scholarly journals Recent Advances in High-Speed Orientation Mapping

2006 ◽  
Vol 14 (6) ◽  
pp. 6-9 ◽  
Author(s):  
Matthew M. Nowell ◽  
Martina Chui-Sabourin ◽  
John O. Carpenter
Keyword(s):  
High Speed ◽  
Electron Backscatter Diffraction ◽  
Microstructural Analysis ◽  
Automated Analysis ◽  
Steady Increase ◽  
Analysis Tool ◽  
Early Adopters ◽  
Orientation Mapping ◽  
Backscatter Diffraction ◽  
Acquisition Rates

Orientation mapping via automated analysis of Electron Backscatter Diffraction (EBSD) patterns has developed into an established microstructural analysis tool in the electron microscopy community. From the early 1990s, when this technique became commercially available, there has been a steady increase in the data acquisition rates as shown in Figure 1. Currently, orientation mapping speeds of over 200 analyzed patterns per second have been achieved. With these types of acquisition rates now available, the strategy on how to best use EBSD and orientation mapping has also shifted. Early adopters of this technique had to allocate hours of Scanning Electron Microscope (SEM) beam time in order to collect statistically significant data. With current technology, what was collected in hours can now be obtained in minutes. The goal of this article is to introduce this high-speed orientation mapping and present results illustrating the benefits of this capability.

scholarly journals EBSD Sample Preparation: Techniques, Tips, and Tricks

2005 ◽  
Vol 13 (4) ◽  
pp. 44-49 ◽  
Author(s):  
Matthew M. Nowell ◽  
Ronald A. Witt ◽  
Brian W. True
Keyword(s):  
Electron Beam ◽  
Electron Backscatter Diffraction ◽  
Microstructural Analysis ◽  
Ccd Camera ◽  
Automated Analysis ◽  
Phase Identification ◽  
Analysis Tool ◽  
Orientation Imaging ◽  
Ebsd Pattern ◽  
Crystallographic Planes

Automated analysis of Electron Backscatter Diffraction (EBSD) patterns for orientation imaging and phase identification in materials and earth sciences has become a widely accepted microstructural analysis tool. To briefly review, EBSD is a scanning electron microscope (SEM) based technique where the sample is tilted approximately 70 degrees and the electron beam is positioned in an analytical spot-mode within a selected grain. An EBSD pattern is formed due to the diffraction of the electron beam by select crystallographic planes within the material. The EBSD pattern is representative of both the phase and crystallographic orientation of the selected area. The pattern is imaged by a phosphor screen and recorded with a digital CCD camera and then analyzed.

Specifics of Microstructure and Phase Composition of High-Speed Steel R6M5

2013 ◽  
Vol 404 ◽  
pp. 20-24 ◽  
Author(s):  
Маzhyn Skakov ◽  
Bauyrzhan Rakhadilov ◽  
Gaukhar Karipbayeva
Keyword(s):  
Phase Composition ◽  
High Speed ◽  
Volume Fraction ◽  
Electron Backscatter Diffraction ◽  
High Speed Steel ◽  
Spherical Shape ◽  
Xrd Analysis ◽  
Steel R6m5 ◽  
Solid Carbide ◽  
Backscatter Diffraction

In this paper microstructure, morphology, elemental composition, phase composition and crystal structure of the sample steel R6M5 were investigate by using the methods of scanning electron microscopy, electron backscatter diffraction (EBSD) analysis and X-ray diffraction (XRD) analysis. Determined that the microstructure of steel R6M5 after hardening and three-time tempering consists of tempered martensite and solid carbide M6C and MC-type with spherical shape and a diameter of less than 3 μm. Detected that the volume fraction of each carbide amounted to 10.4±0.6% and 2.3±0.4% - for grey and bright carbides, respectively, and that the sizes of bright carbides particles in the microstructure of steel R6M5 are 0.4-4,5 μm, and the sizes of grey carbides particles are 0.5-1.1 μm. XRD analysis showed that the main carbides in the studied steel are carbides М6С and MC, which have complicated the FCC crystal lattice and the Fd3m spatial group. Determined that carbides are uniform and monocrystalline. ESBD analysis with the support of the XRD analysis showed that carbides spherical shape М6С fit to Fe3W3C composition.

scholarly journals Microstructural constraints on magmatic mushes under Kīlauea Volcano, Hawaiʻi

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Penny E. Wieser ◽  
Marie Edmonds ◽  
John Maclennan ◽  
John Wheeler
Keyword(s):  
Spatial Distribution ◽  
Dendritic Growth ◽  
Electron Backscatter Diffraction ◽  
Microstructural Analysis ◽  
Kilauea Volcano ◽  
Kīlauea Volcano ◽  
Mantle Peridotites ◽  
Wide Range ◽  
Electron Backscatter ◽  
Backscatter Diffraction

AbstractDistorted olivines of enigmatic origin are ubiquitous in erupted products from a wide range of volcanic systems (e.g., Hawaiʻi, Iceland, Andes). Investigation of these features at Kīlauea Volcano, Hawaiʻi, using an integrative crystallographic and chemical approach places quantitative constraints on mush pile thicknesses. Electron backscatter diffraction (EBSD) reveals that the microstructural features of distorted olivines, whose chemical composition is distinct from undistorted olivines, are remarkably similar to olivines within deformed mantle peridotites, but inconsistent with an origin from dendritic growth. This, alongside the spatial distribution of distorted grains and the absence of adcumulate textures, suggests that olivines were deformed within melt-rich mush piles accumulating within the summit reservoir. Quantitative analysis of subgrain geometry reveals that olivines experienced differential stresses of ∼3–12 MPa, consistent with their storage in mush piles with thicknesses of a few hundred metres. Overall, our microstructural analysis of erupted crystals provides novel insights into mush-rich magmatic systems.

Crystal chemistry of clinker relicts from aged cementitious materials

2014 ◽  
Vol 47 (5) ◽  
pp. 1626-1637 ◽  
Author(s):  
Michele Secco ◽  
Luca Peruzzo ◽  
Laurie Palasse ◽  
Gilberto Artioli ◽  
Alberto Viani ◽  
...  
Keyword(s):  
Electron Backscatter Diffraction ◽  
Microstructural Analysis ◽  
Chemical Properties ◽  
Cementitious Materials ◽  
Operating Conditions ◽  
General Tendency ◽  
Hydration Kinetics ◽  
Definition Of ◽  
Backscatter Diffraction

Despite the general tendency to consider Portland cement virtually fully hydrated within a few years, the occurrence of non-reacted clinker phases in cementitious materials that are several decades old is rather common. In this work, the integration of microstructural analysis by scanning electron microscopy and quantitative microchemical and micromineralogical characterization techniques, such as electron microprobe analysis and electron backscatter diffraction, allowed the definition of the crystal-chemical properties of partially hydrated cement residuals within different types of aged cementitious materials. The results on several clinker relicts show that the calcium silicate phases are transformed systematically and pervasively by hydration reactions, whereas the aluminate and ferrite phases do frequently persist in the anhydrous state. These relict phases may be distinguished through their peculiar chemical, mineralogical and textural features. These observations raise interesting questions concerning the long-term hydration kinetics of clinker phases and the durability behaviour of cementitious materials in operating conditions.

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.

Effect of Cryogenic Temperature Rolling on High Speed Impact Behavior of AA 6082 Thin Targets

2019 ◽  
Author(s):  
Rahul Dubey ◽  
Raja Allavikutty ◽  
R. Velmurugan ◽  
R. Jayaganthan
Keyword(s):  
High Speed ◽  
Electron Backscatter Diffraction ◽  
Impact Behavior ◽  
Final Thickness ◽  
High Speed Impact ◽  
Gas Gun ◽  
Potential Applications ◽  
Ballistic Properties ◽  
Impact Data ◽  
Backscatter Diffraction

Abstract Aluminium alloy AA 6082-T6 was rolled at cryogenic and room temperatures to final thickness of 0.5 mm after 75% thickness reduction and subjected to high speed impact. The deformed alloy was investigated for its ballistic properties due to potential applications in aerospace and automotive sectors. The cryogenic and room temperature rolled samples were subjected to normal high-speed impact using a gas gun arrangement to shoot nosed projectiles at velocities higher than the ballistic limits. Phantom ‘V611’ high-speed camera was used to measure the initial and residual velocities of the projectile. Nano-indentation was performed to relate hardness of the initial sample with the observed impact behaviour. Detailed fractographic studies were conducted using Scanning Electron Microscopy (SEM) to substantiate the possible failure mechanisms upon impact. Electron Backscatter Diffraction (EBSD) and Energy Dispersive X-ray Spectroscopy (EDS) were used to characterize the microstructure of the deformed samples. The high speed impact data is correlated with the metallographic observations in this study.

The Occurrence of a Peripheral Coarse Grain Zone (PCGZ) in Extruded Bars of AA 7108

2021 ◽  
Vol 1016 ◽  
pp. 1141-1146
Author(s):  
Saul Hissaci de Souza ◽  
Ronald Lesley Plaut ◽  
Nelson Batista de Lima ◽  
Rene Ramos de Oliveira ◽  
Angelo Fernando Padilha
Keyword(s):  
Electron Backscatter Diffraction ◽  
Microstructural Analysis ◽  
Polarized Light ◽  
Coarse Grain ◽  
X Ray Diffraction ◽  
Rectangular Section ◽  
X Ray ◽  
Analysis Techniques ◽  
Coarse Grains ◽  
Backscatter Diffraction

Industrial-scale extruded profiles of AA 7108 with a rectangular section (25.60 mm x 15.95 mm) were used in this investigation. Some complementary microstructural analysis techniques, such as polarized light microscopy, EBSD (Electron Backscatter Diffraction) and X-ray diffraction were used to characterize the microstructure, focusing on the PCG zone. It was observed that the extruded profiles presented a totally recrystallized microstructure and a 300 μm layer of peripheral coarse grains. Additionally, the results showed that the PCGZ predominant grain orientation {311} <110> differs from the texture below the PCGZ (Goss and Cube components).

scholarly journals Evolution Of Precipitate Morphology During Extrusion In Mg ZK60A Alloy

2015 ◽  
Vol 60 (2) ◽  
pp. 1423-1426 ◽  
Author(s):  
J. Park ◽  
K.H. Jung ◽  
G.A. Lee ◽  
M. Kawasaki ◽  
B. Ahn
Keyword(s):  
Electron Backscatter Diffraction ◽  
Microstructural Analysis ◽  
Extrusion Process ◽  
Formation Mechanisms ◽  
Precipitate Morphology ◽  
X Ray ◽  
Transmission Electron ◽  
Electron Backscatter ◽  
Backscatter Diffraction ◽  
Evolution Of Precipitates

Abstract In this study, a continuously casted ZK60A magnesium alloy (Mg-Zn-Zr) was extruded in two different extrusion ratios, 6:1 and 10:1. The evolution of precipitates was investigated on the two extruded materials and compared with that of as-casted material. The microstructural analysis was performed by electron backscatter diffraction and transmission electron microscopy, and the compositional information was obtained using energy-dispersive X-ray spectroscopy. Several distinct morphologies of precipitates were observed, such as dot, rod, and disk shaped. The formation mechanisms of those precipitates were discussed with respect to the heat and strain during the extrusion process.

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