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Item Characterization of aluminium-based alloy starting powders morphology for the synthesis of rail components through Selective Laser Melting.(Elsevier, 2023-01-01) Kekana, Neo; Shongwe, Mxolisi B.; Mpofu, Khumbulani; Muvunzi, RumbidzaiAdditive manufacturing is widely acknowledged as a popular fourth-industrial revolution technology used in the production of parts attributed to its numerous advantages. Hence, Selective Laser Melting of AlSi12 alloy presents a unique advantage in producing components with high density and minimal cracks or the initiation of stress. Selective laser melting is also an excellent technique for prototyping functional components. However, the process requires multiple heating cycles because it undergoes chemical and physical changes which causes variations in the powder performance and characteristics. This may lead to powder inconsistency, reactivity, and contamination. The properties of additively manufactured parts depend on the powder morphology and granulometry thus making the powders have significant advantages over standard production materials, however, there are certain restrictions in additive manufacturing. Hence, this study explores the characterization of aluminum-based alloy starting pre-alloyed powders for the synthesis of rail components using selective laser melting technology. It investigates the morphology of starting powders for the synthesis of rail components through selective laser melting. The powders were weighed accurately by using stoichiometry to make up the desired compositions. The mixing was carried out by the tubular mixer at 49 rpm for the period of 1, 4, and 8 hours, to get a uniform distribution of the alloy constituent in a dry environment at room temperature. This study aims at determining powder fitness before fabrication to ensure consistency and part quality through powder quality control, powder process optimization, and cost reduction. Morphology and qualitative phase analysis of the starting and mixed powders will be examined by X-Ray Diffractometer (XRD), field emission scanning electron microscopy (FESEM, JSM-7600F, Jeol, Japan) equipped with an energy dispersive X-ray spectrometer (EDS). The findings provide valuable insights into optimizing the SLM process for rail component synthesis using aluminum-based prealloyed powders. This study contributes to the advancement of additive manufacturing techniques for the railway industry, and potentially for other industries as well.Item FEM analysis on thermo-mechanical behavior and experimental validation of Al20Cr20Fe25Ni25Mn10 high entropy alloy during spark plasma sintering.(EDP Sciences, 2024-03-25) Kanyane, Lehlogonolo Rudolf; Popoolaa, Patricia; Mpofu, Praise; Malatji, Nicholas; Ogbonna, VictorHigh entropy alloy developed with spark plasma sintering was modelled with COMSOL Multiphysics. This focus at examining the effect of spark plasma sintering fabrication parameters on thermal and mechanical stress distribution in the sintered Al20Cr20Fe25Ni25Mn10 high entropy alloy (HEA). And to achieve this, a fully thermal-electrical mechanical integrated and dynamic finite element model (FEM) was adopted. The simulation utilised the optimal parameters employed in the laboratory to produce the samples. The geometry for the modelling was 2D axisymmetric as the parameters were based on temperature-dependent characteristics noting that only the sintered sample was modelled and simulated in order not to simplify the modelling. The FEM maintained constant sintering temperature, pressure, and heating rate but concentrated on the impact of residence durations. To verify the simulation results, morphological alterations and densification validation tests were conducted. The microstructural characterization of the sintered sample demonstrated the relationship between the stress distribution and computational temperature found in the current FEM. Noting good particle-to-particle necking. From the model, results showed that the sintered sample at different points depicted a yield stress far greater than the von Mises stress with least thermal stress at 30 MPa. This validate that the developed sample is mechanically stable based on the factor of safety failure criterion and design. However, the study recommend that further work should be conducted considering different sintering pressure of variation 10 to 30 MPa.Item Spark plasma sintering consolidation of equi-atomic TiAlMoSiW high entropy alloy.(Elsevier, 2019-01-01) Kanyane, Rudolf L.; Popoola, A.P.I.; Malatji, N.; Shongwe, M.B.high strength for optimal performance. This work aims to investigate the microstructural evolution, phase formation and microhardness properties of novel equiatomic TiAlMoSiW high entropy alloy synthesized via spark plasma sintering. The effect of Spark plasma sintering temperature of the fabricated equi atomic TiAlMoSiW HEAs was also investigated. The microstructure and the phases formed for the developed HEAs were examined using scanning electron microscopy (SEM) and X-ray diffractometry (XRD) respectively. The microhardness properties were studied using a diamond base microhardness tester. The synthesized alloys at high sintering temperature showed enhanced microhardness and densification.Item Influence of sintering temperature on microhardness and tribological properties of equi-atomic Ti-Al- Mo-Si-W multicomponent alloy.(Purpose-LED Publishing, 2009-01-01) Kanyane, Rudolf L.; Popoola, Patricia A.; Malatji, NicholusThis work aim to investigate the effect of sintering temperature on microhardness and tribological properties of novel equi-atomic TiAlMoSiW HEA fabricated via spark plasma sintering. The influence of Spark plasma sintering temperature on morphological evolution and phase formation was also investigated. The microstructure and the phases formed for the developed HEA were examined using scanning electron microscopy (SEM) and X-ray diffractometry (XRD) respectively. The microhardness and tribological properties were studied using a diamond base microhardness tester Rtec tribometer. It was noticed that sintering temperature has an effect on microhardness and tribological properties. Phase analysis of the samples displayed that the alloy exhibited a bcc matrix with secondary phase precipitate of ordered fcc TiSi2 phase. The developed HEA showed improved mechanical properties as the sintering temperature increases.Item Experimental study of the interaction of solanum tuberosum fluid as additive in electrodeposition bath in the presence of Zn-Tio2 on mild steel.(Elsevier, 2017-01-23) Kanyane, L.R.; Fayomi, O.S.I.; Popoola, A.P.I.; Monyai, T.Enhancing mild steel properties is necessary to meet global competiveness and performance during application. In this study, we report the effect of Solanum tuberosum as additive to Zn-TiO2 sulphate bath coating by electrodeposition method on low carbon steel. The interfacial and structural characteristics of the produced coating were examined by means of scanning electron microscopy equipped with energy dispersive spectroscopy (SEM/EDS). The corrosion resistance properties of the deposited coatings were assessed in 3.65% NaCl using linear polarization method and characterized by optical microscope (OPM). Diamond based microhardness tester was used to measure hardness of the composites. From the results, it is evident that Zn-TiO2-solanum coating resulted in improved performance as compared to Zn-TiO2 coating; both in hardness properties and corrosion resistance properties propagation as a result of its embedded structural build up.Item Wear characteristics of Electro-deposited Ni-Cu-In Nanoparticle coatings for automotive application.(Institute of Electrical and Electronics Engineers (IEEE), 2024-01-01) Fayomi, O.S.I.; Popoola, A.P.I.; Dada, O.M.; Fayomi, O.J.; Tau, V.; Kanyane, L.R.Despite the massive application of Al-Mg-Si alloy in automobile and engineering components, its application in high friction and aggressive environment are limited due to low corrosion resistance, low hardness and poor resistance wear. This research is aimed at modification of the microstructure and thus enhances the microhardness and corrosion properties of Al-Mg-Si alloy. The low-carbon steel was electrodeposited with Ni-CuO and varied In3O5 (1wt%-5wt%) in the Ni-based solution. Scanning electron microscope (SEM) used to study the microstructural evolution in the fabricated coatings. As well, the microhardness of the coatings were measured using Vickers hardness tester machine. The wear properties of the fabricated coatings were studied using an Anton-paar tribometer. With respect to Al-MgSi alloy as the substrate, the microstructure and hardness of NiCuO/In3O5 coatings on the substrate were enhanced. The coatings also present good metallurgical bonding.Item Microstructure and microhardness characterization of Cp- Ti/SiAlON composite Coatings on Ti-6Al-4V by laser cladding.(Elsevier B.V, 2019-03-08) Sibisi, P.N.; Popoola, A.P.I.; Kanyane, L.R.; Fatoba, O.S.; Adesina, O.S.; Arthur, N.K.K.; Pityana, S.L.Failure of engineering components on application is mainly a result of poor surface behavior of materials under certain conditions. Titanium and its alloys have numerous beneficial properties including light weight, high strength and excellent corrosion resistance which have made them desirable in various industries. However, due to low hardness and poor wear resistance their industrial applications are restricted in harsh conditions. In this study Commercially Pure Titanium and SiAlON powders admixed at varied composition (98%Ti/2%SiAlON and 95%Ti/5%SiAlON) were used to fabricate composite coating on Ti6Al4V substrate by Laser cladding at altered scanning speed (0.6 and 1.2 m/min). The microstructures were examined using SEM/EDS and the phase evolutions were identified using XRD. The cross-section microhardness measurements were carried out by means of a Vickers hardness tester. The results revealed improvement in the hardness property as compared to the unconditioned substrate. The coating average surface hardness values were about twice that of the as-received substrate which was attributed to the presence of hard phases such as Si3N4, TiN and SiO2 as revealed on XRD.Item Effect of MgO/MnO2 additives on the structural properties of zinc electroplated mild steel.(Elsevier B.V., 2019-04) Kanyane, L.R.; Fayomi, O.S.I.; Popoola, A.P.I.; Sibisi, P.N.Low carbon steel is widely used in engineering applications due to its availability, physical properties and reasonable cost. Regardless of the massive use of mild steel in engineering applications, their application is limited to high tribology and corrosive environment are limited due to low corrosion resistance properties, low microhardness and poor tribological properties. The increase in service life and exceptional properties of reinforcement composite coatings for advanced engineering application has attracted many researchers world-wide. In this study, the effect of manganese oxide (MnO2) on Zn-MgO chloride bath coating by co-deposition route on mild steel is studied. The coating micrographs and surface thickness were examined by means of scanning electron microscope (SEM) coupled with energy dispersive spectroscopy (EDS) and PosiTector (SPG) respectively. The thermal stability of the synthesized composite coatings studied in isothermal furnace at 350°C. The findings of the studies are discussed in this paper. © 2019 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the organizing committee of SMPM 2019.Item Assessment of the performance of osmotically driven polymeric membrane processes.(IOP Publishing, 2019-12-01) Agboola, O.; Sanni, S.E.; Oyekunle, D.T.; Ayeni, A.O.; Oni, B.A.; Ayoola, A.; Popoola, A.P.I.The universal water scarceness and the extensive ordeals with energy cost in conjunction with the undesirable ecological effects have advanced the improvement of novel osmotically driven membrane processes. Membrane processes which are osmotically driven are developing type of membrane separation procedures that apply concentrated brines to separate liquid streams. They are adaptable in various applications; hence, allow them to be an attractive substitute for drug release, wastewater treatment and the production and recovery of energy. Although, internal concentration polarization (ICP) occurs in membrane practices which are osmotically driven as a consequence of hindered diffusion of solute in a porous stratum, their interest has even increased. Here we review two natural membrane processes that are osmotically driven; Forward osmosis (FO) and Pressure retarded osmosis (PRO). Thus, the major points are as follows: 1) it was highlighted in this review, that the major developments in FO process, important for the process efficiency is to choose a suitable membrane and draw solution. 2) The recent evaluation, understanding and optimizing the activities of fouling throughout the osmotic dilution of seawater employing FO was discussed. 3) Recent advancements of FO in the application of food processing was reviewed. 4) It was highlighted that the main concept of PRO for power generation is the energy of mixing that offers great assessment of the nonexpansion work which could be generated from mixing; nonetheless, the development of effective membranes with appropriate arrangement and performance is needed for the advancement of PRO process for power generation. 5) One major challenge of osmotically driven membrane processes, most recent developments and model development to predict their performances were discussed.Item Influence of zirconium diboride (ZrB2) on the physio- mechanical behavior of AA8011 alloy base.(IOP Publishing, 2019-12-18) Fayomi, J.; Popoola, A.P.I.; Popoola, O.M.; Fayomi, O.S.I.The AA8011 reinforced with 5 to 20 weight percent of zirconium diboride (ZrB2) were developed via stir casting route. In this current research work, characterization evaluation was conducted on the AA8011 alloy and its composites with the varying composition to investigate the physical and mechanical properties. The results of the mechanical properties obtained revealed an enhanced hardness and strengthening mechanism propagation of the composite in comparison to the base alloy AA8011. The experimental studies show that the addition of ceramic particles into the molten metal alloy resulted in improved properties. Also, an increase in the percentage composition of the particles leads to an increase in the strength value of the composite. Generally, the improvement in the hardening mechanical behavior of the composites can be attributed to the intrinsic properties of the incorporated particulates.Item Influence of zirconium diboride (ZrB2) on the physio- mechanical behavior of AA8011 alloy base.(IOP Publishing, 2019-12-18) Fayomi, J.; Popoola, A.P.I.; Popoola, O.M.; Fayomi, O.S.I.The AA8011 reinforced with 5 to 20 weight percent of zirconium diboride (ZrB2) were developed via stir casting route. In this current research work, characterization evaluation was conducted on the AA8011 alloy and its composites with the varying composition to investigate the physical and mechanical properties. The results of the mechanical properties obtained revealed an enhanced hardness and strengthening mechanism propagation of the composite in comparison to the base alloy AA8011. The experimental studies show that the addition of ceramic particles into the molten metal alloy resulted in improved properties. Also, an increase in the percentage composition of the particles leads to an increase in the strength value of the composite. Generally, the improvement in the hardening mechanical behavior of the composites can be attributed to the intrinsic properties of the incorporated particulates.Item Synthesis and characterization of tantalum oxide deposited by metal-organic chemical vapour deposition (MOCVD).(IOP Publishing, 2018-10-23) Jeje, S.O.; Jeje, S.O.; Akinwunmi, O.O.; Akinwunmi, O.O.; Shongwe, M.B.; Shongwe, M.B.Tantalum oxide thin films have rapidly evolved as a potentially important film material in a wide range of industrial applications such as optical coatings, dielectric films, corrosion and heat-resistant coatings, dental implants and coronary stents, or prosthesis. The preparation of an improved liquid source metal-organic precursor suitable for the deposition of high-quality tantalum oxide thin films on soda lime glass using Metal-organic Chemical Vapour Deposition (MOCVD) was reported. Peroxo–hydroxyl–amino tantalum complex precursor was prepared by a method of ligand-exchange reactions between hydroxo–peroxo tantalum complexes and traditional chelating reagents. Preparation of the thin films was achieved by the pyrolysis of the precursor at four different temperatures (380 °C, 400 °C, 420 °C, 450 °C) with a flow rate of 1.5 dm3/min for 2 hours deposition period. The deposited films were characterized using Ultraviolet-Visible spectroscopy, Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray spectroscopy (EDX). A direct optical band gap of 4.16 eV – 4.70 eV was obtained from the analysis of the absorption spectrum of the thin-films. SEM micrographs revealed that the deposited film had no regular structure, and the layers could be described as amorphous. The EDX results confirmed the presence of Tantalum and Oxygen in the thin films.Item Composite materials on the manufacturing of metallic surface alloys.(Elsevier Ltd., 2020-07-31) Fayomi, O.S.I.; Babaremu, K. O.; Akande, I.G.; Popoola, A.P.I.This study focused on the influence of composite materials on electrodeposition process. The exploit of composite materials due to their exceptional characteristics such as, aesthetic beauty, mechanical performance or electrochemical stability can never be over emphasized. While electrodeposition is seen a unique method for surface improvement development of right bath framework and particle infringement are major concern. Therefore, there is a need to adequately highlight the uniqueness of composite material development, their application using deposition route.Item Development of bacterial resistant acrylamide-polyvinylpyrrolidonemetal oxide hydrogel nanocomposites.(Elsevier Ltd., 2020-05-16) Owonubi, Shesan John; Agwuncha, S.C.; Malima, Nyemaga Masanje; Sadiku, Rotimi E.; Revaprasadu, NeerishFabrication of polymer-based nanocomposites for numerous biomedical applications represents a predominant form of therapeutics for combating microbial and bacterial infections. Herein, we firstly synthesized metal oxide nanoparticles (MONPs) by previously reported precipitation methods. Hydrogel nanocomposites were then prepared by free radical polymerization of a combination of the synthesized MONPs, polyvinylpyrrolidone (PVP) and acrylamide. The hydrogel nanocomposites were characterized by FTIR, XRD and investigated for potential antibacterial protection. FTIR spectra of the prepared hydrogel nanocomposites revealed significant characteristic peaks of the distinctive MONPs within the polymer matrix. XRD micrographs revealed slight shifting of peak positions in nanocomposites; the change in peak intensity, coupled with the observed slight shift in the diffraction peaks of both CuO and ZnO nanoparticles confirmed the successful incorporation of the MONPs into the polymer matrix. The presence of the MONPs, in combination with PVP, displayed a synergistic antibacterial activity, with increasing concentration of the MONPs. The treatment against S.pneumoniae, revealed a zone of inhibition phenomenon which showed zones of PVP-5 > PVP-8 > PVP-6 > PVP-9 > PVP-7. PVP-1, PVP-2, PVP-3, PVP-4 did not show any significant zone of inhibition on treatment due to the quantity of MONPs present. The findings show that the hydrogel nanocomposites are potential topical wound dressing materials for the management of bacterial infections.