Metallurgical and Materials Engineering- Scholarly Publications

Permanent URI for this collection

https://ir.unilag.edu.ng/handle/123456789/3688

Browse

Browsing Metallurgical and Materials Engineering- Scholarly Publications by Title

Now showing 1 - 20 of 187
  • Item
    Open Access
    A Simulation and Experimental Investigation of the Thermal Characteristics of Refractory Bricks Produced Using Fireclay and Agroforestry Wastes
    (Journal of Casting & Materials Engineering, 2022-05-28) Obidiegwu, E. O.; Esezobor, D. E.; Mgbemere, H. E.; Odili, C. C.
    Manufacturing and processing industries usually consume large quantities of materials and energy in the course of their opera tions. The energy supplied for high-temperature processes are used partially for the actual technical process and between 30 to 40% of the energy escapes through the walls of the reactor into the atmosphere, leading to a high degree of thermal inefficiency and fuel consumption. This paper studies the thermal behaviour of insulating refractory bricks produced from a blend of fireclay and agroforestry wastes. The fireclays used were obtained from Ukpor deposit in Anambra State (Latitude 5.95°N, Longitude 6.92°E), Osiele deposit in Abeokuta, Ogun State (Latitude 7.18°N, Longitude 3.45°E) and Kankara Katsina State (Latitude 11.93°N, Longitude 7.41°E), all of which are in Nigeria. Samples were prepared with various weight percentages (60–100 wt.%) clays and (0–40 wt.%) of agroforestry waste, with grain sizes between 212 and 600 µm. Raw materials and the developed refractory bricks were characterised using appropriate standard techniques. The chemical, mineralogical constituents and phases present in the microstructure were examined. Physical and thermo-mechanical properties were investigated. The insulating refractory bricks developed have porosity of 78.83% , cold crushing strength (CCS) 3.144 kN/m2 and thermal conductivity 0.04–0.046 W/(m∙K) that compare favourably with imported bricks 75–85%, 2.756 kN/m2 and 0.049 W/(m∙K) in both physical, mechanical and thermal properties respectively. The reason is that the agroforestry waste used (coconut shell), served to create the pores that improve insulation after burning. Also the ash that remains serves as reinforcement to improve the mechanical properties. The thermal behaviour of the bricks was studied using Finite Element Method and shows a strong correlation with the experimental findings. This indicates that the produced insulating bricks have the thermal properties required for insulation of furnaces.
  • Item
    Open Access
    Acetylation, crystalline and morphological properties of structural polysaccharide from shrimp exoskeleton
    (Engineering Science and Technology, an International Journal, 2017) Gbenebor, O.P.; Adeosun, S.O.; Lawal, G.I.; Olaleye, S.A.
    The extraction of a structural polysaccharide, a-chitin, from shrimp exoskeleton via chemical means using hydrochloric acid (HCl) and sodium hydroxide (NaOH) has been done. Concentrations of 0.4, 0.8 and 1.2 M for both HCl and NaOH were chosen to evaluate the acetylation degree (DA), crystalline structure and morphology of the chitin. The N-acetyl groups’ content in the structural polysaccharide ranged between 65.6 and 99.4% in decreasing order of both acid and alkali concentrations combination used. The magnitude of chitin average hydrogen bond energy EH was majorly influenced by OH(6). . .OC intra and CO. . .HN intermolecular hydrogen bonds as they showed more predominance than OH(3). . .O(5) and OH. . .OC intra and intermolecular hydrogen bonds. Chitin diffraction planes, crystalline index (Crl) and crystallite size (Dhkl) were investigated by X-ray diffraction (XRD) with reflections observed on (021), (110), (130) and (013) planes. The Crl occurred between 79.4 and 87.4%, while crystallite sizes were between 0.544 and 3.64 Å for the samples. Morphological study using scanning electron microscopy with energy dispersive spectroscopy SEM/EDS showed strong calcium and oxygen peaks. This established the shrimp shell surface to be composed of calcite and trace elements such as nitrogen and silicon. The observed a-chitin rough surfaces were attributed to the low degree deacetylation recorded during alkali treatment.
  • Item
    Open Access
    Analysing wear behaviour of Al–CaCO3 composites using ANN and Sugeno-type fuzzy inference systems
    (Neural Computing and Applications, 2020) Sosimi, A.A.; Gbenebor, O.P.; Oyerinde, O.; Bakare, O.O.; Adeosun, S.O.; Olaleye, S.A.
    Design of experiment for the development of stir cast calcium carbonate-reinforced aluminium composite is a search for optimum combination of material and process control parameters for best physical and mechanical properties. A softcomputing model can accurately learn the complex interactions between process parameters to provide great insights in the development of this composite. This paper demonstrates and analyses the potential of artificial neural network (ANN) and Sugeno-type fuzzy inference systems (FIS) for wear behaviour prediction of calcium carbonate-reinforced aluminium composites. The models were trained with data collected from the experiment. The data consist of filler particle size of 150 lm with weights fractions varied from 0 to 25 wt%, in step of 5. Wear test data at different time of contacts (30, 60, 90, 120 and 150 s) and variable loads of 2.27 N, 4.54 N and 6.80 N were collected, resulting to 120 length vectors. Comparing the experimental results of wear test with those predicted using the ANN and Sugeno-type FIS, the integration of calcium carbonate particulate enhanced the wear characteristics of Al matrix up to 200%. On the use of backpropagation neural network with 4–3–1 architecture for wear prediction, the Levenberg–Marquardt training algorithm performs better. For Sugeno-type FIS, the Gaussian membership function resulted to the best prediction of wear rate. When ANN and Sugeno-type FIS performance on the test set were analysed based on some statistical parameters, the later returned an R2 value of 0.9775 as against ANN’s value of 0.3684. The predicted wear rate using ANFIS with Gaussian membership functions was in good agreement with the experimental values.
  • Item
    Open Access
    Analysis of dissimilar weldeing of austenitic stainless steel to low carbon steel by TIG welding process
    (International Journal of Metallurgical & Materials Science and Engineering (IJMMSE), 2015-10) Osoba, L.O.; Ekpe, I.C.; Elemuren, R.A.
    In the current study, the effect of heat treatment on the dissimilar metal welding of austenitic stainless steel (AISI 304L) and low carbon ferritic steel (AISI 1005) using Tungsten Inert Gas (TIG) welding process was investigated with a view to minimize and/ or eliminate the previously reported danger of inhomogeneous hardness distribution experienced across the fusion zone. Heat treatment (Normalizing) of the as welded dissimilar metal was carried out in a muffle furnace at temperatures ranging from 7500C to 8500C and held for varied length of time. Micro structural evaluation and mechanical properties of the fusion zone (FZ), heat affected zone (HAZ) and the base metals (BM) were performed using microscopy and micro hardness evaluation. The result shows that for dissimilar metal weldment, the non-uniform hardness distribution in the fusion zone can be essentially eliminated by using appropriate post weld heat treatment.
  • Item
    Open Access
    Analysis of Dissimilar Welding of Austenitic Stainless Steel to Low Carbon Steel by TIG Welding Process
    (International Journal of Metallurgical & Materials Science and Engineering (IJMMSE), 2015) Osoba, L.O.; Ekpe, I.C.; Elemuren, R.A.
    In the current study, the effect of heat treatment on the dissimilar metal welding of austenitic stainless steel (AISI 304L) and low carbon ferritic steel (AISI 1005) using Tungsten Inert Gas (TIG) welding process was investigated with a view to minimize and/ or eliminate the previously reported danger of inhomogeneous hardness distribution experienced across the fusion zone. Heat treatment (Normalizing) of the as welded dissimilar metal was carried out in a muffle furnace at temperatures ranging from 7500C to 8500C and held for varied length of time. Micro structural evaluation and mechanical properties of the fusion zone (FZ), heat affected zone (HAZ) and the base metals (BM) were performed using microscopy and micro hardness evaluation. The result shows that for dissimilar metal weldment, the non-uniform hardness distribution in the fusion zone can be essentially eliminated by using appropriate post weld heat treatment
  • Item
    Open Access
    Anisotropic responses of mechanical and thermal processed cast Al-Si-Mg-Cu Alloy
    (The Minerals, Metals & Materials Society, 2015) Adeosun, S.O.; Akpan, E.I.; Balogun, S.A.; Onoyemi, O.K.
    The effects of ambient directional rolling and heat treatments on ultimate tensile strength (UTS), hardness (HD), percent elongation (PE), and impact energy (IE) on Al-Si-Mg-Cu alloy casting with reference to inclination to rolling direction are discussed in this article. The results show that rolled and quenched (CQ) sample possess superior UTS and HD to as-cast and those of rolled and aged samples (CA). Improved IE resistance with ductility is shown by both CQ and CA samples. However, these mechanical properties are enhanced as changes in the test sample direction moved away from rolling direction for all heat-treated samples. The CQ samples displayed highest tensile strength (108 MPa) and PE (19.8%) in the 90 direction.
  • Item
    Open Access
    Assessing Susceptibility to Chromium Carbide Precipitation in Cr-Mn Austenitic Stainless Steel Welds
    (Unilag Journal of Medicine, Science and Technology (UJMST), 2017) Amuda, M.O.H.; Enumah, K.S.; Onitiri, M.A.; Osoba, L.O.
    Chromium-manganese austenitic stainless steel is a low cost grade with metallurgical and mechanical properties approximating a standard nickel-chromium austenitic stainless steel. It serves as a good substitute to the standard nickel-chromium grade owing to the high cost of nickel. But, there is little information on its weldability particularly the influence of welding parameters on chromium carbide precipitation in the heat affected zone. This limits its structural application through fusion welding. Therefore, in this paper, carbide precipitation in chromium-manganese austenitic stainless steel welds was investigated in the heat input range 180 - 300 J/mm under different combinations of arc current and welding speeds. Microstructural analysis after 10% oxalic acid electrolytic etch revealed that increasing heat input produced significant changes in microstructure of the welds with wider sensitized structure at heat input greater than 206 J/mm. Microstructure of welds produced at heat input lower than 206 J/mm was free of chromium carbide precipitation. This level of heat input which corresponds to arc current of 110 -125A and welding speeds in the range 319- 395 mm/min show that sensitized region associated with chromium carbide precipitation can be safely avoided during fusion welding of this grade of austenitic stainless steel through carefully selected welding parameters.
  • Item
    Open Access
    Assessment of Mechanical and Wear Properties of Epoxy‐based Hybrid Composites
    (Advances in Production Engineering & Management, 2016) Agunsoye, J.O.; Bello, S.A.; Bello, L.; Idehenre, M.M.
    Discarded florescent tubes and graphite rods obtained from dumped primary cells have been processed to obtain glass and graphite particles. 80 µm glass and graphite particles were used as reinforcements in epoxy resin, LY 556 cured with HY 931 hardener to produce epoxy resin hybrid composites. The morphology, mechanical properties, thermal stability and wear resistance characteristics of the epoxy resin glass/graphite hybrid composites were studied. The thermogravimetric analyser TGA 701 was used to examine the thermal stability of the epoxy resin glass particle/graphite composites. Addi‐ tion of graphite and glass particles enhanced the strength, thermal stability and wear resistance of the epoxy resin. However, tensile strain and impact energy absorption of the epoxy resin hybrid composites started declining at 6 wt% of glass particle addition. The increase in wear rate of the composites with an increment in applied loads is attributable to increase in the normal reaction between the examined sample surfaces and the emery paper. Fur‐ thermore, the increase in wear resistance with an increment in wt% of glass particle additions is attributable to good interfacial adhesion between matrix and the fillers. The textural and appearance differences between the scanning electron micrographs of the control and epoxy resin hybrid composites is attributable to the presence of new phases due to exothermic and cross link‐ ing reaction between the matrix and the fillers. Hence, new vital engineering composites peculiar to automobile, aerospace and building industries have been produced.
  • Item
    Open Access
    Beneficiation of Azara Barite Ore Using A Combination of Jigging, Froth Flotation and Leaching
    (2018-10) Mgbemere, H. E.; Obidiegwu, E.O.; Obareki, E.
    In this research, Jigging, Froth Flotation and leaching have been used to beneficiate barite ore from Azara, Nasarawa State Nigeria. Chemical analysis on the ore indicates that it contains 53.09% of Ba and 11.52% S with a specific gravity value of 3.207±0.03. After the jigging operation, the specific gravity values of the underflow and overflow are 3.77±0.029 and 2.77±0.058 respectively while the Ba and S increased to 78.61% and 15.87% respectively. After the froth-flotation, the specific gravity values obtained are 3.95, 4.1 and 4.05 corresponding to pH values of 5, 7 and 9 respectively. Frothed barite with pH of 7 was leached with 0.2M HCl and a mixture of 0.2M HCl and HOCl. After leaching, the specific gravity values are 4.38±0.03 and 4.27±0.02 for HCl and HCl+HOCl respectively. The X-ray diffraction patterns show that highly crystalline peaks are obtained after froth flotation while more phases are added with leaching.
  • Item
    Open Access
    BENEFICIATION OF AZARA BARITE ORE USING A COMBINATION OF JIGGING, FROTH FLOTATION AND LEACHING
    (Nigerian Journal of Technology (NIJOTECH), 2018-10) Mgbemere, Henry E.; Obidiegwu, Eugenia O.; Obareki, Emmanuel
    In this research, Jigging, Froth Flotation and leaching have been used to beneficiate barite ore from Azara, Nasarawa State Nigeria. Chemical analysis on the ore indicates that it contains 53.09% of Ba and 11.52% S with a specific gravity value of 3.207±0.03. After the jigging operation, the specific gravity values of the underflow and overflow are 3.77±0.029 and 2.77±0.058 respectively while the Ba and S increased to 78.61% and 15.87% respectively. After the froth-flotation, the specific gravity values obtained are 3.95, 4.1 and 4.05 corresponding to pH values of 5, 7 and 9 respectively. Frothed barite with pH of 7 was leached with 0.2M HCl and a mixture of 0.2M HCl and HOCl. After leaching, the specific gravity values are 4.38±0.03 and 4.27±0.02 for HCl and HCl+HOCl respectively. The X-ray diffraction patterns show that highly crystalline peaks are obtained after froth flotation while more phases are added with leaching.
  • Item
    Open Access
    Beneficiation of Barite Ore from Azara in Nassarawa State, Nigeria, using Froth Flotation
    (Nigerian Journal of Technological Development, 2019) Mgbemere, Henry E.; Obidiegwu, Eugenia O.; Obareki, Emmanuel
    Barite ore from Azara in Nassarawa State has been beneficiated using Jigging and Froth Flotation techniques by varying the pH of the solution. The chemical analysis indicates the presence of major elements Ba, S, O and minor elements like Ti, V, Al and Si which confirms that it is barite while the particle size analysis showed that the average particle size is ≈ 150 μm with a 1,167 cm2/g specific surface area. The X-ray diffraction analysis of both the as-mined ore and beneficiated samples indicate increased intensity in the later. The jigging result shows that 51% of the feed is the underflow while 46.7% is the overflow. The measured specific gravity as a function of pH show that values between 3.78 and 4.23 are obtained. The elemental composition of the Barite after beneficiation shows that in addition to high contents of BaO and SO3, the amount of SiO2 present is still very high. The sample with a pH value of 7 gave the highest specific-gravity value of 4.23 while that with pH of 3 gave the lowest specific-gravity value of 3.78. The implication is that the barite sample with pH of 7 is acceptable for oil and gas applications while more work is needed for samples with other pH values.
  • Item
    Open Access
    Cassava Leaf Nanoparticles (CLNPs) as a Potential Additive to Anti-Corrosion Coatings for Oil and Gas Pipeline
    (Tribology in Industry, 2017) Kolawolec; Kolawole, F.O.; Kolawole, S.K.; Agunsoye, J.O.; Bello, S.A.; Adebisi, J.A.; Okoye, O.C.; Hassan, S.B.
    Characterization of synthesized cassava leaf nanoparticles (CLNPs) was carried out using SEM/EDX and Gwyddion software, XRD and TEM for cassava leaves (CL) ball milled at 36, 48, 60 and 72 hours. The morphological study was done using SEM and the Gwyddion software was used to determine the particle sizes from the SEM images. The particle size range for the un-milled cassava leaves (CL) was between 1.88 + 0.09 to 19.53 + 0.98 µm. After milling for 36, 48, 60 and 72 hours the average particle sizes were 4.96 + 0.25, 3.51 + 0.18 µm, 86.90 + 4.35, 74.50 + 3.73 nm respectively. Crystallite size of 23.94 + 1.20 nm was obtained by XRD using Scherrer equation after milling for 72 hours and the XRD results revealed the presence of compounds such as SiO2, CaCO3, Ca2(SO4)2H2O and CaC2O4(H2O). Furthermore, TEM was used to determine nanoparticles after milling for 72 hours and the particle size ranged from 9.16 + 0.46 to 58.20 + 2.91 nm for cassava leaf nanoparticles (CLNPs) and EDX results showed trace element of O, Si, Ca, K, Fe and S in the CL milled for 72 hours . FTIR was also carried out to determine the nature of bond that exist in the organic compounds in CLNPs and GCMS analysis was used to reveal the organic compounds that were present in CLNPs. Anti-Corrosion coatings reduces corrosion activities to the bearest minimum.
  • Item
    Open Access
    Characteristics of aluminum hybrid composites
    (World Academy of Science, Engineering and Technology International Journal of Chemical, Nuclear, Metallurgical and Materials Engineering, 2014) Adeosun, S.O.; Osoba, L.O.; Taiwo, O.O.
    Aluminum hybrid reinforcement technology is a response to the dynamic ever increasing service requirements of such industries as transportation, aerospace, automobile, marine, etc. It is unique in that it offers a platform of almost unending combinations of materials to produce various hybrid composites. This article reviews the studies carried out on various combinations of aluminum hybrid composite and the effects on mechanical, physical and chemical properties. It is observed that the extent of enhancement of these properties of hybrid composites is strongly dependent on the nature of the reinforcement, its hardness, particle size, volume fraction, uniformity of dispersion within the matrix and the method of hybrid production.
  • Item
    Open Access
    Characteristics of Aluminum Hybrid Composites
    (International Journal of Chemical, Molecular, Nuclear, Materials and Metallurgical Engineering, 2014) Adeosun, S.O.; Osoba, L.O.; Taiwo, O.O.
    Aluminum hybrid reinforcement technology is a response to the dynamic ever increasing service requirements of such industries as transportation, aerospace, automobile, marine, etc. It is unique in that it offers a platform of almost unending combinations of materials to produce various hybrid composites. This article reviews the studies carried out on various combinations of aluminum hybrid composite and the effects on mechanical, physical and chemical properties. It is observed that the extent of enhancement of these properties of hybrid composites is strongly dependent on the nature of the reinforcement, its hardness, particle size, volume fraction, uniformity of dispersion within the matrix and the method of hybrid production.
  • Item
    Open Access
    Characteristics of biodegradable implants
    (Journal of Minerals and Materials Characterization and Engineering, 2014, 2014) Adeosun, S.O.; Lawal, G.I.; Gbenebor, O.P.
    The development of synthetic biomaterials for bone fixations has greatly enhanced orthopedic surgery efficiency over the last two decades. With the advancement in medical technology, several materials such as metals, ceramics, polymers and composites have been considered over the years for possible implantation into the body. These materials however, must have the following required properties that will qualify them as potential medical devices: biocompatibility, mechanical properties, corrosion resistance, creep resistance, etc. The quest in making up for the disadvantages of metallic fixations has culminated in a paradigm shift to the use of biodegradable polymers. Biodegradable polymers are light-weight materials with low elastic moduli between 0.4 - 7 GPa. These materials can be engineered to degrade at rates that will slowly transfer load to the bone. In addition, complications like corrosion, release of metal ions and stress shielding associated with metal implants are eliminated. This review considers studies carried out on most commonly investigated and widely used synthetic biodegradable polymers, their successes and limitations. It also provides process for efficient utilization of these polymers as bone fixtures without inflammation and stress shielding.
  • Item
    Open Access
    Characterization of adhesion surface of cellulosic fibers extracted from agro wastes
    (Journal of Natural Fibers, 2016) Akpan, E.I.; Adeosun, S.O.; Lawal, G.I.; Balogun, S.A.; Chen, D.I.
    The adhesion characteristics of agro waste–derived fibers are examined in this study. Fibers obtained from groundnut shell, coconut shell, rice husk, palm fruit bunch, and palm fruit stalk are subjected to a combination of batch treatments in two distinctive ways. These batch fiber treatments involve mechanical defibrillation, steam explosion, acid hydrolysis, alkaline hydrolysis, and enzymatic hydrolysis. Topography, mean surface roughness, maximum surface roughness, skewness, and morphology of the resulting fibers are characterized using the atomic force microscopy and scanning electron microscopy. Results show that the treatments are effective in removal of noncellulosic materials and smoothening of fiber surface. This phenomenon would results in improvement in wettability between fiber and matrix in polymer composite applications. Palm fruit–derived fibers are found to retain a greater portion of noncellulosic materials compared to others. This is attributed to the high amorphous content of palm fruit with very low crystalline portion compared to others.
  • Item
    Open Access
    Characterization of LDPE reinforced with calcium carbonate—fly ash hybrid filler
    (Journal of Minerals and Materials Characterization and Engineering, 2014) Adeosun, S.O.; Usman, M.A.; Akpan, E.I.; Dibie, W.I.
    The synergetic effect of calcium carbonate (CC)-fly ash (FA) hybrid filler particles on the mechanical and physical properties of low density polyethylene (LDPE) has been investigated. Low density polyethylene is filled with varying weight percentages of FA and CC using melt casting. Composites are characterized for mechanical, thermal, microstructural and physical properties. Results show that the flexural strength increases with increases in FA content of the hybrid filler. It is evident from the study that to achieve optimum density a certain combination of both fillers need to be used. The optimum combination of CC and FA for a higher density (1.78 g/cm3) is found to be at 20 wt% FA and 30 wt% CC. An increase of 7.27% in micro-hardness over virgin polyethylene is obtained in composites with 10 wt% FA and 40 wt% CC. The presence of higher amount of CC is seen to be detrimental to the crystallinity of composites. X-ray, FTIR and DSC results show that composite with 45 wt% CC and 5 wt% FA exhibits a typical triclinic polyethylene structure indicating that the composite is amorphous in nature. There was the synergy between FA and CC fillers on flexural strength and crystallinity of composite. However, the fillers show the antagonistic effect on energy at peak and micro-hardness.
  • Item
    Open Access
    CHARACTERIZATION OF TRAIN BRAKE-BLOCKS COMPOSITE REINFORCED WITH ALUMINUM-DROSS
    (Nigerian Journal of Technology (NIJOTECH), 2020-10) Obidiegwu, Eugenia; Mgbemere, Henry; Ochulor, Ezenwanyi; Ajayi, Paul
    Brake blocks are usually made from asbestos, metals and ceramics. It has been realised that asbestos discharges dangerous gases which can be harmful. This problem necessitated the search for human-friendly materials. Therefore, this paper studies the production and characterization of train brake blocks produced from clay reinforced with aluminum dross. This was done by producing samples of composite using clay from a deposit at Osiele and aluminum dross from Tower Rolling Mill Otta, both in Ogun state. The percentage composition of aluminum dross was varied from 0% to 25% to produce brake samples. Their wear rate, tensile strength, compressive strength, hardness, thermal conductivity and microstructure were analysed. The results from this project such as Ultimate tensile strength (UTS) of 7.4Mpa, Impact energy 6.92J, Hardness 28.8 HV, wear rate 0.0071g/sec and thermal conductivity of 0.01075 indicate that, with 5% aluminium dross it is possible to develop brake block that exhibits property recommended by Rail Industry Safety and Standard Board (RISSB).
  • Item
    Open Access
    Combined effect of cold rolling and heat treatment on the mechanical properties of Al-Ti alloy
    (2014) Adeosun, S.O.; Sekunowo, O.I.; Talabi, S.I.
    This study investigated the combined effect of cold rolling and heat treatment on the mechanical properties of Al-Ti alloy. Samples of the alloy are cast in metal mould to obtain 0.94- 2.19wt% mixes of titanium. These samples are grouped into untreated (as-cast) and those that are cold rolled to fifty percent reduction, homogenized at 5000C and soaked for one hour. The cold rolled and heat treated samples are normalized (RTn) and quenchtempered (RTq-t) at 1000C. All these samples are subjected to tensile, micro-hardness and microstructural evaluation. Results show remarkable improvement in the mechanical properties of the cold rolled and heat treated samples compared to the as-cast. In particular, the RTq-t samples containing titanium in the range of 1.7-2.2% demonstrates improve tensile strength by 24.7%, yield strength, 28%, elastic modulus, 38.3% and micro-hardness, 20.5%. The Al3Ti phase being the most stable precipitate in the α-Al matrix appears to have been responsible for the significant improvement in the alloy’s mechanical properties. It is concluded that quench and temper heat treatment is an effective method of improving the strength-strain ratio of cold rolled Al-.0.9-2.2%Ti alloy.
  • Item
    Open Access
    A Comparative Analysis of Three Optimisation Approaches to Free Swell Characterisation of Particulate Coconut Shell Reinforcement Composite Material
    (Faculty of Engineering, Chulalongkorn University, Phayathai Road, Pathumwan, Bangkok 10330, Thailand, 2015) Ajibade O.A.; Agunsoye J.O.; Oke S.A.
    There is paucity of data relating to the free swell properties of composite reinforcement materials in outdoor applications despite the widely-debated need for more investigations in this area. In this paper, a comparative performance analysis of three optimisation models - Taguchi method, simplex algorithm and Taguchi-simplex method - is pursued. We used experimental data of 0.600 mm particulate coconut shell with the theories behind L27 (311) orthogonal arrays, to achieve our aim for the Taguchi method. The simplex algorithm required modelling the free swell problem as the objective function subject to parametric constraints defined by the factors and their respective levels. For the Taguchi-simplex method, the S/N ratios and the optimal parametric setting of the Taguchi method were used to model the objective function and the new constraints that the simplex algorithm optimised. Parameters include initial and final volumes of coconut shell particulates (CSPs), mass of water, volumes of CSPs and water as well as mass of CSPs. The optimised initial and final volumes were 10 and 34 cm3 (Taguchi), 20 and 34 cm3 (simplex) and 16.6 and 24.82 cm3 (Taguchi-simplex). The optimal masses of water were 141.54, 146.81 and 89.12 g while the volumes of CSPs and water were 152, 152 and 106.4 cm3, and the mass of CSPs were 12.07, 12.07 and 6.28 g for Taguchi, simplex and Taguchi-simplex methods, respectively. Confirmatory test validated the results. In conclusion, the optimum parametric setting of the Taguchi-simplex method was the best.