EBSDL: a computer program for determining an unknown Bravais lattice using a single electron backscatter diffraction pattern

2014 ◽  
Vol 47 (4) ◽  
pp. 1466-1468 ◽  
Author(s):  
Lili Li ◽  
Sheng Ouyang ◽  
Yanqing Yang ◽  
Ming Han
Keyword(s):  
Computer Program ◽  
Electron Backscatter Diffraction ◽  
Bravais Lattice ◽  
Chemical Information ◽  
Phase Identification ◽  
Crystalline Materials ◽  
The Poor ◽  
Electron Backscatter ◽  
Ebsd Pattern ◽  
Backscatter Diffraction

Electron backscatter diffraction (EBSD) patterns provide a wealth of crystallographic information but disappointingly low accuracy. Adopting a strategy of compensating the poor accuracy by the large amount of information, a computer program, EBSDL, has been successfully developed to determine the unknown Bravais lattice of bulk crystalline materials using a single EBSD pattern. Unlike programs that perform phase identification, the new application is completely independent of chemical information.

Phase Identification Using EBSD in the SEM: What Can be Done Today and What we Hope to do Tomorrow

1999 ◽  
Vol 5 (S2) ◽  
pp. 220-221
Author(s):  
J. R. Michael
Keyword(s):  
Fiber Optic ◽  
Electron Backscatter Diffraction ◽  
Phase Identification ◽  
Powder Diffraction File ◽  
Crystalline Materials ◽  
Future Developments ◽  
Electron Backscatter ◽  
Ebsd Pattern ◽  
Backscatter Diffraction

Phase identification using electron backscatter diffraction (EBSD) in the SEM has become a useful and important tool for the characterization of crystalline materials. Phase identification is accomplished using EBSD in the following manner. First, a high quality camera must be added to the SEM. Suitable cameras use slow scan CCD imagers coupled either by a lens or a fiber optic bundle to a phosphor screen that is situated near the sample. A EBSD pattern is collected and EDS or WDS is used to determine qualitatively the chemistry of the area. An automated routine is then used to extract the positions and widths of the lines in the pattern followed by a calculation of the unit cell volume. This information coupled with the chemistry of the sample is then used to search a database of crystal structures. Currently, the ICDD's Powder Diffraction file of over 100,000 compounds is used. Once a list of potential matches is found the patterns are indexed and then simulated to demonstrate that the phase has been identified. This paper will demonstrate use of EBSD for phase identification and then will speculate on future developments.A particularly nice application of EBSD is the use of the technique for the identification of phases that form in welds. Figure 1a is an EBSD pattern obtained from a acicular phase in a superalloy weld. The phase was determined to be primarily Ti and Ni. Analysis of the patterns showed that the phase is Ni3Ti. Figure 1b shows the simulation for Ni3Ti overlaid on the experimental pattern demonstrating that the phase has been identified.

Determining the Bravais lattice using a single electron backscatter diffraction pattern

2015 ◽  
Vol 48 (1) ◽  
pp. 107-115 ◽  
Author(s):  
Lili Li ◽  
Ming Han
Keyword(s):  
Electron Backscatter Diffraction ◽  
A Priori ◽  
Single Electron ◽  
Bravais Lattice ◽  
Cell Parameters ◽  
Mineral Sample ◽  
Electron Backscatter ◽  
Ebsd Pattern ◽  
Backscatter Diffraction

Theab initioderivation of the Bravais lattice from the Kikuchi bands detected from a single electron backscatter diffraction (EBSD) pattern is successfully performed. The as-measured band widths and azimuths always suffer from gnomonic distortions which need to be corrected. A primitive reciprocal cell is first reconstructed by means of the corrected data and the cell parameters are then refined by least-squares analysis of hugely over-determined equations. This allows one to further derive a Niggli reduced cell from the primitive cell. The algorithm presented is not related to any crystal symmetry information and is therefore applicable to all crystal systems. The feasibility of the determination of the Bravais lattice type and parameters from a single EBSD pattern is demonstrated using a mineral sample without anya prioriinformation about its crystal structure. The novel application developed in the present work opens the way to the determination of the Bravais lattice of crystalline materials using scanning electron microscopy combined with the EBSD technique.

All You Need to Know About Electron Backscatter Diffraction: Orientation is Only the Tip of the Iceberg

1997 ◽  
Vol 3 (S2) ◽  
pp. 387-388 ◽  
Author(s):  
J. R. Michael
Keyword(s):  
Electron Backscatter Diffraction ◽  
Photographic Film ◽  
Phase Identification ◽  
Electron Backscattered Diffraction ◽  
Bulk Specimen ◽  
Electron Backscatter ◽  
Backscatter Diffraction ◽  
Over 40 Years ◽  
Orientation Determination ◽  
Scanning Electron

This tutorial will describe the technique of electron backscattered diffraction (EBSD) in the scanning electron microscope (SEM). To properly exploit EBSD in the SEM it is important to understand how these patterns are formed. This discussion will be followed by a description of the hardware required for the collection of electron backscatter patterns (EBSP). We will then discuss the methods used to extract the appropriate crystallographic information from the patterns for orientation determination and phase identification and how these operations can be automated. Following this, a number of applications of the technique for both orientation studies and phase identification will be discussed.EBSD in the SEM is a phenomenon that has been known for many years. EBSD in the SEM is a technique that permits the crystallography of sub-micron sized regions to be studied from a bulk specimen. These patterns were first observed over 40 years ago, before the development of the SEM and were recorded using a special chamber and photographic film.

Determination of crystal phase from an electron backscatter diffraction pattern

2009 ◽  
Vol 42 (2) ◽  
pp. 234-241 ◽  
Author(s):  
David J. Dingley ◽  
Stuart I. Wright
Keyword(s):  
Crystal Orientation ◽  
Electron Backscatter Diffraction ◽  
Hexagonal Phase ◽  
Three Dimensional ◽  
Lattice Parameters ◽  
Crystal Phase ◽  
Test Case ◽  
Electron Backscatter ◽  
Ebsd Pattern ◽  
Backscatter Diffraction

Electron backscatter diffraction (EBSD) is a scanning electron microscope-based technique principally used for the determination and mapping of crystal orientation. This work describes an adaptation of the EBSD technique into a potential tool for crystal phase determination. The process can be distilled into three steps: (1) extracting a triclinic cell from a single EBSD pattern, (2) identifying the crystal symmetry from an examination of the triclinic cell, and (3) determining the lattice parameters. The triclinic cell is determined by finding the bands passing through two zone axes in the pattern including a band connecting the two. A three-dimensional triclinic unit cell is constructed based on the identified bands. The EBSD pattern is indexed in terms of the triclinic cell thus formed and the crystal orientation calculated. The pattern indexing results in independent multiple orientations due to the symmetry the crystal actually possesses. By examining the relationships between these multiple orientations, the crystal system is established. By comparing simulated Kikuchi bands with the pattern the lattice parameters can be determined. Details of the method are given for a test case of EBSD patterns obtained from the hexagonal phase of titanium.

scholarly journals ARPGE: a computer program to automatically reconstruct the parent grains from electron backscatter diffraction data

2007 ◽  
Vol 40 (6) ◽  
pp. 1183-1188 ◽  
Author(s):  
Cyril Cayron
Keyword(s):  
Phase Transition ◽  
Computer Program ◽  
Diffraction Data ◽  
Electron Backscatter Diffraction ◽  
Parent Phase ◽  
Martensitic Transformations ◽  
Variant Selection ◽  
Electron Backscatter ◽  
Backscatter Diffraction ◽  
Theoretical Results

A computer program calledARPGEwritten in Python uses the theoretical results generated by the computer programGenOVato automatically reconstruct the parent grains from electron backscatter diffraction data obtained on phase transition materials with or without residual parent phase. The misorientations between daughter grains are identified with operators, the daughter grains are identified with indexed variants, the orientations of the parent grains are determined, and some statistics on the variants and operators are established. Some examples with martensitic transformations in iron and titanium alloys were treated. Variant selection phenomena were revealed.

Electron Backscatter Diffraction in Conservation Science: Phase Identification of Pigments in Paint Layers

2013 ◽  
Vol 19 (4) ◽  
pp. 921-928 ◽  
Author(s):  
A. Gambirasi ◽  
L. Peruzzo ◽  
S. Bianchin ◽  
M. Favaro
Keyword(s):  
Cross Sections ◽  
Electron Backscatter Diffraction ◽  
Small Samples ◽  
Phase Identification ◽  
Conservation Science ◽  
Atomic Number Density ◽  
Electron Backscatter ◽  
Mohs Hardness ◽  
Backscatter Diffraction ◽  
First Time

AbstractElectron backscatter diffraction (EBSD) was used in Conservation Science for characterization of ancient materials collected from works of art. The results demonstrate the feasibility of EBSD analysis on heterogeneous matrices as very small samples of paint layers collected from paintings. Two reference pigments were selected from those used by artists to investigate the relationship existing between EBSD pattern quality and properties of the investigated material (i.e., average atomic number, density, and Mohs hardness). The technique was also tested to investigate the pigment phases on two real samples collected from Romanino's Santa Giustina altarpiece, an oil on wood painting dated 1514 (Civic Museum, Padova, Italy). Results show for the first time the acquisition of EBSD patterns from painting samples mounted in resin, i.e., painting cross sections, opening a new powerful tool to elucidate the pigment phases avoiding large sampling on works of arts and to further study the complex mechanisms of pigment deterioration.

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