Faculty of Engineering

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Corrosion Protection by Novel Conversion Coatings on Structural Al 6061
(Applied Science and Engineering Progress, 2022-02-03) Adesina, Olanrewaju
Chromate conversion coatings have witnessed limited acceptability in recent times. The coatings contain Cr (VI) species that have been classified as environmental hazards and injurious to human health. Thus, the use of environment-friendly and non-carcinogenic novel inorganic-inorganic hybrid conversion coatings are being explored. Vanadate (VCC), hybrid Vanadate/Molybdate (HCC) conversion coatings on Al6061 have been classified in terms of corrosion and adhesion performance with reference to the untreated alloy. Natural exposure tests in the atmosphere and stagnant near-neutral 3.5% sodium chloride solution, as well as potentio-dynamic polarization measurements showed that the corrosion rate for HCC is lower for Vanadate, which in turn outclassed the ‘bare’ alloy. However, clusters of passive incipient pits were revealed on the former after 120 h of exposure in stagnant chloride solution. Both conversion coatings outperformed the untreated aluminium alloy after atmospheric corrosion and adhesion tests.
Design of Aluminum Eco-composite for Sustainable Engineering Application by the Valorization of Municipal Wastes:
(Elsevier, 2024-01-14) Adesina, Olanrewaju
Reprocessing municipal wastes into useful engineering components is one way to reduce their environmental impact. This paper presents a report on an alternative experimental approach to reprocessing common envi ronmental wastes like aluminum scraps, steel shavings, and coconut shells into eco-friendly engineering com posite. Equally, response surface analysis was incorporated in the development and validation of predictive models fit for future prediction of response properties. Aluminum scrap was heated into a liquid state and reinforced with recycled steel particles (RSP) and coconut shell ash particles (CSP) at varying proportions. Specimen design involves three group mixes: A, B, and C. Each of the three groups mixes comprised 0, 1, and 2 % RSP at constant dosage, respectively. Meanwhile, each mix was incorporated with 4, 8, and 12 wt % CSP. The microstructural features, physical (porosity, density, and relative density), and mechanical (tensile strength, hardness, elastic modulus, fracture toughness, impact strength, and percentage ductility) properties were appraised. The outcome revealed that the combination of the two reinforcements (RSP and CSP) contributed to microstructural evolution within the specimens. The porosities of the composite specimens were reported to marginally increase with the reinforcement combination. Interestingly, the composite exhibited lighter weight with improved mechanical performance. Mathematical models derived for the response properties were certified fit for future analysis and predictions. Meanwhile, the optimization procedure revealed that the combination of 1.3 % RSP and 6.7 % CSP was suitable for the design of optimal recycled aluminum composites for sustainable engineering designs. The results clarified that the reinforcement particles (RSP and CSP) are low-cost alternatives to synthetic ceramic reinforcements in the aluminum composite."
Development of Sacrificial Anode from Al, Mg, and Ti from Iron Ore Tailings
(Taylor & Francis Group, 2024-03-07) Adesina, Olanrewaju
This investigation used aluminium, magnesium, iron ore tailings, and low-carbon steel. Iron ore tailings (5–30 wt% Mg and 50 μm in size) in an aluminium matrix formed the anode. In 0.5 M NaCl solution, the weight loss, corrosion rate, and electrochemical properties were measured. Samples A to E have corrosion rates of 0.43, 0.28, 0.36, 0.08, and 0.11 mm/yr, respectively. SEM/ EDS examination revealed the presence of elemental Al, Mg, O, and Si in the anode. The XRD patterns indicate intermetallic compounds such as iron nitride (Fe3N), aluminium silver (Ag-Al), and manganese zirconium (Mn2Zr). In samples A, B, and C, Al and Mg formed a protective coating on the anode, while C and Si reduced passivation and released electrons to protect the steel. IOTs and Mg in the aluminium matrix improve the anodic corrosion resistance. The observed improvements in corrosion resistance highlight the potential of these sacrificial anodes for practical applications in corrosion protection systems
Effect of SiC addition on Laser‑based CoNi Binary Alloy Coatings on Ti‑6Al‑4V alloy
(Springer, 2024-04-25) Adesina, Olanrewaju
This research explores the impact of variations in laser scanning speed and the incorporation levels of SiC-Ni-Co powders on Ti-6Al-4V alloy using laser surface cladding technique. Key parameters, including a consistent laser power of 700 W, a 4 mm beam spot size, a powder feed rate of 1.0 g/min, and a gas fow rate of 3 L/min, along with fxed powder composi tions, were maintained. The laser scanning speeds were adjusted to 0.4 m/min, 0.8 m/min, and 1.2 m/min. Microstructural analyses were carried out using scanning electron microscopy (SEM) while Vickers microhardness was employed to assess coating hardness, and corrosion properties were evaluated using a linear potentiodynamic polarization technique. Follow ing the corrosion attack, the protective oxides formed were identifed through SEM and X-ray difractometer (XRD). The results revealed a strong metallurgical relationship between the clad layer and the substrate, demonstrating the efectiveness of the laser-clad technique. Particularly, the highest laser scan speed exhibited the most signifcant improvements in hardness and corrosion resistance. The coatings displayed an average hardness value of 1269.20 HV0.1, a notable fourfold increase compared to the substrate's value of 334 HV0.1. Concerning corrosion, a clear correlation emerged between scan speed and polarization resistance, confrming that higher scan speeds could lead to enhanced polarization resistance
Effect of Varying Cathode–Anode Parameters on Performance of Mild Steel Cathodically protected by the Aluminum Anode in 0.5 m NaCl Environment
(Springer, 2024-01-19) Adesina, Olanrewaju
This work investigates the efect of varying cathode–anode parameters on the performance of mild steel cathodically pro tected by the aluminum anode in 0.5 M NaCl environment. The study aimed to assess the corrosion protection efcacy of the cathodic protection system and identify optimal parameters for maximizing protection while minimizing energy con sumption. Impressed current system was employed to drive the aluminum electrons from the anode to the cathode to achieve cathodic protection of the mild steel cathode. Using Optical Electron Microscope, Scanning Electron Microscope with an electron difraction spectrometer, and X-ray difraction, the cathodically treated mild steel samples were characterized. The rate of mild steel corrosion was determined by adopting the potentiodynamic polarization method together with the weight loss method in a 0.5 M NaCl environment. Certain parameters including the working voltage, exposure time and electrode separation distance were also used to analyze the optimal features of the cathodic protection during the experiment. The fndings demonstrated that, across the distances and exposure times, an aluminum anode operating at working voltages of 3 and 4 V in a 0.5 M NaCl environment provided sacrifcial protection for the mild steel (cathode). The working voltage of 4 V yielded the best cathodic protection in 0.5 M NaCl at 5 cm for 15 min. Furthermore, at a working voltage of 5 V, efcient protection of the mild steel was achieved only at electrodes separation distances above 15 cm, while overprotection of the cathode which could possibly cause cathodic disbondment was observed at electrodes separation distances of 5 cm, 10 cm and 15 cm. The results of this experiment have practical implications for the development and improvement of cathodic protection systems for mild steel structures in environments with high levels of chloride. This highlights the signifcance of considering cathode–anode parameters to efectively reduce corrosion and ensure the long-term structural stability in the maritime industry and sub-sea operations
Electrochemical Studies of the Corrosion Behavior of Al/SiC/PKSA Hybrid Composites in 3.5% NaCl Solution
(Journal of Composites Science, 2022-09-29) Adesina, Olanrewaju
The corrosion behavior of metal matrix composites (MMCs) is accelerated by the inclusion of reinforcements. Hence, this study investigates the corrosion behavior of MMCs produced from Al 6063 matrix alloy with reinforcement particulates of silicon carbide (SiC) and palm kernel shell ash (PKSA) inclusion at different mix ratios. The MMCs were synthesized using the double stir casting technique. The corrosion behaviors of the composites in NaCl solutions were studied via gravimetric analysis and electrochemical measurements. The gravimetric analysis showed fluctuating dissolution rate of the samples in NaCl solution to indicate flawed film as well as corrosion product formation over the surface of the specimens. The observed corrosion mechanism of the samples was general and pitting corrosion. The presence of reinforcements within the Al6063 matrix acted as active sites for corrosion initiation. The range of values for Ecorr and Icorr obtained in 3.5% NaCl at 24 h was between 220.62 and 899.46 mVandbetween5.45 and 40.87 A/cm2, respectively, while at 72 h, the Ecorr values ranged from 255.88 to 887.28 mV, and the Icorr ranged from 7.19 to 16.85 A/cm2. The Nyquist and Bode plots revealed the electrochemical corrosion behavior of the samples under investigation, with predominant reactions on the surface of the samples linked to charge transfer processes. The relative resistance to corrosion of the samples depends on the thin oxide film formed on the surface of the samples
Electrodeposition of Nickel on Heat-treated Low Carbon Steel for Yam Pounding Beater
(World Scientific, 2022-08-15) Adesina, Olanrewaju
This work focused on the mechanical and corrosion behaviors of electroplated nickel on heat-treated low carbon steel serving as an alternative to austenitic stainless steel for the yam beater in a yam pounding machine. Four standard samples were prepared for electrodeposition from the steel samples by heating to a temperature of 920C with a 60-min holding time. One of the samples was air-cooled while the remaining three were quenched in H2O and later tempered at 450C, 550C and 650C for 60min. After the heat treatment process, the ultimate tensile strength, toughness, and microhardness of the samples were obtained. Nickel electrodeposition was later carried out on the heat-treated mild steel using Watt standard bath concentration. Optical Microscopy (OM) and Scanning Electron Microscope equipped with energy dispersion spectroscopy (SEM/EDS) were used for the characterization of the heat-treated and nickel-electrodeposited samples. More so, the elec trochemical behavior of the nickel-plated samples was studied in a yam °uid environment using the potentiodynamic polarization technique. X-ray °uorescence (XRF) was used to analyze the chemical and oxide composition of the samples. The results showed that among all the heat treatment opera tions, the sample heat-treated at 920Candtemperedatthehighesttemperingtemperature of650C gave the highest toughness value (102MJ/m3) when compared with stainless steel at 124MJ/m3. The sample heat-treated at 920C and tempered at 550C displayed a corrosion rate of 0.022182mm/yr as against the stainless steel sample with a value of 0.0031864mm/yr. From the analysis, the nickel deposited on the heat-treated samples enhanced corrosion resistance in the yam °uid. XRF analysis of the yam before pounding, after processing with nickel electroplated, and stainless beaters shows the content of nickel as 0.0941%, 0.109%, and 0.1113%, respectively. It was concluded that the materials for the yam pounding beater, therefore, perform better if they were both heat-treated and nickel-plated. Invariably, stainless steel could be successfully replaced with heat-treated and nickel-plated mild steel for use as a yam pounding beater.
Experimental analysis, statistical modeling, and parametric optimization of quinary-(CoCrFeMnNi)100 –x/TiCx high-entropy-alloy (HEA) manufactured by laser additive manufacturing
(Elsevier, 2022-11-28) Adesina, Olanrewaju
For additional strength increase, 5, 10, and 15% TiC was added to the quinary CoCrFeMnNi high entropy alloy (HEA) at laser powers of 100, 400, and 700 watts while selective laser melting method was engaged in the fabrication. Microstructure, porosity, density, yield and tensile strengths, elongation, and microhardness are among the parameters analyzed. As TiC appreciated from 5 to 15%, the microstructure revealed that the particles were dispersed within the matrix. Also, the addition ensued grain size refinement with increasing particle proportion. Meanwhile, 15% caused an increase in porosity, 0–10% TiC dosage and 100–700 watts laser power led to a decrease in porosity. The same dosage of TiC resulted in a linear improvement in microhardness even as 0–15% TiC ensued gradual reductions in density and elongation Increases in laser power between 100 and 700 watts were detrimental to elongation but beneficial to density and microhardness enhancement. For composites produced at 100–700 watts laser power, 5–10% TiC increased yield and ultimate tensile strengths whereas 15% TiC decreased strength. For every TiC addition, laser power 100 - 400 watts generally showed an improvement in strength and microhardness, whereas 700 watts depicted a decrease in strength and microhardness. The optimal input combination was predicted by the developed models to be 15% TiC and 504 watts laser power. Since the deviation between anticipated outcome and validation values for the responses is < 0.05, the models are certified for future prediction of the responses. In conclusion, with 504 watt laser power, the entropy alloy’s optimum composition is (CoCrFeMnNi) 85 /TiC 15 .
Hybridization of aluminum–silicon alloy with boron carbide and ferrotitanium
(Springer, 2024-01-13) Adesina, Olanrewaju
The present study investigated the influence of adding FeTi as supplementary reinforcement to B4C in an aluminum–silicon (Al-12Si) matrix for automobile applications. The FeTi alloy was introduced at 3, 6, and 9 wt.% alongside 5 wt.% B4C particles. The effects of such addition on the morphology, physical, and mechanical properties were examined. The X ray diffraction pattern identified the presence of B4C and FeTi reinforcing phases alongside Al3Fe and Ti5Si3 phases. The examined morphology revealed that the particles were well dispersed in the matrix, with consequent effects on their properties. Porosity was reported to reduce linearly with rise in FeTi dosage, consequently resulting in a linear increase in density and relatively high overall density. Inclusive of the hardness, the yield and ultimate strength were enhanced progressively upon a progressive rise in FeTi dosage, with a contrary reduction in ductility. The result revealed that the inclusion of FeTi reinforcing fillers in the matrix is capable of ensuing appreciable improvement in the mechanical properties of the composite.
Mechanical Characterization and Numerical Optimization of Aluminum Matrix Hybrid Composite
(Trans Tech Publications Ltd, 2022-03-30) Adesina, Olanrewaju
Hybridization of aluminum matrix composite is with a view to offset the properties deficient in one composite reinforcement. The present investigation involve a comparative study of AA6063 matrix composites with single reinforcement of A1203, SiC, graphene respectively and various hybridized proportions of the same reinforcements. Physical (density and %porosity) and mechanical (tensile strength, fracture toughness, %elongation, elastic modulus, etc.) properties of composites developed via solidification processing technique were evaluated. "I'he porosity of all the composites fall below the maximum acceptable limit for cast metal matrix composite. Maximum values for UTS, %elongation, and absorbed energy at maximum stress was obtained by hybrid composite with 4wt% A1203, SiC and 2wt% graphene, while the composite with the highest single reinforcement of graphene have the highest value for elastic modulus and fracture toughness. Numerical optimization result show that a matrix and hybrid reinforcements contents of AA6063 (91.413wt.%), SiC (3.679wt.%), A1203 (0.277wt.%), and graphene (4.632wt.%) respectively, will result in optimal values for the evaluated properties.
Microstructure, Process Optimization, and Strength Response Modelling of Green-Aluminium-6061 Composite as Automobile Material
(Ceramics, 2023-02-01) Adesina, Olanrewaju
The use of ashes derived from various waste sources as supplements to synthesized ceramic reinforcement in metal matrices has been established. However, studies involving a combination of particulates from three different sources are rare. In a bid to further knowledge in this aspect of research and develop a green aluminium composite for automobile applications, the present investigation studied the implication of adding palm kernel shell ash (PKA), rice husk ash (RHA), and waste steel particles (STP) to the morphology and strength behaviour of Al-6061-T6 alloy. The experimental design was undertaken via the Box–Behnken design (BBD) of the response surface method. A 4% STPat a constant dose was mixed with PKA and RHA at varying proportions and stirring temperatures according to the BBD. The experimental outcome revealed that the responses were greatly influenced by microstructural evolution. From the surface plots, 2–4% RHA and PKA enhanced tensile and flexural strengths, while 4–6% led to a decline in strength. Meanwhile, 2–6% of the particles are favourable to the enhancement of tensile and compressive strengths and moduli. Temperaturesbetween700and800 Cfavoredresponseimprovement,whereastemperaturesbetween 800 and 900 Cweredetrimental to responses. Developed regression models for the responses were validated to be good representations of the experimental outcomes. The optimum mix was obtained at 4.81% PKA,5.41%RHA,andastirringtemperatureof803 C.Thevalidationexperimentconducted portrayed reliable responses with <5% deviation from the predicted values, thereby certifying the models to be statistically fit for future predictions.
Modeling and Optimization of Green-Al 6061 prepared from environmentally Source Materials
(Heliyon, 2023-03-30) Adesina, Olanrewaju
Recent studies are evaluating the use of particulates fabricated from agro-based residues as reinforcement for enhancing the properties of aluminium alloys. This report focuses on the optimization approach and modeling of responses for future prediction, which are absent from the majority of studies involving particle reinforcement of an aluminum matrix. Herein, palm kernel shell ash (PKA) and rice husk ash (RHA) were incorporated with 4 wt% of WSD and used as fillers in the Aluminium-6061 matrix at variable proportions. The response surface approach was utilized in the experiment design, modeling, and outcome optimization. The independent vari ables are the proportions of PKA and RHA and stir casting temperature. Yield, ultimate tensile, impact strength, elastic modulus, and fracture toughness are examined as response parameters. The results demonstrated that the microstructural property played a significant role in the re sponses. Incorporating PKA and RHA into the Al-6061 matrix improved the response parameters. Temperatures in the range of 700 and 800 ◦C enhanced the property parameters, even though temperatures within 800 and 900 ◦C caused a decline in response. The dependence of the re sponses on the pattern between property variables was revealed by surface and contour plots. The development of models for predicting responses. Optimal conditions were reached at 4.03% PKA, 5.12% RHA, and 787 ◦C, with an error <5% when compared to the forecast responses, thus validating the model. 1. Introduction Agriculture remains an inevitable aspect of human because of the relevance of food being the major need of man. In the last deca
Modeling and Optimizing the Tensile Behavior of Developed Aluminum Hybrid Composite
(World Scientific, 2022-08-05) Adesina, Olanrewaju
Aluminum and its alloy arc versatilc metal materials engaged in various applications based on their high strength, corrosion resistance and light weight. Ilowever, there are rnany lilllitations to its applications when cornpared with steel. In a bid to illiprove 011 the properties, alutninurn cornposites arc dcvclopcd. In this study, Al 6111 cornpositc was developed by the blend of silica and bmnboo leaf ash (BLA) as reinforcement employing stir casting process. The input factors for the experiment were silica dosage (A), BLA proportion (B) and stirring ternperature (C). The experirnental design carried out via Box Behnken design of the response surface methodology. Composites were fabricated through stir casting process by varying the inputs according to the dictations Of the experirnental runs. Parmneters evaluated are yield strength, ultirnate tensile strength, elastic modulus and elongation. Result of the AN()VA analysis showed that the parameters had conscquential effect on the response and the developed model for each parameter are fit for predictions. From the surface plot, interaction between 5 wt.% and 10 wt.% silica and 2 wt.% and 'l wt.% BLA led to improvement in yield, ultimate tensile strength but decrease in elongation even as proportions 10 wt. % and 15 wt.% silica and 4 wt.% and 6 wt. % BLA ensued reduction in the value. Stirring ternperature of 700—800 0 C is favorable to the strength paratneters while led to strength reduction. Optimization via response surface, predicted optimum conditions of 11.62/19 wt.%, 3.957()7 wt.% and 789.()33 0 C for A, B and C, respectively. Predicted values for yield strength, ultimate tensile strength, elastic modulus and elongation are 278.'26 MPa, 378.24 MPa, 97.7885 GPa and 1().132%, respectively. Validation experiment was carried out at the optirnutn condition and the deviation in parameters between the predicted aud validated values is < 5%. Ilence, the Inodels are statistically fit for property predictions.
Morphological Characterization and Tribological Properties of TiCoNi Alloy Coatings on Ti–6Al–4V Alloy via Laser Deposition
(Springer, 2024-09-17) Adesina, Olanrewaju
The goal of this work is to improve the Ti–6Al–4V alloy's hardness and tribological behavior. Coaxial laser surface clad ding was used to develop intermetallic layers of nickel (Ni), cobalt (Co), and titanium (Ti). Laser power of 900 W, beam spot size of 3 mm, powder feed rate of 1.0 g/min, and gas flow rate of 1.2 L/min are the optimized parameters used for laser depositions. The laser scan speeds were adjusted between 0.6 and 1.2 m/min. Investigations were conducted into the effects of powder admixture and laser parameters on the fabricated coatings' microstructure, tribological behavior and hardness. X-ray diffractometry (XRD), energy dispersive spectroscopy (EDS) with Scanning electron microscopy (SEM) was employed for the characterization of the microstructural evolution and phase identification, respectively. Additionally, the tribological experiment was conducted via UMT-2 –CETR reciprocating tribometer, and the coatings’ micro-hardness characteristics were examined using EmcoTEST DURASCAN. The micrographs exhibit no signs of porousness, cracks, or stress introduction, according to the results. For every manufactured sample, good metallurgical adhesion was obtained. By comparing the hardness of the ternary coating (Co–Ni–10Ti deposited at a scan speed of 1.2 m/min, with a hardness of 980 HV) to the substrate (Ti–6Al–4V, with a hardness of 330 HV), a hardness increase of approximately 2.96 times was observed. Furthermore, the Co–Ni–10Ti coating, deposited at a scan speed of 1.2 m/min, demonstrated a 51.1% reduction in the coefficient of friction (COF) compared to the base alloy, indicating superior anti-wear performance. The enhanced properties are attributed to the formation of hard intermetallic compounds such as Ti–Co, Co2Ti, Al5Co2, and Ni3Ti, along with their uniform distribution and finely tuned grain sizes.
Morphological Evolution and Strength Performance of Green-aluminium-7075 Hybrid Composites modeled by response Surface Analysis
(Springer, 2023-06-03) Adesina, Olanrewaju
In developing countries, the importation of synthetic ceramic particles for particulate reinforcement of metal matrixes is costly, so locally sourced and sustainable alternatives are sought after Rice husk ash (RHA) at 3–12 wt.%, glass powder (GP) at 2–10 wt.%, and stirring temperature (ST) at 600–800 °C were evaluated for their effects on the elemental distribution, microstructure,andtensileperformanceofaluminum-7075greencomposite.Responsesurfacewasutilizedintheexperimental design and statistical analysis of the experimental results for the purpose of determining the optimal combination of the three input variables. Yield, ultimate tensile, flexural, and impact strengths, as well as microhardness and compressive strength, are examined as responses. To optimize these parameters, response surface analysis was incorporated into the experimental design, modeling, and optimization procedures. Variation in experimental variables led to microstructural evolution, which in turn caused variation in performance. Response surfaceanalysis (RSA)revealed thattheinputfactors contributed significantly to each response, resulting in regression models statistically suited to represent the experimental data, as confirmed by the diagnostic plots. As a consequence of the optimization, a combination of 7.2% RHA, 6.2 GP, and 695 °C with a desirability of 0.91 was deemed optimal. A comparison between the predicted values for the responses and the values from the validation experiment revealed that each response had an error < 5%. Consequently, the models are certified adequate for response prediction with a confidence level of 95%, and the optimal combination is adequate for the composite’s design.
Numerical Modelling and Optimization of the Surface Qualities of Laser Cladded Ti-6Al-4V Alloy
(Springer, 2023-12-26) Adesina, Olanrewaju
Ti6Al4V alloy is one of the most widely utilized engineering metals, but it has a reduced hardness for high-temperature abrasive applications. In order to modify the surface of a Ti6Al4V alloy plate, a Cobalt-Nickel (Co-Ni) powder combination with increased hardness and corrosion resistance was used during the laser cladding pro cess. For optimal efciency, the Co proportion of the powder was modifed between 30, 50, and 70 wt% respectively. The scan speed and laser power of the operation process were modifed between 0.6, 0.9, and 1.2 m/s and 700, 800, and 900 W respectively. The response properties examined include; microhardness of the coat ing, surface roughness, and clad depth. Response surface methodology was utilized in the experimental design, response property modeling, and process optimization respectively. The statistical analysis revealed that the input variables had signifcant efects on the response properties and that the trend of the responses depended on the interaction pattern between the input variables. The developed numerical mod els were validated for property prediction. It was noted that the optimization pro cedure and confrmation experiments produced response properties with marginal error. The optimal input combination for producing the balanced performance of the Co-Ni coating on the Ti6Al4V alloy substrate yielded 70wt.% Co proportion, 0.86 m/s scan speed, and 900 W laser power respectively.
Optimization and Inhibitive effects of Sweet Potato Leaf Extract (SPLE) on mild steel
(Elsevier, 2023-02-02) Adesina, Olanrewaju
Weight loss and electrochemical techniques were used to evaluate the inhibition efficiency of sweet potato leaf extracts (SPLE) as inhibitor on mild steel in phosphoric acid. Box Behnken design was used to examine the interactions of these variables: acid concentration (0.5–1.5 M); time (5–10 days); inhibitor concentrations (0.3–0.9 g/L) and temperature (30–60 ◦ C) respectively. Polarization and Electrochemical impedance and were used to measure the inhibition efficiency. The surface morphology of coupons was analysed using Scanning Electron Microscope (SEM). The experimental data was statistically analysed and regression equation was generated for inhibition efficiency. The weight loss measurement revealed that extract acts as an inhibitor for mild steel in phosphoric acid and decreases rate of corrosion. The results of inhibition effi ciency derived from polarization studies and impedance analyses agree. The validated experi ment’s coupon created a better protected inhibitive layer than coupon of the best process level as observed from experimental design, according to SEM analysis. It can be concluded that the extract operated as an inhibitor by producing outer film on the surface of mild steel.
Present and Future Impacts of Computer-Aided Design/ Computer-Aided Manufacturing(CAD/CAM)
(International Information and Engineering Technology Association, 2022-06-12) Adesina, Olanrewaju
The world is a growing place with great technological advancement in all areas of life. For some decades now, various disciplines and industries have been engaged in using Computer-Aided Design/Computer-Aided Manufacturing (CAD/CAM) across different nations. CAD/CAM utilizes computers to integrate design and manufacturing processes for quality product attainment. This review article examined the present impacts of CAD/CAM on some sectors such as architecture, manufacturing, engineering and design, electronics, automobile, shipbuilding, aerospace, and medicine. Highlights on some applications and future impacts of CAD/CAM have also been discussed. The numerous impacts of CAD/CAM are discussed in the study. It was concluded that CAD/CAM had become integral parts of our world to ease production against traditional methods. The study recommended more research focus on biomaterials for 3-D bioprinting for tissue engineering applications.
Statistical Analysis and Optimization of the Experimental Results on Performance of Green Aluminum-7075 Hybrid Composites
(Journal of Composites Science, 2023-03-13) Adesina, Olanrewaju
The present study assessed the potential of engaging response surface analysis in the ex perimental design, modeling, and optimization of the strength performance of aluminum-7075 green composite. The design of the experiment was carried out via the Box–Behnken method and the inde pendent variables are rice husk ash (RHA) at 3–12 wt.%, glass powder (GP) at 2–10 wt.%, and stirring temperature (ST) at 600–800 C. Responses examined are yield, ultimate tensile, flexural, and impact strengths, as well as microhardness and compressive strength. ANOVA analysis revealed that the input factors had consequential contributions to each response, eventually presenting regression models statistically fit to represent the experimental data, further affirmed by the diagnostic plots. The result of the optimization envisaged an optimal combination at 7.2% RHA, 6.2 GP, and 695 C with a desirability of 0.910. A comparison between the predicted values for the responses and the values of the validation experiment revealed an error of <5% for each response. Consequently, the models are certified adequate for response predictions at 95% confidence, and the optimum combination is adequate for the design of the composite
Statistical modeling of Si‑based refractory compounds of Bamboo leaf and Alumina reinforced Al–Si–Mg alloy hybrid composites
(Nature Portfolio, 2023) Adesina, Olanrewaju
Wear properties of Al–Mg–Si alloy matrix hybrid composites made with Si-based refractory compounds (SBRC) derived from bamboo leaf ash (BLA) as complimentary reinforcement with alumina have been studied. The experimental result indicate that optimum wear loss was obtained at higher sliding speed. The wear rate of the composites increased with an increase in BLA wt. %, with the composites having 4%SBRC from BLA+ 6% alumina (B4) showing the least wear loss for the diferent sliding speeds and wear loads considered. With increasing BLA weight percent, the composites’ wear mechanism was mostly abrasive wear. Numerical optimization results using central composite design (CCD) reveal that at a wear load of 587.014N, sliding speed of 310.053 rpm and B4 hybrid fller composition level respectively, minimum responses in wear rate (0.572mm2/min), specifc wear rate (0.212cm2 /g.cm3) and wear loss (0.120 g) would be obtained for the developed AA6063 based hybrid composite. Perturbation plots indicate that the sliding speed have more impact on wear loss, while wear load have signifcant impact on the wear rate and specifc wear rate.

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