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Volume 29 (2011): Issue 1 (March 2011)

Journal Details
Format
Journal
eISSN
2083-134X
ISSN
2083-1331
First Published
16 Apr 2011
Publication timeframe
4 times per year
Languages
English

Search

Volume 29 (2011): Issue 4 (December 2011)

Journal Details
Format
Journal
eISSN
2083-134X
ISSN
2083-1331
First Published
16 Apr 2011
Publication timeframe
4 times per year
Languages
English

Search

11 Articles
Open Access

Dependence of growth conditions on copper germanate nanowires and their electrochemical characteristics

Published Online: 08 May 2012
Page range: 241 - 247

Abstract

Abstract

Copper germanate (CuGeO3) nanowires have been synthesized by the hydrothermal deposition process using GeO2 and copper foil as the resource as well as the deposition substrate. The factors including hydrothermal temperature, pressure and duration of the process were investigated in order to analyze the processing parameters that control the formation process, morphology and size of the nanowires. The dependence of the nanowires properties on the growth conditions shows that the CuGeO3 nanowires can be synthesized in a large range of different hydrothermal parameters from 400 °C to 250 °C. The hydrothermal pressure has an important effect on the formation and growth of the CuGeO3 nanowires. The CuGeO3 nanowires exhibit good electrochemical cyclic voltammetry characteristics owing to offering many advantages in sensing applications including their small size, high aspect ratio and conductance.

Keywords

  • copper germanate nanowires
  • growth condition dependence
  • electrochemical characteristics
Open Access

Fabrication and thermal shock resistance of HfB2-SiC composite with B4C additives

Published Online: 08 May 2012
Page range: 248 - 252

Abstract

Abstract

A HfB2 based ceramic matrix composite containing 20 vol.% SiC particles with 2 vol.% B4C as sintering additives was fabricated by hot-pressed sintering. The microstructure and properties, especially the thermal shock resistance of the composite were investigated. Results showed that the addition of B4C improved the powder sinterability and led to obtaining nearly full dense composite. The flexural strength and fracture toughness of the composite were 771 MPa and 7.06 MPam1/2, respectively. The thermal shock resistance tests indicated that the residual strength decreased significantly when the thermal shock temperature difference was higher than 600 °C. The large number of microcracks on the sample surface was the main reason for the catastrophic failure.

Keywords

  • ceramic matrix
  • mechanical properties
  • microstructure
Open Access

Electrical properties comparison of NTC thermistors prepared from nanopowders and in mixed oxide process

Published Online: 08 May 2012
Page range: 253 - 259

Abstract

Abstract

We have synthesized and studied the effect of cobalt doping on the electrical properties of NTC thermistors with the composition of NiCoxMn2−x O4 (x = 0.0, 0.4, 0.8, 1.2, 1.6). The electrical properties of NTC thermistors prepared from nanopowders by gel auto-combustion and mixed oxides processes have been compared. The measurement results indicate that the fluctuations of B value in the samples made from nanopowders are smaller than that in the samples prepared using mixed oxides method. The electrical properties of these ceramics depend strongly on their grain size. The sintering time and temperature were chosen the same for the samples made from the powders prepared by the two methods. It was found that the samples made from nanopowders have smaller grain sizes.

Keywords

  • nanopowders
  • Ni-Co-Mn
  • NTC thermistors
Open Access

Reactive ion etching of GaN and AlGaN/GaN assisted by Cl2/BCl3

Published Online: 08 May 2012
Page range: 260 - 265

Abstract

Abstract

This work reports on the latest results of etching of different AlxGa1−x N/GaN heterostructures in relation to percentage composition of aluminum. The etching processes were carried out in a reactive ion etching (RIE) system using the mixture of BCl3/Cl2/Ar. The topography of the heterostructures surfaces and the slope were controlled using atomic force microsopy (AFM) technique. The photoluminescence spectra were used to determine the surface damage and to calculate the Al content in AlGaN/GaN heterostructures commonly used for high electron mobility transistors (HEMTs) fabrication.

Keywords

  • plasma
  • RIE
  • reactive ion etching
  • Cl2
  • BCl3
  • HEMT
Open Access

A general formula for the transmission coefficient through a barrier and application to I–V characteristic

Published Online: 08 May 2012
Page range: 266 - 271

Abstract

Abstract

A general formula providing the transmission coefficient through a given barrier, sandwiched by semiconductor reservoirs under bias is presented in terms of the incoming carrier energy and the logarithmic wave function derivative at the start of the barrier. Furthermore, the formula involves the carrier effective masses in the barrier and reservoir regions. The procedure employed is based on solving an appropriate Riccati equation governing the logarithmic derivative along the barrier width at the end of which it is known in terms of the carrier energy and applied bias. On account of the facility provided for obtaining the transmission coefficient we obtained the I–V characteristic of a quantum dot carved barrier, which exhibits a region of quite a large negative differential resistance together with a high peak to valley ratio. Under the circumstances, the possibility of developing a nanostructure switch utilizing a small variation in the applied bias exists.

Keywords

  • transmission coefficient
  • momentum related quantity
  • I–V characteristic
Open Access

Characterization of various Eu2+ sites in Ca2SiO4:Eu2+ and Ba2SiO4:Eu2+ by high-pressure spectroscopy

Published Online: 08 May 2012
Page range: 272 - 277

Abstract

Abstract

Photoluminescence of Ba2SiO4 and Ca2SiO4 activated with Eu2+ was investigated at various temperatures (from 10 K to 300 K) and pressures (from ambient to 200 kbar). At ambient pressure and room temperature, under UV excitation both phosphors yielded a green emission band with maxima at 505 nm and 510 nm for Ba2SiO4 and Ca2SiO4, respectively. The energies of these bands depended on pressure; the pressure shifts were −12:55 cm−1/kbar for Ba2SiO4:Eu2+; and −5:59 cm−1/kbar for Ca2SiO4:Eu2+. In the case of Ca2SiO4:Eu2+, we observed additional broadband emission at lower energies with a maximum at 610 nm (orange band). The orange and green emission in Ca2SiO4:Eu2+ had different excitation spectra: the green band could be excited at wavelengths shorter than 470 nm, whereas the orange band — at wavelengths shorter than 520 nm. The pressure caused a red shift of orange emission of 7.83 cm−1/kbar. The emission peaked at 510 nm was attributed to the 4f65d→4f7(8S7=2) transition of Eu2+ in the β — Ca2SiO4:Eu2+ phase, whereas the emission peaked at 610 nm — to the γ — Ca2SiO4:Eu2+ phase. The emission of Ba2SiO4:Eu2+ peaked at 505 nm was attributed to the 4f65d→ 4f7(8S7/2) transition of Eu2+ in the β — Ba2SiO4 phase.

Keywords

  • high pressure spectroscopy
  • Eu2+
  • silicates
Open Access

Study on etching anisotropy of Si(hkl) planes in solutions with different KOH and isopropyl alcohol concentrations

Published Online: 08 May 2012
Page range: 278 - 284

Abstract

Abstract

The paper deals with wet chemical anisotropic etching of Si(hkl) wafers in KOH solutions containing isopropyl alcohol. The impact of KOH and alcohol concentrations on the etch rates of (hkl) planes is shown. The effect of KOH concentration in pure KOH solutions resembles the one in KOH solutions non-saturated with alcohol and is different from the one in KOH solutions saturated with isopropanol. The increase in alcohol concentration in the etching solution generally reduces the etch rates of the selected (hkl) planes. However, when the alcohol concentration reaches the saturation level, the (100) and (311) etch rates increase. This is difficult to explain since the increased alcohol concentration should cause enhanced adsorption of the alcohol molecules on Si surface, as it is suggested by surface tension measurements. Thus, the denser adsorption layer should lead to the etch rate reduction. The influence of isopropanol concentration on the morphology of the (hkl) surfaces is also studied. The increase in the alcohol concentration leads to disappearance of hillocks on (100) and (h11) surfaces.

Keywords

  • anisotropic etching
  • silicon surface
  • potassium hydroxide
  • isopropanol concentration
  • (hkl) planes
Open Access

Barrier properties of hydrogenated acrylonitrile-butadiene rubber composites containing modified layered aluminosilicates

Published Online: 08 May 2012
Page range: 285 - 291

Abstract

Abstract

The resistance to permeation by the selected solvents of flat membranes made of cured hydrogenated acrylonitrile-butadiene rubber (HNBR) materials without any fillers and containing 5 phr of layered aluminosilicate nanofiller (bentonite), modified with various types of ammonium salts or N330 type carbon black, was investigated. The barrier properties were assessed on the basis of the breakthrough time of a liquid with low (cyclohexane) or average (butyl acetate) thermodynamic affinity to HNBR, determined according to EN 6529:2001, through a cured elastomer sample.

The addition of bentonite, irrespectively of the method of modification of its particles, was found to increase the cured HNBR breakthrough time by 20 – 35 % in the case of slowly permeating non-polar cyclohexane, and by 50 – 130 % in the case of polar butyl acetate permeating more rapidly, in comparison with the barrier material containing no filler. The layered aluminosilicate nanofillers increased the breakthrough time of the material sample for both the tested solvents. In particular, the breakthrough time for polar butyl acetate was even longer than for conventional carbon black. Additionally, the increase of the breakthrough time was observed to depend on the modifier of bentonite particle surface.

Keywords

  • solvents permeation
  • barrier material
  • elastomer
  • nanofillers
  • layered aluminosilicate
Open Access

Systematic study on synthesis and purification of double-walled carbon nanotubes synthesized via CVD

Published Online: 08 May 2012
Page range: 292 - 298

Abstract

Abstract

Carbon nanotubes have unique properties, such as thermal and electrical conductance, which could be useful in the fields of aerospace, microelectronics and biotechnology. However, these properties may vary widely depending on the dimensions, uniformity and purity of the nanotube. Nanotube samples typically contain a significant percentage of more allotropes forms of carbon as well as metal particles left over from catalysts used in manufacturing. Purity characterization of double-walled carbon nanotubes (DWCNTs) is an increasingly popular topic in the field of carbon nanotechnology. In this study, DWCNTs were synthesized in a catalytic reaction, using Fe:MgO as catalyst and methane or methane/ethanol as carbon feedstock for chemical vapor deposition (CVD). The addition of ethanol as carbon feedstock allowed to investigate the influence of oxygen on the sample quality. The purification of the as-produced material from the metallic particles and the catalyst support was performed by sonication in an acid solution. The influence of the duration of the acid treatment using ultrasound on the sample purity was investigated, and the optimal value of this parameter was found. Transmission electron microscopy (TEM) images confirmed the removal of impurities and served to elucidate the morphology of the samples. The purity of carbon nanotubes was analyzed using thermal gravimetric analysis (TGA). The Raman spectra of the samples, as a measure of the concentration of defects, were also reported.

Keywords

  • Chemical vapor deposition (CVD)
  • carbon nanotubes
  • Raman spectroscopy
  • high-resolution transmission electron microscopy (HRTEM)
Open Access

Synthesis and characterization of iron-filled multi-walled nanotubes

Published Online: 08 May 2012
Page range: 299 - 304

Abstract

Abstract

The growth of iron filled multiwalled carbon nanotubes (Fe-MWCNT) using chemical vapour deposition (CVD) has been widely studied. Considering the remarkable magnetic and structural properties of Fe-MWCNT, these materials have been applied in numerous areas. In particular their biomedical application has been explored, where Fe-MWCNT can be used in hyperthermia, acting as a local nano-heater at cellular level. Regarding this aim, the reproducible and highly purified ferromagnetically filled samples of carbon nanotubes are still required. There are several parameters during the synthesis process that influence the properties of the nanotubes. The most favourable temperature of the CNT growth is probably one of the most important issues and its optimisation is crucial. In the current study, the Fe-MWCNT were grown at different temperatures ranging from 650 °C to 1050 °C. Additionally, a comparison between two different CVD systems and two carbon sources are also here presented. The Fe-MWCNT were characterised using diverse techniques regarding the evaluation of their morphology, filling ratio, and purity. Observations showed a strong influence of the growth temperature on the morphology and properties of the Fe-MWCNT. The samples characterisation was performed using Raman spectroscopy, thermogravimetric analysis (TGA), X ray diffraction (XRD), and transmission electron microscopy analysis (TEM).

Keywords

  • carbon nanotubes
  • iron filling
  • endohedral functionalization
  • TEM
  • Raman spectroscopy
Open Access

Influence of grain boundaries misorientation angle on intergranular corrosion in 2024-T3 aluminium

Published Online: 08 May 2012
Page range: 305 - 311

Abstract

Abstract

The special attention has been paid to the influence of misorientation angle of a random grain boundary (GB) on susceptibility to intergranular attack. The detailed observations of the microstructure of the intergranular corrosion (IGC) in 2024-T3 aluminium alloy (AA2024-T3) subjected to galvanic corrosion tests in two different solutions containing chloride ions (0.1 M and 0.5 M NaCl) were carried out using Scanning Electron Microscopy (SEM). The Electron Backscattered Diffraction (EBSD) technique was used to determine the grain boundary character distribution (GBCD) in the initial sample and a GBCD of corroded grain boundaries on a sample subjected to the corrosion test. The results are discussed in terms of the influence of the misorientation angle on the susceptibility of the grain boundaries to corrosion.

Keywords

  • EBSD 2024
  • intergranular corrosion
  • grain boundaries
11 Articles
Open Access

Dependence of growth conditions on copper germanate nanowires and their electrochemical characteristics

Published Online: 08 May 2012
Page range: 241 - 247

Abstract

Abstract

Copper germanate (CuGeO3) nanowires have been synthesized by the hydrothermal deposition process using GeO2 and copper foil as the resource as well as the deposition substrate. The factors including hydrothermal temperature, pressure and duration of the process were investigated in order to analyze the processing parameters that control the formation process, morphology and size of the nanowires. The dependence of the nanowires properties on the growth conditions shows that the CuGeO3 nanowires can be synthesized in a large range of different hydrothermal parameters from 400 °C to 250 °C. The hydrothermal pressure has an important effect on the formation and growth of the CuGeO3 nanowires. The CuGeO3 nanowires exhibit good electrochemical cyclic voltammetry characteristics owing to offering many advantages in sensing applications including their small size, high aspect ratio and conductance.

Keywords

  • copper germanate nanowires
  • growth condition dependence
  • electrochemical characteristics
Open Access

Fabrication and thermal shock resistance of HfB2-SiC composite with B4C additives

Published Online: 08 May 2012
Page range: 248 - 252

Abstract

Abstract

A HfB2 based ceramic matrix composite containing 20 vol.% SiC particles with 2 vol.% B4C as sintering additives was fabricated by hot-pressed sintering. The microstructure and properties, especially the thermal shock resistance of the composite were investigated. Results showed that the addition of B4C improved the powder sinterability and led to obtaining nearly full dense composite. The flexural strength and fracture toughness of the composite were 771 MPa and 7.06 MPam1/2, respectively. The thermal shock resistance tests indicated that the residual strength decreased significantly when the thermal shock temperature difference was higher than 600 °C. The large number of microcracks on the sample surface was the main reason for the catastrophic failure.

Keywords

  • ceramic matrix
  • mechanical properties
  • microstructure
Open Access

Electrical properties comparison of NTC thermistors prepared from nanopowders and in mixed oxide process

Published Online: 08 May 2012
Page range: 253 - 259

Abstract

Abstract

We have synthesized and studied the effect of cobalt doping on the electrical properties of NTC thermistors with the composition of NiCoxMn2−x O4 (x = 0.0, 0.4, 0.8, 1.2, 1.6). The electrical properties of NTC thermistors prepared from nanopowders by gel auto-combustion and mixed oxides processes have been compared. The measurement results indicate that the fluctuations of B value in the samples made from nanopowders are smaller than that in the samples prepared using mixed oxides method. The electrical properties of these ceramics depend strongly on their grain size. The sintering time and temperature were chosen the same for the samples made from the powders prepared by the two methods. It was found that the samples made from nanopowders have smaller grain sizes.

Keywords

  • nanopowders
  • Ni-Co-Mn
  • NTC thermistors
Open Access

Reactive ion etching of GaN and AlGaN/GaN assisted by Cl2/BCl3

Published Online: 08 May 2012
Page range: 260 - 265

Abstract

Abstract

This work reports on the latest results of etching of different AlxGa1−x N/GaN heterostructures in relation to percentage composition of aluminum. The etching processes were carried out in a reactive ion etching (RIE) system using the mixture of BCl3/Cl2/Ar. The topography of the heterostructures surfaces and the slope were controlled using atomic force microsopy (AFM) technique. The photoluminescence spectra were used to determine the surface damage and to calculate the Al content in AlGaN/GaN heterostructures commonly used for high electron mobility transistors (HEMTs) fabrication.

Keywords

  • plasma
  • RIE
  • reactive ion etching
  • Cl2
  • BCl3
  • HEMT
Open Access

A general formula for the transmission coefficient through a barrier and application to I–V characteristic

Published Online: 08 May 2012
Page range: 266 - 271

Abstract

Abstract

A general formula providing the transmission coefficient through a given barrier, sandwiched by semiconductor reservoirs under bias is presented in terms of the incoming carrier energy and the logarithmic wave function derivative at the start of the barrier. Furthermore, the formula involves the carrier effective masses in the barrier and reservoir regions. The procedure employed is based on solving an appropriate Riccati equation governing the logarithmic derivative along the barrier width at the end of which it is known in terms of the carrier energy and applied bias. On account of the facility provided for obtaining the transmission coefficient we obtained the I–V characteristic of a quantum dot carved barrier, which exhibits a region of quite a large negative differential resistance together with a high peak to valley ratio. Under the circumstances, the possibility of developing a nanostructure switch utilizing a small variation in the applied bias exists.

Keywords

  • transmission coefficient
  • momentum related quantity
  • I–V characteristic
Open Access

Characterization of various Eu2+ sites in Ca2SiO4:Eu2+ and Ba2SiO4:Eu2+ by high-pressure spectroscopy

Published Online: 08 May 2012
Page range: 272 - 277

Abstract

Abstract

Photoluminescence of Ba2SiO4 and Ca2SiO4 activated with Eu2+ was investigated at various temperatures (from 10 K to 300 K) and pressures (from ambient to 200 kbar). At ambient pressure and room temperature, under UV excitation both phosphors yielded a green emission band with maxima at 505 nm and 510 nm for Ba2SiO4 and Ca2SiO4, respectively. The energies of these bands depended on pressure; the pressure shifts were −12:55 cm−1/kbar for Ba2SiO4:Eu2+; and −5:59 cm−1/kbar for Ca2SiO4:Eu2+. In the case of Ca2SiO4:Eu2+, we observed additional broadband emission at lower energies with a maximum at 610 nm (orange band). The orange and green emission in Ca2SiO4:Eu2+ had different excitation spectra: the green band could be excited at wavelengths shorter than 470 nm, whereas the orange band — at wavelengths shorter than 520 nm. The pressure caused a red shift of orange emission of 7.83 cm−1/kbar. The emission peaked at 510 nm was attributed to the 4f65d→4f7(8S7=2) transition of Eu2+ in the β — Ca2SiO4:Eu2+ phase, whereas the emission peaked at 610 nm — to the γ — Ca2SiO4:Eu2+ phase. The emission of Ba2SiO4:Eu2+ peaked at 505 nm was attributed to the 4f65d→ 4f7(8S7/2) transition of Eu2+ in the β — Ba2SiO4 phase.

Keywords

  • high pressure spectroscopy
  • Eu2+
  • silicates
Open Access

Study on etching anisotropy of Si(hkl) planes in solutions with different KOH and isopropyl alcohol concentrations

Published Online: 08 May 2012
Page range: 278 - 284

Abstract

Abstract

The paper deals with wet chemical anisotropic etching of Si(hkl) wafers in KOH solutions containing isopropyl alcohol. The impact of KOH and alcohol concentrations on the etch rates of (hkl) planes is shown. The effect of KOH concentration in pure KOH solutions resembles the one in KOH solutions non-saturated with alcohol and is different from the one in KOH solutions saturated with isopropanol. The increase in alcohol concentration in the etching solution generally reduces the etch rates of the selected (hkl) planes. However, when the alcohol concentration reaches the saturation level, the (100) and (311) etch rates increase. This is difficult to explain since the increased alcohol concentration should cause enhanced adsorption of the alcohol molecules on Si surface, as it is suggested by surface tension measurements. Thus, the denser adsorption layer should lead to the etch rate reduction. The influence of isopropanol concentration on the morphology of the (hkl) surfaces is also studied. The increase in the alcohol concentration leads to disappearance of hillocks on (100) and (h11) surfaces.

Keywords

  • anisotropic etching
  • silicon surface
  • potassium hydroxide
  • isopropanol concentration
  • (hkl) planes
Open Access

Barrier properties of hydrogenated acrylonitrile-butadiene rubber composites containing modified layered aluminosilicates

Published Online: 08 May 2012
Page range: 285 - 291

Abstract

Abstract

The resistance to permeation by the selected solvents of flat membranes made of cured hydrogenated acrylonitrile-butadiene rubber (HNBR) materials without any fillers and containing 5 phr of layered aluminosilicate nanofiller (bentonite), modified with various types of ammonium salts or N330 type carbon black, was investigated. The barrier properties were assessed on the basis of the breakthrough time of a liquid with low (cyclohexane) or average (butyl acetate) thermodynamic affinity to HNBR, determined according to EN 6529:2001, through a cured elastomer sample.

The addition of bentonite, irrespectively of the method of modification of its particles, was found to increase the cured HNBR breakthrough time by 20 – 35 % in the case of slowly permeating non-polar cyclohexane, and by 50 – 130 % in the case of polar butyl acetate permeating more rapidly, in comparison with the barrier material containing no filler. The layered aluminosilicate nanofillers increased the breakthrough time of the material sample for both the tested solvents. In particular, the breakthrough time for polar butyl acetate was even longer than for conventional carbon black. Additionally, the increase of the breakthrough time was observed to depend on the modifier of bentonite particle surface.

Keywords

  • solvents permeation
  • barrier material
  • elastomer
  • nanofillers
  • layered aluminosilicate
Open Access

Systematic study on synthesis and purification of double-walled carbon nanotubes synthesized via CVD

Published Online: 08 May 2012
Page range: 292 - 298

Abstract

Abstract

Carbon nanotubes have unique properties, such as thermal and electrical conductance, which could be useful in the fields of aerospace, microelectronics and biotechnology. However, these properties may vary widely depending on the dimensions, uniformity and purity of the nanotube. Nanotube samples typically contain a significant percentage of more allotropes forms of carbon as well as metal particles left over from catalysts used in manufacturing. Purity characterization of double-walled carbon nanotubes (DWCNTs) is an increasingly popular topic in the field of carbon nanotechnology. In this study, DWCNTs were synthesized in a catalytic reaction, using Fe:MgO as catalyst and methane or methane/ethanol as carbon feedstock for chemical vapor deposition (CVD). The addition of ethanol as carbon feedstock allowed to investigate the influence of oxygen on the sample quality. The purification of the as-produced material from the metallic particles and the catalyst support was performed by sonication in an acid solution. The influence of the duration of the acid treatment using ultrasound on the sample purity was investigated, and the optimal value of this parameter was found. Transmission electron microscopy (TEM) images confirmed the removal of impurities and served to elucidate the morphology of the samples. The purity of carbon nanotubes was analyzed using thermal gravimetric analysis (TGA). The Raman spectra of the samples, as a measure of the concentration of defects, were also reported.

Keywords

  • Chemical vapor deposition (CVD)
  • carbon nanotubes
  • Raman spectroscopy
  • high-resolution transmission electron microscopy (HRTEM)
Open Access

Synthesis and characterization of iron-filled multi-walled nanotubes

Published Online: 08 May 2012
Page range: 299 - 304

Abstract

Abstract

The growth of iron filled multiwalled carbon nanotubes (Fe-MWCNT) using chemical vapour deposition (CVD) has been widely studied. Considering the remarkable magnetic and structural properties of Fe-MWCNT, these materials have been applied in numerous areas. In particular their biomedical application has been explored, where Fe-MWCNT can be used in hyperthermia, acting as a local nano-heater at cellular level. Regarding this aim, the reproducible and highly purified ferromagnetically filled samples of carbon nanotubes are still required. There are several parameters during the synthesis process that influence the properties of the nanotubes. The most favourable temperature of the CNT growth is probably one of the most important issues and its optimisation is crucial. In the current study, the Fe-MWCNT were grown at different temperatures ranging from 650 °C to 1050 °C. Additionally, a comparison between two different CVD systems and two carbon sources are also here presented. The Fe-MWCNT were characterised using diverse techniques regarding the evaluation of their morphology, filling ratio, and purity. Observations showed a strong influence of the growth temperature on the morphology and properties of the Fe-MWCNT. The samples characterisation was performed using Raman spectroscopy, thermogravimetric analysis (TGA), X ray diffraction (XRD), and transmission electron microscopy analysis (TEM).

Keywords

  • carbon nanotubes
  • iron filling
  • endohedral functionalization
  • TEM
  • Raman spectroscopy
Open Access

Influence of grain boundaries misorientation angle on intergranular corrosion in 2024-T3 aluminium

Published Online: 08 May 2012
Page range: 305 - 311

Abstract

Abstract

The special attention has been paid to the influence of misorientation angle of a random grain boundary (GB) on susceptibility to intergranular attack. The detailed observations of the microstructure of the intergranular corrosion (IGC) in 2024-T3 aluminium alloy (AA2024-T3) subjected to galvanic corrosion tests in two different solutions containing chloride ions (0.1 M and 0.5 M NaCl) were carried out using Scanning Electron Microscopy (SEM). The Electron Backscattered Diffraction (EBSD) technique was used to determine the grain boundary character distribution (GBCD) in the initial sample and a GBCD of corroded grain boundaries on a sample subjected to the corrosion test. The results are discussed in terms of the influence of the misorientation angle on the susceptibility of the grain boundaries to corrosion.

Keywords

  • EBSD 2024
  • intergranular corrosion
  • grain boundaries

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