Papers by Keyword: ODF

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Authors: Roumen H. Petrov, Orlando León-García, Hemant Sharma, Kyoo Young Lee, S. Eric Offerman, Leo Kestens
Abstract: Texture formation during an austempering treatment of a TRIP-assisted steel was studied by in-situ texture measurements with a high energy source (synchrotron). Samples from a cold rolled sheet were subjected to a complete heat treatment cycle for TRIP steels including reheating to the intercritical (α+γ) temperature region, isothermal soaking and bainitic holding (austempering) at 400°C for 600s. At specific points of the thermal cycle {200}γ, {220}γ {222}γ, {331}γ and {200}α, {211}α and {220}α Debye rings were recorded and the corresponding incomplete pole figures were calculated. The latter were used to derive the orientation distribution functions (ODFs) of BCC and FCC phases at specific steps of the annealing process after assuming the orthotropic sample symmetry. The acquired data for the texture evolution during the α–γ–α phase transformation showed that during the reheating for intercritical annealing the gamma phase with {011} orientation is among the first to nucleate from the recrystallized α phase during heating and the Goss and Cube orientations are among the principal gamma phase components which transform to BCC phase after cooling.
Authors: Kurt Helming, R. Tamm, B. Fels
Authors: T.I. Bucharova, T.M. Ivanova, D.I. Nikolayev, T.I. Savyolova
Authors: Robert A. Schwarzer
Abstract: The surface texture in fcc metals has been investigated after wear tests in a dry-running pin-on-disk test machine and after metallographic surface grinding. X-ray pole figures have been measured at a low angle of incidence of the primary beam, using an area detector for recording the diffraction patterns. SAD pole figures have been acquired on cross sections on-line in the TEM for examining the gradient of texture and microstructure beneath the surface. The XRD and SAD pole figures have been evaluated by ODF calculation. Wear and abrasion textures are distinctly different both for copper and bronze as well as for brass.
Authors: K.Gerald van den Boogaart, Ralf Hielscher
Abstract: A long time has past since the introduction of the harmonic method for the reconstruction of the ODF from polefigure measurements, and it has been replaced by discrete methods of inversion, because of its incapability with respect to ghost effects. The harmonic method is still not in its best possible state: it disregards the high order harmonics; it disregards measurement errors and therefore gives suboptimal results; it does not provide standard errors, neither for the C-coefficients nor for the ODF; and there are the ghost effects. However, the harmonic method is a well established inversion method and it can improved at these points. Statistical considerations based on geostatistics and a model of the unknown ODF as a random function in a Baysian approach yields an inversion method, which can be characterized as a smoothing spline method. This new method is statistically optimal among all linear methods and resembles favorable features of the harmonic method in an improved way. It provides an optimal linear reconstruction of the even part of the ODF. It does not truncate the harmonic series expansion at a fixed level, but accounts for every even harmonic space in an optimal way with respect to its signal to noise ratio in the polefigure measurements. The method applies for irregularly sampled and incomplete pole figures. The method accomplishes standard errors for the ODF and the C-coefficients. Discrete inversion methods, explicitly or not, reconstruct the odd harmonic part of the function based on the principle of maximum entropy. Based on the theory of exponential families a continuous odd part (and the truncated even part) can be computed based on the entropy principle and the C-coefficients estimated by the spline method.
Authors: Kazuto Okayasu, Hiroki Takekoshi, Hiroshi Fukutomi
Abstract: Uniaxial compression deformation is conducted on solid solution Al-3mass%Mg and Al-3mass%Mg-0.2mass%Sc with Al3Sc precipitates in the strain rates ranging from 1.0×10-4s-1 to 5.0×10-3s-1 at 723K. High temperature yielding is observed. Fiber texture is constructed in all the deformation conditions. While the main component of the fiber texture changes from {011} to {001} in Al-3mass%Mg alloy with an increase in strain rate, no big change in texture main component is seen for Al-3mass%Mg-0.2mass%Sc alloy with Al3Sc precipitates. It is experimentally shown that the development of {001} fiber texture can be attributed to the grain boundary migration.
Authors: Zi Li Jin, Wei Li, Yi Ming Li
Abstract: With the help of orientation distribution function (ODF) analysis, experiments of different hot band grain microstructure 0.33% silicon steel were cold-rolled and annealed in the laboratory,to study the effect of the microstructure hot-rolled steel strip for cold rolled non-oriented silicon steel microstructure and texture of recrystallization annealing. The results show that hot rolled microstructure on cold rolled Non-Oriented Electrical Steel cold-rolled sheet evolution of texture and recrystallization have important influence, the quiaxed grain structure of steel by cold rolling and recrystallization annealing, the recrystallization speed than the fiber grain-based mixed crystals recrystallization fast , With the equiaxed grains made of cold rolled silicon steel after annealing the {110} texture components was enhanced and {100} texture components weakened. Different microstructure condition prior to cold rolling in the recrystallization annealing process the texture evolution has the obvious difference, the equiaxial grain steel belt cold rolling and annealing, has the strong crystal orientation. This shows that the equiaxed grain when hot microstructure is detrimental to the magnetic properties of cold-rolled non-oriented silicon steel to improve and increase.
Authors: Takehito Saitou, Makoto Koizumi, Hirosuke Inagaki
Authors: Su Young Kim, Il Dong Choi, Ik Min Park, Kyung Mok Cho
Abstract: The influence of the texture development in Ti-added (0.03, 0.05 and 0.07wt%) IF (Interstitial Free) steels on physical properties, especially ř -value was investigated. It was intended to determine the proper Ti content for the promotion of deep drawability as well as mechanical properties of IF steels. The precipitation behavior in the IF steels was clarified with the aid of computer simulation. The quantitative X-ray analysis on the texture development of IF steels was performed using pole figure and orientation distribution function measurement. For the IF steel with the composition of 0.025C, 0.070Mn, 0.002N and 0.007S, the optimum Ti content was found to be 0.05wt%.
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