Measuring Type II Stresses Using 3DXRD

2010 ◽  
Vol 652 ◽  
pp. 63-69 ◽  
Author(s):  
Jette Oddershede ◽  
Søren Schmidt ◽  
Henning Friis Poulsen ◽  
Walter Reimers
Keyword(s):  
Polycrystalline Sample ◽  
Interstitial Free ◽  
Type Ii ◽  
If Steel ◽  
Outlier Rejection ◽  
X Ray Diffraction ◽  
Elastic Loading ◽  
Loading And Unloading ◽  
Stress States

An algorithm is presented for characterization of the grain resolved (type II) stress states in a polycrystalline sample based on monochromatic X-ray diffraction data. The algorithm is a robust 12-parameter-per-grain fit of the centre-of-mass grain positions, orientations and stress tensors including error estimation and outlier rejection. As examples of use results from two experiments – one on interstitial free (IF) steel and one on copper – will be presented. In the first experiment 96 grains in one layer of IF steel were monitored during elastic loading and unloading. Very consistent results were obtained, with resolutions for each grain of approximately 10 μm in position, 0.05˚ in orientation and 80 μstrain. When averaging over all grains a resolution of 10 μstrain was obtained. In the second experiment it was demonstrated that the strain states of more than 1000 grains in a plastically deformed Cu specimen could be determined to an accuracy of 100 μstrain.

Determining grain resolved stresses in polycrystalline materials using three-dimensional X-ray diffraction

2010 ◽  
Vol 43 (3) ◽  
pp. 539-549 ◽  
Author(s):  
Jette Oddershede ◽  
Søren Schmidt ◽  
Henning Friis Poulsen ◽  
Henning Osholm Sørensen ◽  
Jonathan Wright ◽  
...  
Keyword(s):  
Near Field ◽  
Three Dimensional ◽  
Polycrystalline Sample ◽  
Polycrystalline Materials ◽  
Interstitial Free ◽  
Outlier Rejection ◽  
X Ray Diffraction ◽  
Positional Accuracy ◽  
X Ray ◽  
Elastic Loading

An algorithm is presented for characterization of the grain resolved (type II) stress states in a polycrystalline sample based on monochromatic X-ray diffraction data. The algorithm is a robust 12-parameter-per-grain fit of the centre-of-mass grain positions, orientations and stress tensors including error estimation and outlier rejection. The algorithm is validated by simulations and by two experiments on interstitial free steel. In the first experiment, using only a far-field detector and a rotation range of 2 × 110°, 96 grains in one layer were monitored during elastic loading and unloading. Very consistent results were obtained, with mean resolutions for each grain of approximately 10 µm in position, 0.05° in orientation, and 8, 20 and 13 × 10−5in the axial, normal and shear components of the strain, respectively. The corresponding mean deviations in stress are 30, 50 and 15 MPa in the axial, normal and shear components, respectively, though some grains may have larger errors. In the second experiment, where a near-field detector was added, ∼2000 grains were characterized with a positional accuracy of 3 µm.

The In Situ Study on the Micro-Structural Characters of IF Steel at Early Stage of Recrystallization Using High-Energy X-Ray

2008 ◽  
Vol 575-578 ◽  
pp. 972-977
Author(s):  
He Tong ◽  
Yan Dong Liu ◽  
Q.W. Jiang ◽  
Y. Ren ◽  
G. Wang ◽  
...  
Keyword(s):  
Annealing Temperature ◽  
Early Stage ◽  
High Energy ◽  
Fiber Texture ◽  
Interstitial Free ◽  
If Steel ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cold Rolled

High-energy synchrotron diffraction offers great potential for experimental study of recrystallization kinetics. A fine experimental design to study the recrystallization mechanism of Interstitial Free (IF) steel was implemented in this work. In-situ annealing process of cold-rolled IF steel with 80% reduction was observed using high-energy X-ray diffraction. Results show that, the diffraction intensity of {001}<110> and {112}<110> belong to α-fiber texture component decreased with the annealing temperature increased while {111}<110> did nearly not change and {111}<112> increased; the FMTH decreasing and d-space changing with annealing temperature increasing indicated that the residual stress relaxed completely during recovery.

Formability Evaluation of Galvannealed (GA), Hot-Dip Pure Zn Galvanized (GI), Electrogalvanized (EG) and Electrogalvanized Prephosphated (EGP) Interstitial Free Steelaluation

2005 ◽  
Author(s):  
W. J. Miranda ◽  
J. R. G. Carneiro ◽  
P. P. Brito
Keyword(s):  
Friction Coefficient ◽  
Crystallographic Texture ◽  
Large Scale ◽  
Pressure Range ◽  
Interstitial Free ◽  
If Steel ◽  
X Ray Diffraction ◽  
X Ray ◽  
Steel Sheets ◽  
Optic Microscopy

The formability of galvannealed (GA), hot-dip pure Zn galvanized (GI), electrogalvanized (EG), and electrogalvanized prephosphated (EGP) interstitial free (IF) steel sheets was studied. The phases in the Fe-Zn system were characterized using electronic and optic microscopy as well as X-ray diffraction. Behavior of the Zn coating when subjected to stretching, bending and drawing was also assessed. Comparison between the performance of large-scale industrial production of GA, GI, EG and EGP coated steels was made possible. The GI steels presented the best results, due to the predominantly basal crystallographic texture, lower friction coefficient with commercial oils and better press-forming response in the pressure range of 135-180kgf/cm2. It was also observed that the phosphate present in the EGP steels protected the structure of the EG coating, reducing the friction coefficient. Lastly, differences between the coatings, regarding stretching, bending and drawing, were confirmed.

scholarly journals USE OF DUST X-RAY DIFFRACTION IN THE CHARACTERIZATION OF PEROVSKITAS TYPE FERRITES

2008 ◽  
Vol 05 (9) ◽  
pp. 23-30
Author(s):  
Márcio DE PAULA ◽  
Regina Helena Porto FRANCISCO
Keyword(s):  
Solid State ◽  
Powder Diffraction ◽  
Structural Changes ◽  
Solid Phase ◽  
Orthorhombic Phase ◽  
Polycrystalline Sample ◽  
Cubic Phase ◽  
X Ray Diffraction ◽  
X Ray

The X-ray diffraction is one experimental method very important on characterization solids compounds. In the case of polycrystalline samples, the x-ray powder diffraction allows for the identification of the solid phase and the characterization of structural changes. The present paper was prepared any antiferromagnetic ceramic phases, bicalcic ferrite derivate (Ca2Fe2O5) by solid state reaction from pulverized reagents and mixed manually. These were heated in the Pt melting pan, in air oven at temperature between 1000 and 1450oC for 12h. The occurrence of reaction with reagents and the products obtained were identified and structurally characterized by X-ray diffraction by polycrystalline sample. Mixtures of regents CaCO3, SrCO3, BaCO3, Fe2O3, Nb2O5, Have been made with various symmetries: a) Ba2Fe2O5, b) CaBaFe2O5, c) Ba2FeNbO6, d) Ca2Fe2O5, (e) Ba2Nb2O7, (f) Ca2Nb2O7, (g) Sr2Nb2O7, (h) CaBaFeNbO6. The products obtained showed that O2 of the air participated of reactions by providing the anions oxides required for obtaining the cubic phase. The formation of this phase was also helped by the presence of barium and niobium, since in the absence of these elements, can be seen the formation of orthorhombic phase, characteristic of Ca2Fe2O5.

Synthesis and Characterization of Inorganic Clathrate-II Materials

2007 ◽  
Vol 1044 ◽  
Author(s):  
Matt Beekman ◽  
George S. Nolas
Keyword(s):  
Electrical Transport ◽  
Structural Response ◽  
Rietveld Analysis ◽  
Synthesis And Characterization ◽  
Type Ii ◽  
X Ray Diffraction ◽  
X Ray ◽  
New Type ◽  
Silicon And Germanium

AbstractPreliminary results from an investigation into the synthesis and characterization of silicon and germanium type II clathrates are reported. A series of NaxSi136 (0 < x < 24) clathrates was synthesized and characterized by powder X-ray diffraction and Rietveld analysis. The NaxSi136 lattice parameters are observed to first decrease, then increase with increasing Na content, indicating a non-monotonic structural response to Na filling. New type II Ge clathrate compositions Cs8Na16MyGe136-y (M = Cu, In) utilizing framework substitution are reported. Electrical transport measurements on a Cu substituted specimen indicate framework substitution modifies the transport properties of these materials. The potential type II clathrate phases possess for thermoelectric applications is discussed.

scholarly journals STRENGTH AND MICROSTRUCTURE OF COLD-ROLLED IF STEEL

2016 ◽  
Vol 22 (1) ◽  
pp. 35
Author(s):  
Anh-Hoa Bui ◽  
Hoang Le
Keyword(s):  
Steel Plates ◽  
Interstitial Free ◽  
If Steel ◽  
Low Carbon ◽  
X Ray Diffraction ◽  
Factors Affecting ◽  
Steel Sheets ◽  
Vacuum Technology ◽  
Cold Rolled ◽  
Soaking Temperature

<p>With the emerge of vacuum technology, it is possible to produce ultra low carbon (ULC) steels with carbon content of less than 0.005 %mass which is called interstitial free (IF) steels. In this study, strength and microstructure of IF steel after cold-rolling have been determined. The initial steel plates were cold-rolled using two different cold reductions (CR) as 80 and 90% in total, thereafter the steel sheets were cut into specimens for tensile test and optical microscopy. Ultimate tensile strength (UTS) of the cold-rolled steel was high (650¸807 MPa), but the elongation (EL) was low (3.5¸5.3%). Meanwhile, UTS of the annealed steels was decreased to 290 MPa when soaking temperature was 800<sup>o</sup>C because of stress relief and recrystallization. It was concluded that higher CR (more severe deformation) increased the strength but decreased the ductility of the IF steels. In consistence with micrograph of the steels, X-ray diffraction (XRD) results showed that microstructure of the cold-rolled and annealed IF steels was only ferrite. Textures, one of the most important factors affecting the recrystallization, were found in cold-rolled steels.</p>

The Use of Advanced Analytical Techniques for Characterization of the Chemical, Physical, and Crystallographic Nature of a Surface

1973 ◽  
Vol 31 ◽  
pp. 132-133 ◽  
Author(s):  
R. E. Herfert
Keyword(s):  
Surface Characterization ◽  
Analytical Techniques ◽  
X Ray Diffraction ◽  
Depth Of Penetration ◽  
X Ray ◽  
The Past ◽  
Transmission Electron ◽  
Scanning Electron

Studies of the nature of a surface, either metallic or nonmetallic, in the past, have been limited to the instrumentation available for these measurements. In the past, optical microscopy, replica transmission electron microscopy, electron or X-ray diffraction and optical or X-ray spectroscopy have provided the means of surface characterization. Actually, some of these techniques are not purely surface; the depth of penetration may be a few thousands of an inch. Within the last five years, instrumentation has been made available which now makes it practical for use to study the outer few 100A of layers and characterize it completely from a chemical, physical, and crystallographic standpoint. The scanning electron microscope (SEM) provides a means of viewing the surface of a material in situ to magnifications as high as 250,000X.

High Resolution Replication of Organoclay Surfaces

1982 ◽  
Vol 40 ◽  
pp. 576-577
Author(s):  
W. W. Barker ◽  
W. E. Rigsby ◽  
V. J. Hurst ◽  
W. J. Humphreys
Keyword(s):  
Clay Mineral ◽  
Organic Molecule ◽  
Organic Molecules ◽  
X Ray Diffraction ◽  
Xrd Pattern ◽  
X Ray ◽  
Naturally Occurring ◽  
Silicate Layers ◽  
Mineral Identification

Experimental clay mineral-organic molecule complexes long have been known and some of them have been extensively studied by X-ray diffraction methods. The organic molecules are adsorbed onto the surfaces of the clay minerals, or intercalated between the silicate layers. Natural organo-clays also are widely recognized but generally have not been well characterized. Widely used techniques for clay mineral identification involve treatment of the sample with H2 O2 or other oxidant to destroy any associated organics. This generally simplifies and intensifies the XRD pattern of the clay residue, but helps little with the characterization of the original organoclay. Adequate techniques for the direct observation of synthetic and naturally occurring organoclays are yet to be developed.

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