The use of waste materials to produce engineering components is currently attracting so much interest due to their low cost, availability and environmental impact. In this study, coconut shell ash (CSA) and kyanite pa...The use of waste materials to produce engineering components is currently attracting so much interest due to their low cost, availability and environmental impact. In this study, coconut shell ash (CSA) and kyanite particles (KP) produced from coconut shells and kyanite mineral respectively were characterized. X-ray Florence (XRF), X-ray diffractometer (XRD) and scanning electron microscope (SEM) were used to analyze the oxide compositions, crystalline phases and microstructures of CSA and KP. The XRF analysis revealed major oxides in CSA and KP as SiO2 and Fe2O3;and Al2O3 and SiO2 respectively. The XRD analysis revealed the presence of Quartz, Hematite, Andradite and Gaultite phases at major peaks in diffractogram of CSA;and Quartz and Beryl phases at major peaks in the diffractogram of KP. The crystallite sizes of the quartz phases in CSA and KP at diffraction angle of 26.72°C and 20.91°C were determined as 638.28 Åand 789.38 Årespectively. From the SEM image of CSA, it was observed that particles of different sizes are present in the microstructure of CSA. The average size of the particles in the microstructure of CSA is 26.24 μm. A similar result was observed in the SEM image of KP and average size of the particles is 3.074 μm. Also, the energy dispersive X-ray (EDX) spectrums of CSA and KP revealed the presence of many elements with calcium as the major element in CSA and Aluminium as major element in KP. The presence of the crystalline phases in CSA (SiO2, Al2O3, andradite, gaultite and hematite) and KP (SiO2 and Al2O3) will make them good strengthening materials for the production of Aluminium based composites that can be used in applications where a good combination of strength and wear characteristics is a basic requirement like brake disc.展开更多
This study adopts the Dantzig’s Simplex method to investigate optimization of sand casting parameters for optimum service performance. Some process variables and mechanical properties were adapted into the Simplex me...This study adopts the Dantzig’s Simplex method to investigate optimization of sand casting parameters for optimum service performance. Some process variables and mechanical properties were adapted into the Simplex method. Aluminium alloy samples were cast, machined and subjected to a series of mechanical tests. From the body of data collected, linear functions and constraint equations were formulated and employed in the Dantzig’s Simplex method for optimization of process parameters. The results showed that the Simplex method can be adapted for studying performance opti- mization of castings.展开更多
文摘The use of waste materials to produce engineering components is currently attracting so much interest due to their low cost, availability and environmental impact. In this study, coconut shell ash (CSA) and kyanite particles (KP) produced from coconut shells and kyanite mineral respectively were characterized. X-ray Florence (XRF), X-ray diffractometer (XRD) and scanning electron microscope (SEM) were used to analyze the oxide compositions, crystalline phases and microstructures of CSA and KP. The XRF analysis revealed major oxides in CSA and KP as SiO2 and Fe2O3;and Al2O3 and SiO2 respectively. The XRD analysis revealed the presence of Quartz, Hematite, Andradite and Gaultite phases at major peaks in diffractogram of CSA;and Quartz and Beryl phases at major peaks in the diffractogram of KP. The crystallite sizes of the quartz phases in CSA and KP at diffraction angle of 26.72°C and 20.91°C were determined as 638.28 Åand 789.38 Årespectively. From the SEM image of CSA, it was observed that particles of different sizes are present in the microstructure of CSA. The average size of the particles in the microstructure of CSA is 26.24 μm. A similar result was observed in the SEM image of KP and average size of the particles is 3.074 μm. Also, the energy dispersive X-ray (EDX) spectrums of CSA and KP revealed the presence of many elements with calcium as the major element in CSA and Aluminium as major element in KP. The presence of the crystalline phases in CSA (SiO2, Al2O3, andradite, gaultite and hematite) and KP (SiO2 and Al2O3) will make them good strengthening materials for the production of Aluminium based composites that can be used in applications where a good combination of strength and wear characteristics is a basic requirement like brake disc.
文摘This study adopts the Dantzig’s Simplex method to investigate optimization of sand casting parameters for optimum service performance. Some process variables and mechanical properties were adapted into the Simplex method. Aluminium alloy samples were cast, machined and subjected to a series of mechanical tests. From the body of data collected, linear functions and constraint equations were formulated and employed in the Dantzig’s Simplex method for optimization of process parameters. The results showed that the Simplex method can be adapted for studying performance opti- mization of castings.
