Article,
Registration between DCT and EBSD datasets for multiphase microstructures
Affiliations
- [1] University of Birmingham [NORA names: United Kingdom; Europe, Non-EU; OECD];
- [2] Diamond Light Source [NORA names: United Kingdom; Europe, Non-EU; OECD];
- [3] Xnovo Technology ApS, Galoche Alle 15, Køge 4600, Denmark [NORA names: Denmark; Europe, EU; Nordic; OECD];
- [4] University of Warwick [NORA names: United Kingdom; Europe, Non-EU; OECD]
Abstract
The ability to characterise the three-dimensional microstructure of multiphase materials is essential for understanding the interaction between phases and their associated materials properties. Here, laboratory-based diffraction-contrast tomography (lab-based DCT), a recently-established materials characterization technique that can determine grain phases, morphologies, positions and orientations in a voxel-based reconstruction method, was used to map part of a dual-phase steel alloy sample. To assess the resulting microstructures produced by the lab-based DCT technique, an electron backscatter diffraction (EBSD) map was collected within the same sample volume. To identify the two-dimensional (2D) slice of the three-dimensional (3D) lab-based DCT reconstruction that best corresponded to the 2D EBSD map, a novel registration technique based solely on grain-averaged orientations was developed – this registration technique requires very little a priori knowledge of dataset alignment and can be extended to other techniques that only recover grain-averaged orientation data such as far-field 3D X-ray diffraction microscopy. Once the corresponding 2D slice was identified in the lab-based DCT dataset, comparisons of phase balance, grain size, shape and texture were performed between lab-based DCT and EBSD techniques. More complicated aspects of the microstructural morphology such as grain boundary shape and grains less than a critical size were poorly reproduced by the lab-based DCT reconstruction, primarily due to the difference in resolutions of the technique compared with EBSD. However, lab-based DCT is shown to accurately determine the centre-of-mass position, orientation, and size of the large grains for each phase present, austenite and martensitic ferrite. The results reveals a complex ferrite grain network of similar crystal orientations that are absent from the EBSD dataset. Such detail demonstrates that lab-based DCT, as a technique, shows great promise in the field of multi-phase material characterization.