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Your search keyword '"Ayodele Olusoji Oluremi"' showing total 22 results
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22 results on '"Ayodele Olusoji Oluremi"'

1. Spark plasma sintering of CNT-NiAl nanocomposites – Process parameter, densification mechanism, and grain analysis

Author

Ayodele Olusoji Oluremi, Awotunde Mary Ajimegoh, Babalola Bukola Joseph, and Olubambi Peter Apata

Subjects
grain size, electron backscattered diffraction, porosity, densification and heating rate, Engineering (General). Civil engineering (General), TA1-2040, Technology (General), T1-995, Manufactures, TS1-2301
Abstract

The densification process and grain analysis of consolidated NiAl-CNT composites at 1000 °C, and at varied heating rates from 50 °C/min to 150 °C/min was investigated. The results revealed the effect of heating rate on the densification behaviour of the samples. The displacement of the composites decreased from 3.39 mm to 2.63 mm with increasing heating rate, while the porosity increased by 69% at rapid heating rate. The grain analysis of the sintered samples through the electron backscattered (EBSD) technique indicates the evolution of bigger grains as the heating rate proceeds higher. Furthermore, the mean grain size of the consolidated composites increased from 3.93 μm, to 8.05 μm due to the concentration of defects. Interestingly, there was no texture or predominance of any color evolution in the sintered materials.

Published
2021
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13. Nanoindentation and Structural Analysis of Sintered TiAl (100−x) - x TaN Composites at Room Temperature.

Author

Babalola, Bukola Joseph, Ayodele, Olusoji Oluremi, and Olubambi, Peter Apata

Subjects
*ELASTIC modulus, *TEMPERATURE, *MICROSTRUCTURE, *NANOINDENTATION
Abstract

The nanohardness, elastic modulus, anti-wear, and deformability characteristics of TiAl(100−x)-xTaN composites containing 0, 2, 4, 6, 8, and 10 wt.% of TaN were investigated via nanoindentation technique in the present study. The TiAl(100−x)-xTaN composites were successfully fabricated via the spark plasma sintering technique (SPS). The microstructure and phase formation of the TiAl sample constitute a duplex structure of γ and lamellar colonies, and TiAl2, α-Ti, and TiAl phases, respectively. The addition of TaN results in a complex phase formation and pseudo duplex structure. The depth-sensing indentation evaluation of properties was carried out at an ambient temperature through a Berkovich indenter at a prescribed load of 100 mN and a holding time of 10 s. The nanoindentation result showed that the nanohardness and elastic modulus characteristics increased as the TaN addition increased but exhibited a slight drop when the reinforcement was beyond 8 wt.%. At increasing TaN addition, the yield strain ( H E r ), yield pressure ( H 3 E r 2 ), and elastic recovery index ( W e W t ) increased, while the plasticity index ( W p W t ) and the ratio of plastic and elastic work (RPE) reduced. The best mechanical properties were attained at the 8 wt.%TaN addition. [ABSTRACT FROM AUTHOR]

Published
2023
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21. Evaluation of Wear and Corrosion Behaviour of Hybrid Sintered Ti6Al4V Alloy

Author

Ayodele, Olusoji Oluremi, Awotunde, Mary Ajimegoh, Shongwe, Mxolisi Brendon, Adegbenjo, Adewale Oladapo, Babalola, Bukola J., Obadele, Babatunde A., and Olubambi, Peter Apata

Abstract

Ti6Al4V alloy was consolidated by hybrid spark plasma sintering at a temperature of 1200 °C, pressure of 50 MPa, holding time of 5 min and heating rate of 100 °C/min. This resulted in the maximum value of sintered density. Microstructural evolutions of the sintered compact were analysed with SEM. Sliding wear test were accomplished at different sliding loads of 5, 8 and 10 N using ball on disc tribometer configuration with stainless steel as the counterface material. Wear debris obtained was found to contain mostly the sintered materials with minute traces of the counterface material. The coefficient of friction reaches the maximum with increase in applied load. Worn surface analyses revealed the wear mechanism was abrasive. The potentiodynamic polarisation of the sintered compact showed the sintered compact in 0.9 wt % NaCl solution exhibited more resistance to corrosion.

Published
2019
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22. Influence of Multi-Walled Carbon Nanotube Addition on the Hardness of NiAl-CNT and NiAl3-CNT Composites

Author

Awotunde, Mary Ajimegoh, Ayodele, Olusoji Oluremi, Adegbenjo, Adewale Oladapo, Okoro, Moses, Shongwe, Mxolisi Brendon, and Olubambi, Peter Apata

Abstract

Nickel aluminides have shown great potential as high temperature structural materials. In this study, two classes of nickel aluminide were reinforced with 0.5wt% MWCNTs. Starting powders of nickel, aluminium and MWCNTs were ball milled together using a two stage milling regime and consolidated by spark plasma sintering. The effect of MWCNT reinforcement on the hardness of two classes of nickel aluminide was investigated. Microhardness values revealed a lack of dependence on densification for the NiAl3 composites. The microhardness values of NiAl-CNT reduced with MWCNT addition whereas microhardness values of NiAl3-CNT increased with MWCNT addition.

Published
2019
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