This research investigated the structure and mechanical behaviour of horse eye bean seed shell as... more This research investigated the structure and mechanical behaviour of horse eye bean seed shell ash reinforced aluminium alloy matrix composite. The particle sizes of the reinforcement adopted were 300μm and 500μm. The reinforcement was added in concentrations of 5wt% and 15wt%. The samples were cast using permanent die casting technique, machined and subjected to solution heat treatment at temperature of 410 o C for 30 minutes. The samples were cooled in water and aged at temperature of 100 o C and 300 o C for 2hrs and 6hrs respectively. Mechanical properties such as percentage elongation, ultimate tensile strength, Brinell hardness and impact strength were determined using a 100KN JPL tensile strength tester (Model: 130812), portable dynamic hardness testing machine (Model: DHT-6) and pendulum impact testing machine (Model: U1820) respectively. The structural analysis was conducted using an optical metallurgical microscope (Model: L2003A), scanning electron microscopy (SEM) equipped with energy dispersive spectroscopy (EDS) and X-ray diffractometer (XRD). The microstructure of the control sample revealed the presence of polyhedral-shaped primary silicon particles and needle-like precipitate of intermetallic compound. The composite showed fine intermetallic phases dispersed in the aluminium matrix. The result of the mechanical tests indicated that addition of horse eye bean seed shell ash significantly improved the ultimate tensile strength, hardness and impact strength of the aluminium alloy matrix. The ultimate tensile strength and hardness increased with decrease in reinforcement particle size and increase in percentage by weight of reinforcement and ageing temperature. Maximum ultimate tensile strength was obtained by the composite containing 5wt% reinforcement (500μm), aged at 300 o C for 2hrs. This was attributed to the presence of fine intermetallic phases dispersed in the aluminium matrix. Maximum hardness was obtained by the composite containing 5wt% reinforcement (300μm), aged at 100 o C for 2 hrs. This was attributed to the evenly distributed Al 0.64 Ti 0.36 , Al 12 Mg 17 , C 0.12 Fe 0.79 Si 0.09 , MgAl 2 O 4 , TiC, FeSi, SiC and AlMg phases in the aluminium matrix. Optimum impact strength was obtained by the composite containing 15wt% reinforcement (500μm) and aged at 100 o C for 2hrs.
This research investigated the effect of soaking time and quenching media on the structure and me... more This research investigated the effect of soaking time and quenching media on the structure and mechanical properties of Al-5.6wt%Zn-2.5wt%Mg alloy. The samples were prepared using permanent die casting technique and machined to the required dimensions for the mechanical tests and structural analysis. The samples were solution heat treated at temperature of 300 o C for 30, 90 and 150 minutes and cooled in water, brine, palm oil and SAE40. Mechanical properties studied such as percentage elongation, ultimate tensile strength, hardness and impact strength were determined using 100KN JPL tensile strength tester (Model: 130812), dynamic hardness tester and impact testing machine (Model: U1820) respectively, while the alloy microstructures were studied using an optical metallurgical microscope (Model: L2003A) and scanning electron microscopy (SEM) equipped with energy dispersive spectroscopy (EDS). The microstructural analysis revealed coarse micro-segregation of intermetallic compound (MgZn 2) in the control sample. The solution heat-treated samples revealed the presence of uniformly distributed fine grains of intermetallic compound (MgZn 2). The mechanical tests results showed that heat treatment improved the ultimate tensile strength, impact strength and percentage elongation of the alloy significantly. This was quantified by the presence of uniformly distributed fine grains of intermetallic compound (MgZn 2) in the alloy structure. Heat treatment created no room for solute redistribution of Mg and Zn and hence caused the elimination of micro-segregation of MgZn 2 in the alloy structure. Sample soaked for 30 minutes and quenched in water gave the maximum impact strength of 12J. The control sample had the maximum hardness value because of the presence of coarse intermetallic compound (MgZn 2) in the alloy structure.
This research investigated the effect of zinc content on the structure and mechanical properties ... more This research investigated the effect of zinc content on the structure and mechanical properties of silicon bronze (Cu-3wt%Si). The dopant was added in concentrations of 0.1, 0.3, 0.5, 0.8, 1 and 1.5wt%. The samples were produced using permanent die casting technique and machined to the required dimensions for the structural analysis and mechanical tests. Mechanical properties such as percentage elongation, ultimate tensile strength and Brinell hardness of the developed alloys were investigated using a 100KN JPL tensile strength tester (Model: 130812) and portable dynamic hardness testing machine (Model: DHT-6) respectively. The structural analysis was conducted using an optical metallurgical microscope (Model: L2003A) and scanning electron microscopy (SEM). Results of the structural analysis revealed that the control specimen consisted of dendrite of primary silicon and coarse intermetallic phase (Cu 3 Si). The samples doped with zinc consisted of refined and modified dendritic primary silicon and intermetallic compound respectively. Mechanical tests results indicated that addition of zinc to silicon bronze improved the percentage elongation, ultimate tensile strength and hardness of the alloy significantly. The percentage elongation increased with increase in zinc content up to 1wt%. Further increase in zinc content resulted to decrease in percentage elongation with corresponding increase in hardness. It was observed that the ultimate tensile strength increased with increase in zinc content. This trend in mechanical properties was concluded to be because of the precipitation of β-phase from the α-phase as the zinc content increased to 1.5wt%.
The aim of this research was to investigate the structural modification and mechanical properties... more The aim of this research was to investigate the structural modification and mechanical properties of silicon bronze doped with different concentrations of tin. The concentrations of tin adopted were 0.1, 0.3, 0.5, 0.8, 1 and 1.5% by weight. The samples were cast using permanent die casting method and prepared for structural analysis and mechanical tests. 100KN JPL tensile strength tester (Model: 130812) and portable dynamic hardness testing machine (Model: DHT-6) were used to investigate the percentage elongation, ultimate tensile strength and hardness of the developed alloys respectively. The microstructure of the developed alloys was analysed using an optical metallurgical microscope (Model: L2003A) and scanning electron microscopy (SEM). The structural analysis of the control sample (Cu-3wt%Si) revealed the presence of segregated primary silicon and coarse intermetallic phase (Cu 3 Si). The surface morphology of the doped alloys consisted of refined and modified intermetallic phase of spherical pattern in the alloy structure. Results of the mechanical tests showed that the percentage elongation, ultimate tensile strength and hardness of the alloy improved significantly by addition of 0.1wt%Sn. The ultimate tensile strength and hardness of the alloy increased with increase in tin content with corresponding decrease in percentage elongation.
The main objective of this research was to investigate the effect of soaking time and quenching m... more The main objective of this research was to investigate the effect of soaking time and quenching media on the structure and mechanical properties of aluminium bronze (Cu-10%wt.Al). Sand casting method was adopted in casting the samples. Standard specimens were prepared from the as-cast and heat treated samples for tensile, hardness and impact strength tests as well as microstructural analysis according to standard. The samples were solutionized at temperature of 900 o C for 30, 60 and 180mins and quenched in water, brine and SAE 40 respectively. The tensile, hardness and impact strength test were conducted using JPL tensile strength tester (Model: 130812), dynamic hardness tester and impact testing machine (U1820) respectively. The alloy microstructures were studied using an optical metallurgical microscope (Model: L2003A). Microstructural analysis result indicated coarse sparse distribution of α+ γ2 precipitates in the as-cast specimen and presence of fine pearlite (α + γ2) in a matrix of α dominance in the heat treated specimens. The presence of coarse intermetallic compounds (β`-phase) was revealed as the soaking time increased. The obtained results indicated that heat treatment significantly improved all the tested mechanical properties except the impact strength. Optimum ultimate tensile strength and hardness values of 710MPa and 513MPa respectively were recorded for the specimen solutionized at 900 o C for 30 minutes and quenched in water and brine respectively. Among all the quenching media used, brine gave the best combination of mechanical properties.
This research investigated the structure and mechanical behaviour of horse eye bean seed shell as... more This research investigated the structure and mechanical behaviour of horse eye bean seed shell ash reinforced aluminium alloy matrix composite. The particle sizes of the reinforcement adopted were 300μm and 500μm. The reinforcement was added in concentrations of 5wt% and 15wt%. The samples were cast using permanent die casting technique, machined and subjected to solution heat treatment at temperature of 410 o C for 30 minutes. The samples were cooled in water and aged at temperature of 100 o C and 300 o C for 2hrs and 6hrs respectively. Mechanical properties such as percentage elongation, ultimate tensile strength, Brinell hardness and impact strength were determined using a 100KN JPL tensile strength tester (Model: 130812), portable dynamic hardness testing machine (Model: DHT-6) and pendulum impact testing machine (Model: U1820) respectively. The structural analysis was conducted using an optical metallurgical microscope (Model: L2003A), scanning electron microscopy (SEM) equipped with energy dispersive spectroscopy (EDS) and X-ray diffractometer (XRD). The microstructure of the control sample revealed the presence of polyhedral-shaped primary silicon particles and needle-like precipitate of intermetallic compound. The composite showed fine intermetallic phases dispersed in the aluminium matrix. The result of the mechanical tests indicated that addition of horse eye bean seed shell ash significantly improved the ultimate tensile strength, hardness and impact strength of the aluminium alloy matrix. The ultimate tensile strength and hardness increased with decrease in reinforcement particle size and increase in percentage by weight of reinforcement and ageing temperature. Maximum ultimate tensile strength was obtained by the composite containing 5wt% reinforcement (500μm), aged at 300 o C for 2hrs. This was attributed to the presence of fine intermetallic phases dispersed in the aluminium matrix. Maximum hardness was obtained by the composite containing 5wt% reinforcement (300μm), aged at 100 o C for 2 hrs. This was attributed to the evenly distributed Al 0.64 Ti 0.36 , Al 12 Mg 17 , C 0.12 Fe 0.79 Si 0.09 , MgAl 2 O 4 , TiC, FeSi, SiC and AlMg phases in the aluminium matrix. Optimum impact strength was obtained by the composite containing 15wt% reinforcement (500μm) and aged at 100 o C for 2hrs.
This research investigated the effect of soaking time and quenching media on the structure and me... more This research investigated the effect of soaking time and quenching media on the structure and mechanical properties of Al-5.6wt%Zn-2.5wt%Mg alloy. The samples were prepared using permanent die casting technique and machined to the required dimensions for the mechanical tests and structural analysis. The samples were solution heat treated at temperature of 300 o C for 30, 90 and 150 minutes and cooled in water, brine, palm oil and SAE40. Mechanical properties studied such as percentage elongation, ultimate tensile strength, hardness and impact strength were determined using 100KN JPL tensile strength tester (Model: 130812), dynamic hardness tester and impact testing machine (Model: U1820) respectively, while the alloy microstructures were studied using an optical metallurgical microscope (Model: L2003A) and scanning electron microscopy (SEM) equipped with energy dispersive spectroscopy (EDS). The microstructural analysis revealed coarse micro-segregation of intermetallic compound (MgZn 2) in the control sample. The solution heat-treated samples revealed the presence of uniformly distributed fine grains of intermetallic compound (MgZn 2). The mechanical tests results showed that heat treatment improved the ultimate tensile strength, impact strength and percentage elongation of the alloy significantly. This was quantified by the presence of uniformly distributed fine grains of intermetallic compound (MgZn 2) in the alloy structure. Heat treatment created no room for solute redistribution of Mg and Zn and hence caused the elimination of micro-segregation of MgZn 2 in the alloy structure. Sample soaked for 30 minutes and quenched in water gave the maximum impact strength of 12J. The control sample had the maximum hardness value because of the presence of coarse intermetallic compound (MgZn 2) in the alloy structure.
This research investigated the effect of zinc content on the structure and mechanical properties ... more This research investigated the effect of zinc content on the structure and mechanical properties of silicon bronze (Cu-3wt%Si). The dopant was added in concentrations of 0.1, 0.3, 0.5, 0.8, 1 and 1.5wt%. The samples were produced using permanent die casting technique and machined to the required dimensions for the structural analysis and mechanical tests. Mechanical properties such as percentage elongation, ultimate tensile strength and Brinell hardness of the developed alloys were investigated using a 100KN JPL tensile strength tester (Model: 130812) and portable dynamic hardness testing machine (Model: DHT-6) respectively. The structural analysis was conducted using an optical metallurgical microscope (Model: L2003A) and scanning electron microscopy (SEM). Results of the structural analysis revealed that the control specimen consisted of dendrite of primary silicon and coarse intermetallic phase (Cu 3 Si). The samples doped with zinc consisted of refined and modified dendritic primary silicon and intermetallic compound respectively. Mechanical tests results indicated that addition of zinc to silicon bronze improved the percentage elongation, ultimate tensile strength and hardness of the alloy significantly. The percentage elongation increased with increase in zinc content up to 1wt%. Further increase in zinc content resulted to decrease in percentage elongation with corresponding increase in hardness. It was observed that the ultimate tensile strength increased with increase in zinc content. This trend in mechanical properties was concluded to be because of the precipitation of β-phase from the α-phase as the zinc content increased to 1.5wt%.
The aim of this research was to investigate the structural modification and mechanical properties... more The aim of this research was to investigate the structural modification and mechanical properties of silicon bronze doped with different concentrations of tin. The concentrations of tin adopted were 0.1, 0.3, 0.5, 0.8, 1 and 1.5% by weight. The samples were cast using permanent die casting method and prepared for structural analysis and mechanical tests. 100KN JPL tensile strength tester (Model: 130812) and portable dynamic hardness testing machine (Model: DHT-6) were used to investigate the percentage elongation, ultimate tensile strength and hardness of the developed alloys respectively. The microstructure of the developed alloys was analysed using an optical metallurgical microscope (Model: L2003A) and scanning electron microscopy (SEM). The structural analysis of the control sample (Cu-3wt%Si) revealed the presence of segregated primary silicon and coarse intermetallic phase (Cu 3 Si). The surface morphology of the doped alloys consisted of refined and modified intermetallic phase of spherical pattern in the alloy structure. Results of the mechanical tests showed that the percentage elongation, ultimate tensile strength and hardness of the alloy improved significantly by addition of 0.1wt%Sn. The ultimate tensile strength and hardness of the alloy increased with increase in tin content with corresponding decrease in percentage elongation.
The main objective of this research was to investigate the effect of soaking time and quenching m... more The main objective of this research was to investigate the effect of soaking time and quenching media on the structure and mechanical properties of aluminium bronze (Cu-10%wt.Al). Sand casting method was adopted in casting the samples. Standard specimens were prepared from the as-cast and heat treated samples for tensile, hardness and impact strength tests as well as microstructural analysis according to standard. The samples were solutionized at temperature of 900 o C for 30, 60 and 180mins and quenched in water, brine and SAE 40 respectively. The tensile, hardness and impact strength test were conducted using JPL tensile strength tester (Model: 130812), dynamic hardness tester and impact testing machine (U1820) respectively. The alloy microstructures were studied using an optical metallurgical microscope (Model: L2003A). Microstructural analysis result indicated coarse sparse distribution of α+ γ2 precipitates in the as-cast specimen and presence of fine pearlite (α + γ2) in a matrix of α dominance in the heat treated specimens. The presence of coarse intermetallic compounds (β`-phase) was revealed as the soaking time increased. The obtained results indicated that heat treatment significantly improved all the tested mechanical properties except the impact strength. Optimum ultimate tensile strength and hardness values of 710MPa and 513MPa respectively were recorded for the specimen solutionized at 900 o C for 30 minutes and quenched in water and brine respectively. Among all the quenching media used, brine gave the best combination of mechanical properties.
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