scholarly journals Microstructure characterization of a duplex stainless steel weld by electron backscattering diffraction and orientation imaging microscopy techniques

2015 ◽  
Vol 20 (1) ◽  
pp. 212-226 ◽  
Author(s):  
Isabela Viegas Aguiar ◽  
Diana Pérez Escobar ◽  
Dagoberto Brandão Santos ◽  
Paulo J. Modenesi
Keyword(s):  
Electron Microscopy ◽  
Stainless Steel ◽  
Duplex Stainless Steel ◽  
Electron Backscatter Diffraction ◽  
Orientation Imaging Microscopy ◽  
Orientation Distribution ◽  
Orientation Imaging ◽  
Transmission Electron ◽  
Ebsd Technique ◽  
Microscopy Techniques

This paper describes the electron backscatter diffraction (EBSD) technique used to characterize the microstructure (especially the morphology and constitution) of the base metal (BM), the heat-affected zone (HAZ) and the fusion zone (FZ) on a lean duplex stainless steel (LDX). This technique provides advantages due to its simplicity of use and greater depth of information, thereby increasing the amount of information obtained by traditional characterization techniques such as optical microscopy (OM), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The use of EBSD together with orientation imaging microscopy (OIM) as a tool to understand phase transformation paths and ferrite-austenite variant selection was discussed. Vickers microhardness measurements were performed and no significance difference between the different zones was found. Orientation distribution function (ODF) results show that there are no significant changes on the crystallographic texture of the samples after welding. The advantages of using SEM together with EBSD for microstructure analyzing and texture development were also discussed.

Microstructure and Microchemistry of Y-Doped a-Al203

1998 ◽  
Vol 4 (S2) ◽  
pp. 546-547
Author(s):  
M. A. Giilgiin ◽  
M. L. Mulvihill ◽  
V. Putlayev ◽  
M. Riihle
Keyword(s):  
Electron Microscopy ◽  
Large Scale ◽  
Analytical Electron Microscopy ◽  
Orientation Imaging Microscopy ◽  
Second Phase ◽  
Polycrystalline Alumina ◽  
Orientation Imaging ◽  
Transmission Electron ◽  
Scale Range ◽  
Microscopy Techniques

A thorough microstructural study of common ceramics requires analysis at various length scales. Yttrium doped, polycrystalline α-Al203 was studied using a broad selection of microscopy techniques over a scale range covering seven-orders of magnitude (i.e. from mm to Å).Yttrium doped, (1000 (Y/Al) atomic ppm) polycrystalline alumina samples were prepared by hot pressing at 1450°C at 50 MPa. Some were subsequently crept in tension. Microstructure of these samples was studied by optical microscopy, scanning electron/orientation imaging microscopy (OIM™), conventional and high resolution transmission electron microscopy. Analytical electron microscopy was performed on a VG HB501 FEG-STEM equipped with an EDS and PEELS.On a large scale, the microstructure often consisted of bimodal sized alumina grains and second phase YAG (Y3A15012) precipitates. YAG precipitates at grain boundaries (GB) and triple points caused clusters (50μm to 1mm) of small equi-axed alumina grains (0.5-2 μm) randomly distributed over 40 area% of the sample.

scholarly journals Randomly oriented twin domains in electrodeposited silver dendrites

2015 ◽  
Vol 80 (1) ◽  
pp. 107-113 ◽  
Author(s):  
Evica Ivanovic ◽  
Nebojsa Nikolic ◽  
Velimir Radmilovic
Keyword(s):  
Electron Microscopy ◽  
Orientation Imaging Microscopy ◽  
Dark Field ◽  
High Angle ◽  
Orientation Imaging ◽  
Transmission Electron ◽  
Annular Dark Field ◽  
Silver Dendrites ◽  
Z Contrast ◽  
Scanning Electron

Silver dendrites were prepared by electrochemical deposition. The structures of Ag dendrites, the type of twins and their distribution were investigated by scanning electron microscopy (SEM), Z-contrast high angle annular dark field transmission electron microscopy (HAADF), and crystallografically sensitive orientation imaging microscopy (OIM). The results revealed that silver dendrites are characterized by the presence of randomly distributed 180? rotational twin domains. The broad surface of dendrites was of the {111} type. Growth directions of the main dendrite stem and all branches were of <112> type.

scholarly journals Microstructure evaluation of UNS S32205 duplex stainless steel friction stir welds

2013 ◽  
Vol 66 (2) ◽  
pp. 187-191 ◽  
Author(s):  
Tiago F. A. Santos ◽  
Ricardo R. Marinho ◽  
Marcelo T. P. Paes ◽  
Antonio J. Ramirez
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Stainless Steel ◽  
Duplex Stainless Steel ◽  
Ferrite Matrix ◽  
Optical Scanning ◽  
Friction Stir ◽  
Microstructure Evaluation ◽  
Transmission Electron ◽  
Steel Welds

UNS S32205 duplex stainless steel welds were performed by friction stir welding (FSW). Advancing and retreating sides showed distinct characteristics in the welded joint. The advancing side shows the strongest grain refinement which is corroborated by microhardness measurements. The microstructure characterization was carried out by optical, scanning and transmission electron microscopy. The thermomechanically affected zone displays austenite islands deformed in a ferrite matrix. The stir zone (SZ) showed a fine recrystallized microstructure providing an outstanding increase of hardness associated with better corrosion performance. Transmission electron microscopy and corrosion tests have corroborated the absence of intermetallic phases on welded joints.

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 Microstructure Investigations of the Phase Boundaries in the Bridgman TRIP Steel Crystal

2010 ◽  
Vol 160 ◽  
pp. 211-216 ◽  
Author(s):  
D. Borisova ◽  
C. Schimpf ◽  
Andreas Jahn ◽  
V. Klemm ◽  
G. Schreiber ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Trip Steel ◽  
Electron Backscatter Diffraction ◽  
Orientation Distribution ◽  
Phase Boundaries ◽  
Reciprocal Space Mapping ◽  
Transmission Electron ◽  
The Individual ◽  
Backscatter Diffraction

Formation of microstructure defects at the phase boundaries in TRIP steels was investigated with the aid of microstructure analysis on a TRIP steel crystal, which was grown by the Bridgman technique. The microstructure studies comprised scanning electron microscopy (SEM), X-ray diffraction (XRD), electron backscatter diffraction (EBSD), transmission electron microscopy (TEM) and transmission electron microscopy with high resolution (HRTEM). Initial XRD measurements revealed that the crystals under study consist of austenite and ferrite with extremely strong preferred orientations. Subsequent XRD pole figure measurements and EBSD scans have shown that the orientation relationship between austenite and ferrite can be described by the Nishiyama-Wassermann model. For a detailed description of the microstructure of the Bridgman crystal, the orientation distribution of crystallites within the individual phases was investigated using the XRD reciprocal space mapping and the rocking curve measurements. These experiments have shown that the density of microstructure defects is much lower in ferrite than in austenite. The direct information about the defect structures at the phase boundaries between austenite and ferrite was obtained from the TEM micrographs, which revealed complicated micro-twin structures at the boundaries between the neighbouring phases. HRTEM discovered very narrow stripes of ferrite embedded in austenite that were regarded as a source of the microstructure defects in austenite.

Recrystallization in an IF-Ti Steel after Low Deformation Amount by Tensile Strain

2005 ◽  
Vol 495-497 ◽  
pp. 1297-1302
Author(s):  
Amel Samet-Meziou ◽  
Anne Laure Etter ◽  
Thierry Baudin ◽  
Richard Penelle
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Cell Walls ◽  
Tensile Strain ◽  
Orientation Imaging Microscopy ◽  
Continuous Growth ◽  
Orientation Imaging ◽  
Transmission Electron ◽  
Deformation Amount ◽  
Electron Back Scattered Diffraction

The first steps of recovery and recrystallization in an IF-Ti steel after 35% deformation by uniaxial tension have been studied by Electron Back Scattered Diffraction (EBSD), Orientation Imaging Microscopy(™) (OIM) and Transmission Electron Microscopy (TEM). Two types of substructure are created after tensile strain: diamond shaped cells for the {111}<110> component and equiaxed cells for {001}<110> component. The recovery is by the decrease of dislocation density inside cells, the refinement of the cell walls, the vanishing of the cell wall, the cell coalescence and the cell growth. Recrystallized grains developed by two main recrystallization mechanisms: the “generalized recovery” and the “bulging”. Both mechanisms are based on continuous growth of subgrains followed or not by the migration of the prior grain boundaries.

scholarly journals Mechanical Property of Duplex Stainless Steel with Nanostructured Layer by Surface Mechanical Attrition Treatment

2011 ◽  
Vol 682 ◽  
pp. 123-130 ◽  
Author(s):  
Liu Chen ◽  
Xiao Lei Xu
Keyword(s):  
Electron Microscopy ◽  
Mechanical Property ◽  
Stainless Steel ◽  
Tensile Test ◽  
Duplex Stainless Steel ◽  
Electron Backscatter Diffraction ◽  
Annealed Sample ◽  
Surface Mechanical Attrition Treatment ◽  
Mechanical Attrition ◽  
Deformed Layer

A grain size gradient layer material was produced by means of surface mechanical attrition treatment on a UNS S32304 duplex stainless steel. In this study, the mechanical property was characterized by tensile test, while microstructure was investigated by transmission electron microscopy, scanning electron microscopy and electron backscatter diffraction. The deformed layer enhanced both the yield strength and maximum strength with large ductility retained, as revealed by tensile test that the yield stress of 30 minutes processed sample was 702 MPa as compared with 454 MPa of as-annealed sample. The elongation to failure, however, decreased from 0.41 to 0.27.

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