tanaji paul - Academia.edu (original) (raw)
Papers by tanaji paul
Metallic glasses are a novel class of amorphous materials that have diverse potential application... more Metallic glasses are a novel class of amorphous materials that have diverse potential applications due to their superior mechanical, electrochemical and tribological properties as compared to their polycrystalline counterparts. However, the requirement of extremely high cooling rates in solidification processing severely limits the manufacturing of these materials to small dimensions such as powder and ribbons. In order to circumvent this problem, this research investigates three thermal responses, namely sintering, oxidation and crystallization in an iron-based metallic glass powder. The resulting original scientific contribution of this dissertation is the establishment of the mechanism and kinetics of sintering, crystallization and oxidation in this iron based metallic glass powder. During sintering at a constant rate of heating, the activation energy of viscous flow decreases linearly with the logarithm of the heating rate while the macroscopic applied pressure is amplified thre...
Materials Today Communications
Journal of Materials Research, Sep 6, 2022
Journal of Thermal Spray Technology, Sep 8, 2022
ACS Applied Materials & Interfaces
Frontiers in Materials
The quantification of spatially variable mechanical response in structural materials remains a ch... more The quantification of spatially variable mechanical response in structural materials remains a challenge. Additive manufacturing methods result in increased spatial property variations—the effect of which on component performance is of key interest. To assist iterative design of additively manufactured prototypes, lower-cost benchtop test methods with high precision and accuracy will be necessary. Profilometry-based indentation plastometry (PIP) promises to improve upon the instrumented indentation test in terms of the measurement uncertainty. PIP uses an isotropic Voce hardening model and inverse numerical methods to identify plasticity parameters. The determination of the baseline uncertainty of PIP test is fundamental to its use in characterizing spatial material property variability in advanced manufacturing. To quantify the uncertainty of the PIP test, ninety-nine PIP tests are performed on prepared portions of a traditionally manufactured Al 7075 plate sample. The profilometry...
Advanced Engineering Materials
International Thermal Spray Conference and Exposition - ITSC 2021, May 25, 2021
Journal of the American Ceramic Society, 2021
Journal of the American Ceramic Society, 2021
SSRN Electronic Journal, 2021
The dynamic elastic behavior of cold sprayed aluminum 6061 coatings is analyzed to understand the... more The dynamic elastic behavior of cold sprayed aluminum 6061 coatings is analyzed to understand the inherent role of in-situ splat sintering from ambient to 400 oC for air and helium sprayed coatings. Higher surface energy and lower flattening ratio of air sprayed coating in as-sprayed condition result in 28% densification during splat sintering compared to 15% in heat-treated helium sprayed ones. Elastic modulus and damping behavior can be divided into three distinct temperature regimes based on dynamic sintering and progressive intersplat structure. A theoretical analysis is established, which shows that normalized elastic modulus is an exponential function of the inter-splat porosity. This study establishes the correlation between inter-splat thermal phenomena and coating’s dynamic mechanical properties at elevated temperatures.
Materials Science and Engineering: A, 2021
Abstract This paper presents the first report of ultrasonic treatment (UST) assisted casting of i... more Abstract This paper presents the first report of ultrasonic treatment (UST) assisted casting of independent 2D layered hexagonal boron nitride (hBN) reinforced aluminum matrix composites. A linear enhancement of nucleation density is obtained with treatment time from 0 to 90 s from dispersion of hBN platelets by UST. Outstanding grain refinement of 72% from 375.3 to 103.6 μm is obtained from UST for 90 s. The corresponding nanohardness is 709.2 MPa, a hardening of 36% due to symbiotic refinement and dispersion contributions. Anchoring and orientation of hBN platelets dictate that the elastic modulus improved up to 150% by ultrasonication for 90 s. The exfoliated 2D reinforcement layers reduce the coefficient of friction during sliding wear by 15% and loss of worn material by 46% in these composites. The mechanism of dispersion, improvement of properties, and quantitative correlations constitute a step of advancement towards understanding the role of 2D particle morphology and dimensionality on the ultrasonic casting of metal matrix composites.
Scripta Materialia, 2021
Abstract The dynamic elastic behavior of cold sprayed aluminum 6061 coatings is analyzed to under... more Abstract The dynamic elastic behavior of cold sprayed aluminum 6061 coatings is analyzed to understand the inherent role of in-situ splat sintering from ambient to 400 °C for air and helium sprayed coatings. Higher surface energy and lower flattening ratio of air sprayed coating in as-sprayed condition result in 28% densification during splat sintering compared to 15% in heat-treated helium sprayed ones. Elastic modulus and damping behavior can be divided into three distinct temperature regimes based on sintering and progressive inter-splat structure. A theoretical analysis is established, which shows that normalized elastic modulus is an exponential function of the inter-splat porosity. This study establishes the correlation between inter-splat thermal phenomena and coating's dynamic mechanical properties at elevated temperatures.
Advanced Engineering Materials, 2020
A fundamental understanding of second phase reinforcement addition techniques during ultrasonic c... more A fundamental understanding of second phase reinforcement addition techniques during ultrasonic casting is necessary for the advancement of metal matrix composite manufacturing technology. This review evaluates the comparative efficacy of various addition techniques for incorporating reinforcements under the framework of ultrasonic processing. The evolution of these techniques over time is deciphered in light of the scientific background behind challenges, principles, and methods. Their role in the improvement of microstructure and properties of the composites, intertwined with ultrasonic treatment, is delineated. Techniques introducing greater kinetic disorder during solidification, such as 'Stirring' and 'Gas Assisted Injection,' are found to be superior for reinforcement addition. More significant enhancement of microstructural and mechanical characteristics is also obtained in composites manufactured by the techniques with higher kinetics. This culminates in the identification of the limitations and perspectives on the progress of research in this scope. This analytical review of second phase reinforcement addition techniques operates as a tool for researchers to steer the advancement of future procedures and hence metal matrix composite manufacturing technology. GA: Analytical review of the ultrasonic treatment process for manufacturing metal matrix composites is presented. The role of the matrix, reinforcement, second phase addition technique, sonotrode, and ultrasonication parameters are discussed. This can be utilized for Accepted Article This article is protected by copyright. All rights reserved the identification of processing 'sweet spots' for the advancement of MMC manufacturing technology.
Advanced Engineering Materials, 2020
A quantitative understanding of the role of ultrasonic treatment process variables on microstruct... more A quantitative understanding of the role of ultrasonic treatment process variables on microstructure and mechanical properties is critical for the development of process maps for manufacturing metal matrix composites. This paper presents a novel mathematical framework to delineate the functional correlations between ultrasonication time, grain refinement, and hardening in SiC nanoparticle reinforced Al matrix composites. Ultrasonic treatment generates microbubbles and deagglomerates SiC to increase heterogeneous nucleation sites synergistically. The increase in volumetric nucleation density due to SiC addition exhibits slow exponential kinetics with varying ultrasonication time. An outstanding grain refinement efficiency of 62.8% is achieved upon ultrasonication for 90 s. The contributions to an increase in the hardness due to grain refinement and SiC dispersion are isolated to develop correlations between ultrasonication time and hardening. Hardening increases exponentially with treatment time due to the reduction of interparticle distance from sonication induced SiC dispersion. These fundamental mathematical correlations constitute a significant advancement towards the development of ultrasonic process maps and metal matrix composite manufacturing technology.
Scientific Reports, 2020
Understanding the thermal stability of metallic glasses is critical to determining their safe tem... more Understanding the thermal stability of metallic glasses is critical to determining their safe temperatures of service. In this paper, the crystallization mechanism in spark plasma sintered Fe48Cr15Mo14Y2C15B6 metallic glass is established by analyzing the crystal size distribution using x-ray diffraction, transmission electron microscopy and in-situ small angle neutron scattering. Isothermal annealing at 700 °C and 725 °C for 100 min resulted in the formation of (Fe,Cr)23C6 crystals, measured from transmission electron micrographs, to be from 10 to 30 nm. The small angle neutron scattering intensity measured in-situ, over a Q-range of 0.02 to 0.3 Å−1, during isothermal annealing of the sintered samples, confirmed the presence of (Fe,Cr)23C6 crystals. The measured scattering intensity, fitted by the maximum entropy model, over the Q-range of 0.02 to 0.06 Å−1, revealed that the crystals had radii ranging from 3 to 18 nm. The total volume fraction of crystals were estimated to be 0.13 ...
Scripta Materialia, 2019
Evaluation of the diffusion coefficient of metal powders was attempted by using the power-law cre... more Evaluation of the diffusion coefficient of metal powders was attempted by using the power-law creep model in conjunction with the isothermal densification kinetics during spark plasma sintering (SPS). The diffusion coefficients obtained from the densification data of elemental Fe, Ni and Al powders are found to be higher than those reported in the literature. The higher values of diffusivity can be attributed to electric current effects. Our analysis demonstrates that it is possible to evaluate diffusion coefficients from experimental SPS densification data.
Metallic glasses are a novel class of amorphous materials that have diverse potential application... more Metallic glasses are a novel class of amorphous materials that have diverse potential applications due to their superior mechanical, electrochemical and tribological properties as compared to their polycrystalline counterparts. However, the requirement of extremely high cooling rates in solidification processing severely limits the manufacturing of these materials to small dimensions such as powder and ribbons. In order to circumvent this problem, this research investigates three thermal responses, namely sintering, oxidation and crystallization in an iron-based metallic glass powder. The resulting original scientific contribution of this dissertation is the establishment of the mechanism and kinetics of sintering, crystallization and oxidation in this iron based metallic glass powder. During sintering at a constant rate of heating, the activation energy of viscous flow decreases linearly with the logarithm of the heating rate while the macroscopic applied pressure is amplified thre...
Materials Today Communications
Journal of Materials Research, Sep 6, 2022
Journal of Thermal Spray Technology, Sep 8, 2022
ACS Applied Materials & Interfaces
Frontiers in Materials
The quantification of spatially variable mechanical response in structural materials remains a ch... more The quantification of spatially variable mechanical response in structural materials remains a challenge. Additive manufacturing methods result in increased spatial property variations—the effect of which on component performance is of key interest. To assist iterative design of additively manufactured prototypes, lower-cost benchtop test methods with high precision and accuracy will be necessary. Profilometry-based indentation plastometry (PIP) promises to improve upon the instrumented indentation test in terms of the measurement uncertainty. PIP uses an isotropic Voce hardening model and inverse numerical methods to identify plasticity parameters. The determination of the baseline uncertainty of PIP test is fundamental to its use in characterizing spatial material property variability in advanced manufacturing. To quantify the uncertainty of the PIP test, ninety-nine PIP tests are performed on prepared portions of a traditionally manufactured Al 7075 plate sample. The profilometry...
Advanced Engineering Materials
International Thermal Spray Conference and Exposition - ITSC 2021, May 25, 2021
Journal of the American Ceramic Society, 2021
Journal of the American Ceramic Society, 2021
SSRN Electronic Journal, 2021
The dynamic elastic behavior of cold sprayed aluminum 6061 coatings is analyzed to understand the... more The dynamic elastic behavior of cold sprayed aluminum 6061 coatings is analyzed to understand the inherent role of in-situ splat sintering from ambient to 400 oC for air and helium sprayed coatings. Higher surface energy and lower flattening ratio of air sprayed coating in as-sprayed condition result in 28% densification during splat sintering compared to 15% in heat-treated helium sprayed ones. Elastic modulus and damping behavior can be divided into three distinct temperature regimes based on dynamic sintering and progressive intersplat structure. A theoretical analysis is established, which shows that normalized elastic modulus is an exponential function of the inter-splat porosity. This study establishes the correlation between inter-splat thermal phenomena and coating’s dynamic mechanical properties at elevated temperatures.
Materials Science and Engineering: A, 2021
Abstract This paper presents the first report of ultrasonic treatment (UST) assisted casting of i... more Abstract This paper presents the first report of ultrasonic treatment (UST) assisted casting of independent 2D layered hexagonal boron nitride (hBN) reinforced aluminum matrix composites. A linear enhancement of nucleation density is obtained with treatment time from 0 to 90 s from dispersion of hBN platelets by UST. Outstanding grain refinement of 72% from 375.3 to 103.6 μm is obtained from UST for 90 s. The corresponding nanohardness is 709.2 MPa, a hardening of 36% due to symbiotic refinement and dispersion contributions. Anchoring and orientation of hBN platelets dictate that the elastic modulus improved up to 150% by ultrasonication for 90 s. The exfoliated 2D reinforcement layers reduce the coefficient of friction during sliding wear by 15% and loss of worn material by 46% in these composites. The mechanism of dispersion, improvement of properties, and quantitative correlations constitute a step of advancement towards understanding the role of 2D particle morphology and dimensionality on the ultrasonic casting of metal matrix composites.
Scripta Materialia, 2021
Abstract The dynamic elastic behavior of cold sprayed aluminum 6061 coatings is analyzed to under... more Abstract The dynamic elastic behavior of cold sprayed aluminum 6061 coatings is analyzed to understand the inherent role of in-situ splat sintering from ambient to 400 °C for air and helium sprayed coatings. Higher surface energy and lower flattening ratio of air sprayed coating in as-sprayed condition result in 28% densification during splat sintering compared to 15% in heat-treated helium sprayed ones. Elastic modulus and damping behavior can be divided into three distinct temperature regimes based on sintering and progressive inter-splat structure. A theoretical analysis is established, which shows that normalized elastic modulus is an exponential function of the inter-splat porosity. This study establishes the correlation between inter-splat thermal phenomena and coating's dynamic mechanical properties at elevated temperatures.
Advanced Engineering Materials, 2020
A fundamental understanding of second phase reinforcement addition techniques during ultrasonic c... more A fundamental understanding of second phase reinforcement addition techniques during ultrasonic casting is necessary for the advancement of metal matrix composite manufacturing technology. This review evaluates the comparative efficacy of various addition techniques for incorporating reinforcements under the framework of ultrasonic processing. The evolution of these techniques over time is deciphered in light of the scientific background behind challenges, principles, and methods. Their role in the improvement of microstructure and properties of the composites, intertwined with ultrasonic treatment, is delineated. Techniques introducing greater kinetic disorder during solidification, such as 'Stirring' and 'Gas Assisted Injection,' are found to be superior for reinforcement addition. More significant enhancement of microstructural and mechanical characteristics is also obtained in composites manufactured by the techniques with higher kinetics. This culminates in the identification of the limitations and perspectives on the progress of research in this scope. This analytical review of second phase reinforcement addition techniques operates as a tool for researchers to steer the advancement of future procedures and hence metal matrix composite manufacturing technology. GA: Analytical review of the ultrasonic treatment process for manufacturing metal matrix composites is presented. The role of the matrix, reinforcement, second phase addition technique, sonotrode, and ultrasonication parameters are discussed. This can be utilized for Accepted Article This article is protected by copyright. All rights reserved the identification of processing 'sweet spots' for the advancement of MMC manufacturing technology.
Advanced Engineering Materials, 2020
A quantitative understanding of the role of ultrasonic treatment process variables on microstruct... more A quantitative understanding of the role of ultrasonic treatment process variables on microstructure and mechanical properties is critical for the development of process maps for manufacturing metal matrix composites. This paper presents a novel mathematical framework to delineate the functional correlations between ultrasonication time, grain refinement, and hardening in SiC nanoparticle reinforced Al matrix composites. Ultrasonic treatment generates microbubbles and deagglomerates SiC to increase heterogeneous nucleation sites synergistically. The increase in volumetric nucleation density due to SiC addition exhibits slow exponential kinetics with varying ultrasonication time. An outstanding grain refinement efficiency of 62.8% is achieved upon ultrasonication for 90 s. The contributions to an increase in the hardness due to grain refinement and SiC dispersion are isolated to develop correlations between ultrasonication time and hardening. Hardening increases exponentially with treatment time due to the reduction of interparticle distance from sonication induced SiC dispersion. These fundamental mathematical correlations constitute a significant advancement towards the development of ultrasonic process maps and metal matrix composite manufacturing technology.
Scientific Reports, 2020
Understanding the thermal stability of metallic glasses is critical to determining their safe tem... more Understanding the thermal stability of metallic glasses is critical to determining their safe temperatures of service. In this paper, the crystallization mechanism in spark plasma sintered Fe48Cr15Mo14Y2C15B6 metallic glass is established by analyzing the crystal size distribution using x-ray diffraction, transmission electron microscopy and in-situ small angle neutron scattering. Isothermal annealing at 700 °C and 725 °C for 100 min resulted in the formation of (Fe,Cr)23C6 crystals, measured from transmission electron micrographs, to be from 10 to 30 nm. The small angle neutron scattering intensity measured in-situ, over a Q-range of 0.02 to 0.3 Å−1, during isothermal annealing of the sintered samples, confirmed the presence of (Fe,Cr)23C6 crystals. The measured scattering intensity, fitted by the maximum entropy model, over the Q-range of 0.02 to 0.06 Å−1, revealed that the crystals had radii ranging from 3 to 18 nm. The total volume fraction of crystals were estimated to be 0.13 ...
Scripta Materialia, 2019
Evaluation of the diffusion coefficient of metal powders was attempted by using the power-law cre... more Evaluation of the diffusion coefficient of metal powders was attempted by using the power-law creep model in conjunction with the isothermal densification kinetics during spark plasma sintering (SPS). The diffusion coefficients obtained from the densification data of elemental Fe, Ni and Al powders are found to be higher than those reported in the literature. The higher values of diffusivity can be attributed to electric current effects. Our analysis demonstrates that it is possible to evaluate diffusion coefficients from experimental SPS densification data.