Hostname: page-component-586b7cd67f-rcrh6 Total loading time: 0 Render date: 2024-11-23T17:02:11.485Z Has data issue: false hasContentIssue false
  • English
  • Français

A Computer-Controlled X-Ray Diffractometer for Texture Studies of Polycrystalline Materials

Published online by Cambridge University Press:  06 March 2019

C. Richard Desper
C. Richard Desper*
Affiliation:
Army Materials and Mechanics Research Center, Watertown, Massachusetts
Get access

Abstract

The Picker Four-Angle Computer System (FACS-1), a computercontrolled x-ray diffractometer originally designed for single crystal studies, has been adapted for use with polycrystalline samples. The system is controlled by a PDP-8S, a small time-sharing computer with teletype input and output. Programs have been written to take advantage of the high degree of flexibility inherent in online computer control. Four basic operations are possible: (a) simple 2θ step-scanning with variable step width; (b) 2θ stepscanning with randomization of orientation; (c) determination of Legendre expansion coefficients for oriented specimens; and (d) determination of pole figures. In operation (a), data is gathered at a series of 2θ values at a prefixed count and/or time. In (b), the sample is rotated to average out orientation, giving the “randomized” intensity (2θ) at various 2θ values. The on-line computer reads the scaler and timer every two degrees of x rotation and forms the appropriate integrals for calculating (2θ) as the sample rotates. Operation (c) is an extension of (b): not only is (2θ) determined, but also various moments of the orientation distribution of the form , where Pn is the nth order Legendre polynomial. Operation (d) may be used to measure pole figures of sheet specimens in reflection or transmission, or of fibers or small particles. Optional modes of operation allow for (a) use of the Ross “balanced filter” technique; (b) integration across diffraction peaks by continuous scanning in 2θ, with background correction; and (c) application of absorption corrections.

Type
Research Article
Information
Advances in X-Ray Analysis , Volume 12: Seventeenth Annual Conference on Applications of X-ray Analysis, August 21-23, 1968 , 1968 , pp. 404 - 417
Copyright
Copyright © International Centre for Diffraction Data 1968

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

1. Roe, Ryong-Joon, “Description of Crystallite Orientation in Polycrystalline Materials. III. General Solution to Pole Figure Inversion”, J. Appl. Phys., 36, 1965, pp. 2024–2031.Google Scholar
2. Roe, Ryong-Joon, “inversion of Pole Figures for Materials Having Cubic Crystal Symmetry”, J. Appl. Phys., 37, 1966, pp. 2069–2072.Google Scholar
3. Bunge, H. J., “Zur Darstellung allgemeiner Texturen”, Z. Metallkunde, 56, 1965, p. 872.Google Scholar
4. Bunge, H. J., “The Orientation Distribution Function of the Crystallites in Cold-Rolled and Annealed Low-Carbon Steel Sheets”, phys. stat. sol., 26, 1968, p. 167–172.Google Scholar
5. Morris, P. R. and Heckler, A. J., “Crystallite Orientation Analysis for Rolled Cubic Materials”, in Advances in X-Ray Analysis Vol. 11, Plenum Press, New York, 1968, pp. 454-72.Google Scholar