Department of Mechanical Engineering

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    Chemical and Mechanical Properties of Reinforcing Steel Bars from Local Steel Plants
    (Springer, 2019-06-06) Jamiu Kolawole Odusote; Wasiu Shittu; Adekunle Akanni Adeleke; Peter Pelumi Ikubanni; Olumide Adeyemo
    Steel bars are important engineering materials for structural application. In Nigeria, due to incessant building collapse occurrences, it is important to further investigate some of the mechanical and chemical properties of reinforcing steel bars produced from scrap metals in order to ascertain their compliance with the required standard. Three diameters (10, 12 and 16 mm) of the reinforcing steel bars were chosen from each of the eight steel plants (A–H). Chemical composition analyses and mechanical tests (yield strength, ultimate tensile strength and percentage elongation) were performed using optical emission spectrometer and Instron Satec Series 600DX universal testing machine, respectively. Hardness values of the samples were obtained by conversion of tensile strength based on existing correlation. The results showed that carbon contents, hardness values, yield and ultimate tensile strengths of some of the steel bars were found to be higher than the BS4449, NIS and ASTM A706 standards. The steel bar samples were also found to possess good ductility with samples from steel plants C and D. By observation, all the 12 mm steel bars from steel plants A to H met the required ASTM and BS4449 standards except samples from plant G. This study revealed that most of the investigated reinforcing steel bars have reasonable yield strength, ultimate tensile strength, ductility and hardness properties when compared with the relevant local and international standards. Therefore, they are suitable for structural applications where strength and ductility will be of paramount interest
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    Effect of copper addition and solution heat treatment on the mechanical properties of aluminum alloy using formulated bio-quenchant oils
    (Engineering and Applied Science Research, 2020-01-01) Adekunle A.S.; Adekunle Akanni Adeleke; Peter Pelumi Ikubanni; Omoniyi P. O.; Gbadamosi T. A.; Jamiu Kolawole Odusote
    Addition of copper and use of solution heat treatment solution with bio degradable vegetable oils as quenchants has great potential to improve the mechanical properties of aluminum and its alloys. In this study, copper was added to as-received Al- Si-Mg alloy to produce Al-Si-Cu-Mg alloy. The specimens were quenched with blended bleached bio-quenchant oils and a petroleum-based oil after solution heat treatment. The alloy was heat treated at 500℃, soaked for 20 minutes in a muffle furnace before quenching in the formulated bio-quenchant oils. The cooling properties, mechanical properties and microstructure of the solution treated specimens were determined. Blended bleached melon (BBM) oil was observed to have offered a higher cooling rate of 49.3 ℃ s-1 compared to the petroleum-based (PB) oil with a cooling rate of 25.8 ℃ s-1. Blended bleached melon oil exhibited the highest quench severity value of 1.0074 m-1, while petroleum-based oil was 0.6133 m-1. The as-received alloy and as-cast alloy specimens exhibited tensile strength values of 125.33 and 131.37 N mm-2, respectively, while a higher tensile strength value of 139.30 Nmm-2 was obtained using the blended bleached melon oil. The highest Rockwell hardness number, 61.00 HRB, was obtained using blended bleached melon oil. The overall mechanical properties of specimens improved after the addition of copper and heat treatment in various bio-quenchant oils
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    Microstructural assessment of AISI 1021 steel under rapid cyclic heat treatment process
    (Elsevier, 2019-10-13) Adekunle Akanni Adeleke; Peter Pelumi Ikubanni; T. A. Orhadahwe; J.O. Aweda; Jamiu Kolawole Odusote; O.O. Agboola
    This research was aimed at using image analysis to describe the effects of rapid cyclic heating on mild steel. AISI 1021 steel sample used in this study was subjected to quenching heat treatment followed by 1, 2, 3, and 4-cycles of rapid heat treatment. The as-treated steel samples were characterized by Brinell hardness tests, Charpy V-notch impact tests, optical microscopy, and image analysis using Image J software. The results revealed that the grain size decreased from 1.07 μm in the control sample to 0.79 μm in the third cycle sample and increased to 0.86 μm in the fourth cycle sample. However, the results revealed that two-cycles of rapid heat treatment was enough to produce ultra-fine grains and impact ductility in mild carbon steel. Keywords: Mechanical properties, Collapsed building, Steel rods, Chemical compositions, Percentage elongation
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    Magnesium inclusion effect on Al-Zn-Cu alloys: A study on microstructure and mechanical properties
    (Elsevier, 2021-04-14) Jamiu Kolawole Odusote; Adekunle Akanni Adeleke; S.A. Muraina; Peter Pelumi Ikubanni; Ibrahim Momoh-Bello Omiogbemi
    The microstructure and mechanical properties of Al-Zn-Cu alloy with magnesium inclusion varying between 0.5 and 1.5 wt% were explored in this investigation. Al-Zn-Cu-Mg alloy was prepared by sand casting. Heat-treatment was done on the cast alloy samples at 460 °C for 2 h, which was then water-quenched. The samples at 160 °C were age-hardened for 5 h. Mechanical tests were done on both the heat-treated and as-cast alloy samples. Optical and scanning electron microscopy were used for the surface morphology of the samples. The maximum tensile strength (178.04 N/mm2) and hardness value (42.49 HB) were obtained from the Al-Zn-Cu-Mg alloy samples with 0.33 wt% Mg and 0.001 wt% Mg, respectively. In the as-cast samples, the reinforcing intermetallic phases present was coarse in nature while the precipitation hardened samples showed well-distributed reinforcing intermetallic phases which are fine grain size. Hence, the tensile strength of the cast Al-Zn-Cu-Mg alloy was positively influenced with the addition of magnesium while precipitation hardening eliminates micro segregations, thus, Al-Zn-Cu-Mg alloy mechanical properties were improved. Thus, the Al-Zn-Cu-Mg alloy can be useful in automobile industry.