The effect of particulate strengthening on microstructure and mechanical characterization of binary-modified composites on mild steel

This article presents the microstructure, tribological behavior, and hardness properties of the Zn-TiO2 functional composite coating produced using electrolytic co-deposition technique. The 7.0–13.0 weight fractions of Ti particles were incorporated in a Zn bath to form Zn-TiO2 alloy in the presence of other additives. The microstructural properties of the fabricated coating were investigated using a scanning electron microscope equipped with an energy-dispersive spectroscope, X-ray diffraction, and an atomic force microscope. The anticorrosion behavior in 3.65% NaCl medium was studied using potentiodynamic polarization technique and characterized using high-resolution optical microscope. The hardness and wear properties of the coated alloys were measured with high diamond microhardness tester and reciprocating sliding tester, respectively. From the results, the increases in hardness and wear resistance are attributed to the formation of the incorporated particulate and uniform precipitation of the metal grains at the metal lattice. The contribution of TiO2 particles especially with Zn-13Ti-0.3 V-S provides new orientation of metal–matrix-modified coated structure and decrease in friction coefficient. The anticorrosion resistance characteristics were found to improve significantly in response to concentration of additive

Performance comparison of hydraulic and gravitation HybridICE filters in freeze desalination of mine waters

HybridICE is an emerging freeze desalination technology for treating complex mine wastewaters. The technology works on the principle that growing ice crystals reject impurities during freezing. The bottleneck in the freeze desalination processes may be the separation of ice from the ice slurry generated in the freeze engine. Two types of HybridICE filter have been developed to effect ice separation from ice slurry. The two types differ in the design of the filter elements, mode of feeding the slurry into the filter, and the mechanism of separation of ice from the slurry. In both types of filter, an extruded continuous ice column is formed around the filtering element, which has some openings to allow excess concentrated process water to flow out of the filter. However, the driving force in the gravitation filter is buoyancy, while in the hydraulic filter the ice column is driven by the pressure generated from the flow of the slurry. Salt removal and ice yield from each of the filter types was evaluated when a solution of approximately 4% m/m NaCl solution, prepared by dissolving 25.1 kg of NaCl in 674 litres of water, was treated in a HybridICE freeze crystallisation pilot plant. The objective was to describe the operation of the two types of filter and compare their performance. Salt removal and ice yield were found to be higher with the gravitation filter than the hydraulic filter.Keywords: freeze, desalination, filter, yield, salt removal, ic

Surface modification, strengthening effect and electrochemical comparative study of Zn-Al2O3-CeO3 and Zn-TiO2-CeO3 coating on mild steel

Surface enhancement of engineering materials is necessary for preventing service failure and corrosion attacks industrially. The surface modification, strengthening effect and electrochemical comparative study of Zn-Al2O3-CeO3 and Zn-TiO2-CeO3 coating on mild steel was investigated. Deposition was performed to obtain a better surface adherent coating using the electrodeposition technique. Co-deposition of mild steel resulted into surface modification attributes to the complex alloys that were developed. Films of mild steel were electrodeposited on zinc electrodes using the chloride bath solutions. The effect of deposition potentials was systematically studied using a focus ion beam scanning electron microscope (FIB-SEM) and an atomic force microscope (AFM) to observe the surface morphology, topography and the surface adherent properties of the coatings. The elemental composition and the phases evolved in composite coatings were measured by means of the energy dispersed spectrometer (EDS). The microhardness measurements and corrosion behaviours of the deposits were investigated. Weight loss measurement was conducted on the plated samples to observe the rate of corrosion and it was observed that there was severe corrosion on the controlled sample in comparison to the plated samples and that Zn-TiO2-CeO3 resisted more corrosion attacks

Corrosion Resistance of AA6063-Type Al-Mg-Si Alloy by Silicon Carbide in Sodium Chloride Solution for Marine Application

The present work focused on corrosion inhibition of AA6063 type Al-Mg-Si alloy in sodium chloride (NaCl) solution with a silicon carbide inhibitor, using the potentiodynamic electrochemical method. The aluminium alloy surface morphology was examined, in the as-received and as-corroded in the un-inhibited state, with scanning electron microscopy equipped with energy dispersive spectroscopy (SEM-EDS). The results obtained via linear polarization indicated a high corrosion potential for the unprotected as-received alloy. Equally, inhibition efficiency as high as 98.82% at 10.0 g/v silicon carbide addition was obtained with increased polarization resistance (Rp), while the current density reduced significantly for inhibited samples compared to the un-inhibited aluminium alloy. The adsorption mechanism of the inhibitor aluminium alloy follows the Langmuir adsorption isotherm. This shows that the corrosion rate of aluminium alloy with silicon carbide in NaCl environment decreased significantly with addition of the inhibito

Effect of WO3 Nanoparticle Loading on the Microstructural, Mechanical and Corrosion Resistance of Zn Matrix/TiO2-WO3 Nanocomposite Coatings for Marine Application

In this study, for marine application purposes, we evaluated the effect of process parameter and particle loading on the microstructure, mechanical reinforcement and corrosion resistance properties of a Zn-TiO2-WO3 nanocomposite produced via electrodeposition. We characterized the morphological properties of the composite coatings with a Scanning Electron Microscope (SEM) equipped with an Energy Dispersive Spectrometer (EDS). We carried out mechanical examination using a Dura Scan hardness tester and a CERT UMT-2 multi-functional tribological tester. We evaluated the corrosion properties by linear polarization in 3.5% NaCl. The results show that the coatings exhibited good stability and the quantitative particle loading greatly enhanced the structural and morphological properties, hardness behavior and corrosion resistance of the coatings. We observed the precipitation of this alloy on steel is greatly influenced by the composite characteristics

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

Performance Evaluation Effect of Nb2O5 Particulate on the Microstructural, Wear and Anti-corrosion Resistance of Zn–Nb2O5 Coatings on Mild Steel for Marine Application

In this study, we developed Zn–Nb2O5 composite coatings from sulfate bath for wear and corrosion performance on mild steel by electrodeposition technique. The effect of Nb2O5 particulate on the Zn–Nb2O5 properties was investigated. The particle volume fraction was varied within between 10 and 20 wt%. The structural properties of the composite coatings were characterized using scanning electron microscope equipped with energy-dispersive spectrometer. The hardness and wear of the composite coating were measured with diamond base microhardness indenter tester and sliding CETR reciprocating wear testers, respectively. The corrosion properties were examined in 3.65% NaCl using AUTOLAB 101 Metrohm potentiostat–galvanostat with linear polarization technique. The results showed that average hardness value of 192.6 and 200.6 HV and passivation potential of 4.39E?08 and 5.30E?08(X) were obtained for the 10–20 wt% Nb2O5 particulate on the Zn–Nb2O5 coatings. The wear performance improves by 63.4% as against the control sample. In all, this study established that up to 20 wt% of Nb2O5 in Zn–Nb2O5 composite coating significant corrosion, wear and microhardness propagation resistance of mild steel was attained

Multifaceted incorporation of Zn-Al2O3/Cr2O3/SiO2 nanocomposite coatings: anti-corrosion, tribological, and thermal stability

Nano-sized particle incorporation into metal matrix has gained worldwide acceptance. Al2O3, Cr2O3, and SiO2 nanoparticles have been co-deposited with Zn using electrodeposition process to produce advanced alloy. The coatings were characterized using SEM/EDX and XRD. The mechanical properties of the coatings were studied using microhardness indenter and dry abrasive wear tester. Zn-10 g/L Cr2O3 nanocomposite exhibited the highest microhardness of 228 HVN; Zn-5 g/L Al2O3 nanocomposite possessed the highest corrosion resistance and lowest wear loss. Zn-5 g/L SiO2 nanocomposite showed good stability against other composite coatings. The incorporation of the Al2O3, Cr2O3, and SiO2 shows grain refinement and modify orientation on Zn matrix