Nanoindentation studies and a alysis of the mechanical properties of Ti-Nb2O5 based composites
- Authors: Alaneme, Kenneth Kanayo , Fatokun, Ayoyemi Adebanji , Oke, Samuel Ranti , Olubambi, Peter Apata
- Date: 2020
- Subjects: Titanium based composites , Niobium pentoxide , Nanoindentation
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/10210/453348 , uj:40020 , Citation: Alaneme, K.K. et al. 2020. Nanoindentation studies and a alysis of the mechanical properties of Ti-Nb2O5 based composites. , DOI: https://doi.org/10.1051/mfreview/2020017
- Description: Abstract: In this study, nanoindentation tests were used to evaluate the mechanical properties of spark plasma sintered Ti based composites containing 5, 10 and 15 wt.% Nb2O5, targeted for potential use as biomedical material. Nanoindentation tests were performed on the samples using indenter loads of 20 and 100 mN, while the microstructures were characterized using scanning electron microscopy. It was noted that with increasing Nb2O5 wt.%, there is transition from the lamellar structure of pure Ti to fully bimodal structures for the Ti-10 wt.% Nb2O5 and Ti-15 wt.% Nb2O5 composites. The hardness (6.0–40.67 GPa (20 mN) and 2.4–12.03 GPa (100 mN)) and reduced elastic modulus (115–266.91 GPa (20 mN) and (28.05–96.873 GPa (100 mN)) of the composites increases with increase in the Nb2O5 content, attributed to contributions of load transfer from the Ti matrix to the relatively harder Nb2O5 particles, particle and dispersion strengthening mechanisms. The elastic recovery index also improved with increase in Nb2O5 content, while the inverse was noted with respect to plasticity index. The elastic strain to failure and yield pressure both improved with increase in Nb2O5 content, which suggests that the antiwear properties and resistance to impact loading equally improves with Nb2O5 addition.
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Nanoindentation studies and analysis of the mechanical properties of Ti-Nb2O5 based composites
- Authors: Alaneme, Kenneth Kanayo , Fatokun, Ayoyemi Adebanji , Oke, Samuel Ranti , Olubambi, Peter Apata
- Date: 2020
- Subjects: Titanium based composites , Niobium pentoxide , Nanoindentation
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/10210/464025 , uj:41433 , Citation: Alaneme, K.K. et al. 2020. Nanoindentation studies and analysis of the mechanical properties of Ti-Nb2O5 based composites. , DOI: https://doi.org/10.1051/mfreview/2020017
- Description: Abstract: Please refer to full text to view abstract.
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Nanoindentation studies on titanium nitride nanoceramic reinforced titanium-aluminium-vanadium alloys
- Authors: Maja, Mosima Edith
- Date: 2018
- Subjects: Titanium-aluminum-vanadium alloys - Testing , Nanoelectronics , Metals - Mechanical properties , Nanoindentation
- Language: English
- Type: Masters (Thesis)
- Identifier: http://hdl.handle.net/10210/285986 , uj:30937
- Description: M.Tech. (Chemical Engineering) , Abstract: Recent development in nanoindentation techniques has enabled investigations on the mechanical properties of materials under dynamic conditions as the technique offers unique capabilities for direct measurement of hardness, modulus of elasticity and contact stiffness among other properties. In this study, ultra nanoindentation (UNHT) technique was used to investigate the mechanical properties of spark plasma sintered Ti-6Al-4V reinforced with 1 to 4 vol% TiN nanoparticles. The morphology and microstructure of the as-sintered samples were examined using field emission scanning electron microscopy (FESEM) equipped with energy dispersive X-ray spectroscopy (EDS) and Electron Backscattered Diffraction (EBSD). The hardness, modulus of elasticity and creep properties were examined using Berkovich diamond indenter which is equipped with a three-sided pyramid. Microstructural results indicated that sintered samples containing 1 vol % of TiN nanoparticles was fully transformed from lamellar to bimodal and duplex structures. It was also observed that TiN nanoparticles segregated at the grain boundaries of the Ti-6Al-4V matrix. Results obtained from the EBSD revealed that α phase, hexagonal close packed (HCP) was stabilised at the expense of β phase Body centered cubic crystal structure (BCC). The nanoindentation results showed that both hardness and modulus of elasticity depend on the presence of volume fraction of TiN in Ti-6Al-4V matrix. There was significant increase in bulk hardness, modulus of elasticity while subsequently decreasing the contact depth and maximum depth of the indentation with increase in volume fraction of TiN. The mechanical properties (hardness and modulus of elasticity) of each phase (α and β) were derived from the grid indentation technique, where the β phase exhibited the highest hardness against α phase and the grain boundary, which may be due to uniform distribution of TiN along the grain boundary and β phases were found along the grain boundary. Optimum properties were obtained with the addition of 2 vol % of TiN which had highest creep resistance compared with that of Ti base alloy.
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