A correlation between nano and micro-hardness properties of TiN nanoparticles strengthened SAF 2205
- Oke, S R, Ige, O O, Falodun, O E, Obadele, B A, Olubambi, P A, Shongwe, M B, Mphahlele, M R
- Authors: Oke, S R , Ige, O O , Falodun, O E , Obadele, B A , Olubambi, P A , Shongwe, M B , Mphahlele, M R
- Date: 2019
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/405216 , uj:34018 , Citation: Mphahlele, M.R. et al. 2019 : A correlation between nano and micro-hardness properties of TiN nanoparticles strengthened SAF 2205. IOP Conf. Series: Materials Science and Engineering 499 (2019) 012009. DOI: 10.1088/1757-899X/499/1/012009
- Description: Abstract : This work studied the correlation between Vickers and nano-hardness of SAF 2205 reinforced with TiN nanoparticles for the convenience of assessing its mechanical properties. Spark plasma sintering was used to fabricate the composites. Micro and nanoindentations were performed to determine micro and nanohardness values of the fabricated composite. Optical microscope was used to assess the microstructure. The microstructure revealed that the TiN dominated the ferrite/ferrite, ferrite/austenite and austenite/austenite grain boundaries. The micro and nanohardness at the TiN dominated grain boundaries were higher compared to the grain hardness. Hardness also increased considerably as the TiN nanoparticles increases. This is also owed to the strengthening effect played by TiN at the grain boundaries by disrupting dislocation motion in the composite. The determined Vickers hardness was plotted as a function of the corresponding nanohardness, a good linear relation was found between Vickers hardness and nanohardness. A linear relationship (HV = 215.15 + 15.03Hnano) was established which indicates that there is no difference in behavior for the Vickers hardness and nano- hardness.
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- Authors: Oke, S R , Ige, O O , Falodun, O E , Obadele, B A , Olubambi, P A , Shongwe, M B , Mphahlele, M R
- Date: 2019
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/405216 , uj:34018 , Citation: Mphahlele, M.R. et al. 2019 : A correlation between nano and micro-hardness properties of TiN nanoparticles strengthened SAF 2205. IOP Conf. Series: Materials Science and Engineering 499 (2019) 012009. DOI: 10.1088/1757-899X/499/1/012009
- Description: Abstract : This work studied the correlation between Vickers and nano-hardness of SAF 2205 reinforced with TiN nanoparticles for the convenience of assessing its mechanical properties. Spark plasma sintering was used to fabricate the composites. Micro and nanoindentations were performed to determine micro and nanohardness values of the fabricated composite. Optical microscope was used to assess the microstructure. The microstructure revealed that the TiN dominated the ferrite/ferrite, ferrite/austenite and austenite/austenite grain boundaries. The micro and nanohardness at the TiN dominated grain boundaries were higher compared to the grain hardness. Hardness also increased considerably as the TiN nanoparticles increases. This is also owed to the strengthening effect played by TiN at the grain boundaries by disrupting dislocation motion in the composite. The determined Vickers hardness was plotted as a function of the corresponding nanohardness, a good linear relation was found between Vickers hardness and nanohardness. A linear relationship (HV = 215.15 + 15.03Hnano) was established which indicates that there is no difference in behavior for the Vickers hardness and nano- hardness.
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Development of MgAl2O4 grain refiner in Al in-situ composite through H3BO3 addition
- Chandramohan, P, Olubambi, P A, Raghu, R, Obadele, B A
- Authors: Chandramohan, P , Olubambi, P A , Raghu, R , Obadele, B A
- Date: 2019
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/405925 , uj:34107 , Citation: Chandramohan, P., Olubambi, P.A., Raghu, R., Obadele, B.A. 2019 : Development of MgAl2O4 grain refiner in Al in-situ composite through H3BO3 addition. IOP Conf. Series: Materials Science and Engineering 655 (2019) 012039. DOI:10.1088/1757-899X/655/1/012039.
- Description: Abstract : In the present work, a novel approach has been made for synthesis of in-situ Magnesium Aluminate (MgAl2O4) particles in the Al-4Mg alloy by Boric Acid (H3BO3) precursor addition (1 wt %, 1.5 wt % and 2 wt %) during the casting process. The developed composite has been investigated for its microstructural characteristics and corrosion performance. Scanning Electron Microscopy and Energy Dispersive Spectroscopy examination revealed the formation of MgAl2O4 particles in the composite. Potentiodynamic polarization corrosion experiments were performed on the Al-4Mg/H3BO3 composite specimens (1 wt %, 1.5 wt % and 2 wt %) in three different medium (3.5 % Sodium Chloride-NaCl, 1 M Sulphuric Acid-H2SO4 and 1 M Hydrochloric Acid-HCl). Corrosion results showed that Al-4Mg/1.5 wt % H3BO3 composite specimen exhibited better corrosion resistance in 3.5 % NaCl, 1 M H2SO4 and 1 M HCl medium due to the significant grain refinement produced by MgAl2O4 particles. The developed composite with better corrosion properties can be utilized for marine and naval application.
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- Authors: Chandramohan, P , Olubambi, P A , Raghu, R , Obadele, B A
- Date: 2019
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/405925 , uj:34107 , Citation: Chandramohan, P., Olubambi, P.A., Raghu, R., Obadele, B.A. 2019 : Development of MgAl2O4 grain refiner in Al in-situ composite through H3BO3 addition. IOP Conf. Series: Materials Science and Engineering 655 (2019) 012039. DOI:10.1088/1757-899X/655/1/012039.
- Description: Abstract : In the present work, a novel approach has been made for synthesis of in-situ Magnesium Aluminate (MgAl2O4) particles in the Al-4Mg alloy by Boric Acid (H3BO3) precursor addition (1 wt %, 1.5 wt % and 2 wt %) during the casting process. The developed composite has been investigated for its microstructural characteristics and corrosion performance. Scanning Electron Microscopy and Energy Dispersive Spectroscopy examination revealed the formation of MgAl2O4 particles in the composite. Potentiodynamic polarization corrosion experiments were performed on the Al-4Mg/H3BO3 composite specimens (1 wt %, 1.5 wt % and 2 wt %) in three different medium (3.5 % Sodium Chloride-NaCl, 1 M Sulphuric Acid-H2SO4 and 1 M Hydrochloric Acid-HCl). Corrosion results showed that Al-4Mg/1.5 wt % H3BO3 composite specimen exhibited better corrosion resistance in 3.5 % NaCl, 1 M H2SO4 and 1 M HCl medium due to the significant grain refinement produced by MgAl2O4 particles. The developed composite with better corrosion properties can be utilized for marine and naval application.
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Fretting biocorrosion behaviour of titanium-zirconia composites in foetal bovine serum
- Semetse, L, Obadele, B A, Raganya, L, Geringer, J, Olubambi, P A
- Authors: Semetse, L , Obadele, B A , Raganya, L , Geringer, J , Olubambi, P A
- Date: 2019
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/405352 , uj:34035 , Citation: Semetse, L., et al. 2019 : Fretting biocorrosion behaviour of titanium-zirconia composites in foetal bovine serum. IOP Conf. Series: Materials Science and Engineering 655 (2019) 012034. DOI:10.1088/1757-899X/655/1/012034.
- Description: Abstract : This work aims at studying the fretting biocorrosion response of newly developed Ti-6Al-4V/ZrO2 in simulated body fluid. Ti-6Al-4V alloy with different volume fractions of ZrO2 produced via powder metallurgy techniques were spark plasma sintered to produce Ti- 6Al-4V composites with improved properties. The microstructures of the resulting spark plasma sintered composites were examined using a scanning electron microscope (SEM). Fretting corrosion tests were conducted for each material composition with a special device used for fretting corrosion investigations with a cylinder-on-flat configuration. The tests were done in foetal bovine serum maintained at ambient temperature. Open circuit potential, dissipated energy and coefficient of friction were monitored throughout the experiments. The results show that the microstructures produced after zirconia additions were very different from those observed in pure Ti-6Al-4V. The presence of zirconia promoted the formation of globular zirconia-rich agglomerates throughout the matrix, leading to more improved fretting biocorrosion properties of Ti-6Al-4V.
- Full Text:
- Authors: Semetse, L , Obadele, B A , Raganya, L , Geringer, J , Olubambi, P A
- Date: 2019
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/405352 , uj:34035 , Citation: Semetse, L., et al. 2019 : Fretting biocorrosion behaviour of titanium-zirconia composites in foetal bovine serum. IOP Conf. Series: Materials Science and Engineering 655 (2019) 012034. DOI:10.1088/1757-899X/655/1/012034.
- Description: Abstract : This work aims at studying the fretting biocorrosion response of newly developed Ti-6Al-4V/ZrO2 in simulated body fluid. Ti-6Al-4V alloy with different volume fractions of ZrO2 produced via powder metallurgy techniques were spark plasma sintered to produce Ti- 6Al-4V composites with improved properties. The microstructures of the resulting spark plasma sintered composites were examined using a scanning electron microscope (SEM). Fretting corrosion tests were conducted for each material composition with a special device used for fretting corrosion investigations with a cylinder-on-flat configuration. The tests were done in foetal bovine serum maintained at ambient temperature. Open circuit potential, dissipated energy and coefficient of friction were monitored throughout the experiments. The results show that the microstructures produced after zirconia additions were very different from those observed in pure Ti-6Al-4V. The presence of zirconia promoted the formation of globular zirconia-rich agglomerates throughout the matrix, leading to more improved fretting biocorrosion properties of Ti-6Al-4V.
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