The Correlative Multiscale Tomography (CMT) workflow combines advantages of many imaging modalities (see Figure 1), e.g. electron/ion microscopy (EM, IM), X-Ray computed tomography (CT), and scalar and vector fields mapping, e.g. EBSD, EDS, Raman, electromagnetic field, residual stress field, etc.
Combining two and three dimensional data of these imaging modalities and the spatial registration of scalar and vector fields, at different length scales and time (temporal 4D imaging) for the same region of interest (ROI), ultimately leads to true material’s insight and understanding. Current trends point to CMT as a crucial element of an intelligent closed-loop feedback control and sensing system for advanced and “green” manufacturing techniques, like additive manufacturing.
Advent of additive manufacturing (AM) techniques, such as Electron Beam Melting (EBM), Selective Laser Melting (SLM), Laser Powder Deposition (LPD), Wire + Arc Additive Manufacturing (WAAM), etc. to some extent allow simulating the natural materials and complex structures that cannot be produced using metallurgical routes and subtractive methods. Design and additive manufacturing of these components can be assisted with computer-aided design (CAD) and finite-element analysis (FEA) for better control of shape, interconnectivity and tailored mechanical properties. Furthermore, AM technology promises to reduce part cost by reducing material wastage and time to market.
However, AM processing conditions, material powder size, morphology and impurities may have a significant impact on the component morphology and mechanical performance leading to large deviations from the designed parameters. The subject of additive manufacturing is very recent, leading to various aspects that remain to be established. The most important are: (i) functional design and mechanical properties modelling, (ii) AM-specific alloy and precursor compositions/morphology, (iii) processing control, monitoring and operation, (iv) component testing (static, dynamic and environmental), and (v) multiscale microstructure characterization, detects detection and micromechanical testing. Thus, a complete understanding of these five major aspects (i-v) requires a multiscale correlative imaging approach, which brings together 3D (or 4D temporal study) multimodal information at each length scale and feeds-back various information (grain size and orientation, defect locations, detrimental residual stress distribution, variation of chemical composition, etc.) to the additive manufacturing workflow. Thermo Fisher Scientific instruments such as the FEI HeliScan microCT, FEI Helios Plasma FIB DualBeam and FEI Talos S/TEM enable a correlative multiscale tomography workflow from macro scale down to the atomic level for additively manufactured components.
- HeliScan is an innovative and unique X-Ray micro CT using a helical trajectory for stitching free imaging of larger volumes, high aspect ratio components and region of interest scans. HeliScan has a high cone angle X-ray source for higher flux and an iterative reconstruction algorithm combined with patented movement correction software.
- Helios PFIB, a high-end plasma-based DualBeam enables dramatically improved material removal rates compared to traditional Ga FIB milling, while maintaining exceptional surface quality and high-contrast, ultra-high resolution imaging performance. It is designed for high-throughput sample processing, large-volume 3D materials characterization and extreme high-resolution imaging in both 2D and 3D. For large-scale cross-sectioning, large-volume 3D data collection (multidetector SEM, EBSD, EDS), large-scale TEM sample preparation and large-scale patterning, the Helios PFIB provides the highest quality of data in the shortest time.
- Talos S/TEM is designed for fast, precise and quatitative characterization of nano-materials. It accelerates materials imaging and analysis through higher data quality and faster acquisition by simplified and automated operation. It combines outstanding high-resolution STEM and TEM imaging, unparalleled advances in EDS signal detection and 3-D chemical characterization with compositional mapping via its unique integrated detector solutions.
Authors: Bartlomiej Winiarski1,2, Dirk Laeveren3, Charles Austin Wade3, 4
1 Thermo Fisher Scientific (FEI Czech Republic s.r.o.), Vlastimila Pecha 12, Brno 627 00, Czech Republic
2 Henry Moseley X-ray Imaging Facility, School of Materials, University of Manchester, M13 9PL, U.K.
3 Thermo Fisher Scientific, Achtseweg Noord 5, 5651GG Eindhoven, The Netherlands
4 Materials Performance Centre, University of Manchester, Manchester M13 9PL, UK