The Experts below are selected from a list of 8211 Experts worldwide ranked by ideXlab platform
John H. Root - One of the best experts on this subject based on the ideXlab platform.
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Neutron Diffraction Method for stored energy measurement in interstitial free steel
Acta Materialia, 1997Co-Authors: N. Rajmohan, Y. Hayakawa, Jerzy A. Szpunar, John H. RootAbstract:Part of the energy acquired by polycrystalline metals during plastic deformation is stored in the form of dislocations and other crystal defects. A Method is described for the measurement of the orientation dependence of the stored energy of cold work, using Neutron Diffraction line broadening. To illustrate the Method, the measured stored energy values for 80% cold rolled interstitial free (IF) steel are compared with the stored energy in a stress relieved specimen. The correlation between the Taylor factor and the stored energy for an 80% cold rolled specimen is discussed.
Shihoon Choi - One of the best experts on this subject based on the ideXlab platform.
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stress partitioning behavior of an alsi10mg alloy produced by selective laser melting during tensile deformation using in situ Neutron Diffraction
Journal of Alloys and Compounds, 2016Co-Authors: Dongkyu Kim, Wanchuck Woo, Jihyun Hwang, Shihoon ChoiAbstract:Abstract Micromechanical stress partitioning between Al and Si constituents in an AlSi10Mg alloy fabricated by selective laser melting was determined during uniaxial tensile loading. In situ Neutron Diffraction Method was utilized for the measurements of the lattice strains from a set of Al and Si grains separately and the strain components were correlated to the stress evolution of each alloy constituent. The elastic strain of the Al matrix saturated at about 3800 μe while it continuously increases up to 9000 μe in the plastic deformation region of the Si particles. The stress partitioning was estimated as 260 MPa for the Al matrix and 680 MPa for the Si particles on fracture. Microstructure of the fracture surface shows a number of large voids and cracks propagated along the soft Al matrix.
S R Agnew - One of the best experts on this subject based on the ideXlab platform.
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modeling lattice strain evolution at finite strains and experimental verification for copper and stainless steel using in situ Neutron Diffraction
International Journal of Plasticity, 2010Co-Authors: C J Neil, James A Wollmershauser, Bjorn Clausen, C N Tome, S R AgnewAbstract:An elasto-plastic self-consistent (EPSC) polycrystal model is extended to account, in an approximate fashion, for the kinematics of large strains, rigid body rotations, texture evolution and grain shape evolution. In situ Neutron Diffraction measurements of the flow stress, internal strain, texture and Diffraction peak intensity evolutions were performed on polycrystalline copper and stainless steel, up to true tensile strains of e = 0.3. Suitably adjusted slip system hardening model parameters enable the model to quantitatively describe the flow stress of the polycrystalline aggregate. Quantitative predictions of the texture evolution and the internal strain evolution along the stress axis are good, while predictions of transverse internal strains (perpendicular to the tensile loading direction) are less satisfactory. The latter exhibit a large dispersion from grain to grain around a macroscopic average, and the implications of this finding for the interpretation of in situ Neutron Diffraction Method are explored. Finally, as a demonstration of the applicability of the model to problems involving finite rotation, as well as deformation, simulations of simple shear were conducted which predict a texture evolution in agreement with published experimental data, and other modeling approaches as well.
Thierry Baudin - One of the best experts on this subject based on the ideXlab platform.
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measurement of stored energy in fe 48 ni alloys strongly cold rolled using three approaches Neutron Diffraction dillamore and kam approaches
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2014Co-Authors: Yanick Ateba Betanda, Annelaure Helbert, Francois Brisset, Mariehelene Mathon, Thierry Waeckerle, Thierry BaudinAbstract:Abstract The stored energy, which is the main driving energy of the primary recrystallization, was measured in two Fe–48%Ni cold-rolled samples using three different approaches: the Neutron Diffraction Method based on the peak broadening, the Kernel Average misorientation (KAM) and the Dillamore Methods both based on the misorientation and dislocation cell size estimation using EBSD (Electron Back Scatter Diffraction) data. The results were compared with each other and showed differences in stored energy values. In this paper, it is demonstrated that the stored energy calculated by both KAM and Dillamore approaches is underestimated compared to that one calculated from Neutron Diffraction peak broadening. This is because Dillamore approach considers only the GND (Geometrically Necessary Dislocations), blocked in the cell walls, the KAM Method takes into account only the GND in all of the microstructure (cells and walls) and the Neutron Diffraction Method takes into consideration all types of dislocations (SSD (Statistically Stored Dislocations) and GND) within the microstructure. The measurement principle and the energy gap observed between the different approaches were discussed.
N. Rajmohan - One of the best experts on this subject based on the ideXlab platform.
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Neutron Diffraction Method for stored energy measurement in interstitial free steel
Acta Materialia, 1997Co-Authors: N. Rajmohan, Y. Hayakawa, Jerzy A. Szpunar, John H. RootAbstract:Part of the energy acquired by polycrystalline metals during plastic deformation is stored in the form of dislocations and other crystal defects. A Method is described for the measurement of the orientation dependence of the stored energy of cold work, using Neutron Diffraction line broadening. To illustrate the Method, the measured stored energy values for 80% cold rolled interstitial free (IF) steel are compared with the stored energy in a stress relieved specimen. The correlation between the Taylor factor and the stored energy for an 80% cold rolled specimen is discussed.