Texture & Residual Stress Reference Samples

Texture analysis based on experimental pole figures registered by the X-ray diffraction techniques both by the transmission method (Decker, Asp and Harker, 1948, J.Appl. Phys., 19, 388 ) and by the back-reflection one (Schulz, 1949, J.Appl. Phys., 20, 1033) needs appropriately prepared input data.

Due to defocusing effects, background of diffraction signal (non-coherent scattering), changeable penetration depth (statistics of counts), etc., a suitable correction of experimental data should be assured. Such a refined data set in the form of the experimental, corrected and normalized pole figure(s) is a basis of texture analysis. Applying the suitable calculating procedures enable to obtain the orientation distribution function (ODF) and then the complete pole figures or the inverse ones. Verification of the experimental conditions of measurement and correction of the rough texture data should be done on the basis of data collected on the reference samples for analysis of crystallographic texture.

Texture Reference Samples

Thanks to the reference samples, the imperfections in the geometrical arrangement of texture goniometer, correctness of beam optics set-up, and regularity of detection of diffraction effects can be verified. Each of the kit texture standards contains following reference samples for analysis of crystallographic texture:

  • texture free - random orientation distribution (powdered sample),
  • texturized with orthorhombic sample symmetry (massive sample),
  • texturized with triclinic sample symmetry - (massive sample).
  • Each of the set of texture standards has own unique serial number and hermetic container. The name of standard samples is "BK".

    Samples are in form of metal disks of 27 mm in diameter and of ca. 6 mm in thickness. The reference samples have a circles form of 20 mm in diameter. Each of the samples is surrounded by an outside metal ring with a suitable colour marker (dots) placed on its co-sample surface. The markers indicate the Longitudinal Direction which together with the Transverse Direction and Normal one determines the sample framework (LD, TD, ND) established as it is shown in Table below (table contains also others details by way of example for the austenitic stainless steel standards):

    Schematic view with ascribed framework (LD, TD, ND) Type of marker Description of Figures Related Filenames (LaboTex format)* Crystallographic Lattice Sample Symmetry
    one dot Austenite-powder Austenite-powd_.epf Austenite-powd.epf Austenite-powd_.pow Austenite-powd.pow cubic arbitrarily chosen
    two dots Austenite-ort Austenite-ort_.epf Austenite-ort.epf cubic orthorhombic
    three dots Austenite-tri Austenite-tri_.epf Austenite-tri.epf cubic triclinic
    • *) FileName_ - denotes experimental data corresponding to intensity of diffraction peak (by PIM).
    • *) FileName - denotes experimental data corresponding to integrated intensity of peak profile (by IM).

    In the case of the powdered reference sample, because of lack of any planar anisotropy, the LD direction can be chosen arbitrarily during measurement and data processing procedures. Marker on powdered samples indicates direction of mounting in goniometer analogically as LD direction for massive samples.

    Experimental:

    The measurable areas of the reference samples (top sample surface) are homogeneous from the texture viewpoint and have been prepared for registration of the diffraction effects in the backreflection mode by the Schulz method. Because of the measurement technique of the backreflection pole figures (tilting the sample and its rotation around the normal direction), recommended beam size (the largest dimension of its cross section) should not exceeds the values given in table:

    Range of pole figure (alpha angle) Recommended beam size [mm]
    0 ÷ 75° 5.1
    0 ÷ 80° 3.4
    0 ÷ 85° 1.7

    If the largest beam size will be applied, the additional diffraction effects coming from the external metal ring of the reference sample can be registered. To eliminate the undesirable effects, a suitable numerical procedure or a shaded mask should be applied. A global crystallographic texture of the reference samples are analyzed by the Accredited Testing Laboratory in the field of texture analysis. The laboratory meets requirements of the European Norm EN ISO/IEC 17025. For initial data processing a DAMfit (Bonarski, 1999) computer program has been used. The DAMfit package enables to process the rough experimental data collected in a pseudo Position-Sensitive Detection (pPSD) mode of the diffraction effect (Bonarski et al., 2000). The pPSD consists in registering the intensity of the diffracted beam in the chosen angular range, using a scanning Theta-2Theta or Omega-2Theta mode. As a result of such process a diffraction profile is obtained. Then, the optimal curve of a theoretical distribution according to: Gauss, Lorenz (Couchy), Modified Lorentz or Marlos & Thomas is fitted to each of the profile, and the integrated intensity is a value of the experimental pole figure in a determined point. This procedure eliminates also the effect of presence of other phases. Such integrating method (IM) (see the LaboTex manual Pole Figure: Plot and Registration Conventions) was applied in texture measurements. Independently of the integrated intensity, the peak intensity can be applied to estimate the measured pole figure too. The way, termed here as a peak intensity method (PIM) represent the registration mode by means of a "point" counter. It should be noticed that the IM is more precise texture measurement technique then the PIM one. Finally, the DAMfit program prepares input data for the LaboTex computer package. Applying both the integrating method of registration and correcion by means of the random (texture free) sample assures obtaining a reliable "device-independent" pole figures for quantitative texture analysis. The delivered reference samples and the attached results allow evaluating the correctness of the procedure of texture analysis applied in your laboratory. The measurement details, files with data and results of the texture analysis are on the CD and in the brochure.

    The package with Texture Standards includes the following:

    • Standard samples (in triclinic sample symmetry and orthorhombic sample symmetry) (in hermetic(s) container(s));
    • "Random" sample(s) (in hermetic container);
    • Manual - brochure;
    • Pole figures plots (in manual);
    • ODF plots (in manual);
    • Inverse pole figures plots (in manual);
    • Files containing experimental pole figures (evaluated by PIM, EPF format) (on CD);
    • Data for defocussing correction: files containing "random" (powder) pole figures files (evaluated by PIM and IM, POW format) (on CD);
    • Files containing pole figures (evaluated by IM, EPF format) (on CD);
    • Report from Accredited Testing Laboratory (in manual);
    • All information about Accredited Testing Laboratory which made measurements - Name, Address, Number of Acreditation Certificate of Testing Laboratory (Laboratory meets requirements of the European Norm EN ISO/IEC 17025), Acreditation areas, Number of Report (in manual);
    • Recommended storage conditions & warranty (in manual);
    • Serial Number of Standard (in manual);
    • Quality of powder samples (texture free): Texture Index below 1.1 (Texture Index = 1.0 for perfect texture free sample);
    • Container(s) (hermetic);
    • Additional plots or files (on demand);
    • Special LaboTex version (limited) for analysis of standards (on demand).

    Recommended storage conditions:

    The reference samples for texture analysis of crystallographic texture have been designed and prepared to give years of stabile materials structure and safe usage in the industrial and research laboratories. As with all materials standards, however, there are a few basic precautions that should be taken to avoid damage:

    • Read the documentation carefully and save it for future reference.
    • Keep the reference samples into the delivered metal box when the measurements are not performed.
    • Keep in dry at stable temperature, protect it before direct heat/cool sources, such as radiators/refrigerator, and avoid mechanical shocks.
    • Do not insert additional things into the sample box.
    • Do not touch the measurable surface of the samples.
    • Apart from the routine maintenance, like careful wiping the sample surface by the enclosed cloth disk or clean it using alcohol - if necessary - delicate polishing by a fine-grain diamond paste, do not try to make any other treatment of the samples.
    • Use the reference samples for the X-ray examination only.
    Standard samples with container have the weight of about 310 g.

    The Types of the Texture Standards

    reference samples for analysis of crystallographic texture
    Material/Type Description
    Al Aluminium samples: triclinic sample symmetry, orthorhombic sample symmetry, "random"
    Ti Titanium (alpha,hcp) samples: triclinic sample symmetry, monoclinic/orthorhombic sample symmetry, "random"
    Steel (ferritic, bcc) samples: triclinic sample symmetry, orthorhombic sample symmetry, "random"
    Steel (austenitic, fcc) samples: triclinic sample symmetry, orthorhombic sample symmetry, "random"
    Cu (alloy) samples: triclinic sample symmetry, orthorhombic sample symmetry, "random"
    All Standards samples: triclinic sample symmetry, orthorhombic sample symmetry, "random"
    Texture "Free" Samples and Special Samples
    "Random" samples (A) texture free samples: Aluminium, Titanium, Ferritic Steel
    "Random" samples (B) texture free samples: Aluminium, Austenitic steel, Ferritic Steel
    "Random" samples (C) texture free samples: Austenitic steel, Ferritic Steel, Cu-Al
    "Random" samples (D) texture free samples: Austenitic steel, Ferritic Steel, Titanium
    "Random" samples (ALL) texture free samples: Austenitic Steel, Ferritic Steel, Titanium, Cu-Al, Al
    Special Cu (SCU) samples (Copper): "random" + two samples with different volume fraction of <110>fiber component

    red - texturized with orthorhombic sample symmetry (after defocusing correction),

    blue - powder sample ("random" - texture free) sample (after defocusing correction).

    Example: Section of pole figures for azimuthal angle=0.0: Aluminium samples.

    Image made by LaboTex.

    Example: Pole figures Aluminium samples - texturized with orthorhombic sample symmetry, Image made by LaboTex.
    Example: ODF Ferritic stainless steel - texturized with monoclinic sample symmetry, Image made by LaboTex.
    Example: Pole figures 3D - defocusing effect for the powder sample Strong defocusing effect (left) , slight defocusing efect (right) Powder sample - Ferritic Stainless Steel (reflection XRD technique, axial symmetrization), left - pole figure {110} (2Theta=52.3 deg.) , right - pole figure {211} (2Theta=99.5 deg.) Radial angle range: 0 to 75 degrees, Image made by LaboTex.
    Example: Pole figures - Sections. Magnesium "random" samples. Errors of recalculated pole figure (red line - no defocusing correction, blue line - with correction by BK Standard sample, black line - perfect "random" sample). Calculation of RPF and image made by LaboTex

    Residual Stress Reference Samples (X-ray diffraction technique)

    BK-RSRS - The residual stress reference sample
    Denotation Material/Type Description of kit
    BK-RSRS-Ni Nickel 1) Fixed Ni powder sample Negligible residual stresses for zero-point calibration
    2) Electrodeposited Ni coating on steel substrate Simple stress state with equal principle stresses σ1 = σ2 for verification of basic techniques like directional sin2ψ measurements
    3) Grinded bulk Ni sample Stress state with σ1 ≠ σ2 for verification of principle stresses estimation techniques like multidirectional sin2ψ measurements or generalized least-squares stress tensor fitting
    4) Grinded bulk Ni sample with electrodeposited Ni coating Sample with essential and known stress and texture depth gradient, both rapidly changing their character within 5.0 μm of material’s thickness – sample established by combining the properties of standards number 2 and 3, designed for validation of advanced techniques of stress and texture investigations in the thin coatings
    The package with the Residual Stress Reference Samples includes the following:
    • Standard samples (in hermetic container(s));
    • Manual - brochure;
    • Report from Accredited Testing Laboratory (in manual);
    • All information about Accredited Testing Laboratory which made measurements - Name, Address, Number of Accreditation Certificate of Testing Laboratory (Laboratory meets requirements of the European Norm EN ISO/IEC 17025), Accreditation areas, Number of Report (in manual);
    • Recommended storage conditions & warranty (in manual);
    • Serial Number of Standard (in manual).

    Bibliography

    • Bonarski J.T.; (1999) Computer programms: DAMfit
    • Bonarski J.T., Wróbel M. and Pawlik K.; (2000). Quantitative phase analysis of duplex stainless steel using incomplete pole figures, Materials Science and Technology Vol. 16 No 6, p. 657-662.
    • Decker B.F., Asp E.T. and Harker D.; (1948). J.Appl. Phys., 19, 388.
    • Pawlik K., Ozga P.; (1999). LaboTex: The Texture Analysis Software, Göttinger Arbeiten zur Geologie und Paläontologie, SB4.
    • LaboTex. (1997-2004). The Texture Analysis Software, by LaboSoft s.c.
    • Schulz L.G.; (1949). J.Appl. Phys., 20, 1033.

    Hardware

    Custom Measurement Software (CMS) - offered by IMMS PAS:
  • Equal Solid Angle (ESA) measurement grid,
  • Ability to registration of diffraction reflections at a specified information depth,
  • The CMS package extends the Bruker D8 Discover to a tomographic XRD-system,
  • On-line visualization of registering pole figures with possible definition of the spectral range of the interest for imaging, baseline subtraction, real-time color scale modifications and view of the measured spectrum for each grid point or the pole figure value at any coordinates,
  • Pole figures registered in one type of measurement-grid can be easily transformed to the other grids with different parameters,
  • Arbitrary software rotation of the registering (or earlier registered) pole figure and its extraction for export and further analysis related to a chosen, valuable part of the obtained diffraction spectrum, as well as by the LaboTex-package,
  • Ability to defining a big variety of results or procedure correction,
  • X/Y loops in control scripts with automatically- or manually defined coordinates of measurement areas on the sample surface,
  • Implementing the correction of measurement time,
  • Providing an open and easy to read collected data format (in ASCII text file) for the experimentally registered pole figures with a possibility to export to the *.epf format accepted by the LaboTex-package,
  • The Buyer of the CMS package can also benefit from future variant of the ESA-grid developed especially to incorporate a procedure of stress measurement simultaneously with registration of related pole figure(s) in one experimental session without increasing time, including a tomographic texture- and stress measurements,
  • more about X-ray texture tomography
  • Seifert/GE Sensing & Inspection Technologies

    XRD3003pts Systems for Texture Analysis (4 circle goniometer). You can order of LaboTex Software (The Texture Analysis Software) with hardware directly from GE Inspection Technologies.

    Rigaku

    ATX-G, ATX-E, UltimaIII->SmartLab, UltimaIV, RAPID II. Ultima IV with Cross Beam Optics, Advanced Thin Film Attachment and In-Plane unit --> original pole figure measurement method, the perfect pole figure map of the thin film, which could not be produced using the conventional method, can be obtained. (The grazing incidence condition, which can eliminate data coming from the substrate). Multipurpose X-ray diffraction system (not only to texture measurements). You can order of LaboTex Software (The Texture Analysis Software) with hardware directly from Rigaku.

    INEL

    Inel detectors can measure even 120 degrees about one axis of 2 theta in real time which dramatically simplifies goniometer design. 4 circle goniometer and an Inel single linear PSD detector enabling both texture and stress measurements to be made simultaneously and at high speed. You can order of LaboTex Software (The Texture Analysis Software) with hardware directly from Inel Company.

    PANalytical

    X'Pert PRO series You can order of LaboTex Software (The Texture Analysis Software) with hardware directly from PANalytical.

    Hardware Modernization

  • Nuclear Electronics" Company You can order of LaboTex Software (The Texture Analysis Software) with hardware modernization from LaboSoft s.c. Company or from "Nuclear Electronics" Company. After modernization you receive pole figure data in LaboTex EPF format. All European Union.
  • "X-ray Instruments " Company You can order of LaboTex Software (The Texture Analysis Software) with hardware modernization from "X-ray Instruments " Company. After modernization you receive pole figure data in LaboTex EPF format. Pakistan: E-mail: xrayinstruments@yahoo.com