The Experts below are selected from a list of 7851 Experts worldwide ranked by ideXlab platform
F. J. Humphreys - One of the best experts on this subject based on the ideXlab platform.
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Review Grain and subgrain characterisation by electron backscatter diffraction
Journal of Materials Science, 2001Co-Authors: F. J. HumphreysAbstract:The application of automated Electron Backscatter Diffraction (EBSD) in the scanning electron microscope, to the quantitative analysis of grain and subgrain structures is discussed and compared with conventional methods of quantitative Metallography. It is shown that the technique has reached a state of maturity such that linescans and maps can routinely be obtained and analysed using commercially available equipment and that EBSD in a Field Emission SEM (FEGSEM) allows quantitative analysis of grain/subgrains as small as ∼0.2 μm. EBSD can often give more accurate measurements of grain and subgrain size than conventional imaging methods, often in comparable times. Subgrain/cell measurements may be made more easily than in the TEM although the limited angular resolution of EBSD may be problematic in some cases. Additional information available from EBSD and not from conventional microscopy, gives a new dimension to quantitative Metallography. Texture and its correlation with grain or subgrain size, shape and position are readily measured. Boundary misorientations , which are readily obtainable from EBSD, enable the distribution of boundary types to be determined and CSL boundaries can be identified and measured. The spatial distribution of Stored Energy in a sample and the amount of Recrystallization may also be measured by EBSD methods.
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Quantitative Metallography by electron backscattered diffraction
Journal of Microscopy, 1999Co-Authors: F. J. HumphreysAbstract:Although electron backscattered diffraction (EBSD) in the scanning electron microscope is used mainly to investigate the relationship between local textures and microstructures, the technique has now developed to the stage where it requires serious consideration as a tool for routine quantitative characterization of microstructures. This paper examines the application of EBSD to the characterization of phase distributions, grain and subgrain structures and also textures. Comparisons are made with the standard methods of quantitative Metallography and it is shown that in many cases EBSD can produce more accurate and detailed measurements than the standard methods and that the data may sometimes be obtained more rapidly. The factors which currently limit the use of EBSD for quantitative microstructural characterization, including the speed of data acquisition and the angular and spatial resolutions, are discussed, and future developments are considered.
H P Degischer - One of the best experts on this subject based on the ideXlab platform.
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high temperature strength of compacted sub micrometer aluminium powder
Acta Materialia, 2010Co-Authors: Cecilia Poletti, Martin Balog, Frantisek Simancik, H P DegischerAbstract:Abstract Aluminium powders with a mean particle size of around 1 μm were compacted by cold isostatic pressing (CIP) and additional forging. The specimens are characterized by hot compression tests, dilatometry and Metallography. A 3D interconnected structure of alumina films −1 . The compressive strength was 100–150 and 130–180 MPa for the CIPed and forged samples, respectively. The low strain rate sensitivity m (
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three dimensional characterization of as cast and solution treated alsi12 sr alloys by high resolution fib tomography
Acta Materialia, 2007Co-Authors: Fernando Lasagni, Andres Fabian Lasagni, E Marks, Christian Holzapfel, Frank Mucklich, H P DegischerAbstract:Abstract In this study, the three-dimensional (3D) microstructure of different unmodified and Sr-modified Al–Si base alloys is characterized by a novel focused ion beam-energy dispersive spectroscopy (FIB-EDX) for tomography. Al–Si alloys containing >7% Si present a percolating Si network in the ‘as-cast’ condition. Modification treatment with the addition of small quantities of Sr produces the formation of an extremely fine eutectic architecture of coral-like morphology. The spheroidization and coarsening of the eutectic Si structure during solution treatment is studied in 2D cross-sections and 3D reconstruction. The connectivity of the ‘as-cast’ Si networks is lost rapidly when reheated to >400 °C, and the Si particles coarsen with holding time. Both aluminum and silicon phases are identified with a resolution of ∼60 × 75 nm 2 in the image plane and ∼60–300 nm between each slice to reconstruct a FIB tomography of the eutectic Si in the ‘as-cast’ and solution-treated conditions. The combination of EDX element mapping with low-contrast secondary electron or backscattered electron imaging of a series of parallel cross-sections produced by FIB yield 3D geometrical parameters for the Si which differ from those determined by 2D Metallography. The stereological data obtained from FIB tomography quantify the spheroidization of Si much better than those derived from 2D Metallography.
Wenhui Zhang - One of the best experts on this subject based on the ideXlab platform.
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Effect of Hot Deformation on the Nitride Precipitation Behavior in High Nitrogen Austenitic Steel
Journal of Materials Engineering and Performance, 2009Co-Authors: Zhenhua Wang, Shuhua Sun, Deli Zhao, Guoli Zhang, Wenhui ZhangAbstract:High nitrogen CrMn austenitic steel specimens were compressed at 1000 °C and 0.1 s−1 to different strains and then held at 850 °C for 360 s. The nitride precipitation behavior after the deformation was investigated using physical simulation, x-ray diffraction, and quantitative Metallography. The results showed that the precipitate in 18Mn18Cr0.5N steel after the deformation and holding was Cr2N. The amount of Cr2N precipitate was significantly affected by the defect density. Precipitation was promoted by the hardening matrix compared to the recrystallized matrix.
Philippe Pilvin - One of the best experts on this subject based on the ideXlab platform.
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characterization of strain induced martensitic transformation in a metastable austenitic stainless steel
Materials & Design, 2010Co-Authors: Petr Hausild, V Davydov, Jan Drahokoupil, Michal Landa, Philippe PilvinAbstract:Kinetics of deformation-induced martensitic transformation in metastable austenitic steel AISI 301 was characterized by several techniques including classical light Metallography, scanning electron microscopy, X-ray diffraction, neutron diffraction and electron back scattered diffraction. In situ monitoring of magnetic properties, acoustic emission and temperature increase during tensile tests at different strain rates was also performed. Results obtained by different methods are compared and discussed.
V Davydov - One of the best experts on this subject based on the ideXlab platform.
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characterization of strain induced martensitic transformation in a metastable austenitic stainless steel
Materials & Design, 2010Co-Authors: Petr Hausild, V Davydov, Jan Drahokoupil, Michal Landa, Philippe PilvinAbstract:Kinetics of deformation-induced martensitic transformation in metastable austenitic steel AISI 301 was characterized by several techniques including classical light Metallography, scanning electron microscopy, X-ray diffraction, neutron diffraction and electron back scattered diffraction. In situ monitoring of magnetic properties, acoustic emission and temperature increase during tensile tests at different strain rates was also performed. Results obtained by different methods are compared and discussed.
