scholarly journals Experimental Investigation of the Blanked Surface of C5191 Phosphor Bronze Sheet over a Wide Range of Blanking Speeds

Materials ◽  
2020 ◽  
Vol 13 (15) ◽  
pp. 3335 ◽  
Author(s):  
Lei Wang ◽  
Daochun Hu ◽  
Minghe Chen ◽  
Hongjun Wang
Keyword(s):  
Electron Microscope ◽  
High Speed ◽  
Electron Backscatter Diffraction ◽  
Local Area ◽  
Selected Area Electron Diffraction ◽  
Transmission Electron ◽  
Low Dislocation Density ◽  
Wide Range ◽  
Backscatter Diffraction

The influence of blanking speed on the blanked surface quality of C5191 bronze phosphorus sheets, with a thickness of 0.12 mm, was systematically studied to demonstrate the mechanism under high speed blanking. The morphology and microstructure of the blanked edge were observed by using a variety of techniques, including optical microscopy (OM), scanning electron microscope (SEM), electron backscatter diffraction (EBSD), and transmission electron microscope (TEM). The results revealed that the local temperature and microhardness of the shear zone increased with the increase in blanking speed. Moreover, the quality of blanked edge significantly improved with the increase in blanking speed due to the combined influence of strain rate hardening and thermal softening. In addition, the blanked edge grains were elongated along the blanking direction and formed dislocation cells and sub-grains in some areas. The blanked edge is dominated by {000} <100> cubic texture at higher blanking speeds, and {112} <111> texture at lower blanking speeds. When punched at an ultra-high speed of 3000 strokes per minute (SPM 3000), the local area of the blanked edge exhibited distinct microstructural features, including low dislocation density, nanocrystals with high-angle grain boundaries, and significant differences in grain orientation. Additionally, the selected area electron diffraction (SAED) pattern exhibited a discontinuous ring-like structure, indicating the occurrence of adiabatic shearing with dynamic recrystallization.

Reduced Unit Cell Determination From Unindexed EBSD Patterns

2000 ◽  
Vol 6 (S2) ◽  
pp. 946-947 ◽  
Author(s):  
J. R. Michael ◽  
R. P. Goehner
Keyword(s):  
Electron Microscope ◽  
Electron Backscatter Diffraction ◽  
Unit Cell ◽  
Phase Identification ◽  
High Quality ◽  
Charge Coupled Device ◽  
Transmission Electron ◽  
Single Pattern ◽  
Backscatter Diffraction

Electron backscatter diffraction (EBSD) is a technique that can provide identification of unknown crystalline phases while exploiting the excellent imaging capabilities of the scanning electron microscope (SEM). Phase identification using EBSD has now progressed to the point that it is commercially available. Phase identification in the SEM requires high quality EBSD patterns that can only be collected using either film or charge coupled device (CCD)-based cameras. High quality EBSD patterns obtained in this manner show many diffraction features that are useful in the determination of the unit cell of the sample.’ This paper will discuss the features in the EBSD patterns and the procedure used to determine the reduced unit cell of the sample.One of the major advantages of EBSD over electron diffraction in the transmission electron microscope is the remarkable field of view that is routinely attained. The large angular view of the diffraction pattern permits many zone axes and their associated symmetries to be viewed in a single pattern or at most a few patterns.

scholarly journals Cryogenic Deformation Behavior and Microstructural Characteristics of 2195 Alloy

Metals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1406
Author(s):  
Jin Zhang ◽  
Wenfu Tan ◽  
Cheng Wang ◽  
Chunnan Zhu ◽  
Youping Yi
Keyword(s):  
Electron Microscope ◽  
Electron Backscatter Diffraction ◽  
Underlying Mechanism ◽  
Optical Microscope ◽  
W State ◽  
Grain Structure ◽  
Cryogenic Deformation ◽  
Transmission Electron ◽  
Strength And Plasticity ◽  
Backscatter Diffraction

Cryogenic deformation can improve the strength and plasticity of Al–Li alloy, although the underlying mechanism is still not yet well understood. The effects of cryogenic temperature on the tensile properties and microstructure of an Al–Cu–Li alloy were investigated by means of tensile property test, roughness measurement, scanning electron microscope (SEM), optical microscope (OM), electron backscatter diffraction (EBSD), and transmission electron microscope (TEM). The results indicated that the strength and elongation of the as-annealed (O-state) and solution-treated (W-state) alloys increased with the decrease in deformation temperature, where the increasing trend of elongation of the W-state alloy was more significant than that of the O-state alloy. In addition, a temperature range was observed at approximately 178 K that caused the strength of the W-state alloy to slightly decrease. The decrease in temperature inhibited the dynamic recovery of the Al–Cu–Li alloy, which increased the dislocation density and the degree of work hardening, thus improving the strength of the alloy. At cryogenic temperatures, the internal grain structure was more involved in the deformation and the overall deformation was more uniform, which caused the alloy to have higher plasticity. This study provides a theoretical basis for the cryogenic forming of Al–Li alloy.

scholarly journals Characterization of the Interface Between α and β Titanium Alloys in the Diffusion Couple

2020 ◽  
Vol 51 (12) ◽  
pp. 6584-6591
Author(s):  
Maciej Motyka ◽  
Wojciech J. Nowak ◽  
Bartek Wierzba ◽  
Witold Chrominski
Keyword(s):  
Electron Microscope ◽  
Diffusion Couple ◽  
Titanium Alloys ◽  
Solid Solutions ◽  
Electron Backscatter Diffraction ◽  
Inert Atmosphere ◽  
Microstructural Changes ◽  
Transmission Electron ◽  
Titanium Grade ◽  
Backscatter Diffraction

AbstractThe aim of the research was to investigate the microstructural changes caused by diffusion through interface between α and β titanium solid solutions. For this purpose, a diffusion couple composed of two single-phase titanium alloys—α type commercially pure (CP) titanium Grade 2 and near-β Ti-15V-3Al-3Cr-3Sn—was made by annealing at a temperature of 850 °C in an inert atmosphere. The performed heat treatment caused partial diffusion bonding (DB) where the α/β-interface was clearly visible. Based on the results of microscopic (light microscope (LM), scanning electron microscope/electron backscatter diffraction (SEM/EBSD), and transmission electron microscope (TEM)) examination, a significant microstructure evolution of near-β alloy in the region near the interface (diffusion-affected zone) was revealed. It was found that needlelike phases were formed both in α and β solid solutions. Moreover, in the near-β titanium alloy, pores aligned in the Frenkel plane were found. The latter finding indicated that the diffusion of alloying elements of near-β alloy is the most probable reason for the observed microstructural changes. Additionally, the “grooving” phenomenon at the α/β interface was found and it was correlated with faster diffusion through grain boundaries, rather than volume diffusion. Finally, the pore size was measured and numerically modeled. The calculated values were in good agreement with the experimental ones.

Characterization of Precipitates in 3xxx Series Alloys with Zirconium

2015 ◽  
Vol 231 ◽  
pp. 81-85
Author(s):  
Mariusz Bigaj ◽  
Sonia Boczkal ◽  
Monika Mitka ◽  
Zbigniew Zamkotowicz ◽  
Janusz Żelechowski ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Electron Backscatter Diffraction ◽  
Scanning Transmission Electron Microscope ◽  
Phase Identification ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Backscatter Diffraction ◽  
Ebsd Method ◽  
Eds Microanalysis

The study presents the results of microstructure examinations and phase identification of precipitates in AlMn alloys containing zirconium after heat treatment and rolling. Chemical composition in microareas was determined by Energy Dispersive Spectrometry (EDS) microanalysis performed in Scanning Electron Microscope (SEM-EDS) and Scanning Transmission Electron Microscope (STEM-EDS) modes. Phase identification was carried out using Electron Backscatter Diffraction (EBSD) method. Studies have shown that Al6Mn and α- Al17(Fe3.2Mn0.8)Si2 phases were formed in the melt. Microstructure examined by TEM showed the presence of finely dispersed spherical precipitates of zirconium. In the alloy with an addition of silicon and magnesium, numerous precipitates of an Mg2Si phase were also found.

Crystallographic Mapping in Scanning and Transmission Electron Micrsocopy with Application to Semiconductor Materials

1998 ◽  
Vol 523 ◽  
Author(s):  
D. J. Dingley ◽  
S. I. Wright ◽  
D. J. Dingley
Keyword(s):  
Electron Microscope ◽  
Electron Backscatter Diffraction ◽  
Orientation Imaging Microscopy ◽  
Lattice Parameter ◽  
Dark Field ◽  
Polycrystalline Materials ◽  
Orientation Imaging ◽  
Transmission Electron ◽  
Dark Field Microscopy ◽  
Backscatter Diffraction

AbstractThe two sister techniques, Electron Backscatter Diffraction and Orientation Imaging Microscopy which operate in a scanning electron microscope, are well established tools for the characterization of polycrystalline materials. Experiment has shown that the limiting resolution for mapping is the order of 0.1 microns. The basic techniques have been extended to include multiphase mapping. Whereas it has been possible to distinguish between phases of different crystal systems easily, it has not been possible to distinguish between phases that differ in lattice parameter by less than 5 %.An equivalent transmission electron microscope procedure has been developed. The technique couples standard hollow cone microscopy procedures with dark field microscopy. All possible dark field images that can be produced by tilting the electron beam are scanned to detect under what settings each crystal is brought into a diffracting condition. Subsequent analysis permits determination of both crystal phase and orientation.

scholarly journals Grain size dependent photoresponsivity in GaAs films formed on glass with Ge seed layers

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
T. Nishida ◽  
K. Igura ◽  
T. Imajo ◽  
T. Suemasu ◽  
K. Toko
Keyword(s):  
Electron Microscopy ◽  
Grain Size ◽  
Electron Backscatter Diffraction ◽  
Gaas Film ◽  
Size Dependent ◽  
Transmission Electron ◽  
Wide Range ◽  
Gaas Films ◽  
Backscatter Diffraction ◽  
Seed Layers

AbstractThe strong correlation between grain size and photoresponsivity in polycrystalline GaAs films on glass was experimentally demonstrated using Ge seed layers with a wide range of grain sizes (1‒330 μm). The crystal evaluations using Raman spectroscopy, scanning electron microscopy, electron backscatter diffraction, and transmission electron microscopy revealed that 500-nm-thick GaAs films epitaxially grown from the Ge seed layers at 550 °C inherited the grain boundaries and crystal orientations in Ge. With increasing grain size, the photoresponsivity corresponding to GaAs increased from 0.01 to 3 A W−1 under a bias voltage of 0.3 V. The maximum value approached that of the GaAs film formed simultaneously on a single-crystal Ge wafer, indicating the high potential of the large-grained GaAs film. Knowledge gained from this study will be essential for designing advanced solar cells based on polycrystalline III–V compound semiconductors using inexpensive substrates.

scholarly journals TEM Sample Preparation and FIB-Induced Damage

MRS Bulletin ◽  
2007 ◽  
Vol 32 (5) ◽  
pp. 400-407 ◽  
Author(s):  
Joachim Mayer ◽  
Lucille A. Giannuzzi ◽  
Takeo Kamino ◽  
Joseph Michael
Keyword(s):  
Electron Microscope ◽  
Focused Ion Beam ◽  
Electron Backscatter Diffraction ◽  
Ion Beam ◽  
X Ray ◽  
Transmission Electron ◽  
Electron Backscatter ◽  
Future Potential ◽  
Backscatter Diffraction ◽  
Composite Samples

AbstractOne of the most important applications of a focused ion beam (FIB) workstation is preparing samples for transmission electron microscope (TEM) investigation. Samples must be uniformly thin to enable the analyzing beam of electrons to penetrate. The FIB enables not only the preparation of large, uniformly thick, sitespecific samples, but also the fabrication of lamellae used for TEM samples from composite samples consisting of inorganic and organic materials with very different properties. This article gives an overview of the variety of techniques that have been developed to prepare the final TEM specimen. The strengths of these methods as well as the problems, such as FIB-induced damage and Ga contamination, are illustrated with examples. Most recently, FIB-thinned lamellae were used to improve the spatial resolution of electron backscatter diffraction and energy-dispersive x-ray mapping. Examples are presented to illustrate the capabilities, difficulties, and future potential of FIB.

On the reliability of fully automatic indexing of electron diffraction patterns obtained in a transmission electron microscope

2006 ◽  
Vol 39 (1) ◽  
pp. 101-103 ◽  
Author(s):  
A. Morawiec ◽  
E. Bouzy
Keyword(s):  
Electron Microscope ◽  
Electron Diffraction ◽  
Transmission Electron Microscope ◽  
Current Practice ◽  
Electron Backscatter Diffraction ◽  
Automatic Indexing ◽  
Transmission Electron ◽  
Fully Automatic ◽  
Diffraction Patterns ◽  
Backscatter Diffraction

Orientation maps similar to electron backscatter diffraction maps can be obtained in a transmission electron microscope. A method of such mapping by automatic indexing of electron diffraction patterns has been proposed recently. The procedure is relatively simple and fast but it does not avoid the 180° ambiguity. Using tests on simulated patterns, it is shown that under current practice automatic indexing may give a considerable fraction of erroneous solutions. Optimization of measurement conditions leading to a reduction of that fraction is considered.

scholarly journals Formation pathways of oriented magnetite micro-inclusions in plagioclase from oceanic gabbro

2021 ◽  
Vol 176 (12) ◽  
Author(s):  
Ge Bian ◽  
Olga Ageeva ◽  
Aleksander Rečnik ◽  
Gerlinde Habler ◽  
Rainer Abart
Keyword(s):  
Electron Backscatter Diffraction ◽  
External Source ◽  
Mineral Chemistry ◽  
Orientation Relationships ◽  
Formation Pathway ◽  
Selected Area Electron Diffraction ◽  
Orientation Relations ◽  
Transmission Electron ◽  
Mid Atlantic Ridge ◽  
Backscatter Diffraction

AbstractPlagioclase hosted needle- and lath-shaped magnetite micro-inclusions from oceanic gabbro dredged at the mid-Atlantic ridge at 13° 01–02′ N, 44° 52′ W were investigated to constrain their formation pathway. Their genesis is discussed in the light of petrography, mineral chemistry, and new data from transmission electron microscopy (TEM). The magnetite micro-inclusions show systematic crystallographic and shape orientation relationships with the plagioclase host. Direct TEM observation and selected area electron diffraction (SAED) confirm that the systematic orientation relations are due to the alignment of important oxygen layers between the magnetite micro-inclusions and the plagioclase host, a hypothesis made earlier based on electron backscatter diffraction data. Precipitation from Fe-bearing plagioclase, which became supersaturated with respect to magnetite due to interaction with a reducing fluid, is inferred to be the most likely formation pathway. This process probably occurred without the supply of Fe from an external source but required the out-diffusion of oxygen from the plagioclase to facilitate partial reduction of the ferric iron originally contained in the plagioclase. The magnetite micro-inclusions contain oriented lamellae of ilmenite, the abundance, shape and size of which indicate high-temperature exsolution from Ti-rich magnetite constraining the precipitation of the magnetite micro-inclusions to temperatures in excess of ~ 600 °C. This is above the Curie temperature of magnetite, and the magnetic signature of the magnetite-bearing plagioclase grains must, therefore, be considered as the thermoremanent magnetization.

Microstructure Characterization of Large Strain Deformed Fe-32%Ni Alloy

2010 ◽  
Vol 146-147 ◽  
pp. 248-251
Author(s):  
Bai Xiong Liu ◽  
Bao Jun Han
Keyword(s):  
Electron Microscope ◽  
Grain Boundaries ◽  
Electron Backscatter Diffraction ◽  
Large Strain ◽  
Internal Stresses ◽  
Transmission Electron ◽  
Resolution Electron ◽  
Ni Alloy ◽  
Backscatter Diffraction

High-resolution electron backscatter diffraction (EBSD) in scanning electron microscope and transmission electron microscope (TEM) were used to investigate the microstructure of Fe-32%Ni alloy processed by large strain multi-axial forging. The samples were compressed with loading direction changed through 90º from pass to pass at temperature of 500°C and a strain rate of 10-2/s. The results show the microstructure evolution is characterized by full development of almost equi-axed fine grains, not well-developed grain boundaries accompanied by high dislocation density and the existence of extensive extinction contours in the vicinity of grain boundaries, and the structure characteristics indicate that the grain boundaries are in a non-equilibrium state with high internal stresses.

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