This study included the experimental production and investigation of the mechanicalproperties of ... more This study included the experimental production and investigation of the mechanicalproperties of paving tiles produced from a mixture of laterite, silica sand, pulverized cow bones,and cement. Empirical models of compressive and flexural strength were also developed andherein presented for the paving tiles. The maximum compressive strength of the paving tiles wereobtained for 20, 15, and 10% cement content as 5.05, 5.05 and 3.08 MPa, while the maximumflexural strength for similar values of cement content were obtained as 1.83, 1.21 and 0.26 MParespectively. The results indicate that there was no noticeable difference in the values of thecompressive strength at 20 and 15% cement content, while a sharp reduction of the mechanicalproperties was experienced as the cement content reduces from 15 to 10%. Recommendedcomposition for paving tiles with pulverized cow bones composite is cement, 15%; pulverized cowbones, 30%; laterite 35% and silica sand, 20% respectively. Sustainable productio...
This research was aimed at using image analysis to describe the effects of rapid cyclic heating o... more 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 Vnotch 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.
European Journal of Materials Science and Engineering, 2021
Simulation of welding temperature fields during TIG arc the welding process of Cr-Mo steel bar (A... more Simulation of welding temperature fields during TIG arc the welding process of Cr-Mo steel bar (ASTM A304) was studied. The results of Simulation models of welding processes help to predict welding parameters effects on the temperature field during and after welding and by this, the failure rate could be estimated and minimized. This paper presents the welding profile model, assembled from 100 mm by 50 mm by 20 mm thick, a Double-Sided Half V-Groove Weld Joint, moving heat source was employed to methodically examine welding temperature fields and transformation in the single-pass butt-welded joint. Unfortunately, the precision of the model rests on many parameters, which cannot be precisely dictated. To resolve this proposition, a calibration process was made by using a Datalogger type K thermocouple-3 channel-LU-MTM-380SD during the welding process on Cr-Mo steel bar. The obtained Experimental results were used as input to run the simulation. Depending on weld joint profile, temperature fields were discovered to vary with distance from the weld centerline which altered the yield stress of weld metal. To realize this goal, a pattern of the 3D model of heat transfer with a moving heat source during welding was simulated in Autodesk Inventor Simulation CFD 2018 Application Software. The results shown that the welding temperature fields have a higher value at the welding center line and decreased towards the edges of the bar. An indication that simulation is a veritable tool to access likely consequence of the welding process at both welded and non-welded portions of steel bar before real machine structural development.
The corresponding qualitative wellness (health) by the residents and roadside businesses around a... more The corresponding qualitative wellness (health) by the residents and roadside businesses around a motorized urban arterial was reported. The traffic sound level manifesting on the nodes and links was quantified by the equivalent noise level (Leq) of 73.5 dB (A), a value that is higher than the WHO (World Health Organization) allowable threshold for the comfort and wellness of residential communities was obtained. The perception of the dwellers around the studied arterial about the prevailing traffic induced noise pollution agreed with the common health stress indicators of headache, insomnia and annoyance, among others. It is recommended that the Nigerian noise level bench mark of 90 dB (A) be reviewed to a lower value in order to reflect the global best practices on noise pollution control and wellness of human dwellers around a motorised corridor.
The study is focused on using an image analysis to explain the effects of several cycles of rapid... more The study is focused on using an image analysis to explain the effects of several cycles of rapid heat treatment on the microstructure of 0.213 wt. % carbon steel. The samples examined are subjected to a diffusional heat treatment followed by several cycles of a rapid heat treatment. The process of the diffusional heat treatment involves heating the samples from an ambient temperature to 850oC in an electric muffle furnace for 56 min and then quenching in running water. In order to improve further the mechanical properties of the heat treated samples, they are subjected to several cycles of rapid heating. Each cycle comprises preheating the furnace to 900oC prior to the samples charging. The treated samples are subjected to a microstructural examination using optical microscopy followed by an image analysis using Image J software. The mechanical properties of the heat treated samples are characterized through ultimate tensile, hardness and impact tests. The results reveal that the g...
This study considers the effect of ferrosilicon manganese addition to austempered ductile iron, (... more This study considers the effect of ferrosilicon manganese addition to austempered ductile iron, (ADI) in order to reduce its sulphur level for improved engineering applications of the material. The cast samples were austenitised in a mixture of potassium chloride, sodium chloride and barium chloride solutions and austempered in sodium nitrate and potassium nitrate solutions. Ferrosilicon manganese was added to ADI in various amounts ranging from between 47 to 326 g. The study revealed that the sulphur level retained in ADI decreased from 0.088 wt % for as-cast to 0.027 wt % when 93 g of ferrosilicon manganese was added. Below this amount of ferrosilicon manganese addition, there was no significant reduction in the sulphur level recorded in ADI. The microstructure of the metal revealed bigger graphite nodules scattered in ferrite solutions for the situation when the sulphur level was 0.027 wt. %. From the study, it was discovered that addition of small amount of ferrosilicon manganese was required to produce ADI of low level sulphur content to make the metal more acceptable for other engineering applications.
This study considers the effect of ferrosilicon manganese addition to austempered ductile iron, (... more This study considers the effect of ferrosilicon manganese addition to austempered ductile iron, (ADI)in order to reduce its sulphur level for improved engineering applications of the material. The cast samples were austenitised in a mixture of potassium chloride, sodium chloride and barium chloride solutions and austempered in sodium nitrate and potassium nitrate solutions. Ferro-silicon-manganese was added to ADI in various amounts ranging from between 47 to326 g. The study revealed that the sulphur level retained in ADI decreased from 0.088 wt % for as-cast to 0.027 wt% when 93 g of ferro-silicon-manganese was added. Below this amount of ferro-silicon-manganese addition, there was no significant reduction in the sulphur level recorded in ADI. The microstructure of the metal revealed bigger graphite nodules scattered in ferrite solutions for the situation when the sulphur level was 0.027 wt. %. From the study, it was discovered that addition of small amount of ferrosilicon manganes...
IOP Conference Series: Materials Science and Engineering
The effect of subjecting mild steel to several cycles of rapid heat treatment on its mechanical p... more The effect of subjecting mild steel to several cycles of rapid heat treatment on its mechanical properties and microstructure was investigated. Mild steel of 0.213 wt % carbon was subjected to transformation heat treatment from austenite to pearlite and quenched in running water. Rapid heating was achieved by preheating an electric muffle furnace to 840 oC before charging the samples into it. Each cyclic heat treatment was for a period of 200 seconds held at 840 0C and cooled to 700 0C which was repeated four times. The effects of cycle numbers were evaluated by testing for impact, hardness, ultimate tensile strength and microstructural properties. The results showed that after 4th cycle of rapid heating the samples had impact energy 64.6 J, Brinell hardness number 563 and ultimate tensile strength 1257.78 N/mm2. The samples after one cycle had ultimate tensile strength 1027.45 N/mm2, % elongation 10.396% and impact energy 286.174 N.m before failure. Through cyclic heating, grain refinement was achieved by the fast simultaneous nucleation at the grain boundaries and the fast martensite to austenite transformation due to the fast heating rate which prevented austenite grain growth. Mechanical properties of the studied steel sample were improved with the rapid heat treatment cycles given.
The effects of applied pressure and die pre-heat temperature on the electrical conductivity of sq... more The effects of applied pressure and die pre-heat temperature on the electrical conductivity of squeeze cast aluminium rods were experimentally investigated and presented. The results show that applied pressure and die temperature have significant and positive effects on the electrical properties of squeeze cast aluminium rods up to certain levels. With increase in applied pressure, there is a steady increase in the electrical conductivity up to a pressure level of 105MPa, which gives a maximum value of electrical conductivity. Increasing the values of the applied pressure further leads to a decrease in the electrical conductivity up to a pressure of 150MPa. Beyond this pressure, increase in applied pressure has no significant effect on the values of electrical conductivities. With die pre-heating, electrical conductivity increases with increase in die temperature, reaching a maximum value at die temperature of 150 0 C. Further increase in the die temperature beyond 150 0 C leads to ...
Zinc is a non-ferrous metal with potential application in orthopaedic implant materials. However,... more Zinc is a non-ferrous metal with potential application in orthopaedic implant materials. However, its poor mechanical properties were major challenge to its application. Therefore, this paper studies the mechanical properties of biodegradable Zn-based alloy for biomedical application. Pure zinc powder with varying (0, 1, 2, 3 & 6) wt% of magnesium powders were ball milled using ball-topowder ratio (B:P) of 10:1 at 350 rpm for 4 hours. The resulting milled powders were compacted and sintered at 300 MPa and 350 °C respectively. Microstructural, phase and mechanical properties analyses were performed following American standard of testing and measurement. The results show that magnesium has influence on the mechanical properties of zinc. The compressive strength, hardness and elastic modulus of 210 ± 8.878 MPa, 76 ± 5.707 HV and 45 ± 11.616 GPa respectively as obtained in Zn-2Mg alloy were optimum and meet the minimum requirement of biodegradable metal for orthopaedics application. These results indicate an increase of 111, 93 and 93% in compressive strength, hardness and elastic modulus respectively as compared to pure zinc. The increase in mechanical properties was adduced to effectiveness of compaction pressure and intermetallic phase formation within the matrix resulting in high dislocation density for improving strength. The study concluded that, Zn-2Mg alloy with optimum mechanical properties can therefore be considered a potential candidate for orthopaedic application.
This study considers the effect of ferrosilicon manganese addition to austempered ductile iron, (... more This study considers the effect of ferrosilicon manganese addition to austempered ductile iron, (ADI) in order to reduce its sulphur level for improved engineering applications of the material. The cast samples were austenitised in a mixture of potassium chloride, sodium chloride and barium chloride solutions and austempered in sodium nitrate and potassium nitrate solutions. Ferrosilicon manganese was added to ADI in various amounts ranging from between 47 to 326 g. The study revealed that the sulphur level retained in ADI decreased from 0.088 wt % for as-cast to 0.027 wt % when 93 g of ferrosilicon manganese was added. Below this amount of ferrosilicon manganese addition, there was no significant reduction in the sulphur level recorded in ADI. The microstructure of the metal revealed bigger graphite nodules scattered in ferrite solutions for the situation when the sulphur level was 0.027 wt. %. From the study, it was discovered that addition of small amount of ferrosilicon manganes...
Permanent steel mold was designed, machined and evaluated by monitoring the temperature of squeez... more Permanent steel mold was designed, machined and evaluated by monitoring the temperature of squeeze cast aluminum and brass rods on a Vega hydraulic press. The operation was performed with and without pressure on the cast specimen at pouring temperature of 700 0 C and 980 0 C for aluminum and brass metals, respectively. The solidification rate (temperature with time) was monitored with a three-channel digital temperature monitor data logger while the tensile strengths of both samples were also determined. The results showed an increase in the solidification rate for both samples with increase in the applied pressure. The maximum solidification rate for aluminum was obtained at an applied pressure of 127 MPa and 95 MPa for brass. The tensile strength of both samples increased with increase in applied pressure. The maximum tensile strength of 34.38 MPa was obtained for aluminum at applied pressure of 127 MPa and 80.21 MPa for brass at an applied pressure of 95 MPa. Above these values t...
Effects of applied pressures and die pre-heat temperatures on the heat transfer coefficients of a... more Effects of applied pressures and die pre-heat temperatures on the heat transfer coefficients of aluminium were determined using the solidification temperature histories of the cast metal. The heat transfer coefficients at the cast metal/steel mould interface during solidification of squeeze cast aluminium were investigated using the inverse heat conduction method. The heat transfer coefficients were determined by both experimental and numerical methods. The results show an increase in the value of heat transfer coefficients with applied pressure and a decrease with high die pre-heat temperatures. The numerical heat transfer coefficients were in good agreement with the experimental values.
The effects of parameters such as applied pressure, die pre-heat temperature, delay time and rete... more The effects of parameters such as applied pressure, die pre-heat temperature, delay time and retention time of applied pressure on the temperature distributions within the casting have been considered. The results using this method were compared with those of experimental and heat transfer differential equations’ methods and found to be about 1.7% higher in value. The semi-empirical equations’ method can be used to predict the temperature distribution of other metals and alloys at any location, if the empirical equations relating the heat transfer coefficients to applied pressures and solidifying temperatures for their three stages of solidification are known.
International Journal of Engineering Materials and Manufacture
High temperature generated and stresses induced as a result of turning of Ti6Al4V results in poor... more High temperature generated and stresses induced as a result of turning of Ti6Al4V results in poor surface finish. The aim of this study was to investigate the effect of coolant temperature on the surface roughness of Ti6Al4V which is a core material used as an implant. A cooling system was developed to reduce the temperature of the coolant (soluble oil) from room temperature to 2oC. Ti6Al4V was turned in dry and cooled (at temperatures 5, 7, 9 and 11 oC) conditions. The experiment was designed using central composite design of (Response surface methodology) Design Expert 11.0 to generate an array and optimize the machining parameters. The machining parameters used were cutting speed, feed rate, depth of cut and coolant temperature. Results analyses show that cutting speed and depth of cut had considerable effect on surface roughness of Ti6Al4V. Surface roughness reduced when coolant temperature was reduced. The results of this study shows that turning Ti6Al4V at a very low cutting t...
This study included the experimental production and investigation of the mechanicalproperties of ... more This study included the experimental production and investigation of the mechanicalproperties of paving tiles produced from a mixture of laterite, silica sand, pulverized cow bones,and cement. Empirical models of compressive and flexural strength were also developed andherein presented for the paving tiles. The maximum compressive strength of the paving tiles wereobtained for 20, 15, and 10% cement content as 5.05, 5.05 and 3.08 MPa, while the maximumflexural strength for similar values of cement content were obtained as 1.83, 1.21 and 0.26 MParespectively. The results indicate that there was no noticeable difference in the values of thecompressive strength at 20 and 15% cement content, while a sharp reduction of the mechanicalproperties was experienced as the cement content reduces from 15 to 10%. Recommendedcomposition for paving tiles with pulverized cow bones composite is cement, 15%; pulverized cowbones, 30%; laterite 35% and silica sand, 20% respectively. Sustainable productio...
This research was aimed at using image analysis to describe the effects of rapid cyclic heating o... more 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 Vnotch 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.
European Journal of Materials Science and Engineering, 2021
Simulation of welding temperature fields during TIG arc the welding process of Cr-Mo steel bar (A... more Simulation of welding temperature fields during TIG arc the welding process of Cr-Mo steel bar (ASTM A304) was studied. The results of Simulation models of welding processes help to predict welding parameters effects on the temperature field during and after welding and by this, the failure rate could be estimated and minimized. This paper presents the welding profile model, assembled from 100 mm by 50 mm by 20 mm thick, a Double-Sided Half V-Groove Weld Joint, moving heat source was employed to methodically examine welding temperature fields and transformation in the single-pass butt-welded joint. Unfortunately, the precision of the model rests on many parameters, which cannot be precisely dictated. To resolve this proposition, a calibration process was made by using a Datalogger type K thermocouple-3 channel-LU-MTM-380SD during the welding process on Cr-Mo steel bar. The obtained Experimental results were used as input to run the simulation. Depending on weld joint profile, temperature fields were discovered to vary with distance from the weld centerline which altered the yield stress of weld metal. To realize this goal, a pattern of the 3D model of heat transfer with a moving heat source during welding was simulated in Autodesk Inventor Simulation CFD 2018 Application Software. The results shown that the welding temperature fields have a higher value at the welding center line and decreased towards the edges of the bar. An indication that simulation is a veritable tool to access likely consequence of the welding process at both welded and non-welded portions of steel bar before real machine structural development.
The corresponding qualitative wellness (health) by the residents and roadside businesses around a... more The corresponding qualitative wellness (health) by the residents and roadside businesses around a motorized urban arterial was reported. The traffic sound level manifesting on the nodes and links was quantified by the equivalent noise level (Leq) of 73.5 dB (A), a value that is higher than the WHO (World Health Organization) allowable threshold for the comfort and wellness of residential communities was obtained. The perception of the dwellers around the studied arterial about the prevailing traffic induced noise pollution agreed with the common health stress indicators of headache, insomnia and annoyance, among others. It is recommended that the Nigerian noise level bench mark of 90 dB (A) be reviewed to a lower value in order to reflect the global best practices on noise pollution control and wellness of human dwellers around a motorised corridor.
The study is focused on using an image analysis to explain the effects of several cycles of rapid... more The study is focused on using an image analysis to explain the effects of several cycles of rapid heat treatment on the microstructure of 0.213 wt. % carbon steel. The samples examined are subjected to a diffusional heat treatment followed by several cycles of a rapid heat treatment. The process of the diffusional heat treatment involves heating the samples from an ambient temperature to 850oC in an electric muffle furnace for 56 min and then quenching in running water. In order to improve further the mechanical properties of the heat treated samples, they are subjected to several cycles of rapid heating. Each cycle comprises preheating the furnace to 900oC prior to the samples charging. The treated samples are subjected to a microstructural examination using optical microscopy followed by an image analysis using Image J software. The mechanical properties of the heat treated samples are characterized through ultimate tensile, hardness and impact tests. The results reveal that the g...
This study considers the effect of ferrosilicon manganese addition to austempered ductile iron, (... more This study considers the effect of ferrosilicon manganese addition to austempered ductile iron, (ADI) in order to reduce its sulphur level for improved engineering applications of the material. The cast samples were austenitised in a mixture of potassium chloride, sodium chloride and barium chloride solutions and austempered in sodium nitrate and potassium nitrate solutions. Ferrosilicon manganese was added to ADI in various amounts ranging from between 47 to 326 g. The study revealed that the sulphur level retained in ADI decreased from 0.088 wt % for as-cast to 0.027 wt % when 93 g of ferrosilicon manganese was added. Below this amount of ferrosilicon manganese addition, there was no significant reduction in the sulphur level recorded in ADI. The microstructure of the metal revealed bigger graphite nodules scattered in ferrite solutions for the situation when the sulphur level was 0.027 wt. %. From the study, it was discovered that addition of small amount of ferrosilicon manganese was required to produce ADI of low level sulphur content to make the metal more acceptable for other engineering applications.
This study considers the effect of ferrosilicon manganese addition to austempered ductile iron, (... more This study considers the effect of ferrosilicon manganese addition to austempered ductile iron, (ADI)in order to reduce its sulphur level for improved engineering applications of the material. The cast samples were austenitised in a mixture of potassium chloride, sodium chloride and barium chloride solutions and austempered in sodium nitrate and potassium nitrate solutions. Ferro-silicon-manganese was added to ADI in various amounts ranging from between 47 to326 g. The study revealed that the sulphur level retained in ADI decreased from 0.088 wt % for as-cast to 0.027 wt% when 93 g of ferro-silicon-manganese was added. Below this amount of ferro-silicon-manganese addition, there was no significant reduction in the sulphur level recorded in ADI. The microstructure of the metal revealed bigger graphite nodules scattered in ferrite solutions for the situation when the sulphur level was 0.027 wt. %. From the study, it was discovered that addition of small amount of ferrosilicon manganes...
IOP Conference Series: Materials Science and Engineering
The effect of subjecting mild steel to several cycles of rapid heat treatment on its mechanical p... more The effect of subjecting mild steel to several cycles of rapid heat treatment on its mechanical properties and microstructure was investigated. Mild steel of 0.213 wt % carbon was subjected to transformation heat treatment from austenite to pearlite and quenched in running water. Rapid heating was achieved by preheating an electric muffle furnace to 840 oC before charging the samples into it. Each cyclic heat treatment was for a period of 200 seconds held at 840 0C and cooled to 700 0C which was repeated four times. The effects of cycle numbers were evaluated by testing for impact, hardness, ultimate tensile strength and microstructural properties. The results showed that after 4th cycle of rapid heating the samples had impact energy 64.6 J, Brinell hardness number 563 and ultimate tensile strength 1257.78 N/mm2. The samples after one cycle had ultimate tensile strength 1027.45 N/mm2, % elongation 10.396% and impact energy 286.174 N.m before failure. Through cyclic heating, grain refinement was achieved by the fast simultaneous nucleation at the grain boundaries and the fast martensite to austenite transformation due to the fast heating rate which prevented austenite grain growth. Mechanical properties of the studied steel sample were improved with the rapid heat treatment cycles given.
The effects of applied pressure and die pre-heat temperature on the electrical conductivity of sq... more The effects of applied pressure and die pre-heat temperature on the electrical conductivity of squeeze cast aluminium rods were experimentally investigated and presented. The results show that applied pressure and die temperature have significant and positive effects on the electrical properties of squeeze cast aluminium rods up to certain levels. With increase in applied pressure, there is a steady increase in the electrical conductivity up to a pressure level of 105MPa, which gives a maximum value of electrical conductivity. Increasing the values of the applied pressure further leads to a decrease in the electrical conductivity up to a pressure of 150MPa. Beyond this pressure, increase in applied pressure has no significant effect on the values of electrical conductivities. With die pre-heating, electrical conductivity increases with increase in die temperature, reaching a maximum value at die temperature of 150 0 C. Further increase in the die temperature beyond 150 0 C leads to ...
Zinc is a non-ferrous metal with potential application in orthopaedic implant materials. However,... more Zinc is a non-ferrous metal with potential application in orthopaedic implant materials. However, its poor mechanical properties were major challenge to its application. Therefore, this paper studies the mechanical properties of biodegradable Zn-based alloy for biomedical application. Pure zinc powder with varying (0, 1, 2, 3 & 6) wt% of magnesium powders were ball milled using ball-topowder ratio (B:P) of 10:1 at 350 rpm for 4 hours. The resulting milled powders were compacted and sintered at 300 MPa and 350 °C respectively. Microstructural, phase and mechanical properties analyses were performed following American standard of testing and measurement. The results show that magnesium has influence on the mechanical properties of zinc. The compressive strength, hardness and elastic modulus of 210 ± 8.878 MPa, 76 ± 5.707 HV and 45 ± 11.616 GPa respectively as obtained in Zn-2Mg alloy were optimum and meet the minimum requirement of biodegradable metal for orthopaedics application. These results indicate an increase of 111, 93 and 93% in compressive strength, hardness and elastic modulus respectively as compared to pure zinc. The increase in mechanical properties was adduced to effectiveness of compaction pressure and intermetallic phase formation within the matrix resulting in high dislocation density for improving strength. The study concluded that, Zn-2Mg alloy with optimum mechanical properties can therefore be considered a potential candidate for orthopaedic application.
This study considers the effect of ferrosilicon manganese addition to austempered ductile iron, (... more This study considers the effect of ferrosilicon manganese addition to austempered ductile iron, (ADI) in order to reduce its sulphur level for improved engineering applications of the material. The cast samples were austenitised in a mixture of potassium chloride, sodium chloride and barium chloride solutions and austempered in sodium nitrate and potassium nitrate solutions. Ferrosilicon manganese was added to ADI in various amounts ranging from between 47 to 326 g. The study revealed that the sulphur level retained in ADI decreased from 0.088 wt % for as-cast to 0.027 wt % when 93 g of ferrosilicon manganese was added. Below this amount of ferrosilicon manganese addition, there was no significant reduction in the sulphur level recorded in ADI. The microstructure of the metal revealed bigger graphite nodules scattered in ferrite solutions for the situation when the sulphur level was 0.027 wt. %. From the study, it was discovered that addition of small amount of ferrosilicon manganes...
Permanent steel mold was designed, machined and evaluated by monitoring the temperature of squeez... more Permanent steel mold was designed, machined and evaluated by monitoring the temperature of squeeze cast aluminum and brass rods on a Vega hydraulic press. The operation was performed with and without pressure on the cast specimen at pouring temperature of 700 0 C and 980 0 C for aluminum and brass metals, respectively. The solidification rate (temperature with time) was monitored with a three-channel digital temperature monitor data logger while the tensile strengths of both samples were also determined. The results showed an increase in the solidification rate for both samples with increase in the applied pressure. The maximum solidification rate for aluminum was obtained at an applied pressure of 127 MPa and 95 MPa for brass. The tensile strength of both samples increased with increase in applied pressure. The maximum tensile strength of 34.38 MPa was obtained for aluminum at applied pressure of 127 MPa and 80.21 MPa for brass at an applied pressure of 95 MPa. Above these values t...
Effects of applied pressures and die pre-heat temperatures on the heat transfer coefficients of a... more Effects of applied pressures and die pre-heat temperatures on the heat transfer coefficients of aluminium were determined using the solidification temperature histories of the cast metal. The heat transfer coefficients at the cast metal/steel mould interface during solidification of squeeze cast aluminium were investigated using the inverse heat conduction method. The heat transfer coefficients were determined by both experimental and numerical methods. The results show an increase in the value of heat transfer coefficients with applied pressure and a decrease with high die pre-heat temperatures. The numerical heat transfer coefficients were in good agreement with the experimental values.
The effects of parameters such as applied pressure, die pre-heat temperature, delay time and rete... more The effects of parameters such as applied pressure, die pre-heat temperature, delay time and retention time of applied pressure on the temperature distributions within the casting have been considered. The results using this method were compared with those of experimental and heat transfer differential equations’ methods and found to be about 1.7% higher in value. The semi-empirical equations’ method can be used to predict the temperature distribution of other metals and alloys at any location, if the empirical equations relating the heat transfer coefficients to applied pressures and solidifying temperatures for their three stages of solidification are known.
International Journal of Engineering Materials and Manufacture
High temperature generated and stresses induced as a result of turning of Ti6Al4V results in poor... more High temperature generated and stresses induced as a result of turning of Ti6Al4V results in poor surface finish. The aim of this study was to investigate the effect of coolant temperature on the surface roughness of Ti6Al4V which is a core material used as an implant. A cooling system was developed to reduce the temperature of the coolant (soluble oil) from room temperature to 2oC. Ti6Al4V was turned in dry and cooled (at temperatures 5, 7, 9 and 11 oC) conditions. The experiment was designed using central composite design of (Response surface methodology) Design Expert 11.0 to generate an array and optimize the machining parameters. The machining parameters used were cutting speed, feed rate, depth of cut and coolant temperature. Results analyses show that cutting speed and depth of cut had considerable effect on surface roughness of Ti6Al4V. Surface roughness reduced when coolant temperature was reduced. The results of this study shows that turning Ti6Al4V at a very low cutting t...
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