Department of Mechanical Engineering
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- ItemEffect of SiC addition on Laser‑based CoNi Binary Alloy Coatings on Ti‑6Al‑4V alloy(Springer, 2024-04-25) Adesina, OlanrewajuThis 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
- ItemOptimization and Inhibitive effects of Sweet Potato Leaf Extract (SPLE) on mild steel(Elsevier, 2023-02-02) Adesina, OlanrewajuWeight 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.
- ItemDevelopment of Sacrificial Anode from Al, Mg, and Ti from Iron Ore Tailings(Taylor & Francis Group, 2024-03-07) Adesina, OlanrewajuThis 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
- ItemMorphological Evolution and Strength Performance of Green-aluminium-7075 Hybrid Composites modeled by response Surface Analysis(Springer, 2023-06-03) Adesina, OlanrewajuIn 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.
- ItemPresent and Future Impacts of Computer-Aided Design/ Computer-Aided Manufacturing(CAD/CAM)(International Information and Engineering Technology Association, 2022-06-12) Adesina, OlanrewajuThe 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.