.5 % NaCl solution respectively for the conventional alloy. Results from the linear polarization technique indicate a higher potential value with an increase in the polarization resistance (Rp) and lower current density in the inhibited samples than the uninhibited Al-Si-Mg alloy as obtained from the Tafel plot extrapolation. There exist some levels of correlation in the inhibitor efficiency between the conventional and the thermally pre-aged Al-Si-Mg alloy/Avogadro oil in 3.5 % NaCl solution.

Microstructural evolution and characterization of super-induced MgO composite on zinc-rich coatings

Abstract The effect of Zn-MgO deposition prepared through direct electrolytic co-deposition on mild steel was studied. The experiment was conducted at current density between 0.5 and 1 A/cm−2. The morphologies of the coated surfaces were characterized using Atomic Force Microscope (AFM), high resolution Nikon Optical Microscope (OPM) and Scanning Electron Microscopy attached with Energy Dispersive Spectrometer (SEM/EDX). The corrosion behavior was studied using linear potentiodynamic polarization method in 3.5% simulated environment. The phase change was evaluated using X-ray Diffractogram (XRD). The microhardness characteristics of the obtained deposits were analyzed with dura scan hardness tester. The stability of the ceramic composite was determined using heat-treatment processes at 200 oC for 4 h. The results show that the structural behavior and corrosion resistance of the coating is dependent on the composite induced particulate and applied current density. It is found that increasing MgO contents beyond optimum level does not cause increase in microhardness progression. A decrease in applied current maximally influences the deposit adhesion characteristics. The enhanced thermal stability of 236.4 HVN for Zn-20MgO at 0.5 A/cm2 alloy and increase corrosion behavior was thus attributed to its chemical composition, phase content and the synergistic effect of Zn and MgO on the carbon steel.