Density of stacking faults and twin boundaries in ultrafine-grained materials determined by X-ray line profile analysis

Tamás Ungár, Levente Balogh, Yuntian T. Zhu, Cheng Xu, Gábor Ribárik, Zenji Horita, Terence G. Langdon

    Research output: Chapter in Book/Report/Conference proceedingConference contribution

    3 Citations (Scopus)


    Planar faults, especially stacking faults and twins, can play an important role in the defect structure of ultrafme-grained materials. X-ray line broadening and line shift caused by planar faults is highly anisotropic as a function of the hkl indices, the anisotropy being qualitatively different from both strain and size anisotropy. This makes it possible to distinguish the line broadening components corresponding to planar faults, dislocations and subgrain size. The numerical procedure, the CMWP (convolutional multiple whole profile) method for the evaluation of diffraction patterns based on the model of dislocations and grain size for strain and size broadening, has been extended for the evaluation of planar faults present concomitantly with dislocations and subgrains. The effect of planar faults on diffraction profiles has been evaluated numerically by using the DIFFAX software. About 15.000 diffraction profiles have been produced for intrinsic, extrinsic and twin faults as a function of different hkl indices and planar fault concentrations. It was found that the numerically calculated diffraction profiles can be well simulated by Lorentzian functions as far as down to 104 relative intensities into the tails. Thus, about 15.000 simulated Lorentzians have been systematically parameterized for hkl fault types and fault densities, respectively, and the compiled parameter files have been incorporated into the CMWP numerical procedure; The dislocation structure, the subgrain size and size distribution and the densities of twin boundaries have been determined in specimens of Cu and Cu-Zn alloys processed by high-pressure torsion as a function of the distance along the radius of the samples.

    Original languageEnglish
    Title of host publicationUltrafine Grained Materials IV
    Number of pages8
    Publication statusPublished - 2006
    Event2006 TMS Annual Meeting - San Antonio, TX, United States
    Duration: Mar 12 2006Mar 16 2006

    Publication series

    NameTMS Annual Meeting


    Other2006 TMS Annual Meeting
    Country/TerritoryUnited States
    CitySan Antonio, TX

    All Science Journal Classification (ASJC) codes

    • Condensed Matter Physics
    • Mechanics of Materials
    • Metals and Alloys


    Dive into the research topics of 'Density of stacking faults and twin boundaries in ultrafine-grained materials determined by X-ray line profile analysis'. Together they form a unique fingerprint.

    Cite this