Identification by Electron Microdiffraction of Intermetallic Phases in a Duplex Stainless Steel

1990 ◽  
Vol 48 (2) ◽  
pp. 494-495
Author(s):  
A. Redjaïmia ◽  
J.P. Morniroli ◽  
G. Metauer ◽  
M. Gantois
Keyword(s):  
Stainless Steel ◽  
Duplex Stainless Steel ◽  
Convergent Beam Electron Diffraction ◽  
Intermetallic Phases ◽  
Small Particles ◽  
Parallel Beam ◽  
Diffraction Patterns ◽  
Average Size ◽  
Convergent Beam ◽  
Electron Microdiffraction

2D and especially 3D symmetry information required to determine the crystal structure of four intermetallic phases present as small particles (average size in the range 100-500nm) in a Fe.22Cr.5Ni.3Mo.0.03C duplex stainless steel is not present in most Convergent Beam Electron Diffraction (CBED) patterns. Nevertheless it is possible to deduce many crystal features and to identify unambiguously these four phases by means of microdiffraction patterns obtained with a nearly parallel beam focused on a very small area (50-100nm).From examinations of the whole pattern reduced (RS) and full (FS) symmetries the 7 crystal systems and the 11 Laue classes are distinguished without ambiguity (1). By considering the shifts and the periodicity differences between the ZOLZ and FOLZ reflection nets on specific Zone Axis Patterns (ZAP) which depend on the crystal system, the centering type of the cell and the glide planes are simultaneously identified (2). This identification is easily done by comparisons with the corresponding simulated diffraction patterns.

The application of convergent beam electron diffraction and selected area diffraction techniques to interfacial studies in a duplex stainless steel

1983 ◽  
Vol 41 ◽  
pp. 210-211
Author(s):  
T. R. Parayil ◽  
P. R. Howell
Keyword(s):  
Stainless Steel ◽  
Electron Diffraction ◽  
Grain Boundaries ◽  
Duplex Stainless Steel ◽  
Convergent Beam Electron Diffraction ◽  
Orientation Relationships ◽  
Two Phase ◽  
Beam Electron ◽  
Diffraction Patterns ◽  
Convergent Beam

As part of a wider investigation into the mechanism of recrystallization in a Duplex stainless steel, the structure of grain boundaries and interphase interfaces has been examined. In this later study, both convergent beam electron diffraction (C.B.E.D.) and selected area electron diffraction have been employed to determine the misorientation between grain boundaries and the orientation relationships developed between austenite and ferrite. The application of C.B.E.D. in this study has been particularly beneficial since the fine-scale of the microstructures encountered (e.g. see figure 1) greatly complicates the analysis of selected area diffraction patterns. The duplex steel (based on a composition 26%Cr, 5%Ni balance Fe) was solution treated at 1400°C, to produce a single phase ferritic structure, and quenched to room temperature. Specimens were then deformed 90% by cold rolling and annealed at 900°C (in the two phase austenite plus ferrite region) for times in the range 10s-8.6×104s. Specimens for transmission electron microscopy were prepared using standard techniques and examined in either a Philips EM300 or in a JEOL 1200EX.

A library of convergent-beam electron diffraction patterns

1986 ◽  
Vol 44 ◽  
pp. 688-691
Author(s):  
John F. Mansfield
Keyword(s):  
Electron Diffraction ◽  
Materials Science ◽  
Convergent Beam Electron Diffraction ◽  
Beam Electron ◽  
Transmission Electron ◽  
Yield Information ◽  
Analytical Electron ◽  
Diffraction Patterns ◽  
Convergent Beam ◽  
Electron Energy Loss

One of the most important advancements of the transmission electron microscopy (TEM) in recent years has been the development of the analytical electron microscope (AEM). The microanalytical capabilities of AEMs are based on the three major techniques that have been refined in the last decade or so, namely, Convergent Beam Electron Diffraction (CBED), X-ray Energy Dispersive Spectroscopy (XEDS) and Electron Energy Loss Spectroscopy (EELS). Each of these techniques can yield information on the specimen under study that is not obtainable by any other means. However, it is when they are used in concert that they are most powerful. The application of CBED in materials science is not restricted to microanalysis. However, this is the area where it is most frequently employed. It is used specifically to the identification of the lattice-type, point and space group of phases present within a sample. The addition of chemical/elemental information from XEDS or EELS spectra to the diffraction data usually allows unique identification of a phase.

Convergent Beam Electron Diffraction Zone Axis Pattern Map of Zirconium

1990 ◽  
Vol 48 (2) ◽  
pp. 496-497
Author(s):  
E. Silva ◽  
R. Scozia
Keyword(s):  
Electron Diffraction ◽  
Convergent Beam Electron Diffraction ◽  
Zone Axis ◽  
Pole Piece ◽  
Small Particles ◽  
Present Communication ◽  
Beam Electron ◽  
Zero Layer ◽  
Set Up ◽  
Convergent Beam

The purpose in obtaining zone axis pattern map (zap map) from a given material is to provide a quick and reliable tool to identify cristaline phases, and crystallographic directions, even in small particles. Bend contours patterns and Kossel lines patterns maps from Zr single crystal in the [0001] direction have been presented previously. In the present communication convergent beam electron diffraction (CBED) zap map of Zr will be shown. CBED patterns were obtained using a Philips microscope model EM300, which was set up to carry out this technique. Convergent objective upper pole piece for STEM and some electronic modifications in the lens circuits were required, furthermore the microscope was carefully cleaned and it was operated at a vacuum eminently good.CBED patterns in the Zr zap map consist of zero layer disks, showing fine details within them which correspond to intersecting set of higher order Laue zone (HOLZ) deficiency lines.

DIFFRACTION STUDIES OF METAL-SEMICONDUCTOR INTERFACES

1985 ◽  
Vol 56 ◽  
Author(s):  
D. CHERNS ◽  
C.J. KIELY
Keyword(s):  
Convergent Beam Electron Diffraction ◽  
Wide Angle ◽  
Plan View ◽  
Beam Electron ◽  
Semiconductor Interfaces ◽  
Gaas Films ◽  
Rigid Body Displacement ◽  
Diffraction Patterns ◽  
Convergent Beam ◽  
Sensitive Method

AbstractThe use of convergent beam electron diffraction patterns (CBPs) for investigating metal—semiconductor interfaces in plan—view samples is considered. It is shown that a wide—angle diffraction technique provides a sensitive method of measuring tetragonal distortions in NiSi 2/(001)Si bicrystals. A study of CBP symmetry and the detailec branch structure in higher order Laue zone rings has enabled the interfacial rigid body displacement in NiSi 2/(001)Si and Al/(001)GaAs films to be determined.

scholarly journals Determination of Susceptibility to Intergranular Corrosion of UNS 31803 Type Duplex Stainless Steel by Electrochemical Reactivation Method: A Comparative Study

2012 ◽  
Vol 2012 ◽  
pp. 1-14 ◽  
Author(s):  
Mehmet Emin Arıkan ◽  
Rafet Arıkan ◽  
Mustafa Doruk
Keyword(s):  
Weight Loss ◽  
Stainless Steel ◽  
Duplex Stainless Steel ◽  
Intergranular Corrosion ◽  
Intermetallic Phases ◽  
Double Loop ◽  
Degree Of Sensitization ◽  
Hot Rolled ◽  
Standard Weight

In the present study as in our previous studies (Arikan and Doruk, 2008 and Arikan et al., 2012), similar specimens taken from a hot rolled cylindrical duplex stainless steel (DSS) bar with 22% Cr grade were solution annealed at 1050°C and then aged at 800∘C from 100 to 31622 min for sensitization treatment. Double loop electrochemical potentiodynamic reactivation and standard weight loss immersion acid tests were conducted. The solution annealed samples were found unsensitized. The samples aged for 100 min were less sensitized whereas samples aged for 316 min and more time were sensitized. The degree of sensitization (DOS) can be attributed to higher contribution of chromium and molybdenum depleted areas that result from intermetallic phases. However, especially the samples aged from 3162 to 31622 min have revealed chromium replenishment. Consequently, the degree of sensitization was lowered in comparison to the results obtained in previous studies.

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