Mapping of Strain Tensor Components in Polycrystalline Samples using EBSD.

2014 ◽  
Vol 1664 ◽  
Author(s):  
David J Dingley ◽  
Graham Meaden ◽  
Seiichi Suzuki ◽  
Tatsuya Fukino
Keyword(s):  
Hot Spots ◽  
Electron Backscatter Diffraction ◽  
Strain Tensor ◽  
Polycrystalline Materials ◽  
Static Tests ◽  
Stress Relieving ◽  
Elastic Loading ◽  
Residual Strains ◽  
Backscatter Diffraction ◽  
Better Than

ABSTRACTThe advance in Electron Backscatter Diffraction known as High Resolution EBSD has permitted the strain tensor components and neighbour disorientation measurements to be mapped at resolutions better than 2 parts in 10000. Following earlier research into this technique which was focused on verifying the sensitivity and accuracy of the measurements, recent studies have involved investigations on semiconductor and metallic polycrystalline materials. In particular observations of localized regions where residual strains exceeded the macroscopic yield stress have been thoroughly investigated to eliminate experimental error as a possible explanation. No such cause was found. Strain measurements on polycrystalline steels in uniaxial tension and during thermal stress relieving thermal treatment have also been carried out. Maps of the strain distribution during elastic loading and early stages of plastic flow showed hot spots of high strain as in the static tests but overall the measured elastic strain was equal to the applied strain.

Application of Electron Backscatter Diffraction to Grain Boundaries

2010 ◽  
Vol 160 ◽  
pp. 39-46 ◽  
Author(s):  
Valerie Randle
Keyword(s):  
Grain Boundary ◽  
Electron Backscatter Diffraction ◽  
Experimental Methodology ◽  
Polycrystalline Materials ◽  
Grain Boundary Engineering ◽  
Network Characteristics ◽  
Grain Boundary Plane ◽  
Electron Backscatter ◽  
Measurement Strategies ◽  
Backscatter Diffraction

The technique of electron backscatter diffraction (EBSD) is ideal for the characterisation of grain boundary networks in polycrystalline materials. In recent years the experimental methodology has evolved to meet the needs of the research community. For example, the capabilities of EBSD have been instrumental in driving forward the topic of ‘grain boundary engineering’. In this paper the current capabilities of EBSD for grain boundary characterisation will be reviewed and illustrated by examples. Topics are measurement strategies based on misorientation statistics, determination of grain boundary plane distributions and grain boundary network characteristics.

Spatial resolution measurements of electron backscatter diffraction patterns (EBSPs) in the scanning electron microscope

1990 ◽  
Vol 48 (4) ◽  
pp. 404-405 ◽  
Author(s):  
Jarle Hjelen ◽  
Erik Nes
Keyword(s):  
Electron Beam ◽  
Spatial Resolution ◽  
Electron Backscatter Diffraction ◽  
Line Pattern ◽  
Bulk Specimen ◽  
Local Lattice ◽  
Diffraction Patterns ◽  
Backscatter Diffraction ◽  
Stationary Electron ◽  
Better Than

In the EBSP method the stationary electron beam hits a highly tilted bulk specimen in the SEM. The backscattered Bragg diffracted electrons form the Kikuchi line pattern on a phosphor screen. Since the first EBSP experiments were carried out in 1973, this technique has been further developed to determine crystal orientations in connection with texture development in aluminium. Using the EBSP method to calculate local lattice curvatures in heavily deformed aluminium, the spatial resolution has to be better than the selected area channeling pattern (SACP) method.The EBSP resolution (d) was measured by moving the electron beam digitally across grain boundaries in an aluminium sample. The resolution was defined to be the overlapping distance between two diffraction patterns.

Analysis of Multiphase Materials Using Electron Backscatter Diffraction

1997 ◽  
Vol 3 (S2) ◽  
pp. 561-562
Author(s):  
S.I. Wright ◽  
D.P. Field
Keyword(s):  
Crystallographic Orientation ◽  
Electron Backscatter Diffraction ◽  
Computer Control ◽  
Orientation Imaging Microscopy ◽  
Spatial Arrangement ◽  
Polycrystalline Materials ◽  
Orientation Data ◽  
Topological Features ◽  
Electron Backscatter ◽  
Backscatter Diffraction

Image analysis techniques coupled with crystallography computer codes have been used to index electron backscatter diffraction patterns (EBSPs). The ability to automatically obtain the crystallographic orientation from EBSPs coupled with computer control of the electron beam (or stage) in a scanning electron microscope (SEM) provides a much more complete description of the spatial distribution of crystallographic orientation in polycrystalline materials than has been previously attainable using conventional metallography techniques. Orientation data obtained using this technique can be used to form images reflecting the spatial arrangement of crystallographic orientation in a microstructure. Such images enable the topological features of a microstructure to be linked with the orientation characteristics. The formation of these images, as well as the data collection technique, is sometimes termed Orientation Imaging Microscopy (OIM). The utility of this technique for exploring the property/structure relationship in polycrystalline material has been demonstrated by numerous researchers. However, as yet, this technique has almost exclusively been applied to single phase materials.

Crystallographic Mapping in Scanning and Transmission Electron Micrsocopy with Application to Semiconductor Materials

1998 ◽  
Vol 523 ◽  
Author(s):  
D. J. Dingley ◽  
S. I. Wright ◽  
D. J. Dingley
Keyword(s):  
Electron Microscope ◽  
Electron Backscatter Diffraction ◽  
Orientation Imaging Microscopy ◽  
Lattice Parameter ◽  
Dark Field ◽  
Polycrystalline Materials ◽  
Orientation Imaging ◽  
Transmission Electron ◽  
Dark Field Microscopy ◽  
Backscatter Diffraction

AbstractThe two sister techniques, Electron Backscatter Diffraction and Orientation Imaging Microscopy which operate in a scanning electron microscope, are well established tools for the characterization of polycrystalline materials. Experiment has shown that the limiting resolution for mapping is the order of 0.1 microns. The basic techniques have been extended to include multiphase mapping. Whereas it has been possible to distinguish between phases of different crystal systems easily, it has not been possible to distinguish between phases that differ in lattice parameter by less than 5 %.An equivalent transmission electron microscope procedure has been developed. The technique couples standard hollow cone microscopy procedures with dark field microscopy. All possible dark field images that can be produced by tilting the electron beam are scanned to detect under what settings each crystal is brought into a diffracting condition. Subsequent analysis permits determination of both crystal phase and orientation.

Anisotropy of Mechanical Properties and Microstructure Evolutions of Tensile AZ80 Magnesiumat Room Temperature

2012 ◽  
Vol 560-561 ◽  
pp. 1000-1004
Author(s):  
Dan Dan Zhang ◽  
Meng Li ◽  
Ya Chen Xiao ◽  
Yang Ping
Keyword(s):  
Mechanical Properties ◽  
Room Temperature ◽  
Electron Backscatter Diffraction ◽  
Prismatic Plane ◽  
Alloy Plate ◽  
Ebsd Technique ◽  
Backscatter Diffraction ◽  
Tension Direction ◽  
Anisotropy Of Mechanical Properties ◽  
Better Than

It is obviously different mechanical properties of the rolled magnesium alloy plate when stretched along different directions at room temperature. In this study, three groups of samples for uniaxial tension were cut from the as-rolled AZ80 plate with their tension directions either at 0°, 45°or 90°to the rolled direction (RD) of the sheet. Results show that the ductility of the 45°samples was significantly better than that of 0°and 90°samples. The electron backscatter diffraction (EBSD) technique was used to investigate the microstructure and textures evolution. Along with the increase of deformation, more low-angle grain boundaries arise in the 0°and 45°samples than the 90°samples. At the same time, the texture components that {10-10} prismatic plane perpendicular to the tension direction were significantly enhanced in three groups of samples.

Characterization of Dual-Phase Steel Microstructure by Combined Submicrometer EBSD and EPMA Carbon Measurements

2013 ◽  
Vol 19 (4) ◽  
pp. 996-1006 ◽  
Author(s):  
Philippe T. Pinard ◽  
Alexander Schwedt ◽  
Ali Ramazani ◽  
Ulrich Prahl ◽  
Silvia Richter
Keyword(s):  
Dual Phase Steel ◽  
Electron Backscatter Diffraction ◽  
Hydrocarbon Contamination ◽  
Dual Phase ◽  
Kernel Average Misorientation ◽  
Steel Microstructure ◽  
Backscatter Diffraction ◽  
Induced Dislocation ◽  
Better Than

AbstractElectron backscatter diffraction (EBSD) and electron probe microanalysis (EPMA) measurements are combined to characterize an industrial produced dual-phase steel containing some bainite fraction. High-resolution carbon mappings acquired on a field emission electron microprobe are utilized to validate and improve the identification of the constituents (ferrite, martensite, and bainite) performed by EBSD using the image quality and kernel average misorientation. The combination eliminates the ambiguity between the identification of bainite and transformation-induced dislocation zones, encountered if only the kernel average misorientation is considered. The detection of carbon in high misorientation regions confirms the presence of bainite. These results are corroborated by secondary electron images after nital etching. Limitations of this combined method due to differences between the spatial resolution of EBSD and EPMA are assessed. Moreover, a quantification procedure adapted to carbon analysis is presented and used to measure the carbon concentration in martensite and bainite on a submicrometer scale. From measurements on reference materials, this method gives an accuracy of 0.02 wt% C and a precision better than 0.05 wt% C despite unavoidable effects of hydrocarbon contamination.

scholarly journals Effects of Trace Amounts of Mn, Zr and Sc on the Recrystallization and Corrosion Resistance of Al-5Mg Alloys

Crystals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 926
Author(s):  
Sheng-Long Lee ◽  
Yang-Chun Chiu ◽  
Tse-An Pan ◽  
Mien-Chung Chen
Keyword(s):  
Corrosion Resistance ◽  
Grain Boundary ◽  
Grain Growth ◽  
Intergranular Corrosion ◽  
Electron Backscatter Diffraction ◽  
Recrystallization Process ◽  
Corrosion Morphology ◽  
Electron Microscopes ◽  
Backscatter Diffraction ◽  
Better Than

This study aimed to explore the effects of trace amounts of Mn, Zr, and Sc on the recrystallization behavior and corrosion resistance of Al-5Mg alloys after process annealing by means of alloy design and microstructure analysis of electron backscatter diffraction (EBSD), electron microprobe (EPMA), and electron microscopes (TEM and SEM). The main objective was to obtain alloys with better corrosion resistance. The results show that the fine Al3Zr and Al3Sc precipitated particles were both superior to the MnAl6 particles in inhibiting grain and sub-grain boundary migrations. Therefore, the Zr-containing and Sc-containing alloys were better than the Mn-containing alloy in inhibiting recrystallization. For further comparison, the thermal stability of the Al3Sc particles was better than that of the Al3Zr particles, so the Sc-containing alloy at the high temperature above 350 °C inhibited grain growth better than the Zr-containing alloy. During the recovery stage of the alloy in the recrystallization process, the β-Mg2Al3 phase precipitated on the sub-grain boundary, thus reducing the occurrence of intergranular corrosion. However, in the initial stage of recrystallization, the β-Mg2Al3 phase continuously precipitated on the grain boundary, causing obvious intergranular corrosion. For the Sc-containing alloy, because there was no obvious grain growth stage, the β-Mg2Al3 phase continuously precipitated on the grain boundary, and thereby intergranular corrosion occurred. Therefore, its corrosion resistance was greatly reduced. By contrast, for the alloy containing Mn or Zr, because of obvious grain growth, magnesium atoms aggregated. As a result, the β-Mg2Al3 phase discontinuously precipitated on the grain boundary. The corrosion morphology was local pitting corrosion rather than intergranular corrosion, and thus the corrosion resistance of the alloy was enhanced. As a novelty, this study clearly observed the sensitized precipitation and corrosion morphology of the β-Mg2Al3 phase of Al-5Mg alloy under different recrystallization methods. This will be of benefit to the design of anti-corrosion measures for the future manufacturing and application of Al-5Mg alloy.

Electron Backscatter Diffraction

2019 ◽  
Author(s):  
David P. Field ◽  
Mukul Kumar
Keyword(s):  
Electron Microscope ◽  
Friction Stir Welding ◽  
Integrated Circuit ◽  
Electron Backscatter Diffraction ◽  
Local Information ◽  
Polycrystalline Materials ◽  
Friction Stir ◽  
Electron Backscatter ◽  
Backscatter Diffraction ◽  
Scanning Electron

Electron backscatter diffraction (EBSD) is a scanning electron microscope (SEM) based technique that is used to obtain local information on the crystallographic character of bulk crystalline and polycrystalline materials. Topics discussed in this article include: EBSD system overview, multiphase analysis, and application to aluminum integrated circuit interconnects, dislocation structure analysis, analysis of grain boundary networks, and application to friction stir welding of aluminum alloys.

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