1、December 2015 English price group 14No part of this translation may be reproduced without prior permission ofDIN Deutsches Institut fr Normung e. V., Berlin. Beuth Verlag GmbH, 10772 Berlin, Germany,has the exclusive right of sale for German Standards (DIN-Normen).ICS 71.040.50!%JwY“2398454www.din.d
2、eDIN ISO 13067Microbeam analysis Electron backscatter diffraction Measurement of average grain size (ISO 13067:2011),English translation of DIN ISO 13067:2015-12Mikrobereichsanalyse Elektronenrckstreubeugung Messung der mittleren Korngre (ISO 13067:2011),Englische bersetzung von DIN ISO 13067:2015-1
3、2Analyse par microfaisceaux Diffraction dlectrons rtrodiffuss Mesurage de la taille moyenne des grains (ISO 13067:2011),Traduction anglaise de DIN ISO 13067:2015-12www.beuth.deDocument comprises pagesDTranslation by DIN-Sprachendienst.In case of doubt, the German-language original shall be considere
4、d authoritative.2312.15Introduction 1 Scope 2 Normative references .3 Terms and definitions .3.1 Terminology associated with EBSD measurement of grain size 3.2 Terminology associated with grains and grain boundaries determined via EBSD .3.3 Terminology associated within grain size measurement .3.4 T
5、erminology associated with data correction and uncertainty of EBSD maps 4 Acquiring a map by EBSD for grain size measurement .4.1 Hardware requirements .4.2 Software requirements .5 Acquiring the map for grain sizing by EBSD .5.1 Specimen preparation 5.2 Defining specimen axes 5.3 Stage positioning
6、and calibration .5.4 Linear calibration .5.5 Preliminary examination 5.6 Choice of step size 5.7 Determination of the level of angular accuracy needed78.5.8 Choice of areas to be mapped and map size .5.9 Considerations when examining plastically deformed materials 6 Analytical procedure 156.1 Defini
7、tion of boundaries 156.2 Post-acquisition treatment of raw data .166.3 Data-cleaning steps 166.4 Measurement of grain size 196.5 Representation of data .197 Measurement uncertainty .8 Reporting of analysis results .Annex A (informative) Grain size measurement .Bibliography .DIN ISO 13067:2015-12 A c
8、omma is used as the decimal marker. Contents Page National foreword .3 National Annex NA (informative) Bibliography 4 56666891010101111111111111212121414202021232National foreword This document (ISO 13067:2011) has been prepared by Technical Committee ISO/TC 202 “Microbeam analysis” (Secretariat: SA
9、C, China). The responsible German body involved in its preparation was DIN-Normenausschuss Materialprfung (DIN Standards Committee Materials Testing), Working Committee NA 062-08-18 AA Elektronenmikroskopie und Mikrobereichsanalyse. Attention is drawn to the possibility that some of the elements of
10、this document may be the subject of patent rights. DIN and/or DKE shall not be held responsible for identifying any or all such patent rights. In this standard the “map of local orientation” is referred to as “map” throughout the text. The term “specimen” is used in this standard within the meaning
11、of “preparation” (i. e. the object analysed by means of EBSD) and does not denote a “sample”. As regards the term “pattern quality” defined in 3.1.7 it should be noted that “pattern” stands for the image from the phosphor screen of the EBSD system focused onto the CCD camera. The DIN Standards corre
12、sponding to the International Standards referred to in this document are as follows: ISO/IEC 17025 DIN EN ISO/IEC 17025 ISO 21748 DIN ISO 21748 ISO 24173 DIN ISO 24173 DIN ISO 13067:2015-12 3National Annex NA (informative) Bibliography DIN EN ISO/IEC 17025, General requirements for the competence of
13、 testing and calibration laboratories DIN ISO 21748, Guidance for the use of repeatability, reproducibility and trueness estimates in measurement uncertainty estimation DIN ISO 24173, Microbeam analysis Guidelines for orientation measurement using electron backscatter diffraction DIN ISO 13067:2015-
14、12 4IntroductionThe mechanical and electromagnetic properties of engineering materials are strongly influenced by their crystal grain size and distribution. For example, strength, toughness and hardness are all important engineering properties that are strongly influenced by these parameters. Both b
15、ulk materials and thin films, even as narrow two-dimensional structures, are influenced by grain size. For this reason, it is important to have standard methods for its measurement with commonly used and agreed terminology. This International Standard describes procedures for measuring average grain
16、 size from maps of local orientation measurements using electron backscatter diffraction.Microbeam analysis Electron backscatter diffraction Measurement of average grain sizeDIN ISO 13067:2015-12 5IMPORTANT The electronic file of this document contains colours which are considered to be useful for t
17、he correct understanding of the document. Users should therefore consider printing this document using a colour printer.1 ScopeThis International Standard describes procedures for measuring average grain size derived from a two-dimensional polished cross-section using electron backscatter diffractio
18、n (EBSD). This requires the measurement of orientation, misorientation and pattern quality factor as a function of position in the crystalline specimen1.NOTE 1 While conventional methods for grain size determination using optical microscopy are well-established, EBSD methods offer a number of advant
19、ages over these techniques, including increased spatial resolution and quantitative description of the orientation of the grains.NOTE 2 The method also lends itself to the measurement of the grain size of complex materials, for example those with a significant duplex content.NOTE 3 The reader is war
20、ned to interpret the results with care when attempting to investigate specimens with high levels of deformation.2 Normative referencesThe following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated reference
21、s, the latest edition of the referenced document (including any amendments) applies.ISO 16700, Microbeam analysis Scanning electron microscopy Guidelines for calibrating image magnificationISO/IEC 17025, General requirements for the competence of testing and calibration laboratoriesISO 21748, Guidan
22、ce for the use of repeatability, reproducibility and trueness estimates in measurement uncertainty estimationISO 23833, Microbeam analysis Electron probe microanalysis (EPMA) VocabularyISO 24173:2009, Microbeam analysis Guidelines for orientation measurement using electron backscatter diffraction3 T
23、erms and definitionsFor the purposes of this document, the following terms and definitions apply. The reader is also referred to ISO 24173 and ISO 23833 for additional terms and definitions.3.1 Terminology associated with EBSD measurement of grain size3.1.1step sizedistance between adjacent points f
24、rom which individual EBSD patterns are acquired during collection of data for an EBSD mapDIN ISO 13067:2015-12 63.1.2pixelpicture elementsmallest area of an EBSD map, with the dimensions of the step size, to which is assigned the result of a single orientation measurement made by stopping the beam a
25、t a point at the centre of that area3.1.3orientationmathematical description of the angular relationship between the crystal axes of the analysis point and a reference frame, usually the specimen axes3.1.4indexeda pixel is said to be indexed if the orientation calculated from the EBSD pattern acquir
26、ed for that pixel meets a predetermined threshold for reliability3.1.5indexing reliabilitynumerical value that indicates the confidence/reliability that the indexing software places in an automatic analysisNOTE This parameter varies between EBSD manufacturers, but can include:a) the average differen
27、ce between the experimentally determined angles between diffracting planes and those angles calculated for the orientation determined by EBSD software;b) the difference between the number of triplets (intersections of three Kikuchi bands) in the EBSD pattern matched by the chosen orientation and the
28、 next best possible solution, divided by the total number of triplets.3.1.6orientation mapcrystal orientation mapmap-like display of pixels derived from the sequential measurement of crystal orientation at each point in a grid see Figures 1 b) to 1 f) showing the crystallographic relationship betwee
29、n the pixels and the reference frame3.1.7pattern qualitymeasure of the sharpness of the diffraction bands or the range of contrast within a diffraction patternNOTE Different terms are used in different commercial software packages, including, for example, band contrast, band slope and image quality.
30、3.1.8pattern quality mapmap-like display of pixels derived from the sequential collection of EBSD patterns at each point in a grid see Figure 1 a) showing the pattern quality of the individual pixelsNOTE 1 Since measures of pattern quality can change at features such as grain boundaries and with ori
31、entation, the pattern quality map can give an indication of grain shape and size.NOTE 2 Pattern quality maps can also indicate areas of heavy deformation and inadequate preparation, such as residual scratches.NOTE 3 Small particles and features also contribute to the pattern quality map.3.1.9pseudos
32、ymmetrypotential for an EBSD pattern to be indexed in several different ways due to internal similarities within the EBSD patternNOTE 1 Pseudosymmetry is a problem with some crystal orientations, usually when a main zone axis is in the centre of the pattern. Typical cases are a 0001 pole for a hexag
33、onal structure and a pole for a cubic structure.DIN ISO 13067:2015-12 7NOTE 2 Structures such as high-symmetry tetragonal crystals with an axial ratio, c/a, approximately equal to 1 are also likely to exhibit pseudosymmetry in EBSD patterns.3.1.10misorientationgiven two crystal orientations, the mis
34、orientation is the rotation, often defined by an angle/axis pair, required to rotate one set of crystal axes into coincidence with the other set of crystal axes3.1.11disorientationdue to crystal symmetry, there can be several axis/angle pairs which represent the same misorientation, in which case th
35、e one having the smallest angle is called the disorientationNOTE 1 For most crystal symmetries, there are multiple symmetrically equivalent axes for the disorientation with the smallest misorientation angle.NOTE 2 Misorientation and disorientation are terms which are often used interchangeably. Diso
36、rientation is the more rigorous term here, but misorientation is the more frequently used.3.1.12forescatter imagingorientation contrast produced from electrons which channel out of the specimen3.1.13electron-channelling contrast imagingECCIorientation contrast produced from electrons which channel i
37、nto the specimen3.1.14barrel distortiondifference in lateral magnification between the central and peripheral areas of an image such that the lateral magnification is less at the peripheryNOTE A square object in the centre of the field appears barrel-shaped (i.e. with convex sides).3.1.15pincushion
38、distortiondifference in lateral magnification between the central and peripheral areas of an image such that the lateral magnification is greater at the peripheryNOTE A square object in the centre of the field appears cushion-shaped (i.e. with concave edges).3.2 Terminology associated with grains an
39、d grain boundaries determined via EBSD3.2.1grain boundaryline separating adjacent regions of points in an EBSD orientation map with disorientation across the line greater than a minimum angle chosen to define the grain boundaries3.2.2grainregion of points with similar orientation (within a tolerance
40、), completely enclosed by grain boundaries and greater than the minimum size defined to exclude isolated (often badly indexed) points as small grains3.2.3sub-grain boundaryline separating adjacent regions of points in a grain with a difference in orientation across the line smaller than that definin
41、g a grain but greater than that defining a sub-grainNOTE Effectively, sub-grain boundaries are grain boundaries with a smaller misorientation limit than that defining a grain boundary. These boundaries can have a characteristic linear appearance and exhibit a characteristic misorientation.DIN ISO 13
42、067:2015-12 83.2.4sub-grainregion of points with similar orientation completely enclosed by boundaries greater than the minimum sub-grain boundary angle3.2.5special boundaryboundary between two grains having a special orientation relationship within a tolerance associated with identifying them in or
43、ientation maps3.2.6twin boundaryparticular case of a special boundary between crystals oriented with respect to one another according to some symmetry rule, in which the boundary itself is planar and is a characteristic crystallographic plane (for both crystals) and, frequently, one crystal is the m
44、irror image of the otherNOTE For example, in face-centred-cubic structures, the characteristic misorientation defining a common twin can be described as a 60 rotation about the axis with the boundary plane normal to the rotation axis.3.2.7recrystallized grainsnew set of undeformed grains formed by c
45、onsuming deformed grains through nucleation and growth processesNOTE Measurements of misorientation within grains by EBSD can be used to distinguish between deformed and undeformed grains.3.2.8phasephysically homogeneous volume in a material having the same crystal structure and chemical composition
46、3.3 Terminology associated within grain size measurementThere are a variety of ways of representing average grain size. This subclause outlines some of the more common terms used, and the reader is referred to Annex A for more details about other terms, about the standards available and about the ap
47、plicability of methods for particular grain shapes and distributions.3.3.1line interceptdistance between the points at which a straight line crossing a grain intersects the grain boundary on each sideNOTE See ASTM E112 for more details.3.3.2equivalent circle diameterDcirclediameter of the circle wit
48、h an area equivalent to the grain section area, given by:Dcircle= (4A/)1/2where A is the area of the grain.NOTE The ASTM grain size number, G, is given by:G = 6,64log10Dcircle 2,95where Dcircleis measured in millimetres.DIN ISO 13067:2015-12 93.3.3Feret diameterperpendicular distance between two par
49、allel lines drawn in a given direction tangential to the perimeter of an object on opposite sides of the objectNOTE 1 It is also known as the calliper diameter.NOTE 2 Different variants of the Feret diameter are used. For example, the Feret diameter can be measured in the vertical and horizontal directions or in any two directions at right angles to each other.3.3.4grain shapeproperty whose value is determined by fitting an ellipse round the grain and measuring the aspect ratio, i.e. the ratio of the length of the minor axis to the lengt
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