Neutron diffraction pole figure measurements for the microstructure analysis of meteorites

1989 ◽  
Vol 156-157 ◽  
pp. 675-677 ◽  
Author(s):  
S. Höfler ◽  
W. Schäfer ◽  
G. Will
Keyword(s):  
Neutron Diffraction ◽  
Pole Figure ◽  
Microstructure Analysis

scholarly journals Volume Texture of a Deformed Quartzite Observed With U-Stage Microscopy and Neutron Diffractometry

1999 ◽  
Vol 31 (4) ◽  
pp. 239-248 ◽  
Author(s):  
H. Ghildiyal ◽  
E. Jansen ◽  
A. Kirfel
Keyword(s):  
Neutron Diffraction ◽  
Pole Figure ◽  
North West ◽  
Pole Figures ◽  
Slip Planes ◽  
Subsequent Calculation ◽  
Kaoko Belt ◽  
Universal Stage ◽  
Active Slip

The volume texture of a naturally deformed quartzite from the Kaoko belt, North-West Namibia, has been analysed by both universal stage microscopy and neutron diffraction. Universal stage microscopy is restricted to the determination of the base pinacoid preferred orientation in quartzite. For a more complete description of the texture, the orientations of additional crystal planes, such as first and second order prisms as well as positive and negative rhombs, must be known. Neutron methods allow the evaluation of pole figures of all Bragg reflecting planes, of which those of the first order prisms being considered to be the most active slip planes, are of particular interest. Drawbacks of neutron diffraction, i.e. the faking of an eventually absent inversion centre and lack of resolution, can be overcome by pole figure inversion and subsequent calculation of desired pole figures. Both, universal stage microscopy and neutron diffraction yield well comparable results, of course only with respect to the pole figure of the c-axis.

Neutron diffraction pole figure measurements on iron meteorites

1988 ◽  
Vol 90 (1) ◽  
pp. 1-10 ◽  
Author(s):  
Sabine Höfler ◽  
Georg Will ◽  
Hanns-Martin Hamm
Keyword(s):  
Neutron Diffraction ◽  
Pole Figure ◽  
Iron Meteorites

On the Development of Copper Textures – Neutron Diffraction Control over a Period of 12 Years –

2004 ◽  
Vol 443-444 ◽  
pp. 239-242 ◽  
Author(s):  
E. Jansen ◽  
Wolfgang Schäfer ◽  
A. Kirfel ◽  
J. Palacios
Keyword(s):  
Data Analysis ◽  
Neutron Diffraction ◽  
Pole Figure ◽  
Texture Component ◽  
Copper Specimen ◽  
Continuous Decrease ◽  
Cold Rolled

The longtime stability of copper textures has been periodically monitored over 12 years by neutron diffraction pole figure measurements on a cold rolled and a partially recrystallized copper specimen, always using the same diffractometer and the same procedure of data analysis. The texture component fractions of 'rolled' copper suffered a continuous decrease over about 8 years and seem to reverse since then. The decrease is accompanied by recrystallization from initial 3 to 34 vol. % at present. Texture changes in the partially recrystallized specimen are less pronounced. In this sample, the fraction of random orientations changed from initially 11 % to 31 % over the about first six years and followed by a decrease to 24 % at present.

scholarly journals Multi-scale phase analyses of strain-induced martensite in austempered ductile iron (ADI) using neutron diffraction and transmission techniques

2020 ◽  
Vol 56 (8) ◽  
pp. 5296-5306
Author(s):  
Xiaohu Li ◽  
Sergio Soria ◽  
Weimin Gan ◽  
Michael Hofmann ◽  
Michael Schulz ◽  
...  
Keyword(s):  
Neutron Diffraction ◽  
Pole Figure ◽  
Ductile Iron ◽  
Imaging Techniques ◽  
Austempered Ductile Iron ◽  
Quantitative Phase Analysis ◽  
Strain Induced Martensite ◽  
Phase Quantification ◽  
Pole Figure Data ◽  
Multi Phase

AbstractThe content of strain-induced martensite in austempered ductile iron has been quantitatively determined using three different kinds of neutron methods: (1) high-resolution powder diffraction with subsequent standard Rietveld refinement, (2) phase quantification using pole figure measurements and (3) Bragg edge neutron transmission. The accuracy and scope of applications of these neutron diffraction and imaging techniques for phase quantification have been compared and discussed in detail. Combination of these methods has been confirmed as effective for dealing with problems like peak overlap in multi-phase materials and texture formation after plastic deformation. Further, the results highlight the potential of using single peak pole figure data for quantitative phase analysis with high accuracy.

scholarly journals Texture Investigations by Neutron Time-of-Flight Diffraction

1989 ◽  
Vol 10 (4) ◽  
pp. 309-323 ◽  
Author(s):  
K. Feldmann
Keyword(s):  
Neutron Diffraction ◽  
Pole Figure ◽  
Magnetic Moments ◽  
Time Of Flight ◽  
Inverse Pole Figure ◽  
X Rays ◽  
Forming Process ◽  
Time Of Flight Diffraction ◽  
Neutron Time ◽  
Neutron Absorption Cross Section

For the majority of isotopes the thermal neutron absorption cross section is two or more orders lower than that for X-rays. This makes neutron diffraction well-suited for bulk texture investigations. Some characteristics of neutron diffraction are discussed. The principles of neutron time-of-flight diffraction are described. The pole figure determination by means of TOF technique is considered. The main parameters of the present Dubna texture facility are given. Further developments of the experimental technique are considered. The application of the TOF technique for inverse pole figure measurement is discussed as an approach to direct observation of the texture forming process. The magnetic moments of neutrons can be used to study magnetic textures. Two different techniques are discussed.

Rietveld texture analysis of Dabie Shan eclogite from TOF neutron diffraction spectra

2001 ◽  
Vol 34 (4) ◽  
pp. 442-453 ◽  
Author(s):  
H.-R. Wenk ◽  
L. Cont ◽  
Y. Xie ◽  
L. Lutterotti ◽  
L. Ratschbacher ◽  
...  
Keyword(s):  
Neutron Diffraction ◽  
Texture Analysis ◽  
Pole Figure ◽  
Rietveld Method ◽  
Orientation Distribution ◽  
Central China ◽  
Harmonic Method ◽  
Dabie Shan ◽  
Orientation Distributions ◽  
Pulsed Neutron

Orientation distributions of garnet and omphacite in eclogite from the ultra-high pressure Dabie Shan belt in east-central China were determined from neutron diffraction data by the Rietveld method. Diffraction spectra were recorded in 16 sample orientations with seven detectors, with a kappa-geometry texture goniometer at the time-of-flight (TOF) neutron facility at the Intense Pulsed Neutron Source (IPNS). The textures of the two minerals were extracted simultaneously from 16 × 7 = 112 diffraction spectra, covering a large portion of the pole figure. The texture analysis was performed both with the Williams–Imhof–Matthies–Vinel (WIMV) method and the harmonic method, implemented in the program packageMAUD. The incomplete pole-figure coverage introduced artificial oscillations in the case of the harmonic method. The discrete WIMV method produced better results, which illustrate a more or less random orientation distribution for cubic garnet. Apparently elongated grains turned out to be layers of randomly oriented crystals. Monoclinic omphacite displays a sharp texture, with [001] parallel to the lineation direction. The texture data obtained by neutron diffraction were verified with EBSP (electron backscatter pattern) measurements.

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