Browsing by Author "Afolalu, S.A."

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    Chip Morphological Behaviour During Machining Of Ti-6Al-4V Using Refrigerated Soluble Oil
    (IOP Conference Series: Materials Science and Engineering, 2021-08) Ogedengbe, T.S.; Abdulkareem, S.; Afolalu, S.A.; Ibitoye, S.O.
    Chips formed during machining are a vital instrument for the assessment both of machinability of material and the effectiveness of the machining method adopted. Various approaches have been proposed by researchers to make machining Ti-6Al-4V easier, ranging from reduction of cutting speed and feed rate to the use of coolant during machining. In this study, investigatation of the effect of refrigerated soluble oil on machinability of Ti-6Al-4V via monitoring of the chips formed during the various machining processes was carried out. The chips formed for various machining conditions were collected using a designed chip receptor medium and was analyzed using a metallographic microscope with an attached stylus. The experiment was planned using central composite designs (CCD) of the Response Surface Methodology (RSM) resulting in a 20 experimental run plan for dry and wet machining. Machining factors considered were cutting speed, feed rate, depth of cut and coolant temperature with corresponding values 40-120 m/min, 0.05-0.20 mm/rev, 0.2-1.0 mm and 5-11°C respectively. Responses monitored chip thickness, tooth profile and peak height. The effect of various factors on responses were discussed. Basically, results show that chip diameter increased with an increase in cutting speed. However, the sawtooth profile on chip reduced with an increase in cutting speed. It was therefore concluded that coolant temperature has an effect on chip morphology during machining of Ti-6Al-4V using refrigerated coolant.
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    Numerical Simulation of Axisymmetric and Asymmetric Extrusion Process Using Finite Element Method
    (International Journal of Scientific & Engineering Research, 2015-06-01) Oyinbo, S.T.; Ikumapayi, O.M.; Ajiboye, J.S.; Afolalu, S.A.
    The deformation load is the most important parameter in the press design. The flow of metal, consequently load, is largely influenced by the geometry of the die and hence the geometric shape of the tools is the main factor by which an optimum load can be developed. In extrusion process the strain distribution, resulting from deformation load, and other important variables that influence material structure, such as a hydrostatic stress, are strongly dependent on the geometry of the die. In the present investigation using linearly converging die profiles, the extrusion of simple and advanced polygons such as circular, square, triangular, hexagonal, heptagonal, octagonal, L-, T-, and H- sections from round billet have been numerically simulated. Mathematical equations describing the die profiles were evaluated. A solid CAD model for the linearly converging die profile was made using Autodesk Inventor 2013 software and numerical analysis using DEFORM 3D software for extrusion of the above sections from round billet was then performed to determined, for dry and lubricated condition, the load prediction, effective stress, effective strain, strain rate, velocity and temperature distribution during the deformation. It is found that the predictive loads for advance (asymmetric) shapes are found to be higher than that of the simple shapes. While there is no marked difference between the predictive load for simple (axisymmetric) shapes, the L-section has the highest extrusion load, followed by T-section and the H-section given the least pressure.