Pt Pinard

An Open-Source Engine for the Processing of Electron Backscatter Patterns: EBSD-Image

An open source software package dedicated to processing stored electron backscatter patterns is presented. The package gives users full control over the type and order of operations that are performed on electron backscatter diffraction (EBSD) patterns as well as the results obtained. The current version of EBSD-Image (www.ebsd-image.org) offers a flexible and structured interface to calculate various quality metrics over large datasets. It includes unique features such as practical file formats for storing diffraction patterns and analysis results, stitching of mappings with automatic reorganization of their diffraction patterns, and routines for processing data on a distributed computer grid. Implementations of the algorithms used in the software are described and benchmarked using simulated diffraction patterns. Using those simulated EBSD patterns, the detection of Kikuchi bands in EBSD-Image was found to be comparable to commercially available EBSD systems. In addition, 24 quality metrics were evaluated based on the ability to assess the level of deformation in two samples (copper and iron) deformed using 220 grit SiC grinding paper. Fourteen metrics were able to properly measure the deformation gradient of the samples.

Towards A More Quantitative Measurement of the Deformation During Metallographic Specimen Preparation Using EBSD and FIB

Surface deformation during metallographic preparation have been previously studied using light optical microscopy (LOM) and transmission electron microscopy (TEM) [1]. With its submicron resolution, electron backscattered diffraction (EBSD) can provide quantitative deformation analysis at a smaller length scale than LOM while provide higher statistics than TEM. This work aims to determine the level of deformation produced during different metallographic preparation steps of common materials. As a first iteration, the deformation profile induced by 80, 240 and 600 ANSI grit SiC papers on commercially pure iron (BCC), copper (FCC) and titanium (HCP) was measured.

Development of Tools to Increase the Spatial Resolution of EBSD Maps

APPARENT RESOLUTION • At a tilt of 70◦, the volume of interaction of electrons is asymmetric, elliptical in the direction perpendicular to the tilt axis. • Backscattered electrons forming the Kikuchi patterns are however coming from a much smaller generation volume. [1] • The lateral resolution is therefore smaller than the longitudinal resolution (approximately 3 times smaller). [2,3] EFFECTIVE RESOLUTION • Convolution of two patterns can be seen as a linear combination of two patterns: P = xPA + (1− x)PB • Depending on the pattern quality and if there is a significant difference in intensity, an indexing algorithm could identify the pattern with the highest intensity. [4] • The effective resolution is therefore smaller than the apparent resolution. [1,4–7]

On the Precision of EDS Analysis with Sample Tilted at 70

Simultaneous collection of electron backscattered diffraction (EBSD) pattern and X-Ray spectrum using energy dispersive spectrometer (EDS) promise to greatly improve upon the phase differentiation by combining chemical and crystallographic information[1-2]. To achieve the promised level of indexation accuracy, quantitative X-Ray analysis must be performed with noisy spectra of highly tilted samples (usually 70°). The accuracy of X-ray quantification using EDS was demonstrated for spectra acquired from specimens normal to the beam and with sufficient statistics to give at least 10k counts on the lowest intensity peaks. This scenario is far from the one that prevailed for the spectra acquired during an EBSD automatic run.