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Cios G, Winkelmann A, Nolze G, Tokarski T, Rychłowski Ł, Dan L, Bała P. Mapping of lattice distortion in martensitic steel-Comparison of different evaluation methods of EBSD patterns. Ultramicroscopy 2023; 253:113824. [PMID: 37572392 DOI: 10.1016/j.ultramic.2023.113824] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Revised: 07/11/2023] [Accepted: 07/28/2023] [Indexed: 08/14/2023]
Abstract
To visualize the varying tetragonal distortions in high carbon martensitic steels by EBSD, two different approaches have been applied on backscattered Kikuchi diffraction (BKD) patterns. A band-edge refinement technique called Refined Accuracy (RA) (Oxford Instruments) is compared with a technique called Pattern Matching (PM), which optimizes the fit to a simulated BKD signal. RA distinguishes between hypothetical phases of different fixed c/a, while PM determines a best fitting continuous c/a by projective transformation of a master pattern. Both techniques require stored BKD patterns. The sensitivity of the c/a-determination was tested by investigating the microstructure of a ferritic steel with an expected c/a=1. The influence of the Kikuchi pattern noise on c/a was compared for a single or 40 averaged frames per measuring point, and turned out to be not significant. The application of RA and PM on the martensitic microstructure delivered qualitatively similar maps of c/a. The comparison of RA and PM shows that RA is suitably fast and precise during mapping the martensite c/a ratio in analyses of high carbon martensite, especially for fast initial surveys. As RA leads quantitatively to higher noise in c/a, the PM analysis can be used for higher precision results.
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Affiliation(s)
- Grzegorz Cios
- Academic Centre for Materials and Nanotechnology, AGH University of Krakow, al. A. Mickiewicza 30, 30-059 Kraków, Poland.
| | - Aimo Winkelmann
- Academic Centre for Materials and Nanotechnology, AGH University of Krakow, al. A. Mickiewicza 30, 30-059 Kraków, Poland
| | - Gert Nolze
- Federal Institute for Materials, Research and Testing (BAM), Unter den Eichen 87, 12205 Berlin, Germany; TU Bergakademie Freiberg, Institute for Mineralogy, Brennhausgasse 14, 09596 Freiberg, Germany
| | - Tomasz Tokarski
- Academic Centre for Materials and Nanotechnology, AGH University of Krakow, al. A. Mickiewicza 30, 30-059 Kraków, Poland
| | - Łukasz Rychłowski
- Academic Centre for Materials and Nanotechnology, AGH University of Krakow, al. A. Mickiewicza 30, 30-059 Kraków, Poland
| | - Leonid Dan
- Academic Centre for Materials and Nanotechnology, AGH University of Krakow, al. A. Mickiewicza 30, 30-059 Kraków, Poland
| | - Piotr Bała
- Academic Centre for Materials and Nanotechnology, AGH University of Krakow, al. A. Mickiewicza 30, 30-059 Kraków, Poland; Faculty of Metals and Industrial Computer Science, AGH University of Krakow, al. A. Mickiewicza 30, 30-059 Kraków, Poland
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