Department of Mechanical Engineering

Permanent URI for this collection

https://repository.run.edu.ng/handle/123456789/2321

Browse

Recent Submissions

Now showing 1 - 5 of 13
  • No Thumbnail Available
    Item
    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.
  • No Thumbnail Available
    Item
    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."
  • No Thumbnail Available
    Item
    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 .
  • No Thumbnail Available
    Item
    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
  • No Thumbnail Available
    Item
    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