Papers by Keyword: Pole Figure

Abstract: The Goss texture, or {110}<001>, shows soft magnetic property due to the <100>. Therefore, it is one of the most important texture in Si steels. The Goss texture is one of the shear deformation texture in steel which has bcc structure. During the asymmetric rolling, shear deformation is imposed on steel sheets. To obtain the Goss texture, the carbon and Si steel sheets were asymmetrically rolled by 50-85% reduction in thickness at room temperature and at 770 °C. The asymmetric rolling of steel sheets gave rise to the well-developed Goss texture to them.

Abstract: This research uses pellets of non- and sintered pure Nb and the superconducting intermetallic compound of Nb₃Sn. Sintering was undertaken at 700 °C for 96 hours. The texture data were obtained by using XRD Brüker D8 Advance equipped with gonio-texture and interpreted into namely inverse pole figures, pole figures, and orientation distribution function (ODF). In general, the pole figure analysis indicates that sintering process can lead to a change in the crystal orientation distribution from symmetric or random orientation into preferred orientation. Uni-axial compacting pressure in samples prior to sintering favors the appearance of a preferred orientation on a specific direction. However, this texture is not only retained upon subsequent sintering, but can become much more pronounced or weaker due to the crystal growth occurring at elevated temperatures. The main feature of initial texture for pure compacted Nb obtained in this study is Brass, S, and Copper with Brass being the maximum, whereas Cube and Goss appear as minor components. Upon sintering, it has been found that S, Brass, and Copper retained as the dominant ones, with S has been developed and being the maximum. On the contrary, a significant change in texture upon sintering has been obtained for Nb₃Sn, namely Copper, S and Brass components with minor Cube and Goss components for initial condition, and Copper, Goss and Brass with minor Cube and S components for sintered sample. It is noted that the Copper intensity of Nb₃Sn decreases from 50.4 to 39.3 multiple of random distribution (m.r.d) for the initial and upon sintering conditions, respectively.

Abstract: Possibilities for depth resolving texture analysis applying energy-dispersive X-ray synchrotron diffraction are presented. Exploiting the advantage of having the complete diffraction spectra observed in a fixed but arbitrary measuring direction, two different approaches for high spatial resolution analyses are discussed. The first allows fast access of intensity distribution from plan families {hkl} parallel to the sample surface. The latter allows successful pole figure assessment despite the complex and time consuming slit alignment and data processing. The size of the sampling volume can be tailored to the sample problem ranging from 10 to 100 µm in height or more if necessary.

Abstract: Microstructures of the Fe-29.6at%Pd alloy ribbons were observed with an X-ray diffractometer and a transmission electron microscope. The X-ray diffraction profiles at room temperature showed that the ribbon consists of FCT martensitic phase and FCC parent phase. Moreover, the ribbon exhibits a strongly 200-oriented texture analyzing with pole figure measurements. TEM bright field images for the cross section of the ribbon showed high-density striation in the FCT martensite variants. Twin-related two sets of reflections were observed in the SAED patterns taken of the FCT martensite variants. _FCT was nearly parallel to the thickness direction according to the analysis of the SAED patterns. This result corresponds to the pole figure measurements.

Abstract: Under rolling of Ti-48%Ni-2%Fe single crystals in the phase B2 at 350oC the twinning is the main mechanism of plastic deformation by many initial orientations of these single crystals, as texture data show clearly. Splitting of initial maxima in the stereographic projection of single crystal into several new ones is an evident manifestation of twinning. But this mode of reorientation is observed only at initial stages of rolling, when deformation degrees do not exceed ~10-15%. A geometrical analysis of pole figures for rolled single crystals showed, that at the used rolling temperature the preferable twinning planes there were {114} and {118}.

Abstract: This work describes the development of texture during hot rolling of two alloys namely, Ti-12Nb and Ti-16Nb. The alloys have been unidirectionally hot rolled to 80 % reductions at 800°C and air cooled. Both the alloys show the presence of a² (orthorhombic) and small volume fraction of b (bcc) phases in hot rolled condition. The alloy Ti-12Nb exhibit moderate intensity texture while the alloy Ti-16Nb displays quite strong texture. The high overall intensity of texture in alloy Ti-16Nb in 80 % HR specimen can be attributed to the presence of large volume fraction of b phase in comparison to that of the alloy Ti-12Nb. This has been extended to study the textural changes after b solution treatment. This heat treatment consists of two types of phase transformations that are a² ® b ® a² and a² ® b ® a after water quenching and furnace cooling from β phase field.

Abstract: The principle and method of analysis of the crystallographic planes standard equator plane projection are described in this article. Under different technological using similar Fe-3% Si silicon steel samples, conventional grain oriented silicon steel, 1150°C conventional hot-rolled grain oriented silicon steel and non-oriented silicon steel are obtained, respectively. Their pole figures of {200} planes for the samples are also obtained with XRD. The results state that the conventional Fe-3% Si grain oriented silicon steel has good Gauss texture, and 1150°C conventional hot-rolled grain oriented silicon steel has weak Gauss texture, meanwhile, non-oriented silicon steel has no Gauss texture, which prove the process has great the effect on the texture.

Abstract: The Sr0.75La0.25Fe11.75-xCo0.25ZnxO19 hexaferrites are prepared by the ceramic process. Influences of the substitution of Zn2+ ions on crystallographic texture have systematically been investigated by pole figure analysis. The (008) and (107) pole figure shows that the pole intensities are axisymmetric at the center of c axis. With the increase of x, the lattice parameters a and c increase gradually till x=0.15. Excessive Zn2+ addition induces the much coarse grain. The easy-axis alignment of grains decreases from 77.5% to 75.5% for the substitution of Zn2+ ions from 0 to 0.25. When Zn2+ content was from 0 to 0.25, the magnetic properties of Br and (BH)max were increased, while Hcb and Hcj were decreased till x>0.2.

Abstract: Technology developments of implant composition and manufacture have been used in the medical field. Several different implants have been developed with varying degrees of commercial success. As a long-term establishment is a measure of the therapeutic success, it is necessary to use biocompatible implants in order to have good mechanical and fracture resistance of new bone reconstructed at the interface with the implant. Titanium (Ti-Al-4V) implants coated with hydroxyapatite (HAp), Ca10 (PO4)6 (OH)2 are widely used in orthopedic applications in order to obtain a stable and functional direct connection between the bone and the implant. At the implant-bone interface the new bone reconstituted after implantation must have the same orientation as the natural bone in order to accept the implant. Therefore we studied the texture and the crystallinity of the new bone crystals reconstituted at the interface applying by high-energy synchrotron radiation on beamline ID15 at ESRF in Grenoble, France.

Abstract: The exoskeleton of the crustacean Homarus americanus, the American lobster, is a biological multiphase composite consisting of a crystalline organic matrix (chitin), crystalline biominerals (calcite), amorphous calcium carbonate and proteins. One special structural aspect is the occurrence of pronounced crystallographic orientations and resulting directional anisotropic mechanical properties. The crystallographic textures of chitin and calcite have been measured by wide-angle Bragg diffraction, calculating the Orientation Distribution Function (ODF) from pole figures by using the series expansion method according to Bunge. A general strong relationship can be established between the crystallographic and the resulting mechanical and physical properties.