Microstructural and electrochemical studies of spark plasma sintered multiwall carbon nanotubes reinforced TiO2eMnO2 based composite
- Authors: Lephuthing, Senzeni Sipho , Okoro, Avwerosuoghene Moses , Ige, Oladeji Oluremi , Olunambi, Peter Apata
- Date: 2020
- Subjects: Microstructure , Spark plasma sintering , Electrochemical study
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/10210/480894 , uj:43549 , Citation: Lephuting, S.S., Okoro, A.M., Ige, O.O., Olunambi, P.A. 2020. Microstructural and electrochemical studies of spark plasma sintered multiwall carbon nanotubes reinforced TiO2eMnO2 based composite. DOI:
- Description: Abstract: An electrochemical study was conducted to investigate the suitability of TiO2, TiO2- MWCNTs and (5,10 and 15 wt.%) of MnO2 in TiO2-MWCNTs composites as dimensional stable electrodes which were developed via conventional powder processing and spark plasma sintering. The following electrochemical tests were carried out including open circuit potential, galvanostatic chronoamperometry and cyclic voltammetry measurements. The results showed that an increase on MnO2 content in the composites did not only lower the potentials but enhanced the stability of the composites. The degradation which translates to corrosion susceptibility was favorable on composite samples with lower MnO2 content. Also, the presence of MWCNTs in the composites improved the electrocatalytic capacity of the material. Furthermore, the anodic layers formed on the composites during polarization was analyzed using SEM, XRD and cyclic voltammetry. The results showed that the formation of anodic layer during 24 h of polarization increased with the addition of MnO2 content and 15 MnO2eTiO2-MWCNT composite grade showed minimal pores after polarization which translates to higher protection.
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Fabrication and characterization of titanium-nickel-zirconia matrix composites prepared by spark plasma sintering
- Authors: Obadele, Babatunde Abiodun , Ige, Oladeji Oluremi , Olubambi, Peter Apata
- Date: 2017
- Subjects: Spark plasma sintering , Zirconia , Titanium
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/10210/225471 , uj:22773 , Citation: Obadele, B.A., Ige, O.O. & Olubambi, P.A. 2017. Fabrication and characterization of titanium-nickel-zirconia matrix composites prepared by spark plasma sintering.
- Description: Abstract: Ti–Ni–ZrO2 composites were prepared by spark plasma sintering (SPS). The effect of ZrO2 content on the densification, microstructure and microhardness properties of the composites were investigated. Samples were characterized by SEM, EDS and XRD analyses. Noticeably, SPS process under the sintering conditions was achieved at a sintering temperature of 950 ºC, for 10 min holding time, at 100 °C/min of heating rate and at an applied pressure of 50 MPa. This resulted in maximum densification of the powder compact and the formation of a distinguishable spherical globules rich in Ni surrounding the retained Ti. Gradient composition distribution of ZrO2 at the grain boundaries resulted into pinning effect of the grain growth. As the ZrO2 content increased from 5 to 10 vol.%, it was accompanied by a significant increase in hardness values of the sintered composites from 480 to 713 HV.
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