Analysis of Asbestos Fibres in The Scanning Electron Microscope (SEM) by The Use of Electron Backscattering Diffraction (Ebsd).

1997 ◽  
Vol 3 (S2) ◽  
pp. 767-768
Author(s):  
M. Raanes ◽  
J. Hjelen
Keyword(s):  
Specimen Preparation ◽  
Electron Microscopies ◽  
Electron Backscattering ◽  
Selected Area Electron Diffraction ◽  
Electron Backscattering Diffraction ◽  
Transmission Electron ◽  
Ebsd Technique ◽  
Fibrous Mineral ◽  
Mineral Silicates ◽  
Reliable Methods

Asbestos is a common name of a number of fibrous mineral silicates which differ in chemical composition. The asbestos fibres are classified into two groups: serpentine (chrysotile) and amphiboles (anthophyllite, amosite, actinolite, tremolite, crocidolite).Inhalation of asbestos dust fibres involves a health risk. It is therefore of great importance to develop quick and reliable methods to check for the presence of asbestos fibres in suspected materials. Some common analysis methods for asbestos detection are: optical microscopy scanning or transmission electron microscopies (SEM ,TEM) often combined with energy dispersive X-ray analysis (EDX) and selected area electron diffraction (SAED) in the TEM where the crystal structure is determined.The EBSD technique in the SEM has in this work been applied to achieve electron backscattering patterns (EBSP) from four types of asbestos fibres. The pattern quality has been studied as a function of specimen preparation and SEM settings.

Measuring Strains for Hematite Phase in Sinter Ore by Electron Backscattering Diffraction Method

2006 ◽  
Vol 326-328 ◽  
pp. 237-240 ◽  
Author(s):  
Yasushi Sasaki ◽  
Manabu Iguchi ◽  
Mitsutaka Hino
Keyword(s):  
Linear Relationship ◽  
Strain Gauge ◽  
Diffraction Method ◽  
Local Strain ◽  
Electron Backscattering ◽  
Hematite Phase ◽  
Compression Strain ◽  
Electron Backscattering Diffraction ◽  
Ebsd Technique ◽  
The Relationship

Based on the relationship between quantified blurring degree of Kikuchi bands obtained by an electron backscattering diffraction (EBSD) technique and macroscopic strains measured by a strain gauge, the local compression strain SEBSD in sinter ore has been evaluated under various conditions. There is a good linear relationship between the SEBSD and the strains measured by a strain gauge. The local strain SEBSD evaluated by EBSD patterns can be used as an index of local strains.

Energy Filtered Electron Backscattering Images of 10-nm NbC and AIN Precipitates in Steels Computed by Monte Carlo Simulations

1996 ◽  
Vol 54 ◽  
pp. 150-151
Author(s):  
Raynald Gauvin ◽  
Dominique Drouin ◽  
Pierre Hovington
Keyword(s):  
Monte Carlo ◽  
Electron Beam ◽  
Electron Microscope ◽  
Materials Science ◽  
Specimen Preparation ◽  
Backscattered Electrons ◽  
Electron Backscattering ◽  
Transmission Electron ◽  
Properties Of Materials ◽  
Scanning Electron

In modern materials science, it is important to improve the resolution of the Scanning Electron Microscope (SEM) because small phases play a crutial role in the properties of materials. The Transmission Electron Microscope (TEM) is the tool of choice for imaging small phases embedded in a given matrix. However, this technique is expensive and also is slow owing to specimen preparation. In this context, it is important to improve spatial resolution of the SEM.In electron backscattering images, it is well know that the backscattered electrons have an energetic distribution when they escape the specimen.The electrons having loss less energy are those which have travelled less in the specimen and thus escape closer to the electron beam. So, in filtering the energy of the backscattering electron and keeping those which have loss only a small amount of energy to create the image, a significant improvement of the resolution of such images is expected. New detectors are now under development to take advantage of this technique of imaging.

Microstructural characterization of laser-irradiated bulk copper under dry sliding conditions

2012 ◽  
Vol 226 (6) ◽  
pp. 541-551 ◽  
Author(s):  
Brice Raillard ◽  
Carsten Gachot ◽  
Michael Hans ◽  
Peter Leibenguth ◽  
Frank Mücklich
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Friction And Wear ◽  
Wear Behaviour ◽  
Dry Sliding ◽  
Textured Surfaces ◽  
Laser Interference ◽  
Electron Backscattering ◽  
Electron Backscattering Diffraction ◽  
Transmission Electron

The functionalization of surfaces for tribological applications is still a challenging task. There are numerous techniques for improving the friction and wear behaviour of metallic surfaces ranging from different coatings to textured surfaces. A promising approach for textured surfaces is the usage of laser interference patterning by a pulsed nanosecond Nd:YAG laser. Copper samples have been laser patterned using the laser interference metallurgy process. The resulting topographies were evaluated by white light interferometry and scanning electron microscopy in order to study the homogeneity of the structures at both macro- and micro-scales. Electron backscattering diffraction and transmission electron microscopy were performed in order to study the microstructural and oxide layer modifications induced by laser irradiation. Electron backscattering diffraction measurement did not show fine grains but a small proportion of misorientation due to the high quenching rate. Transmission electron microscopy did not allow to observe oxide layers. The friction and wear behaviour of bulk copper samples structured by laser interference metallurgy have been studied under dry sliding conditions using a tribometer in linear reciprocating sliding mode. Friction coefficient measurements revealed that patterned surfaces present a reduction in friction of up to 70% compared to untreated samples due to their good bearing properties and the reduction of the contact area.

Study on the Microstructure and Mechanical Properties of a High Strength Crack-Free Steel

2012 ◽  
Vol 706-709 ◽  
pp. 2265-2270
Author(s):  
Chun Lin Qiu ◽  
Liang Yun Lan ◽  
De Wen Zhao ◽  
Xiu Hua Gao ◽  
Jing Lin Wen
Keyword(s):  
Mechanical Properties ◽  
High Strength ◽  
Accelerated Cooling ◽  
Strengthening Effect ◽  
Microstructural Characteristics ◽  
Tempering Temperature ◽  
Electron Backscattering Diffraction ◽  
Transmission Electron ◽  
Average Grain Size ◽  
Ebsd Technique

Thermo-mechanical process followed by accelerated cooling and high temperature tempering was applied to investigate the microstructure evolution and mechanical properties of a high strength crack-free steel. Optical microscopy, transmission electron microscopy (TEM) and electron backscattering diffraction (EBSD) technique were employed to analyze the complex microstructural characteristics of the steel. The results indicated that the precipitation strengthening effect played an important role in optimizing the tempered strength. According to EBSD results, the average grain size of as-rolled specimens was about 3.2 μm, and it increased slightly with the tempering temperature. Therefore, the grain refinement wasthe major reason for the good mechanical properties of the crack-free steel.

Direct Observation of Heat Exchanger Deposits by Cross Sectioning

1967 ◽  
Vol 25 ◽  
pp. 364-365
Author(s):  
R. W. Anderson ◽  
D. L. Senecal
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Heat Exchanger ◽  
Direct Observation ◽  
Cross Sections ◽  
Preparation Method ◽  
Specimen Preparation ◽  
Flowing Water ◽  
Transmission Electron ◽  
Deposit Layer

A problem was presented to observe the packing densities of deposits of sub-micron corrosion product particles. The deposits were 5-100 mils thick and had formed on the inside surfaces of 3/8 inch diameter Zircaloy-2 heat exchanger tubes. The particles were iron oxides deposited from flowing water and consequently were only weakly bonded. Particular care was required during handling to preserve the original formations of the deposits. The specimen preparation method described below allowed direct observation of cross sections of the deposit layers by transmission electron microscopy.The specimens were short sections of the tubes (about 3 inches long) that were carefully cut from the systems. The insides of the tube sections were first coated with a thin layer of a fluid epoxy resin by dipping. This coating served to impregnate the deposit layer as well as to protect the layer if subsequent handling were required.

Enhancement of Contrast in the CEM and STEM Using Bumpy Specimens and Employing the “Dappled Field” Mode of Operation

1974 ◽  
Vol 32 ◽  
pp. 552-553 ◽  
Author(s):  
L. Gandolfi ◽  
J. Reiffel
Keyword(s):  
Operating Mode ◽  
Scanning Transmission Electron Microscope ◽  
Dark Field ◽  
Specimen Preparation ◽  
Field Mode ◽  
Preparation Methods ◽  
Scanning Transmission Electron ◽  
Transmission Electron ◽  
Mode Of Operation ◽  
Scanning Transmission

Calculations have been performed on the contrast obtainable, using the Scanning Transmission Electron Microscope, in the observation of thick specimens. Recent research indicates a revival of an earlier interest in the observation of thin specimens with the view of comparing the attainable contrast using both types of specimens.Potential for biological applications of scanning transmission electron microscopy has led to a proliferation of the literature concerning specimen preparation methods and the controversy over “to stain or not to stain” in combination with the use of the dark field operating mode and the same choice of technique using bright field mode of operation has not yet been resolved.

Contrast from epitaxially sandwiched macromolecules

1978 ◽  
Vol 36 (2) ◽  
pp. 226-227
Author(s):  
M. Talianker ◽  
D.G. Brandon
Keyword(s):  
Gold Film ◽  
Lattice Defect ◽  
Gold Foil ◽  
Specimen Preparation ◽  
Preparation Technique ◽  
Resolution Limit ◽  
Transmission Electron ◽  
Crystal Lattice Defect ◽  
Void Effect ◽  
Lattice Resolution

A new specimen preparation technique for visualizing macromolecules by conventional transmission electron microscopy has been developed. In this technique the biopolymer-molecule is embedded in a thin monocrystalline gold foil. Such embedding can be performed in the following way: the biopolymer is deposited on an epitaxially-grown thin single-crystal gold film. The molecule is then occluded by further epitaxial growth. In such an epitaxial sandwich an occluded molecule is expected to behave as a crystal-lattice defect and give rise to contrast in the electron microscope.The resolution of the method should be limited only by the precision with which the epitaxially grown gold reflects the details of the molecular structure and, in favorable cases, can approach the lattice resolution limit.In order to estimate the strength of the contrast due to the void-effect arising from occlusion of the DNA-molecule in a gold crystal some calculations were performed.

A Novel TEM Technique for Characterizing As-Grown CVD Diamond Films

1991 ◽  
Vol 49 ◽  
pp. 956-957 ◽  
Author(s):  
Z.L. Wang ◽  
J. Bentley ◽  
R.E. Clausing ◽  
L. Heatherly ◽  
L.L. Horton
Keyword(s):  
Diamond Films ◽  
Chemical Vapor ◽  
Growth Direction ◽  
Dark Field ◽  
Growth Surface ◽  
Specimen Preparation ◽  
Transmission Electron ◽  
Diffraction Patterns ◽  
First Time ◽  
Microstructural Studies

Microstructural studies by transmission electron microscopy (TEM) of diamond films grown by chemical vapor deposition (CVD) usually involve tedious specimen preparation. This process has been avoided with a technique that is described in this paper. For the first time, thick as-grown diamond films have been examined directly in a conventional TEM without thinning. With this technique, the important microstructures near the growth surface have been characterized. An as-grown diamond film was fractured on a plane containing the growth direction. It took about 5 min to prepare a sample. For TEM examination, the film was tilted about 30-45° (see Fig. 1). Microstructures of the diamond grains on the top edge of the growth face can be characterized directly by transmitted electron bright-field (BF) and dark-field (DF) images and diffraction patterns.

Transmission Electron Microscopy of an Aluminum-Silver-Stainless Steel Solid State Bond

1985 ◽  
Vol 43 ◽  
pp. 172-173
Author(s):  
M. J. Carr ◽  
J. F. Shewbridge ◽  
T. O. Wilford
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Solid State ◽  
Specimen Preparation ◽  
Dimensional Control ◽  
Tem Analysis ◽  
Metal Parts ◽  
Dissimilar Metal ◽  
Transmission Electron ◽  
Short Time

Strong solid state bonds are routinely produced between physical vapor deposited (PVD) silver coatings deposited on sputter cleaned surfaces of two dissimilar metal parts. The low temperature (200°C) and short time (10 min) used in the bonding cycle are advantageous from the standpoint of productivity and dimensional control. These conditions unfortunately produce no microstructural changes at or near the interface that are detectable by optical, SEM, or microprobe examination. Microstructural problems arising at these interfaces could therefore easily go undetected by these techniques. TEM analysis has not been previously applied to this problem because of the difficulty in specimen preparation. The purpose of this paper is to describe our technique for preparing specimens from solid state bonds and to present our initial observations of the microstructural details of such bonds.

High-resolution microscopy of twin boundaries in gold

1987 ◽  
Vol 45 ◽  
pp. 260-261
Author(s):  
William Krakow ◽  
David A. Smith
Keyword(s):  
High Resolution ◽  
Specimen Preparation ◽  
Gold Films ◽  
Boundary Area ◽  
Transmission Electron ◽  
Recent Developments ◽  
Tilt Boundaries ◽  
High Resolution Microscopy ◽  
Twist Boundaries

Recent developments in specimen preparation, imaging and image analysis together permit the experimental determination of the atomic structure of certain, simple grain boundaries in metals such as gold. Single crystal, ∼125Å thick, (110) oriented gold films are vapor deposited onto ∼3000Å of epitaxial silver on (110) oriented cut and polished rock salt substrates. Bicrystal gold films are then made by first removing the silver coated substrate and placing in contact two suitably misoriented pieces of the gold film on a gold grid. Controlled heating in a hot stage first produces twist boundaries which then migrate, so reducing the grain boundary area, to give mixed boundaries and finally tilt boundaries perpendicular to the foil. These specimens are well suited to investigation by high resolution transmission electron microscopy.

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