Tajudeen Ajiboye - Academia.edu (original) (raw)
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The importance of various form of heat treatment operations on medium carbon steel in order to fo... more The importance of various form of heat treatment operations on medium carbon steel in order to forester the problem that may arise in making a wrong choice of these steel materials or faulty heat treatment operations which may give rise to serious disruption in terms of human safety, higher cost and untimely failure of the machine components is of great concern. The mechanical properties such as ductility, toughness, strength, hardness and tensile strength can easily be modified by heat treating the medium carbon steel to suit a particular design purpose. Tensile specimens were produced from medium carbon steel and were subjected to various forms of heat treatment processes like annealing, normalizing, hardening and tempering. The stiffness, ductility, ultimate tensile strength, yield strength and hardness of the heat treated samples were observed from their stress-strain curve. The value of the yield strength (σ y ) was observed to be higher for the tempered specimen possibly as a result of the grain re-arrangement, followed by the hardened, normalized and annealed specimens. The value of the ultimate tensile strength (σ u ) were also observed to be in the order; hardened> tempered>normalized>annealed.
Samples of medium carbon steel were examined after heating between 900ºC-980ºC and soaked for 45 ... more Samples of medium carbon steel were examined after heating between 900ºC-980ºC and soaked for 45 minutes in a muffle furnace before quenching in palm oil and water separately. The mechanical behavior of the samples was investigated using universal tensile testing machine for tensile test and Vickers pyramid method for hardness testing. The microstructure of the quenched samples was studied using optical microscope. The tensile strength and hardness values of the quenched samples were relatively higher than those of the as-cast samples, suggesting improved mechanical properties. However, samples quenched in palm oil displayed better properties compared with that of water-quenched samples. This behavior was traced to the fact that the carbon particles in palm oil quenched samples were more uniform and evenly distributed, indicating the formation of more pearlite structure, than those quenched in water and the as-received samples.
The needs in the highly challenging environment for organizational competitiveness with respect t... more The needs in the highly challenging environment for organizational competitiveness with respect to cost, quality services and on-time deliveries through optimum machine functionality, guaranteed long-term stability, increases in productivity and system reliability have contributed to new interest in maintenance planning and assessment. The research work is aimed at developing window based design software that combines flexibility with user interface for maintenance planning and assessment. The Computer Aided Design (CAD) model developed assesses and compares the maintenance plans based on three major parameters which are: the periodicity of the maintenance plans, the equivalent time before full resetting for the maintenance plans and the graph of complexities against time for the plans. The impute parameters are: the preventive maintenance frequency (PF), the preventive maintenance level (PL), the repair level (µ), the number of days the machine operates in a week (D), and failure rate (λ). The plan with higher periodicity is preferred. This indicates that it is more capable of reducing the system complexity which makes it more stable and also an indication that the functional requirements will be satisfied. The preventive maintenance (PM) plans adopted by a construction company in Nigeria was used to illustrate the application of the proposed new CAD model developed.
Nigeria's electricity demand increases due to growth in industrialization and socioeconomic weigh... more Nigeria's electricity demand increases due to growth in industrialization and socioeconomic weight. Regrettably, power industry of the country has not been able to satisfy the need of their customers. Therefore, if the country is to meet its energy demand alternative sources of power generation are very essential. Opportunities abound in hydropower scheme development as a viable energy source of electricity which will curtail and minimize greenhouse gases and emissions into environment. Meanwhile, there are small rivers all over the country with potential sites suitable for small hydropower scheme, development of which will ensure the supply of electricity to remote communities. This can be used as a substitute for commercial fuels, which effect reduce cost of fuelling and raise the earning potential of the rural communities.
The importance of various form of heat treatment operations on medium carbon steel in order to fo... more The importance of various form of heat treatment operations on medium carbon steel in order to forester the problem that may arise in making a wrong choice of these steel materials or faulty heat treatment operations which may give rise to serious disruption in terms of human safety, higher cost and untimely failure of the machine components is of great concern. The mechanical properties such as ductility, toughness, strength, hardness and tensile strength can easily be modified by heat treating the medium carbon steel to suit a particular design purpose. Tensile specimens were produced from medium carbon steel and were subjected to various forms of heat treatment processes like annealing, normalizing, hardening and tempering. The stiffness, ductility, ultimate tensile strength, yield strength and hardness of the heat treated samples were observed from their stress-strain curve. The value of the yield strength (σ y ) was observed to be higher for the tempered specimen possibly as a result of the grain re-arrangement, followed by the hardened, normalized and annealed specimens. The value of the ultimate tensile strength (σ u ) were also observed to be in the order; hardened> tempered>normalized>annealed.
Samples of medium carbon steel were examined after heating between 900ºC-980ºC and soaked for 45 ... more Samples of medium carbon steel were examined after heating between 900ºC-980ºC and soaked for 45 minutes in a muffle furnace before quenching in palm oil and water separately. The mechanical behavior of the samples was investigated using universal tensile testing machine for tensile test and Vickers pyramid method for hardness testing. The microstructure of the quenched samples was studied using optical microscope. The tensile strength and hardness values of the quenched samples were relatively higher than those of the as-cast samples, suggesting improved mechanical properties. However, samples quenched in palm oil displayed better properties compared with that of water-quenched samples. This behavior was traced to the fact that the carbon particles in palm oil quenched samples were more uniform and evenly distributed, indicating the formation of more pearlite structure, than those quenched in water and the as-received samples.
The needs in the highly challenging environment for organizational competitiveness with respect t... more The needs in the highly challenging environment for organizational competitiveness with respect to cost, quality services and on-time deliveries through optimum machine functionality, guaranteed long-term stability, increases in productivity and system reliability have contributed to new interest in maintenance planning and assessment. The research work is aimed at developing window based design software that combines flexibility with user interface for maintenance planning and assessment. The Computer Aided Design (CAD) model developed assesses and compares the maintenance plans based on three major parameters which are: the periodicity of the maintenance plans, the equivalent time before full resetting for the maintenance plans and the graph of complexities against time for the plans. The impute parameters are: the preventive maintenance frequency (PF), the preventive maintenance level (PL), the repair level (µ), the number of days the machine operates in a week (D), and failure rate (λ). The plan with higher periodicity is preferred. This indicates that it is more capable of reducing the system complexity which makes it more stable and also an indication that the functional requirements will be satisfied. The preventive maintenance (PM) plans adopted by a construction company in Nigeria was used to illustrate the application of the proposed new CAD model developed.
Nigeria's electricity demand increases due to growth in industrialization and socioeconomic weigh... more Nigeria's electricity demand increases due to growth in industrialization and socioeconomic weight. Regrettably, power industry of the country has not been able to satisfy the need of their customers. Therefore, if the country is to meet its energy demand alternative sources of power generation are very essential. Opportunities abound in hydropower scheme development as a viable energy source of electricity which will curtail and minimize greenhouse gases and emissions into environment. Meanwhile, there are small rivers all over the country with potential sites suitable for small hydropower scheme, development of which will ensure the supply of electricity to remote communities. This can be used as a substitute for commercial fuels, which effect reduce cost of fuelling and raise the earning potential of the rural communities.