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Brodusch N, Brahimi SV, Barbosa De Melo E, Song J, Yue S, Piché N, Gauvin R. Scanning Electron Microscopy versus Transmission Electron Microscopy for Material Characterization: A Comparative Study on High-Strength Steels. SCANNING 2021; 2021:5511618. [PMID: 34025898 PMCID: PMC8112914 DOI: 10.1155/2021/5511618] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Revised: 03/30/2021] [Accepted: 04/22/2021] [Indexed: 05/27/2023]
Abstract
The microstructures of quenched and tempered steels have been traditionally explored by transmission electron microscopy (TEM) rather than scanning electron microscopy (SEM) since TEM offers the high resolution necessary to image the structural details that control the mechanical properties. However, scanning electron microscopes, apart from providing larger area coverage, are commonly available and cheaper to purchase and operate compared to TEM and have evolved considerably in terms of resolution. This work presents detailed comparison of the microstructure characterization of quenched and tempered high-strength steels with TEM and SEM electron channeling contrast techniques. For both techniques, similar conclusions were made in terms of large-scale distribution of martensite lath and plates and nanoscale observation of nanotwins and dislocation structures. These observations were completed with electron backscatter diffraction to assess the martensite size distribution and the retained austenite area fraction. Precipitation was characterized using secondary imaging in the SEM, and a deep learning method was used for image segmentation. In this way, carbide size, shape, and distribution were quantitatively measured down to a few nanometers and compared well with the TEM-based measurements. These encouraging results are intended to help the material science community develop characterization techniques at lower cost and higher statistical significance.
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Affiliation(s)
- Nicolas Brodusch
- McGill Electron Microscopy Research Group, Department of Mining and Materials Engineering, McGill University, Montréal, Québec, Canada H3A 0C5
| | - Salim V. Brahimi
- McGill Hydrogen Embrittlement Facility, Department of Mining and Materials Engineering, McGill University, Montréal, Québec, Canada H3A 0C5
| | - Evelin Barbosa De Melo
- McGill Hydrogen Embrittlement Facility, Department of Mining and Materials Engineering, McGill University, Montréal, Québec, Canada H3A 0C5
| | - Jun Song
- McGill Hydrogen Embrittlement Facility, Department of Mining and Materials Engineering, McGill University, Montréal, Québec, Canada H3A 0C5
| | - Stephen Yue
- McGill Hydrogen Embrittlement Facility, Department of Mining and Materials Engineering, McGill University, Montréal, Québec, Canada H3A 0C5
| | - Nicolas Piché
- Object Research Systems, 760 St-Paul West, Suite 101, Montreal, Quebec, Canada H3C 1M4
| | - Raynald Gauvin
- McGill Electron Microscopy Research Group, Department of Mining and Materials Engineering, McGill University, Montréal, Québec, Canada H3A 0C5
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Brodusch N, Demers H, Gellé A, Moores A, Gauvin R. Electron energy-loss spectroscopy (EELS) with a cold-field emission scanning electron microscope at low accelerating voltage in transmission mode. Ultramicroscopy 2018; 203:21-36. [PMID: 30595397 DOI: 10.1016/j.ultramic.2018.12.015] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2018] [Revised: 12/18/2018] [Accepted: 12/23/2018] [Indexed: 11/29/2022]
Abstract
A commercial electron energy-loss spectrometer (EELS) attached to a high-resolution cold-field emission scanning electron microscope in transmission mode (STEM) is evaluated and its potential for characterizing materials science thin specimens at low accelerating voltage is reviewed. Despite the increased beam radiation damage at SEM voltages on sensitive compounds, we describe some potential applications which benefit from lowering the primary electrons voltage on less-sensitive specimens. We report bandgap measurements on several dielectrics which were facilitated by the lack of Cherenkov radiation losses at 30 kV. The possibility of volume plasmon imaging to probe local composition changes in complex materials was demonstrated using energy-filtered STEM, either via spectrum imaging or elemental mapping using the "three-windows" method. As plasmonic materials are increasing used for energy, electronics or biomedical applications, the ability of reliably evaluate their properties at low accelerating voltage in a SEM is very appealing and is demonstrated. The energy resolution of the spectrometer, taken as the full width at half maximum of the zero-loss peak, was routinely measured at around 0.55 eV and it is demonstrated that t/λ ratios up to 1.5 allowed practical EEL spectroscopy at 30 kV.
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Affiliation(s)
- Nicolas Brodusch
- Department of Mining and Materials Engineering, McGill University, Montréal, Québec H3A 0C5, Canada.
| | - Hendrix Demers
- Department of Mining and Materials Engineering, McGill University, Montréal, Québec H3A 0C5, Canada
| | - Alexandra Gellé
- Department of Chemistry, McGill University, Montréal, Québec H3A 0C5, Canada
| | - Audrey Moores
- Department of Chemistry, McGill University, Montréal, Québec H3A 0C5, Canada
| | - Raynald Gauvin
- Department of Mining and Materials Engineering, McGill University, Montréal, Québec H3A 0C5, Canada.
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MacRae CM, Hughes AE, Laird JS, Glenn AM, Wilson NC, Torpy A, Gibson MA, Zhou X, Birbilis N, Thompson GE. An Examination of the Composition and Microstructure of Coarse Intermetallic Particles in AA2099-T8, Including Li Detection. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2018; 24:325-341. [PMID: 29911517 DOI: 10.1017/s1431927618000454] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Electron and proton microprobes, along with electron backscatter diffraction (EBSD) analysis were used to study the microstructure of the contemporary Al-Cu-Li alloy AA2099-T8. In electron probe microanalysis, wavelength and energy dispersive X-ray spectrometry were used in parallel with soft X-ray emission spectroscopy (SXES) to characterize the microstructure of AA2099-T8. The electron microprobe was able to identify five unique compositions for constituent intermetallic (IM) particles containing combinations of Al, Cu, Fe, Mn, and Zn. A sixth IM type was found to be rich in Ti and B (suggesting TiB2), and a seventh IM type contained Si. EBSD patterns for the five constituent IM particles containing Al, Cu, Fe, Mn, and Zn indicated that they were isomorphous with four phases in the 2xxx series aluminium alloys including Al6(Fe, Mn), Al13(Fe, Mn)4 (two slightly different compositions), Al37Cu2Fe12 and Al7Cu2Fe. SXES revealed that Li was present in some constituent IM particles. Al SXES mapping revealed an Al-enriched (i.e., Cu, Li-depleted) zone in the grain boundary network. From the EBSD analysis, the kernel average misorientation map showed higher levels of localized misorientation in this region, suggesting greater deformation or stored energy. Proton-induced X-ray emission revealed banding of the TiB2 IM particles and Cu inter-band enrichment.
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Affiliation(s)
- Colin M MacRae
- 1CSIRO,Mineral Resources,Bayview Ave,Clayton,3169, Victoria,Australia
| | - Anthony E Hughes
- 1CSIRO,Mineral Resources,Bayview Ave,Clayton,3169, Victoria,Australia
| | - James S Laird
- 1CSIRO,Mineral Resources,Bayview Ave,Clayton,3169, Victoria,Australia
| | - A M Glenn
- 1CSIRO,Mineral Resources,Bayview Ave,Clayton,3169, Victoria,Australia
| | - Nicholas C Wilson
- 1CSIRO,Mineral Resources,Bayview Ave,Clayton,3169, Victoria,Australia
| | - Aaron Torpy
- 1CSIRO,Mineral Resources,Bayview Ave,Clayton,3169, Victoria,Australia
| | - Mark A Gibson
- 3Department of Materials Science and Engineering,Monash University,Clayton, VIC3800,Australia
| | - Xiaorong Zhou
- 5Corrosion and Protection Centre,School of Materials,The University of Manchester,Manchester M13 9PL,England,UK
| | - Nick Birbilis
- 3Department of Materials Science and Engineering,Monash University,Clayton, VIC3800,Australia
| | - George E Thompson
- 5Corrosion and Protection Centre,School of Materials,The University of Manchester,Manchester M13 9PL,England,UK
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