In this work, SrFe12O19/TiO2 nanocomposites
have been synthesized by a sol-gel method. The pure
S... more In this work, SrFe12O19/TiO2 nanocomposites have been synthesized by a sol-gel method. The pure SrFe12O19/TiO2 nanocomposites were obtained by hydrolysis of titanium tetraisopropoxide at pH = 3.5 with a post-calcination process at 500 ◦C. The magnetic results showed that the saturation magnetization and coercivity decreased with increasing of TiO2 content. Concerning the microwave absorption measurements in the microwave frequency range of 8–12 GHz (X-band), the SrFe12O19-30 wt% TiO2 nanocomposite exhibited the best absorption of −45 dB at 11.2 GHz with an absorption bandwidth of more than 1.5 GHz.
SrFe12O19–TiO2 nanocomposites are usually used for absorbing microwaves in military and civil
app... more SrFe12O19–TiO2 nanocomposites are usually used for absorbing microwaves in military and civil applications. In this work, microwave absorption properties of porous SrFe12O19 nanocomposites with 50% weight ratio of TiO2 have been investigated. 50% TiO2–50% SrFe12O19 nanocomposites were prepared by a controlled hydrolysis of titanium tetraisopropoxide in which SrFe12O19 nanoparticles were synthesized by a sol–gel auto combustion route. The morphology, crystalline structure and crystallite size of SrFe12O19–TiO2 nanocomposites were characterized by field emission scanning electron microscopy and X-ray powder diffraction. The magnetic measurements were carried out with a vibrating sample magnetometer. The microwave absorption was measured by a Vector Network Analyzer. The microwave absorption results indicated that the reflection losses for specimens with 52%–56% porosity and thicknesses of 1.8, 2.1 and 2.6 mm were not very low but minimum reflection loss for a specimen with 4.2 mm thickness reached upto 33 dB.
In this study, the effect of carboxyl-terminated butadiene-acrylonitrile liquid rubber on fractur... more In this study, the effect of carboxyl-terminated butadiene-acrylonitrile liquid rubber on fracture toughness of glassreinforced epoxy composites has been investigated. Fracture toughness tests were conducted in modes I, II and different mixed mode ratios. The data obtained from these tests have been analyzed by using different methods. Results indicated that interlaminar fracture toughness of composite specimens improved considerably through addition of carboxylterminated butadiene-acrylonitrile in modes I, II and mixed mode. Interlaminar fracture surfaces of the specimens were also characterized by field emission scanning electron microscope.
In this study, carboxyl-terminated butadiene acrylonitrile (CTBN) added to epoxy
resin to improve... more In this study, carboxyl-terminated butadiene acrylonitrile (CTBN) added to epoxy resin to improve the fracture property of resin and glass reinforced epoxy (GRE) composites. Tensile strength and Young’s modulus of unreinforced resin with/without modifier were examined. Plane strain fracture toughness (KIC) was calculated using single-edge-notch specimens that tested in three point bending (3PB) geometry. Results indicated that fracture toughness improve through increasing rubber modifier content. Fracture surfaces of the 3PB specimens were observed by using optical microscope and scanning electron microscope. Tensile properties perpendicular and parallel to the fibers direction were tested, respectively. GRE composite interlaminar fracture toughness increased with increasing rubber modifier in composite.
A novel electromagnetic levitational gas condensation (ELGC) system was designed and manufactured... more A novel electromagnetic levitational gas condensation (ELGC) system was designed and manufactured for the synthesis of aluminum nanoparticles. Both liquid and membrane filtration systems were used for collecting the nanoparticles. Effects of induction coil design, input power and gas flow rate were investigated. It was found that the wet collection in toluene resulted in a smaller particle size than the dry collection on membrane filter. While using low argon flow rate, coarser particles were produced, high argon flow rate intensified the particle coalescence. The best argon flow rate for the synthesis of aluminum nanoparticles was found about 10–15 lit/min.
316L stainless steel (SS) is one of the most consumable materials in orthopedic implants. Certain... more 316L stainless steel (SS) is one of the most consumable materials in orthopedic implants. Certain types of orthopedic implants such as monobloc hip stems are often made of two elements welded together. In this study, effect of TIG welding on corrosion behavior of 316L stainless steel in physiological solution was investigated. In this method, filler metal wasn't used due to the small thickness of samples and it was welded to lap form. Corrosion behavior in physiological solution at 37 °C was investigated with potentiodynamic polarization curves. Microstructure of base metal (BM) and weld metal (WM) was studied with scanning electronic microscopy (SEM). The corrosion behavior of weld metal, base metal and couple (BM and WM together) was compared together. For detecting microstructure and phases in BM and WM, X-ray diffraction analysis was done. Finally, post-weld heat treatment (PWHT) was performed on as-welded samples. Results indicated that corrosion behavior of WM was better than the BM. This phenomenon was attributed to secondary phases that were present in the BM. Secondary phases in the weld metal are dissolved when the base metal is melting due to the welding process. Based on the results of electrochemical analysis, it was determined that the corrosion rate of a couple was more than of other parts. Heat affected zone (HAZ) is responsible for this phenomenon. The adjacent zones of the weld metal are classically less corrosion resistant, thereby being attacked preferentially when the steel is exposed to corrosive environments. PWHT decreased the corrosion rate of the couple.
In this work, SrFe12O19/TiO2 nanocomposites
have been synthesized by a sol-gel method. The pure
S... more In this work, SrFe12O19/TiO2 nanocomposites have been synthesized by a sol-gel method. The pure SrFe12O19/TiO2 nanocomposites were obtained by hydrolysis of titanium tetraisopropoxide at pH = 3.5 with a post-calcination process at 500 ◦C. The magnetic results showed that the saturation magnetization and coercivity decreased with increasing of TiO2 content. Concerning the microwave absorption measurements in the microwave frequency range of 8–12 GHz (X-band), the SrFe12O19-30 wt% TiO2 nanocomposite exhibited the best absorption of −45 dB at 11.2 GHz with an absorption bandwidth of more than 1.5 GHz.
SrFe12O19–TiO2 nanocomposites are usually used for absorbing microwaves in military and civil
app... more SrFe12O19–TiO2 nanocomposites are usually used for absorbing microwaves in military and civil applications. In this work, microwave absorption properties of porous SrFe12O19 nanocomposites with 50% weight ratio of TiO2 have been investigated. 50% TiO2–50% SrFe12O19 nanocomposites were prepared by a controlled hydrolysis of titanium tetraisopropoxide in which SrFe12O19 nanoparticles were synthesized by a sol–gel auto combustion route. The morphology, crystalline structure and crystallite size of SrFe12O19–TiO2 nanocomposites were characterized by field emission scanning electron microscopy and X-ray powder diffraction. The magnetic measurements were carried out with a vibrating sample magnetometer. The microwave absorption was measured by a Vector Network Analyzer. The microwave absorption results indicated that the reflection losses for specimens with 52%–56% porosity and thicknesses of 1.8, 2.1 and 2.6 mm were not very low but minimum reflection loss for a specimen with 4.2 mm thickness reached upto 33 dB.
In this study, the effect of carboxyl-terminated butadiene-acrylonitrile liquid rubber on fractur... more In this study, the effect of carboxyl-terminated butadiene-acrylonitrile liquid rubber on fracture toughness of glassreinforced epoxy composites has been investigated. Fracture toughness tests were conducted in modes I, II and different mixed mode ratios. The data obtained from these tests have been analyzed by using different methods. Results indicated that interlaminar fracture toughness of composite specimens improved considerably through addition of carboxylterminated butadiene-acrylonitrile in modes I, II and mixed mode. Interlaminar fracture surfaces of the specimens were also characterized by field emission scanning electron microscope.
In this study, carboxyl-terminated butadiene acrylonitrile (CTBN) added to epoxy
resin to improve... more In this study, carboxyl-terminated butadiene acrylonitrile (CTBN) added to epoxy resin to improve the fracture property of resin and glass reinforced epoxy (GRE) composites. Tensile strength and Young’s modulus of unreinforced resin with/without modifier were examined. Plane strain fracture toughness (KIC) was calculated using single-edge-notch specimens that tested in three point bending (3PB) geometry. Results indicated that fracture toughness improve through increasing rubber modifier content. Fracture surfaces of the 3PB specimens were observed by using optical microscope and scanning electron microscope. Tensile properties perpendicular and parallel to the fibers direction were tested, respectively. GRE composite interlaminar fracture toughness increased with increasing rubber modifier in composite.
A novel electromagnetic levitational gas condensation (ELGC) system was designed and manufactured... more A novel electromagnetic levitational gas condensation (ELGC) system was designed and manufactured for the synthesis of aluminum nanoparticles. Both liquid and membrane filtration systems were used for collecting the nanoparticles. Effects of induction coil design, input power and gas flow rate were investigated. It was found that the wet collection in toluene resulted in a smaller particle size than the dry collection on membrane filter. While using low argon flow rate, coarser particles were produced, high argon flow rate intensified the particle coalescence. The best argon flow rate for the synthesis of aluminum nanoparticles was found about 10–15 lit/min.
316L stainless steel (SS) is one of the most consumable materials in orthopedic implants. Certain... more 316L stainless steel (SS) is one of the most consumable materials in orthopedic implants. Certain types of orthopedic implants such as monobloc hip stems are often made of two elements welded together. In this study, effect of TIG welding on corrosion behavior of 316L stainless steel in physiological solution was investigated. In this method, filler metal wasn't used due to the small thickness of samples and it was welded to lap form. Corrosion behavior in physiological solution at 37 °C was investigated with potentiodynamic polarization curves. Microstructure of base metal (BM) and weld metal (WM) was studied with scanning electronic microscopy (SEM). The corrosion behavior of weld metal, base metal and couple (BM and WM together) was compared together. For detecting microstructure and phases in BM and WM, X-ray diffraction analysis was done. Finally, post-weld heat treatment (PWHT) was performed on as-welded samples. Results indicated that corrosion behavior of WM was better than the BM. This phenomenon was attributed to secondary phases that were present in the BM. Secondary phases in the weld metal are dissolved when the base metal is melting due to the welding process. Based on the results of electrochemical analysis, it was determined that the corrosion rate of a couple was more than of other parts. Heat affected zone (HAZ) is responsible for this phenomenon. The adjacent zones of the weld metal are classically less corrosion resistant, thereby being attacked preferentially when the steel is exposed to corrosive environments. PWHT decreased the corrosion rate of the couple.
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Papers by reza dadfar
have been synthesized by a sol-gel method. The pure
SrFe12O19/TiO2 nanocomposites were obtained by hydrolysis
of titanium tetraisopropoxide at pH = 3.5 with a
post-calcination process at 500 ◦C. The magnetic results
showed that the saturation magnetization and coercivity
decreased with increasing of TiO2 content. Concerning the
microwave absorption measurements in the microwave frequency
range of 8–12 GHz (X-band), the SrFe12O19-30
wt% TiO2 nanocomposite exhibited the best absorption of
−45 dB at 11.2 GHz with an absorption bandwidth of more
than 1.5 GHz.
applications. In this work, microwave absorption properties of porous SrFe12O19 nanocomposites with
50% weight ratio of TiO2 have been investigated. 50% TiO2–50% SrFe12O19 nanocomposites were
prepared by a controlled hydrolysis of titanium tetraisopropoxide in which SrFe12O19 nanoparticles
were synthesized by a sol–gel auto combustion route. The morphology, crystalline structure and
crystallite size of SrFe12O19–TiO2 nanocomposites were characterized by field emission scanning
electron microscopy and X-ray powder diffraction. The magnetic measurements were carried out with
a vibrating sample magnetometer. The microwave absorption was measured by a Vector Network
Analyzer. The microwave absorption results indicated that the reflection losses for specimens with
52%–56% porosity and thicknesses of 1.8, 2.1 and 2.6 mm were not very low but minimum reflection
loss for a specimen with 4.2 mm thickness reached upto 33 dB.
epoxy composites has been investigated. Fracture toughness tests were conducted in modes I, II and different
mixed mode ratios. The data obtained from these tests have been analyzed by using different methods. Results indicated
that interlaminar fracture toughness of composite specimens improved considerably through addition of carboxylterminated
butadiene-acrylonitrile in modes I, II and mixed mode. Interlaminar fracture surfaces of the specimens
were also characterized by field emission scanning electron microscope.
resin to improve the fracture property of resin and glass reinforced epoxy (GRE)
composites. Tensile strength and Young’s modulus of unreinforced resin
with/without modifier were examined. Plane strain fracture toughness (KIC) was
calculated using single-edge-notch specimens that tested in three point bending
(3PB) geometry. Results indicated that fracture toughness improve through
increasing rubber modifier content. Fracture surfaces of the 3PB specimens were
observed by using optical microscope and scanning electron microscope. Tensile
properties perpendicular and parallel to the fibers direction were tested,
respectively. GRE composite interlaminar fracture toughness increased with
increasing rubber modifier in composite.
for the synthesis of aluminum nanoparticles. Both liquid and membrane filtration systems
were used for collecting the nanoparticles. Effects of induction coil design, input power and gas flow
rate were investigated. It was found that the wet collection in toluene resulted in a smaller particle
size than the dry collection on membrane filter. While using low argon flow rate, coarser particles
were produced, high argon flow rate intensified the particle coalescence. The best argon flow rate
for the synthesis of aluminum nanoparticles was found about 10–15 lit/min.
hip stems are often made of two elements welded together. In this study, effect of TIG welding on corrosion behavior of 316L stainless steel
in physiological solution was investigated. In this method, filler metal wasn't used due to the small thickness of samples and it was welded to lap
form. Corrosion behavior in physiological solution at 37 °C was investigated with potentiodynamic polarization curves. Microstructure of base
metal (BM) and weld metal (WM) was studied with scanning electronic microscopy (SEM). The corrosion behavior of weld metal, base metal and
couple (BM and WM together) was compared together. For detecting microstructure and phases in BM and WM, X-ray diffraction analysis was
done. Finally, post-weld heat treatment (PWHT) was performed on as-welded samples. Results indicated that corrosion behavior of WM was
better than the BM. This phenomenon was attributed to secondary phases that were present in the BM. Secondary phases in the weld metal are
dissolved when the base metal is melting due to the welding process. Based on the results of electrochemical analysis, it was determined that the
corrosion rate of a couple was more than of other parts. Heat affected zone (HAZ) is responsible for this phenomenon. The adjacent zones of the
weld metal are classically less corrosion resistant, thereby being attacked preferentially when the steel is exposed to corrosive environments.
PWHT decreased the corrosion rate of the couple.
have been synthesized by a sol-gel method. The pure
SrFe12O19/TiO2 nanocomposites were obtained by hydrolysis
of titanium tetraisopropoxide at pH = 3.5 with a
post-calcination process at 500 ◦C. The magnetic results
showed that the saturation magnetization and coercivity
decreased with increasing of TiO2 content. Concerning the
microwave absorption measurements in the microwave frequency
range of 8–12 GHz (X-band), the SrFe12O19-30
wt% TiO2 nanocomposite exhibited the best absorption of
−45 dB at 11.2 GHz with an absorption bandwidth of more
than 1.5 GHz.
applications. In this work, microwave absorption properties of porous SrFe12O19 nanocomposites with
50% weight ratio of TiO2 have been investigated. 50% TiO2–50% SrFe12O19 nanocomposites were
prepared by a controlled hydrolysis of titanium tetraisopropoxide in which SrFe12O19 nanoparticles
were synthesized by a sol–gel auto combustion route. The morphology, crystalline structure and
crystallite size of SrFe12O19–TiO2 nanocomposites were characterized by field emission scanning
electron microscopy and X-ray powder diffraction. The magnetic measurements were carried out with
a vibrating sample magnetometer. The microwave absorption was measured by a Vector Network
Analyzer. The microwave absorption results indicated that the reflection losses for specimens with
52%–56% porosity and thicknesses of 1.8, 2.1 and 2.6 mm were not very low but minimum reflection
loss for a specimen with 4.2 mm thickness reached upto 33 dB.
epoxy composites has been investigated. Fracture toughness tests were conducted in modes I, II and different
mixed mode ratios. The data obtained from these tests have been analyzed by using different methods. Results indicated
that interlaminar fracture toughness of composite specimens improved considerably through addition of carboxylterminated
butadiene-acrylonitrile in modes I, II and mixed mode. Interlaminar fracture surfaces of the specimens
were also characterized by field emission scanning electron microscope.
resin to improve the fracture property of resin and glass reinforced epoxy (GRE)
composites. Tensile strength and Young’s modulus of unreinforced resin
with/without modifier were examined. Plane strain fracture toughness (KIC) was
calculated using single-edge-notch specimens that tested in three point bending
(3PB) geometry. Results indicated that fracture toughness improve through
increasing rubber modifier content. Fracture surfaces of the 3PB specimens were
observed by using optical microscope and scanning electron microscope. Tensile
properties perpendicular and parallel to the fibers direction were tested,
respectively. GRE composite interlaminar fracture toughness increased with
increasing rubber modifier in composite.
for the synthesis of aluminum nanoparticles. Both liquid and membrane filtration systems
were used for collecting the nanoparticles. Effects of induction coil design, input power and gas flow
rate were investigated. It was found that the wet collection in toluene resulted in a smaller particle
size than the dry collection on membrane filter. While using low argon flow rate, coarser particles
were produced, high argon flow rate intensified the particle coalescence. The best argon flow rate
for the synthesis of aluminum nanoparticles was found about 10–15 lit/min.
hip stems are often made of two elements welded together. In this study, effect of TIG welding on corrosion behavior of 316L stainless steel
in physiological solution was investigated. In this method, filler metal wasn't used due to the small thickness of samples and it was welded to lap
form. Corrosion behavior in physiological solution at 37 °C was investigated with potentiodynamic polarization curves. Microstructure of base
metal (BM) and weld metal (WM) was studied with scanning electronic microscopy (SEM). The corrosion behavior of weld metal, base metal and
couple (BM and WM together) was compared together. For detecting microstructure and phases in BM and WM, X-ray diffraction analysis was
done. Finally, post-weld heat treatment (PWHT) was performed on as-welded samples. Results indicated that corrosion behavior of WM was
better than the BM. This phenomenon was attributed to secondary phases that were present in the BM. Secondary phases in the weld metal are
dissolved when the base metal is melting due to the welding process. Based on the results of electrochemical analysis, it was determined that the
corrosion rate of a couple was more than of other parts. Heat affected zone (HAZ) is responsible for this phenomenon. The adjacent zones of the
weld metal are classically less corrosion resistant, thereby being attacked preferentially when the steel is exposed to corrosive environments.
PWHT decreased the corrosion rate of the couple.