Thermal conductivity of carbon nanotubes (CNTs) copper-matrix nanocomposites was predicted by usi... more Thermal conductivity of carbon nanotubes (CNTs) copper-matrix nanocomposites was predicted by using numerical approach. In the present study, twenty representative volume elements (RVEs) were modeled by assuming that the CNTs are distributed homogeneously in the copper (Cu) matrix. It is assumed that each RVE contains different pattern of CNTs distribution while the direction, diameter and length of CNTs are held constant. The effect of the CNTs-matrix interfacial resistance was also negligible. Therefore, it was observed that the predicted values of thermal conductivity would reach to the upper-bound rule of mixtures.
Due to the rapid growth of high performance electronics devices accompanied by overheating proble... more Due to the rapid growth of high performance electronics devices accompanied by overheating problem, heat dissipater nanocomposites material having ultra-high thermal conductivity and low coefficient of thermal expansion was proposed. In this work, a nanocomposite material made of copper (Cu) reinforced by multi-walled carbon nanotubes (CNTs) up to 10 vol. % was prepared and their thermal behaviour was measured experimentally and evaluated using numerical simulation. In order to numerically predict the thermal behaviour of Cu/CNTs composites, three different prediction methods were performed. The results showed that rules of mixture method records the highest thermal conductivity for all predicted composites. In contrast, the prediction model which takes into account the influence of the interface thermal resistance between CNTs and copper particles, has shown the lowest thermal conductivity which considered as the closest results to the experimental measurement. The experimentally measured thermal conductivities showed remarkable increase after adding 5 vol.% CNTs and higher than the thermal conductivities predicted via Nan models, indicating that the improved fabrication technique of powder injection molding that has been used to produced Cu/CNTs nanocomposites has overcome the challenges assumed in the mathematical models.
Carbon nanotubes (CNTs) with its exceptional thermal and mechanical properties hold the promise
o... more Carbon nanotubes (CNTs) with its exceptional thermal and mechanical properties hold the promise of delivering high performance nanocomposite materials. To utilize CNTs as effective reinforcement in metal nanocomposites, appropriate dispersion and robust interfacial adhesion between individual CNT and metal matrix have to be certain. This work presents a novel combined technique of nanoscale dispersion (NSD) of functionalized multiwalled carbon nanotubes (MWCNTs) in copper (Cu) matrix composite followed by powder injection molding (PIM). MWCNTs contents were varied from 0 to 10 volume fraction. Evidences on the existence of functional groups and microstructural analysis of the fabricated nanocomposites were determined using TEM, EDX, FESEM and FTIR. Thermal conductivity and elasticity measurements were also performed. The results showed that the impurities of the pristine MWCNTs such as Fe, Ni catalyst, and the amorphous carbon have been significantly removed after sonication process. FESEM and TEM observations showed high stability of MWCNTs at elevated temperatures and uniform dispersion of MWCNTs in Cu matrix at different volume fractions and sintering temperatures (950, 1000 and 1050 C). The experimentally measured thermal conductivities of Cu/MWCNTs nanocomposites showed remarkable increase (11.25% higher than pure sintered Cu) with addition of 1 vol.% MWCNTs, while the modulus of elasticity (Young’s modulus) of Cu/MWCNTs nanocomposites sintered at 1050 C for 2 h was increased proportionally to the increment in MWCNTs contents.
In this study, the flow behavior of multi-walledcarbon nanotubes (CNTs) reinforced copper matrix ... more In this study, the flow behavior of multi-walledcarbon nanotubes (CNTs) reinforced copper matrix feedstocks is presented. An acceptable increasing trend in viscosity of the copper feedstock with powder loading was recorded. Cu/CNTs composite feedstocks showed viscosity more than 1000 Pa.s which is most probably due to the addition of CNTs and increasing trend in viscosity of Cu/CNTs was noted as well. The results also identified that the feedstock containing 59 vol. % copper was most suitable for substitution of CNTs in Cu feedstock.
Modified technique of metal injection molding (MIM) was used to fabricate multiwalled carbon nano... more Modified technique of metal injection molding (MIM) was used to fabricate multiwalled carbon nanotube (CNT) reinforced Cu nanocomposites. The effect of adding different amount of CNTs (0-10 vol.%) on the thermal and mechanical behaviour of the fabricated nanocomposites is presented. Scanning electron microscope analysis revealed homogenous dispersion of CNTs in Cu matrices at different CNTs contents. The experimentally measured thermal conductivities of Cu/CNTs nanocomposites showed extraordinary increase (76% higher than pure sintered Cu) with addition of 10 vol.% CNTs. As compared to the pure sintered Cu, increase in modulus of elasticity (Young’s modulus) of Cu/CNTs nanocomposites sintered at 1050qC for 2.5 h was measured to be 48%. However, in case of 7.5 vol.% CNTs, Young’s modulus was increased significantly about 51% compared to that of pure sintered Cu.
This study presents the mechanical properties of Al–12% Si matrix composite reinforced by
variou... more This study presents the mechanical properties of Al–12% Si matrix composite reinforced by
various amounts of Titanium Carbide (TiC) and Titanium Nitride (TiN) particles, the wear
behaviour was investigated using a pin-on-disc wear testing machine with varying parameters
such as normal load, reinforcement’s percentage and track velocity, the results show that the
wear of Al-12Si matrix reinforced by 5%, 10%, 15% of TiC particles at 150 rpm with 15 N
loads were: 73 mm3x 10-3, 61 mm3x 10-3, 50.5 mm3x 10-3 respectively which are less than the
wear for same composites at 225 rpm with 15 N. This is due to the length of rubbing is more
in case of higher speed. The results also show that the wear of the samples were decreased
with increasing the percentage of reinforcement of TiN at both sliding speed (150 rpm, and
225 rpm). The hardness of Al-12Si/TiC composites with 5% of TiC were found 50 and the
hardness of same composites with 15% of TiC reinforcements were 67which are less than the
hardness of Al-12Si/TiN composites with 15% TiN reinforcements. The microstructural
study of the composites before wear test showed uniform distribution of (TiC and TiN)
particles through the cross-section of the specimens and finer surfaces than matrix composite
after wear test. The mechanical properties such as hardness and wear resistance are observed
to be increased considerably compared to the matrix composite.
Uniform dispersion of carbon nanotubes (CNTs) in metal composites has been by far the most signif... more Uniform dispersion of carbon nanotubes (CNTs) in metal composites has been by far the most significant challenge in the field of CNT-reinforced metal matrices. This work presents a new dispersion and fabrication technique of Carbon nanotubes (CNTs) reinforced copper (Cu) matrix nanocomposites. A combination of nanoscale dispersion of functionalized CNTs in low viscose media of dissolved paraffin wax under ultrasonication treatment followed by powder injection molding (PIM) technique was adopted. CNTs contents were varied from 0 to 10 vol.%. TEM, EDX, FESEM and Raman spectroscopy analysis were used for materials characterization. Information about the degree of purification and functionalization processes, evidences on the existence of the functional groups, effects of ultrasonication time on the treated CNTs, and microstructural analysis of the fabricated Cu/CNTs nanocomposites were determined. The results showed that the impurities of the pristine CNTs such as Fe, Ni catalyst and the amorphous carbon have been significantly removed after purification process. Meanwhile, FESEM and TEM observations showed high stability of CNTs at elevated temperatures. It also showed an excellent homogeneous dispersion of CNTs in Cu matrix and led to a strong interfacial bonding between Cu particles and individual CNTs.
A fabrication of high performance heat sink composite material made of copper matrix reinforced b... more A fabrication of high performance heat sink composite material made of copper matrix reinforced by multiwalled carbon nanotubes (MWCNTs) up to 2.5 Vol. % using powder injection molding technique (PIM) has been done successfully. A mixture of Cu/MWCNTs was compounded using a Z-blade mixer for homogenous dispersion of solids in the binder. The flow properties were measured using a capillary rheometer in the shear rate range which expected to occur during metal injection molding. To avoid binder degradation, TGA test was carried out. The TGA results showed that the processing temperature such as mixing and injection molding should be lower than 170°C. The injection molding was carried out at low pressure. A combination of solvent and thermal debinding was used for binder removal from the samples and then the sintering process has taken place in argon gas at 900°C. The results show that the sintered samples experience isotropic shrinkage around 21% with 14% weight loss and the density of the composites was decreased after sintering process.
This research presents the effects of temperature and cooling rate on mechanical properties of po... more This research presents the effects of temperature and cooling rate on mechanical properties of powder injection molded 316L Stainless steel. Steel powder and binder were mixed together to produce the feedstock. The green samples were produced by injection molding and debinded. Brown test samples were sintered in vacuum at 1325ºC, 1360ºC and 1380ºC for 2h with two heating and cooling rates 5ºC/min and 10ºC/ min. The test samples sintered at 1325ºC achieved maximum sintered density. The higher cooling rate improved the strength of the sintered test samples. The maximum sintered density of 96% and tensile strength of 503MPa was achieved and these results are comparable to the wrought 316L stainless steel (according to ASTM standard).
Fiber orientation is a big challenge in short fiber reinforced composites. Powder injection moldi... more Fiber orientation is a big challenge in short fiber reinforced composites. Powder injection molding (PIM) process has some intrinsic fiber alignment associated with it. During PIM process fibers in skin region of moldings are aligned as these regions experience higher shear flow caused by the mold walls. Fibers in the core region remain randomly aligned as these regions are far from mold walls and experience lesser shear flow. In this study short carbon fiber (CF) reinforced copper matrix composite was developed by PIM process. Two copper composite feedstock formulations were prepared having 5 vol% and 10 vol% CFs and a wax based binder system. Fiber orientation was controlled during injection molding by using a modified mold that has a diverging sprue. The sprue creates converging flow when feedstock enters into the mold cavity. Fiber orientation was analysed after molding using FESEM. The orientation of fibers can be controlled by controlling flow of feedstock into the mold.
IOP Conference Series: Materials Science and Engineering, 2014
In the modern construction, fire safety has significant consideration for the protection of peopl... more In the modern construction, fire safety has significant consideration for the protection of people and assets. Several intumescent fire protection systems are in practice and have constrain of releasing toxic gases on degradation forms an insulating char layer protecting underlying substrate. An intumescent coating expands many times of its thickness on exposure to fire and protect the underlying substrate from fire. This study presents the results of thermal performance of an intumescent fire retardant coating (IFRC) developed for structural application. IFRC was developed using expandable graphite (EG), ammonium poly phosphate (APP) and melamine (MEL), epoxy resin Bisphenol-A (BPA) and hardener triethylenetetramine (TETA) were used as a binder as a curing agent. Char expansion of IFRC was measured by furnace fire test at 450°C, thermal performance was measured using a Bunsen burner at 950°C and temperature of substrate was recorded for 60 min at an interval of two min. Results showed that IFRC containing 3wt% alumina showed char expansion X19. After one hour exposure of coating to heat, substrate temperature recorded was 154°C. X-ray Diffraction (XRD) results showed the presence of high temperature compounds present in the char of coating, considered responsible to reduce the penetration of heat to the substrate.
Intumescent coating is an insulating material designed to decrease heat transfer to a substrate s... more Intumescent coating is an insulating material designed to decrease heat transfer to a substrate structure. This research presents the results of different formulations developed to study the effects of kaolin clay on expansion of coating and heat shielding during the fire test. The intumescent coating formulations (ICFs) were tested at 950 o C for one hour. The results showed that the coatings were stable and well bound with substrate. The coatings were characterized by using Field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Thermogravimetric analysis (TGA) and X-ray photoelectron spectroscopy (XPS). The morphology of char was studied by FESEM on the coating after fire test. XRD and FTIR showed the presence of carbon (graphite), boron phosphate, boron oxide, sassolite and kaolinite in the residual char. TGA showed that kaolin clay reinforced formulation; IF5-KC enhanced 49% residual weight than that of IF-Control formulation. XPS analysis showed that elemental composition of IF5-KC char residue gave 41.80% carbon content in the residual char. An accelerated weathering test ASTM D 6695-03 showed that IF5-KC coating sustained its integrity up to 90 days under accelerated weathering chamber.
Abstract: In this paper we have discussed the thermal behaviour of intumescent coating. Intumesce... more Abstract: In this paper we have discussed the thermal behaviour of intumescent coating. Intumescent coating is an insulating system designed to decrease heat transfer from a fire to substrate structure to maintain its integrity. The coating was based on expandable ...
Thermal conductivity of carbon nanotubes (CNTs) copper-matrix nanocomposites was predicted by usi... more Thermal conductivity of carbon nanotubes (CNTs) copper-matrix nanocomposites was predicted by using numerical approach. In the present study, twenty representative volume elements (RVEs) were modeled by assuming that the CNTs are distributed homogeneously in the copper (Cu) matrix. It is assumed that each RVE contains different pattern of CNTs distribution while the direction, diameter and length of CNTs are held constant. The effect of the CNTs-matrix interfacial resistance was also negligible. Therefore, it was observed that the predicted values of thermal conductivity would reach to the upper-bound rule of mixtures.
Due to the rapid growth of high performance electronics devices accompanied by overheating proble... more Due to the rapid growth of high performance electronics devices accompanied by overheating problem, heat dissipater nanocomposites material having ultra-high thermal conductivity and low coefficient of thermal expansion was proposed. In this work, a nanocomposite material made of copper (Cu) reinforced by multi-walled carbon nanotubes (CNTs) up to 10 vol. % was prepared and their thermal behaviour was measured experimentally and evaluated using numerical simulation. In order to numerically predict the thermal behaviour of Cu/CNTs composites, three different prediction methods were performed. The results showed that rules of mixture method records the highest thermal conductivity for all predicted composites. In contrast, the prediction model which takes into account the influence of the interface thermal resistance between CNTs and copper particles, has shown the lowest thermal conductivity which considered as the closest results to the experimental measurement. The experimentally measured thermal conductivities showed remarkable increase after adding 5 vol.% CNTs and higher than the thermal conductivities predicted via Nan models, indicating that the improved fabrication technique of powder injection molding that has been used to produced Cu/CNTs nanocomposites has overcome the challenges assumed in the mathematical models.
Carbon nanotubes (CNTs) with its exceptional thermal and mechanical properties hold the promise
o... more Carbon nanotubes (CNTs) with its exceptional thermal and mechanical properties hold the promise of delivering high performance nanocomposite materials. To utilize CNTs as effective reinforcement in metal nanocomposites, appropriate dispersion and robust interfacial adhesion between individual CNT and metal matrix have to be certain. This work presents a novel combined technique of nanoscale dispersion (NSD) of functionalized multiwalled carbon nanotubes (MWCNTs) in copper (Cu) matrix composite followed by powder injection molding (PIM). MWCNTs contents were varied from 0 to 10 volume fraction. Evidences on the existence of functional groups and microstructural analysis of the fabricated nanocomposites were determined using TEM, EDX, FESEM and FTIR. Thermal conductivity and elasticity measurements were also performed. The results showed that the impurities of the pristine MWCNTs such as Fe, Ni catalyst, and the amorphous carbon have been significantly removed after sonication process. FESEM and TEM observations showed high stability of MWCNTs at elevated temperatures and uniform dispersion of MWCNTs in Cu matrix at different volume fractions and sintering temperatures (950, 1000 and 1050 C). The experimentally measured thermal conductivities of Cu/MWCNTs nanocomposites showed remarkable increase (11.25% higher than pure sintered Cu) with addition of 1 vol.% MWCNTs, while the modulus of elasticity (Young’s modulus) of Cu/MWCNTs nanocomposites sintered at 1050 C for 2 h was increased proportionally to the increment in MWCNTs contents.
In this study, the flow behavior of multi-walledcarbon nanotubes (CNTs) reinforced copper matrix ... more In this study, the flow behavior of multi-walledcarbon nanotubes (CNTs) reinforced copper matrix feedstocks is presented. An acceptable increasing trend in viscosity of the copper feedstock with powder loading was recorded. Cu/CNTs composite feedstocks showed viscosity more than 1000 Pa.s which is most probably due to the addition of CNTs and increasing trend in viscosity of Cu/CNTs was noted as well. The results also identified that the feedstock containing 59 vol. % copper was most suitable for substitution of CNTs in Cu feedstock.
Modified technique of metal injection molding (MIM) was used to fabricate multiwalled carbon nano... more Modified technique of metal injection molding (MIM) was used to fabricate multiwalled carbon nanotube (CNT) reinforced Cu nanocomposites. The effect of adding different amount of CNTs (0-10 vol.%) on the thermal and mechanical behaviour of the fabricated nanocomposites is presented. Scanning electron microscope analysis revealed homogenous dispersion of CNTs in Cu matrices at different CNTs contents. The experimentally measured thermal conductivities of Cu/CNTs nanocomposites showed extraordinary increase (76% higher than pure sintered Cu) with addition of 10 vol.% CNTs. As compared to the pure sintered Cu, increase in modulus of elasticity (Young’s modulus) of Cu/CNTs nanocomposites sintered at 1050qC for 2.5 h was measured to be 48%. However, in case of 7.5 vol.% CNTs, Young’s modulus was increased significantly about 51% compared to that of pure sintered Cu.
This study presents the mechanical properties of Al–12% Si matrix composite reinforced by
variou... more This study presents the mechanical properties of Al–12% Si matrix composite reinforced by
various amounts of Titanium Carbide (TiC) and Titanium Nitride (TiN) particles, the wear
behaviour was investigated using a pin-on-disc wear testing machine with varying parameters
such as normal load, reinforcement’s percentage and track velocity, the results show that the
wear of Al-12Si matrix reinforced by 5%, 10%, 15% of TiC particles at 150 rpm with 15 N
loads were: 73 mm3x 10-3, 61 mm3x 10-3, 50.5 mm3x 10-3 respectively which are less than the
wear for same composites at 225 rpm with 15 N. This is due to the length of rubbing is more
in case of higher speed. The results also show that the wear of the samples were decreased
with increasing the percentage of reinforcement of TiN at both sliding speed (150 rpm, and
225 rpm). The hardness of Al-12Si/TiC composites with 5% of TiC were found 50 and the
hardness of same composites with 15% of TiC reinforcements were 67which are less than the
hardness of Al-12Si/TiN composites with 15% TiN reinforcements. The microstructural
study of the composites before wear test showed uniform distribution of (TiC and TiN)
particles through the cross-section of the specimens and finer surfaces than matrix composite
after wear test. The mechanical properties such as hardness and wear resistance are observed
to be increased considerably compared to the matrix composite.
Uniform dispersion of carbon nanotubes (CNTs) in metal composites has been by far the most signif... more Uniform dispersion of carbon nanotubes (CNTs) in metal composites has been by far the most significant challenge in the field of CNT-reinforced metal matrices. This work presents a new dispersion and fabrication technique of Carbon nanotubes (CNTs) reinforced copper (Cu) matrix nanocomposites. A combination of nanoscale dispersion of functionalized CNTs in low viscose media of dissolved paraffin wax under ultrasonication treatment followed by powder injection molding (PIM) technique was adopted. CNTs contents were varied from 0 to 10 vol.%. TEM, EDX, FESEM and Raman spectroscopy analysis were used for materials characterization. Information about the degree of purification and functionalization processes, evidences on the existence of the functional groups, effects of ultrasonication time on the treated CNTs, and microstructural analysis of the fabricated Cu/CNTs nanocomposites were determined. The results showed that the impurities of the pristine CNTs such as Fe, Ni catalyst and the amorphous carbon have been significantly removed after purification process. Meanwhile, FESEM and TEM observations showed high stability of CNTs at elevated temperatures. It also showed an excellent homogeneous dispersion of CNTs in Cu matrix and led to a strong interfacial bonding between Cu particles and individual CNTs.
A fabrication of high performance heat sink composite material made of copper matrix reinforced b... more A fabrication of high performance heat sink composite material made of copper matrix reinforced by multiwalled carbon nanotubes (MWCNTs) up to 2.5 Vol. % using powder injection molding technique (PIM) has been done successfully. A mixture of Cu/MWCNTs was compounded using a Z-blade mixer for homogenous dispersion of solids in the binder. The flow properties were measured using a capillary rheometer in the shear rate range which expected to occur during metal injection molding. To avoid binder degradation, TGA test was carried out. The TGA results showed that the processing temperature such as mixing and injection molding should be lower than 170°C. The injection molding was carried out at low pressure. A combination of solvent and thermal debinding was used for binder removal from the samples and then the sintering process has taken place in argon gas at 900°C. The results show that the sintered samples experience isotropic shrinkage around 21% with 14% weight loss and the density of the composites was decreased after sintering process.
This research presents the effects of temperature and cooling rate on mechanical properties of po... more This research presents the effects of temperature and cooling rate on mechanical properties of powder injection molded 316L Stainless steel. Steel powder and binder were mixed together to produce the feedstock. The green samples were produced by injection molding and debinded. Brown test samples were sintered in vacuum at 1325ºC, 1360ºC and 1380ºC for 2h with two heating and cooling rates 5ºC/min and 10ºC/ min. The test samples sintered at 1325ºC achieved maximum sintered density. The higher cooling rate improved the strength of the sintered test samples. The maximum sintered density of 96% and tensile strength of 503MPa was achieved and these results are comparable to the wrought 316L stainless steel (according to ASTM standard).
Fiber orientation is a big challenge in short fiber reinforced composites. Powder injection moldi... more Fiber orientation is a big challenge in short fiber reinforced composites. Powder injection molding (PIM) process has some intrinsic fiber alignment associated with it. During PIM process fibers in skin region of moldings are aligned as these regions experience higher shear flow caused by the mold walls. Fibers in the core region remain randomly aligned as these regions are far from mold walls and experience lesser shear flow. In this study short carbon fiber (CF) reinforced copper matrix composite was developed by PIM process. Two copper composite feedstock formulations were prepared having 5 vol% and 10 vol% CFs and a wax based binder system. Fiber orientation was controlled during injection molding by using a modified mold that has a diverging sprue. The sprue creates converging flow when feedstock enters into the mold cavity. Fiber orientation was analysed after molding using FESEM. The orientation of fibers can be controlled by controlling flow of feedstock into the mold.
IOP Conference Series: Materials Science and Engineering, 2014
In the modern construction, fire safety has significant consideration for the protection of peopl... more In the modern construction, fire safety has significant consideration for the protection of people and assets. Several intumescent fire protection systems are in practice and have constrain of releasing toxic gases on degradation forms an insulating char layer protecting underlying substrate. An intumescent coating expands many times of its thickness on exposure to fire and protect the underlying substrate from fire. This study presents the results of thermal performance of an intumescent fire retardant coating (IFRC) developed for structural application. IFRC was developed using expandable graphite (EG), ammonium poly phosphate (APP) and melamine (MEL), epoxy resin Bisphenol-A (BPA) and hardener triethylenetetramine (TETA) were used as a binder as a curing agent. Char expansion of IFRC was measured by furnace fire test at 450°C, thermal performance was measured using a Bunsen burner at 950°C and temperature of substrate was recorded for 60 min at an interval of two min. Results showed that IFRC containing 3wt% alumina showed char expansion X19. After one hour exposure of coating to heat, substrate temperature recorded was 154°C. X-ray Diffraction (XRD) results showed the presence of high temperature compounds present in the char of coating, considered responsible to reduce the penetration of heat to the substrate.
Intumescent coating is an insulating material designed to decrease heat transfer to a substrate s... more Intumescent coating is an insulating material designed to decrease heat transfer to a substrate structure. This research presents the results of different formulations developed to study the effects of kaolin clay on expansion of coating and heat shielding during the fire test. The intumescent coating formulations (ICFs) were tested at 950 o C for one hour. The results showed that the coatings were stable and well bound with substrate. The coatings were characterized by using Field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Thermogravimetric analysis (TGA) and X-ray photoelectron spectroscopy (XPS). The morphology of char was studied by FESEM on the coating after fire test. XRD and FTIR showed the presence of carbon (graphite), boron phosphate, boron oxide, sassolite and kaolinite in the residual char. TGA showed that kaolin clay reinforced formulation; IF5-KC enhanced 49% residual weight than that of IF-Control formulation. XPS analysis showed that elemental composition of IF5-KC char residue gave 41.80% carbon content in the residual char. An accelerated weathering test ASTM D 6695-03 showed that IF5-KC coating sustained its integrity up to 90 days under accelerated weathering chamber.
Abstract: In this paper we have discussed the thermal behaviour of intumescent coating. Intumesce... more Abstract: In this paper we have discussed the thermal behaviour of intumescent coating. Intumescent coating is an insulating system designed to decrease heat transfer from a fire to substrate structure to maintain its integrity. The coating was based on expandable ...
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Papers by Faiz Ahmad
of delivering high performance nanocomposite materials. To utilize CNTs as effective reinforcement
in metal nanocomposites, appropriate dispersion and robust interfacial adhesion between individual
CNT and metal matrix have to be certain. This work presents a novel combined technique of
nanoscale dispersion (NSD) of functionalized multiwalled carbon nanotubes (MWCNTs) in copper
(Cu) matrix composite followed by powder injection molding (PIM). MWCNTs contents were varied
from 0 to 10 volume fraction. Evidences on the existence of functional groups and microstructural
analysis of the fabricated nanocomposites were determined using TEM, EDX, FESEM and FTIR.
Thermal conductivity and elasticity measurements were also performed. The results showed that
the impurities of the pristine MWCNTs such as Fe, Ni catalyst, and the amorphous carbon have
been significantly removed after sonication process. FESEM and TEM observations showed high
stability of MWCNTs at elevated temperatures and uniform dispersion of MWCNTs in Cu matrix at
different volume fractions and sintering temperatures (950, 1000 and 1050 C). The experimentally
measured thermal conductivities of Cu/MWCNTs nanocomposites showed remarkable increase
(11.25% higher than pure sintered Cu) with addition of 1 vol.% MWCNTs, while the modulus of elasticity
(Young’s modulus) of Cu/MWCNTs nanocomposites sintered at 1050 C for 2 h was increased
proportionally to the increment in MWCNTs contents.
(CNT) reinforced Cu nanocomposites. The effect of adding different amount of CNTs (0-10 vol.%) on the thermal and
mechanical behaviour of the fabricated nanocomposites is presented. Scanning electron microscope analysis revealed
homogenous dispersion of CNTs in Cu matrices at different CNTs contents. The experimentally measured thermal
conductivities of Cu/CNTs nanocomposites showed extraordinary increase (76% higher than pure sintered Cu) with
addition of 10 vol.% CNTs. As compared to the pure sintered Cu, increase in modulus of elasticity (Young’s modulus) of
Cu/CNTs nanocomposites sintered at 1050qC for 2.5 h was measured to be 48%. However, in case of 7.5 vol.% CNTs,
Young’s modulus was increased significantly about 51% compared to that of pure sintered Cu.
various amounts of Titanium Carbide (TiC) and Titanium Nitride (TiN) particles, the wear
behaviour was investigated using a pin-on-disc wear testing machine with varying parameters
such as normal load, reinforcement’s percentage and track velocity, the results show that the
wear of Al-12Si matrix reinforced by 5%, 10%, 15% of TiC particles at 150 rpm with 15 N
loads were: 73 mm3x 10-3, 61 mm3x 10-3, 50.5 mm3x 10-3 respectively which are less than the
wear for same composites at 225 rpm with 15 N. This is due to the length of rubbing is more
in case of higher speed. The results also show that the wear of the samples were decreased
with increasing the percentage of reinforcement of TiN at both sliding speed (150 rpm, and
225 rpm). The hardness of Al-12Si/TiC composites with 5% of TiC were found 50 and the
hardness of same composites with 15% of TiC reinforcements were 67which are less than the
hardness of Al-12Si/TiN composites with 15% TiN reinforcements. The microstructural
study of the composites before wear test showed uniform distribution of (TiC and TiN)
particles through the cross-section of the specimens and finer surfaces than matrix composite
after wear test. The mechanical properties such as hardness and wear resistance are observed
to be increased considerably compared to the matrix composite.
of delivering high performance nanocomposite materials. To utilize CNTs as effective reinforcement
in metal nanocomposites, appropriate dispersion and robust interfacial adhesion between individual
CNT and metal matrix have to be certain. This work presents a novel combined technique of
nanoscale dispersion (NSD) of functionalized multiwalled carbon nanotubes (MWCNTs) in copper
(Cu) matrix composite followed by powder injection molding (PIM). MWCNTs contents were varied
from 0 to 10 volume fraction. Evidences on the existence of functional groups and microstructural
analysis of the fabricated nanocomposites were determined using TEM, EDX, FESEM and FTIR.
Thermal conductivity and elasticity measurements were also performed. The results showed that
the impurities of the pristine MWCNTs such as Fe, Ni catalyst, and the amorphous carbon have
been significantly removed after sonication process. FESEM and TEM observations showed high
stability of MWCNTs at elevated temperatures and uniform dispersion of MWCNTs in Cu matrix at
different volume fractions and sintering temperatures (950, 1000 and 1050 C). The experimentally
measured thermal conductivities of Cu/MWCNTs nanocomposites showed remarkable increase
(11.25% higher than pure sintered Cu) with addition of 1 vol.% MWCNTs, while the modulus of elasticity
(Young’s modulus) of Cu/MWCNTs nanocomposites sintered at 1050 C for 2 h was increased
proportionally to the increment in MWCNTs contents.
(CNT) reinforced Cu nanocomposites. The effect of adding different amount of CNTs (0-10 vol.%) on the thermal and
mechanical behaviour of the fabricated nanocomposites is presented. Scanning electron microscope analysis revealed
homogenous dispersion of CNTs in Cu matrices at different CNTs contents. The experimentally measured thermal
conductivities of Cu/CNTs nanocomposites showed extraordinary increase (76% higher than pure sintered Cu) with
addition of 10 vol.% CNTs. As compared to the pure sintered Cu, increase in modulus of elasticity (Young’s modulus) of
Cu/CNTs nanocomposites sintered at 1050qC for 2.5 h was measured to be 48%. However, in case of 7.5 vol.% CNTs,
Young’s modulus was increased significantly about 51% compared to that of pure sintered Cu.
various amounts of Titanium Carbide (TiC) and Titanium Nitride (TiN) particles, the wear
behaviour was investigated using a pin-on-disc wear testing machine with varying parameters
such as normal load, reinforcement’s percentage and track velocity, the results show that the
wear of Al-12Si matrix reinforced by 5%, 10%, 15% of TiC particles at 150 rpm with 15 N
loads were: 73 mm3x 10-3, 61 mm3x 10-3, 50.5 mm3x 10-3 respectively which are less than the
wear for same composites at 225 rpm with 15 N. This is due to the length of rubbing is more
in case of higher speed. The results also show that the wear of the samples were decreased
with increasing the percentage of reinforcement of TiN at both sliding speed (150 rpm, and
225 rpm). The hardness of Al-12Si/TiC composites with 5% of TiC were found 50 and the
hardness of same composites with 15% of TiC reinforcements were 67which are less than the
hardness of Al-12Si/TiN composites with 15% TiN reinforcements. The microstructural
study of the composites before wear test showed uniform distribution of (TiC and TiN)
particles through the cross-section of the specimens and finer surfaces than matrix composite
after wear test. The mechanical properties such as hardness and wear resistance are observed
to be increased considerably compared to the matrix composite.