Studies on Mechanical properties of Graphite reinforced Ti (Cx, N1-x) using nanoindentation techniques
- Authors: Akinribide, Ojo Jeremiah , Mekgwe, Gadifele Nicolene , Ajibola, Olawale Olarewaju , Obadele, Babatunde Abiodun , Akinwamide, Samuel Olukayode , Olubambi, Peter Apata
- Date: 2019
- Subjects: Ti (Cx, N1-x), Spark plasma sintering, Nanoindentation
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/10210/396225 , uj:32888 , ISSN: 2351-9789 (online) , Akinribide, O.J. etal. 2019. Studies on Mechanical properties of Graphite reinforced Ti (Cx, N1-x) using nanoindentation techniques , https://creativecommons.org/licenses/by-nc-nd/4.0/
- Description: Abstract : The innovative headway in nano-indentation improvement in the world of nanotechnology has empowered investigations on materials properties under unstable and dynamic conditions to offer direct evaluation of some outputs like modulus of flexibility, nanoindentation hardness and the contact stiffness among different properties. The present study explored the mechanical properties of sintered Ti (Cx, N1-x); (x= 0.9), for each composition of both carbon and nitrogen in the ceramic matrix composite used. The graphite reinforcements (0, 0.5 and 1.0 wt. % was examined by ultra-nano indentation (UNHT) strategy. Result show that higher weight percent of graphite in each of the Ti (Cx, N1-x) sintered composites had an effect on the grain morphology which resulted in undissolved graphite in the matrix. Furthermore, the moduli of elasticity and nanoindentation hardness depend on the graphite reinforcement in the matrix. The composite with 1.0 wt.% graphite exhibited hardness of 25207 MPa and elastic modulus of 400.41 GPa in Ti (Cx, N1-x) compared to pure TiC0.9N0.1, TiC0.9N0.1 +0.5wt.%Gr to other cermets with hardness of 18,835 MPa, 19209 MPa and modulus of 372.57 GPa, 393.38 GPa respectively.
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Mechanical properties of ultrafine graphite –Ti (C0.9, N0.1) solid solutions fabricated via spark plasma sintering
- Authors: Akinribide, Ojo Jeremiah , Mekgwe, Gadifele Nicolene , Ajibola, Olawale Olarewaju , Obadele, Babatunde Abiodun , Akinwamide, Samuel Olukayode , Falodun, Eso Oluwasegun , Olubambi, Peter Apata
- Date: 2019
- Subjects: Ti (C0.9, N0.1), Graphite, Spark plasma sintering
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/10210/396125 , uj:32876 , 2351-9789 (Online) , Akinribide, O.J. et al. 2019: Mechanical properties of ultrafine graphite –Ti (C0.9, N0.1) solid solutions fabricated via spark plasma sintering , https://creativecommons.org/licenses/by-nc-nd/4.0/
- Description: Abstract : Spark plasma sintering technique was used to consolidate solid solution of graphite–Ti (C0.9, N0.1) using ultrafine size of graphite and titanium carbonitride powder with carbon to nitrogen composition of 90:10 at 2000 oC for 5 mins. The densification of the sintered graphite (0-1 wt. %) –Ti (C0.9, N0.1) was 98-99% at 2000 oC in the matrix. The carbide rich and Ti rich were the two distinct solid solution phases observed, although Graphite –Ti (C0.9, N0.1) solid solution as a solitary phase was attained at 2000 oC. This could be attributed to changes in the parameters with in the lattice site due to excess heat and causing the solid solutions phases to favour the carbide and titanium phases, respectively. The graphite–Ti (C0.9, N0.1) solid solution upon the application of different load the value of the hardness decreases as the load increases for unreinforced and reinforced Ti (C0.9, N0.1). Furthermore, the fracture toughness (KIC ) was within the range of (1.04 – 7.99) in MPa m1/2.
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Corrosion behavior of ductile and austempered ductile cast iron in 0.01M and 0.05M NaCl environments
- Authors: Akinribide, Ojo Jeremiah , Akinwamidea, Samuel Olukayode , Ajibolaa, Olawale Olarewaju , Obadelea, Babatunde Abiodun , Olusunleb, Samuel Oloruntoba Oluwagbenga , Olubambia, Peter Apata
- Date: 2019
- Subjects: Ductile iron, Austempered ductile iron, Pearlite
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/10210/395485 , uj:32794 , ISSN : 2351-9789 , Akinribideab, O.J. et al. 2019. Corrosion behavior of ductile and austempered ductile cast iron in 0.01M and 0.05M NaCl environments , https://creativecommons.org/licenses/by-nc-nd/4.0/
- Description: Abstract : In this investigation the corrosion performance of ductile iron (DI) and austempered ductile cast iron (ADI) used in the In this investigation, the corrosion performance of ductile production of engine sleeve was considered. The significant concentration of sodium chloride (0.01 M and 0.05 M) was utilized to analyse corrosion behaviour of both alloyed materials in the two environments. The microstructural images of the two distinctto analyse corrosion behaviour of both alloyed materials in the two environments. The microstructural images of the two distinct materials in each condition were resolved and diverse stages developed are mainly (carbides and the martensitic stage). Additionally, in Comparism with the DI and ADI not subjected to any condition, the consumption rate of DI was higher than that of ADI. The SEM was used to affirm the uniqueness of each phase. The two imperative components, for example, Cl- and Fe were assessed by SEM-EDS examination. The samples subjected to these conditions were appeared to have comparable corrosion attack. The nearness of delamination of oxide layers and oxidation was essential to each sample attempted under the 0.05 NaCl. As a result of silicon content, the DI indicates more oxidation at the surface accessible to the conditions. Thus, releases an impression of being the materials with the most raised corrosion resistance as a result of more broad scope of passive layers.
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Development of binderless ultra-tough titanium carbonitride (TiCN) using spark plasma sintering technique
- Authors: Akinribide, Ojo Jeremiah
- Date: 2019
- Subjects: Titanium , Sintering , Nanoparticles
- Language: English
- Type: Doctoral (Thesis)
- Identifier: http://hdl.handle.net/10210/443738 , uj:38757
- Description: Abstract: Binderless ultra–tough titanium carbonitride (TiCN) was successfully consolidated by spark plasma sintering. The impact of blending and milling parameters on the formation of titanium carbonitride from milled titanium nitride, graphite and multiwalled carbon nanotube (MWCNTs) admixture were investigated. The effect of wet milling and dry milling on the phases and morphology of the developed composites were also studied. The morphology, microstructure and the chemical composition of as – received powders, admilled powders and the sintered compact were characterized by using energy dispersive Xray spectroscopy (EDS), X-ray diffractometer, and scanning electron microscopy respectively. The varying compositions of the ad-milled powders were sintered at 100 oC/min (heating rate), 10 mins (holding time), 50 MPa sintering pressure and 2000 oC (sintering temperature). Vickers hardness test, fracture toughness and modulus of elasticity were carried out on the sintered sample to evaluate the mechanical properties. The sintered TiN-based composites were completely formed without cracks, however with very fewer pores, an indication of a good metallurgical bonding quality achieved at the composite grain boundary interface. The structure of the grains has completely transformed to bimodal grains within the composites at 1 wt.% graphite in TiN for 40 h of milling, and subsequent composites developed was based on the result obtained at 1 wt.% graphite in TiN for 24 and 40 h of milling at different compositions. Much increment was observed in microindentation hardness and fracture toughness values of the sintered compact as the percentage graphite increased. The results show that grain size of the sintered sample decreases as the percentage composition of graphite/MWCNTs particles and milling time increases. Based on the results of the analysis, it was concluded that the incorporation of graphite/MWCNTs enhances the microstructures which ultimately are crucial to the mechanical behaviour of the sintered compacts. , D.Phil. (Metallurgical Engineering)
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Evaluation of microstructural and nanomechanical performance of spark plasma sintered TiFe-SiC reinforced aluminium matrix composites
- Authors: Akinwamide, Samuel Olukayode , Lesufi, Miltia , Akinribide, Ojo Jeremiah , Mpolo, Peggy , Olubam, Peter Apata
- Date: 2020
- Subjects: Spark plasma sintering , Aluminium , Silicon carbide
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/10210/444284 , uj:38831 , Citation: Akinwamide, S.O. et al. 2020. Evaluation of microstructural and nanomechanical performance of spark plasma sintered TiFe-SiC reinforced aluminium matrix composites.
- Description: Abstract: tDue to the increasing demand for lighter materials with enhanced properties, the upgrade oftechniques to improve the production of high-performance composite materials is of greatinterest in modern technology. The microstructural and mechanical properties of sparkplasma sintered aluminium based composites with ferrotitanium (TiFe) and silicon carbide(SiC) reinforcements were investigated. High energy ball milling technique was adopted toeffectively disperse the particles SiC and TiFe reinforcements into the matrix of aluminium,and the admixed powders were compacted using spark plasma sintering technique. Thespecimens sectioned from the sintered compacts were analysed using an X-ray diffractome-ter (XRD), optical microscope (OM), and field emission scanning electron microscope (FESEM)to understand the microstructural features and phase evolution of the sintered compos-ites. The mechanical properties of the composites were also investigated through hardness,nanomechanical and tribology tests. Results from the microstructural examinations con-ducted shows that the reinforcement particles were evenly dispersed within the aluminiummatrix, as a result of the milling process. Furthermore, all the sintered composites hadtheir microstructural features enhanced, but properties such as hardness, frictional coeffi-cient, and elastic modulus were more enhanced in specimen reinforced with 2%SiC+2%TiFeparticles. The reduced crystallite size recorded by the sintered specimens confirmed theeffectiveness of the milling process, and powder metallurgy route adopted for fabrication.
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Crystallite size determination of thermally deposited gold nanoparticles
- Authors: Ogundare, Olasupo Daniel , Akinribide, Ojo Jeremiah , Adetunjib, Adelana Rasak , Adeoye, Mosobalaje Oyebanji , Olubambi, Peter Apata
- Date: 2018
- Subjects: Crystallite size, Thermal deposition, Gold nanoparticles,
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/10210/395693 , uj:32825 , 2351-9789 (Online) , https://creativecommons.org/licenses/by-nc-nd/4.0/) , Citation : Ogundare, O.D. et al. 2018. Crystallite size determination of thermally deposited gold nanoparticles
- Description: Abstract : This paper has x-rayed an approach to investigate the crystallite size of thermally deposited gold nanoparticles on a glass substrate. The mined and beneficiated gold sample was deposited on glass slide in Nano-38 thermal depositor after the substrate has been technically prepared. The crystallite size and profile fitting of the nanoparticles were determined by X-ray Diffractometer (XRD). The result showed that the average crystallite size of Au nanoparticles thermally deposited on glass slide was 14.4 ± 6.7 nm with lattice constants: a, b, c; 4.0789, 4.0789, and 4.0789 (Å) respectively. The TEM images have confirmed that high quality spherical Au NPs that were between 18 nm – 24 nm were successfully synthesized. The XRD has shown that the material of the gold nanoparticles is gold and crystalline in structure. Narrow size distribution and small monosize gold nanoparticles produced may proffer advantages for self-assembled monolayer formation and enhanced surface area.
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