scholarly journals Twinning in SnO2-based ceramics doped with CoO and Nb2O5: morphology of multiple twins revealed by electron backscatter diffraction

2020 ◽  
Vol 76 (5) ◽  
pp. 875-883
Author(s):  
José Alberto Padrón-Navarta ◽  
Fabrice Barou ◽  
Nina Daneu
Keyword(s):  
Solid State ◽  
Grain Growth ◽  
Electron Backscatter Diffraction ◽  
Automated Identification ◽  
Twin Domain ◽  
Electron Backscatter ◽  
Different Types ◽  
Average Size ◽  
Grain Misorientation ◽  
Backscatter Diffraction

Electron backscatter diffraction (EBSD) was used for the analysis of multiple cyclic twins in cassiterite (SnO2), which form during sintering of SnO2 with small additions of CoO and Nb2O5. Grain misorientation analysis has shown that about one third of all grains contain {101} twin boundaries (TBs). The majority of these grains are contact twins, whereas a small fraction of grains are multiple, mainly cyclic twins. A procedure was developed in MTEX [Bachmann, Hielscher & Schaeben (2010). Solid State Phenom. 160, 63–88] for automated identification of crystallographically different types of cyclic twins and found two main types: coplanar twins composed of three or four domains with a common [010] axis and alternating twins composed of three to seven domains oriented along the [111] axis. Both types of cyclic twins have a characteristic common origin (nucleus) of all TBs, which is positioned eccentric relative to the grain section and the cycle is closed with a shorter non-crystallographic contact between the first and the last twin domain. The morphology of cyclic twins suggests that they form by nucleation in the initial stages of grain growth. The average size of twinned grains increases with the number of twin domains indicating the influence of TBs formation on the growth of composite grains.

scholarly journals Analysis of Strain Partitioning in Intercritically Deformed Microstructures via Interrupted Tensile Tests

Metals ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 112
Author(s):  
Unai Mayo ◽  
Nerea Isasti ◽  
José M. Rodríguez-Ibabe ◽  
Pello Uranga
Keyword(s):  
Electron Backscatter Diffraction ◽  
Tensile Tests ◽  
Correlation Technique ◽  
Strain Partitioning ◽  
High Angle ◽  
Electron Backscatter ◽  
Different Types ◽  
Final Deformation ◽  
Micro Alloyed Steel ◽  
Backscatter Diffraction

Intercritically deformed steels present combinations of different types of ferrite, such as deformed ferrite (DF) and non-deformed ferrite (NDF) grains, which are transformed during the final deformation passes and final cooling step. Recently, a grain identification and correlation technique based on EBSD has been employed together with a discretization methodology, enabling a distinction to be drawn between different ferrite populations (NDF and DF grains). This paper presents a combination of interrupted tensile tests with crystallographic characterization performed by means of Electron Backscatter Diffraction (EBSD), by analyzing the evolution of an intercritically deformed micro-alloyed steel. In addition to this, and using the nanoindentation technique, both ferrite families were characterized micromechanically and the nanohardness was quantified for each population. NDF grains are softer than DF ones, which is related to the presence of a lower fraction of low-angle grain boundaries. The interrupted tensile tests show the different behavior of low- and high-angle grain boundary evolution as well as the strain partitioning in each ferrite family. NDF population accommodates most of the deformation at initial strain intervals, since strain reaches 10%. For higher strains, NDF and DF grains behave similarly to the strain applied.

scholarly journals Optimizing Electron Backscatter Diffraction of Carbonate Biominerals—Resin Type and Carbon Coating

2009 ◽  
Vol 15 (3) ◽  
pp. 197-203 ◽  
Author(s):  
Alberto Pérez-Huerta ◽  
Maggie Cusack
Keyword(s):  
Carbon Coating ◽  
Blue Mussel ◽  
Electron Backscatter Diffraction ◽  
Diffraction Intensity ◽  
Ebsd Data ◽  
Electron Backscatter ◽  
Different Types ◽  
The Common ◽  
Biogenic Carbonates ◽  
Backscatter Diffraction

AbstractElectron backscatter diffraction (EBSD) is becoming a widely used technique to determine crystallographic orientation in biogenic carbonates. Despite this use, there is little information available on preparation for the analysis of biogenic carbonates. EBSD data are compared for biogenic aragonite and calcite in the common blue mussel, Mytilus edulis, using different types of resin and thicknesses of carbon coating. Results indicate that carbonate biomineral samples provide better EBSD results if they are embedded in resin, particularly epoxy resin. A uniform layer of carbon of 2.5 nm thickness provides sufficient conductivity for EBSD analyses of such insulators to avoid charging without masking the diffracted signal. Diffraction intensity decreases with carbon coating thickness of 5 nm or more. This study demonstrates the importance of optimizing sample preparation for EBSD analyses of insulators such as carbonate biominerals.

scholarly journals Dislocation Creep of Olivine and Amphibole in Amphibole Peridotites from Åheim, Norway

Minerals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1018
Author(s):  
Sejin Jung ◽  
Takafumi Yamamoto ◽  
Jun-ichi Ando ◽  
Haemyeong Jung
Keyword(s):  
Electron Microscopy ◽  
Slip System ◽  
Electron Backscatter Diffraction ◽  
Microstructural Analysis ◽  
Dislocation Creep ◽  
Transmission Electron ◽  
Electron Backscatter ◽  
Different Types ◽  
Localized Shear Deformation ◽  
Backscatter Diffraction

Amphibole peridotite samples from Åheim, Norway, were analyzed to understand the deformation mechanism and microstructural evolution of olivine and amphibole through the Scandian Orogeny and subsequent exhumation process. Three Åheim amphibole peridotite samples were selected for detailed microstructural analysis. The Åheim amphibole peridotites exhibit porphyroclastic texture, abundant subgrain boundaries in olivine, and the evidence of localized shear deformation in the tremolite-rich layer. Two different types of olivine lattice preferred orientations (LPOs) were observed: B- and A-type LPOs. Electron backscatter diffraction (EBSD) mapping and transmission electron microscopy (TEM) observations revealed that most subgrain boundaries in olivine consist of dislocations with a (001)[100] slip system. The subgrain boundaries in olivine may have resulted from the deformation of olivine with moderate water content. In addition, TEM observations using a thickness-fringe method showed that the free dislocations of olivine with the (010)[100] slip system were dominant in the peridotites. Our data suggest that the subgrain boundaries and free dislocations in olivine represent a product of later-stage deformation associated with the exhumation process. EBSD mapping of the tremolite-rich layer revealed intracrystalline plasticity in amphibole, which can be interpreted as the activation of the (100)[001] slip system.

scholarly journals Large Dimension and Low-Cost Fe-SMA Rods

2019 ◽  
Vol 271 ◽  
pp. 01005
Author(s):  
Hande Ozcan ◽  
Ji Ma ◽  
Jeremy E. Schaffer ◽  
Ibrahim Karaman
Keyword(s):  
Grain Growth ◽  
Single Phase ◽  
Electron Backscatter Diffraction ◽  
Low Cost ◽  
Large Diameter ◽  
Heat Treatments ◽  
Two Phase ◽  
Electron Backscatter ◽  
Bamboo Structure ◽  
Backscatter Diffraction

The effects on sample size on abnormal grain growth in inexpensive FeMnAlNi shape memory alloy (SMAs) wires and rod were investigated. It was shown that repeated heat treatments between single phase (bcc) and two phase (bcc + fcc) region resulted in abnormal grains with bamboo structure both in small sized wires and large diameter rods. Microstructural features were investigated using electron backscatter diffraction (EBSD) and it was found that 0.5 mm wires possess strong [011] texture whereas, large diameter rods have random texture after grain growth heat treatments.

scholarly journals Twin domain imaging in topological insulator Bi2Te3 and Bi2Se3 epitaxial thin films by scanning X-ray nanobeam microscopy and electron backscatter diffraction

2017 ◽  
Vol 50 (2) ◽  
pp. 369-377 ◽  
Author(s):  
Dominik Kriegner ◽  
Petr Harcuba ◽  
Jozef Veselý ◽  
Andreas Lesnik ◽  
Guenther Bauer ◽  
...  
Keyword(s):  
Crystal Orientation ◽  
Electron Backscatter Diffraction ◽  
Domain Size ◽  
Epitaxial Thin Films ◽  
X Ray Diffraction ◽  
X Ray ◽  
Twin Domain ◽  
Electron Backscatter ◽  
Backscatter Diffraction ◽  
Diffraction Microscopy

The twin distribution in topological insulators Bi2Te3 and Bi2Se3 was imaged by electron backscatter diffraction (EBSD) and scanning X-ray diffraction microscopy (SXRM). The crystal orientation at the surface, determined by EBSD, is correlated with the surface topography, which shows triangular pyramidal features with edges oriented in two different orientations rotated in the surface plane by 60°. The bulk crystal orientation is mapped out using SXRM by measuring the diffracted X-ray intensity of an asymmetric Bragg peak using a nano-focused X-ray beam scanned over the sample. By comparing bulk- and surface-sensitive measurements of the same area, buried twin domains not visible on the surface are identified. The lateral twin domain size is found to increase with the film thickness.

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