Papers by Keyword: Pole Figure

Abstract: The objective of the present work is to study of errors on measured pole figures of hexagonal materials. We used neutron time-of-flight (TOF) technique for texture measurements and obtained spectra for estimating of error values of measured pole figures. Peak profile analysis of an each individual spectrum allows gain pole figure value itself and the corresponding error at each pole figure point as well. Such results could be obtained for measurements on stationary source of radiation with the usage of a position sensitive detector.

Abstract: The mathematical method of the texture function restoration according to diffraction experiment is offered. The texture function is represented as superposition of standard texture functions with the identical dispersions, located on a regular three-dimensional grid in orientation space. Applicability of the method is shown by model examples and in an example of a cold rolled texture of a copper sheet.

Abstract: A new method of computing of normal distributions [1] on rotation groups is suggested. Monte Carlo method allows to calculate the orientation of grains function (ODF) and correspondent pole figures (PFs) using approximation by normal distributions [2]. The developed Monte Carlo method is applied for construction of PFs mathematical statistical model corresponding to experimental measurement. This model is based on statistical simulation of normal distributions on SO(3) group for discrete representation of pole figures. It is possible to calculate effective physical properties of polycrystals using the given discrete representation. The mathematical simulation for texture with two components of polycrystalline sample with hexagonal symmetry is developed. Two experimental PFs } 0 1 10 { and } 0002 { for Be measured by X-ray experiment are being used. For this case the effective property as a tensor of elastic compliance was calculated. The mathematical simulation of PFs also allows to determine the statistical errors of pole figures measurement.

Abstract: This article presents the results of texture investigations of Zircaloy-4 tubes. Neutron diffraction and inversion pole figures were used to chracterize the texture of samples. The main interest is given to the analysis of texture changes under different tensile test conditions including tensile force direction, annealing temperature and tensile test temperature. Four different specimens of different orientation to the tube axis were tested.

Abstract: Method to process neutron time of flight spectra for extracting texture information is suggested. Local peak fit is used to gain integral peak intensities as well as errors of fitted peak parameters. The usage of the method illustrated on spectra collected for Mg sample measured at Dubna on IBR-2 pulsed reactor at SKAT texture diffractometer. Reconstructed pole figures and corresponding errors are presented and discussed. It is important to underline that obtained errors are independent of the further method of pole figure processing.

Abstract: With area detector X-ray diffraction system, the orientation of superconductor films and their relationships with substrates can be easily examined. For YBCO high temperature superconductor films having complex crystalline orientation relationship fore and after melting process, 2-dimesional X-ray diffraction provides us much more information than common X-ray diffraction. This is very helpful for understanding the peritectic reaction during melting process because the growth mechanism of Y211 crystalline can be explained from its orientation information. Y211 phrase in the film and its orientation relationship with YBCO phase and MgO substrate have been analyzed at first. It is found that Y211 crystalline is well match with both MgO substrate and YBCO parent phase. Then the melting process of YBCO has been discussed from the view of the orientation relationship between each phase.

Abstract: We studied the effects of the processing variables on the texture development of Ni tapes prepared from Ni powder compact rods. The Ni power was compacted into rods by cold isostatic pressing(CIP). The CIP-processed Ni rods were sintered for densification and made into Ni tapes of 100 microns by cold rolling. For the development of a cube texture, the rolled Ni tapes were annealed at various temperatures. The brass texture was converted into a cube texture during annealing and the degree of the formed cube textured was dependent on the annealing temperature. We analyzed the (200) cube texture by X-ray diffraction and pole figure analysis and EBSD(Electron beam backscattered diffraction pattern).