Advancing characterisation with statistics from correlative electron diffraction and X-ray spectroscopy, in the scanning electron microscope.
File(s)1908.04084v2.pdf (4.2 MB)
Accepted version
Author(s)
Type
Journal Article
Abstract
The routine and unique determination of minor phases in microstructures is critical to materials science. In metallurgy alone, applications include alloy and process development and the understanding of degradation in service. We develop a correlative method, exploring superalloy microstructures, which are examined in the scanning electron microscope (SEM) using simultaneous energy dispersive X-ray spectroscopy (EDS) and electron backscatter diffraction (EBSD). This is performed at an appropriate length scale for characterisation of carbide phases' shape, size, location, and distribution. EDS and EBSD data are generated using two different physical processes, but each provide a signature of the material interacting with the incoming electron beam. Recent advances in post-processing, driven by 'big data' approaches, include use of principal component analysis (PCA). Components are subsequently characterised to assign labels to a mapped region. To provide physically meaningful signals, the principal components may be rotated to control the distribution of variance. In this work, we develop this method further through a weighted PCA approach. We use the EDS and EBSD signals concurrently, thereby labelling each region using both EDS (chemistry) and EBSD (crystal structure) information. This provides a new method of amplifying signal-to-noise for very small phases in mapped regions, especially where the EDS or EBSD signal is not unique enough alone for classification.
Date Issued
2020-01-21
Date Acceptance
2020-01-19
Citation
Ultramicroscopy, 2020, 211, pp.1-16
ISSN
0304-3991
Publisher
Elsevier
Start Page
1
End Page
16
Journal / Book Title
Ultramicroscopy
Volume
211
Copyright Statement
© 2020 Elsevier Ltd. All rights reserved. This manuscript is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International Licence http://creativecommons.org/licenses/by-nc-nd/4.0/
Sponsor
Royal Academy Of Engineering
Shell Global Solutions International BV
Rolls-Royce Plc
Identifier
https://www.ncbi.nlm.nih.gov/pubmed/32000031
PII: S0304-3991(19)30277-3
Grant Number
RF/129
PO 4550133349
PO: 6000-00128045
Subjects
Carbides
EBSD
EDS
Microstructure
Principal component analysis
Superalloy
Publication Status
Published online
Coverage Spatial
Netherlands
Date Publish Online
2020-01-21