Browsing by Author "Doddamani, D."

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    Indentation fracture toughness of Aluminium-Graphite composites: influence of nano-particles
    (Gruppo Italiano Frattura, 2025) Ibrahim, A.; Niyaz Ahamed, M.B.; Ashoka, E.; Rajesh, A.M.; Bharath, P.B.; Doddamani, D.
    In the field of composite materials, extensive research has been undertaken on aluminum-graphite composites. However, a research gap has been identified regarding the specific influence of nano-sized graphite particles on their fracture toughness. Previous studies have predominantly focused on larger graphite particles or different reinforcement materials, resulting in relatively unexplored effects of nano-graphite particles. This research is deemed critical as it has the potential to generate lightweight, high-strength materials, aligning with the demands of aerospace, automotive, and structural engineering. The primary objective of this study is to investigate how the inclusion of nano-sized graphite particles affects the fracture toughness of aluminum-graphite composites. To achieve this objective, systematic dispersion and incorporation of nano-sized graphite particles into an aluminum matrix will be carried out. Mechanical testing, including fracture toughness assessments, will be conducted to evaluate the performance of the composite materials. Factors such as particle size, distribution, volume fraction, and interfacial bonding will also be characterized within the study. It is anticipated that the presence of nano-sized graphite particles will lead to a significant enhancement of the fracture toughness of the aluminum-graphite nanocomposites. This enhancement is expected to be attributed to crack deflection, tortuosity, altered stress distribution, and increased plastic deformation around cracks. © 2024.
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    Mechanical properties of SiC nanoparticle-reinforced Al-2024 alloy
    (Gruppo Italiano Frattura, 2025) Niyaz Ahamed, M.B.; Naveen Kumar, H.S.; Anilkumar, S.K.; Ibrahim, A.; Doddamani, D.; Hareesha, G.
    This study investigates the mechanical properties of Al-2024 alloy reinforced with SiC nanoparticles, highlighting the effectiveness of ultrasonic-assisted stir casting in achieving uniform dispersion of the nanoparticles. The aim is to enhance the material's inherent limitations in hardness and overall mechanical performance under demanding conditions by incorporating SiC nanoparticles. The experimental investigation explores varying SiC content (1%, 2%, 3%, and 4%) and its relationship with tensile strength and hardness. The results indicate a substantial 31% enhancement in hardness and a 25% improvement in tensile strength, demonstrating the effectiveness of nanoparticle reinforcement. Furthermore, several strengthening mechanisms were found to be important contributors to yield strength, including the Orowan mechanism, dislocation strengthening, and grain refinement strengthening. A maximum variation of 13% between the experimental and predicted yield strength of the Al2024-SiCnp composite confirms the reliability of the predictive models employed. Overall, the results support SiC nanoparticles' ability to improve Al-2024 composites' mechanical characteristics for cutting-edge engineering uses. © 2025, Fracture and Structural Integrity (F&SI). All rights reserved.
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    Sacrificial sulphonated polystyrene template-assisted synthesis of mesoporous hollow core-shell silica nanoparticles for drug-delivery application
    (Springer, 2020) Doddamani, D.; JagadeeshBabu, J.
    Spherical mesoporous hollow core-shell silica nanoparticles (HCSNs) of size 200 ± 50 nm with tunable thickness from 20 to 60 nm are synthesized using a sacrificial sulphonated polystyrene (PS, particle size 160 nm) template. A facile method is adopted for the sulphonation of PS using sulphuric acid, which enhanced the negative charge on the surface of PS as confirmed by zeta potential analysis and Fourier transform infrared radiation analysis. The thickness of the silica shell is tuned by altering the concentration of the silica precursor and is found to increase due to the use of the sulphonated PS template. N2 adsorption/desorption studies reported the variation of specific surface area of HCSNs from 644.1 to 197.8 m2 g?1 and average pore size from 1.55 to 3.4 nm. The drug release behaviour of HCSNs with different shell thicknesses is investigated using doxorubicin as the model drug. A delay in the drug release for ~300 min is successfully achieved by employing HCSNs with enhanced thickness of 60 nm. Application of HCSNs in targeted drug delivery was further supported by the in-vitro cytotoxicity studies carried out on lung adenocarcinoma cells. © 2020, Indian Academy of Sciences.