scholarly journals Investigation of the Effect of Magnification, Accelerating Voltage, and Working Distance on the 3D Digital Reconstruction Techniques

Scanning ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Seyed Mahmoud Bayazid ◽  
Nicolas Brodusch ◽  
Raynald Gauvin ◽  
Michela Relucenti
Keyword(s):  
Spherical Particles ◽  
Reconstruction Technique ◽  
Quantitative Characterization ◽  
Sem Images ◽  
Digital Reconstruction ◽  
Backscattered Electron ◽  
Working Distance ◽  
Backscattered Signals ◽  
2D Images

In this study, the effect of Scanning Electron Microscopy (SEM) parameters such as magnification ( M ), accelerating voltage ( V ), and working distance (WD) on the 3D digital reconstruction technique, as the first step of the quantitative characterization of fracture surfaces with SEM, was investigated. The 2D images were taken via a 4-Quadrant Backscattered Electron (4Q-BSE) detector. In this study, spherical particles of Ti-6Al-4V (15-45 μm) deposited on the silicon substrate were used. It was observed that the working distance has a significant influence on the 3D digital rebuilding method via SEM images. The results showed that the best range of the working distance for our system is 9 to 10 mm. It was shown that by increasing the magnification to 1000x, the 3D digital reconstruction results improved. However, there was no significant improvement by increasing the magnification beyond 1000x. In addition, results demonstrated that the lower the accelerating voltage, the higher the precision of the 3D reconstruction technique, as long as there are clean backscattered signals. The optimal condition was achieved when magnification, accelerating voltage, and working distance were chosen as 1000x, 3 kV, and 9 mm, respectively.

scholarly journals Three-Dimensional Digital Reconstruction of Ti2AlC Ceramic Foams Produced by the Gelcast Method

Materials ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4085
Author(s):  
Christos S. Stiapis ◽  
Eugene D. Skouras ◽  
Vasilis N. Burganos
Keyword(s):  
Structural Information ◽  
Gas Permeability ◽  
Small Deviation ◽  
Hard Spheres ◽  
Three Dimensional ◽  
Reconstruction Technique ◽  
Sem Images ◽  
Reconstruction Process ◽  
Ceramic Foams ◽  
Digital Reconstruction

A digital reconstruction technique is presented that generates three-dimensional (3D) digital representations of ceramic foams created by the foam-gelcasting technique. The reconstruction process uses information that is directly extracted from Scanning Electron Microscopy (SEM) images and offers a 3D representation of the physical sample accounting for the typically large pore cavities and interconnecting windows that are formed during the preparation process. Contrary to typical tessellation-based foam treatments, a spherical representation of the pores and the pore windows of the foams is assumed and a novel hybrid algorithm that combines a variation of Lubachevsky-type and Random Close Packing of Hard Spheres (RCPHS) algorithms has been developed to obtain near-optimum solutions to the packing problem of the spheres that represent the pores. Numerical simulations are performed directly on the 3D reconstructed foams to determine their gas permeability. The model predictions are compared with experimental gas permeability data that were obtained for the physical samples. The pore wall thickness can be treated as the single fitting parameter in the entire reconstruction process, although it is shown that images of sufficient resolution could eliminate the need even for that. The foams that are produced by this method yield quantitatively similar pressure drops with experiments for various superficial velocity values, with a very small deviation in the range of 1.7–2.8%. The proposed methodology could be utilized for the prediction of the permeability and transport properties of complex foamy porous structures, similar to the gelcast-type of foams, from a single SEM image of the foam sample without resorting to serial tomography or other structural information, thus saving considerable time and effort from experimental work.

Fractal and Lacunarity Analyses: Quantitative Characterization of Hierarchical Surface Topographies

2016 ◽  
Vol 22 (1) ◽  
pp. 168-177 ◽  
Author(s):  
Edwin J. Y. Ling ◽  
Phillip Servio ◽  
Anne-Marie Kietzig
Keyword(s):  
Processing Parameters ◽  
Surface Structures ◽  
Quantitative Characterization ◽  
Sem Images ◽  
Length Scales ◽  
Sem Image ◽  
Multiple Length Scales ◽  
Surface Topographies ◽  
Lacunarity Analysis

AbstractBiomimetic hierarchical surface structures that exhibit features having multiple length scales have been used in many technological and engineering applications. Their surface topographies are most commonly analyzed using scanning electron microscopy (SEM), which only allows for qualitative visual assessments. Here we introduce fractal and lacunarity analyses as a method of characterizing the SEM images of hierarchical surface structures in a quantitative manner. Taking femtosecond laser-irradiated metals as an example, our results illustrate that, while the fractal dimension is a poor descriptor of surface complexity, lacunarity analysis can successfully quantify the spatial texture of an SEM image; this, in turn, provides a convenient means of reporting changes in surface topography with respect to changes in processing parameters. Furthermore, lacunarity plots are shown to be sensitive to the different length scales present within a hierarchical structure due to the reversal of lacunarity trends at specific magnifications where new features become resolvable. Finally, we have established a consistent method of detecting pattern sizes in an image from the oscillation of lacunarity plots. Therefore, we promote the adoption of lacunarity analysis as a powerful tool for quantitative characterization of, but not limited to, multi-scale hierarchical surface topographies.

scholarly journals Mineralogical Imaging for Characterization of the Per Geijer Apatite Iron Ores in the Kiruna District, Northern Sweden: A Comparative Study of Mineral Liberation Analysis and Raman Imaging

Minerals ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 544 ◽  
Author(s):  
Patrick Krolop ◽  
Anne Jantschke ◽  
Sabine Gilbricht ◽  
Kari Niiranen ◽  
Thomas Seifert
Keyword(s):  
Raman Imaging ◽  
Northern Sweden ◽  
Quantitative Characterization ◽  
Advantages And Disadvantages ◽  
Mineral Liberation ◽  
Processing Strategies ◽  
Backscattered Electron ◽  
Liberation Analysis ◽  
Ore Types

The Per Geijer iron oxide apatite deposits are important potential future resources for Luossavaara-Kiirunavaara Aktiebolag (LKAB) which has been continuously mining magnetite/hematite ores in northern Sweden for over 125 years. Reliable and quantitative characterization of the mineralization is required as these ores inherit complex mineralogical and textural features. Scanning electron microscopy-based analyses software, such as mineral liberation analyzer (MLA) provide significant, time-efficient analyses. Similar elemental compositions of Fe-oxides and, therefore, almost identical backscattered electron (BSE) intensities complicate their discrimination. In this study, MLA and Raman imaging are compared to acquire mineralogical data for better characterization of magnetite and hematite-bearing ores. The different approaches demonstrate advantages and disadvantages in classification, imaging, discrimination of iron oxides, and time consumption of measurement and processing. The obtained precise mineralogical information improves the characterization of ore types and will benefit future processing strategies for this complex mineralization.

The Vertical Mill Slag Micro-Powders' Particle Size Distribution and Microstructure Analysis

2014 ◽  
Vol 487 ◽  
pp. 308-312
Author(s):  
Tao Ye ◽  
Xiao Dong Chen ◽  
Bin Jiang
Keyword(s):  
Particle Size ◽  
Particle Image ◽  
Preparation Method ◽  
Shape Index ◽  
Analysis Software ◽  
Quantitative Characterization ◽  
Sem Images ◽  
Cement Grinding ◽  
Grinding System

Vertical mill grinding system is one of the important cement grinding equipments developed in recent years. In this paper, through the industry vertical mill grinding GGBS carried out a detailed analysis of particle size, on this basis, using the attached to the sample preparation method, obtained the typical SEM images of GGBS through industrial vertical mill, and using particle image analysis software for slag microstructure has carried on the qualitative analysis, obtained the change rule of microstructure of the grinding process. Meanwhile, using shape index, roundness coefficient, flat degree, angularity and surface roughness quantitative characterization of the microstructure of slag powders.

scholarly journals Contrast of Backscattered Electron SEM Images of Nanoparticles on Substrates with Complex Structure

Scanning ◽  
2017 ◽  
Vol 2017 ◽  
pp. 1-12 ◽  
Author(s):  
Thomas Kowoll ◽  
Erich Müller ◽  
Susanne Fritsch-Decker ◽  
Simon Hettler ◽  
Heike Störmer ◽  
...  
Keyword(s):  
Experimental Data ◽  
Indium Tin Oxide ◽  
Complex Structure ◽  
Quantitative Agreement ◽  
Primary Electron ◽  
Sem Images ◽  
Backscattered Electron ◽  
Material Contrast ◽  
Optimum Material ◽  
Working Distance

This study is concerned with backscattered electron scanning electron microscopy (BSE SEM) contrast of complex nanoscaled samples which consist of SiO2 nanoparticles (NPs) deposited on indium-tin-oxide covered bulk SiO2 and glassy carbon substrates. BSE SEM contrast of NPs is studied as function of the primary electron energy and working distance. Contrast inversions are observed which prevent intuitive interpretation of NP contrast in terms of material contrast. Experimental data is quantitatively compared with Monte-Carlo- (MC-) simulations. Quantitative agreement between experimental data and MC-simulations is obtained if the transmission characteristics of the annular semiconductor detector are taken into account. MC-simulations facilitate the understanding of NP contrast inversions and are helpful to derive conditions for optimum material and topography contrast.

Mosaic Mapping: A Means of Tiling Images to Shorten Acquisition Speed for Lower - Magnification SEM Images and Wavelength Dispersive Spectrometers (WDS) X-Ray Maps

1996 ◽  
Vol 54 ◽  
pp. 438-439
Author(s):  
J.D. Geller ◽  
C.R. Herrington
Keyword(s):  
Limiting Factors ◽  
X Rays ◽  
Angular Range ◽  
Acceptance Angle ◽  
Sem Images ◽  
Worst Case ◽  
X Ray ◽  
Focusing Distance ◽  
Layered Crystals ◽  
Working Distance

The minimum magnification for which an image can be acquired is determined by the design and implementation of the electron optical column and the scanning and display electronics. It is also a function of the working distance and, possibly, the accelerating voltage. For secondary and backscattered electron images there are usually no other limiting factors. However, for x-ray maps there are further considerations. The energy-dispersive x-ray spectrometers (EDS) have a much larger solid angle of detection that for WDS. They also do not suffer from Bragg’s Law focusing effects which limit the angular range and focusing distance from the diffracting crystal. In practical terms EDS maps can be acquired at the lowest magnification of the SEM, assuming the collimator does not cutoff the x-ray signal. For WDS the focusing properties of the crystal limits the angular range of acceptance of the incident x-radiation. The range is dependent upon the 2d spacing of the crystal, with the acceptance angle increasing with 2d spacing. The natural line width of the x-ray also plays a role. For the metal layered crystals used to diffract soft x-rays, such as Be - O, the minimum magnification is approximately 100X. In the worst case, for the LEF crystal which diffracts Ti - Zn, ˜1000X is the minimum.

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