Acta Materialia 51 (2003) 677–686 www.actamat-journals.com Disorientations as a function of distance: a new procedure to analyze local orientation data A. Vorhauer a , T. Hebesberger a , R. Pippan a,b a Erich Schmid-Institute for Materials Science, Austrian Academy of Sciences, Jahnstrasse 12, 8700 Leoben, Austria b Christian Doppler Laboratory for Local Analyses of Deformation and Fracture, Jahnstrasse 12, 8700 Leoben, Austria Received 8 February 2002; received in revised form 23 September 2002; accepted 23 September 2002 Abstract A new procedure for analyzing local orientation data has been developed to investigate the relation between orien- tations and data point distances. The key idea is to determine the distribution of the disorientation angle as a function of the distance between the data points. The evolution of the disorientation angle distribution with increasing data point distance provides quantitative information about average local variation of the crystal orientation which can be used to classify structural elements, to determine the average structural size, and allows the quantification (crystallographically) of the boundaries between adjacent structural elements. The potential of this analyzing procedure is demonstrated by investigating the orientation data of Electron Backscattering Diffraction (EBSD)-measurements performed on severe deformed copper samples. The benefits in comparison to other commonly used methods to quantify local disorientations are discussed.  2002 Acta Materialia Inc. Published by Elsevier Science Ltd. All rights reserved. Keywords: Microstructure; Grain size; Disorientations; Orientation imaging microscopy; Electron Backscattering Diffraction (EBSD) 1. Introduction The characterization of the microstructural changes of natural or technological materials dur- ing plastic deformation, recrystallization, thermo- mechanical treatment and phase transformation are of special interest in many fields of materials and geological sciences. It is well known that many materials properties, for example Young’s Modu- lus, strength, ductility, magnetic permeability, are influenced by the macrotexture of the material [1]. The macrotexture describes the average texture of a large number of structural elements (crystallites, grains) without any relation between the crystallo- 1359-6454/03/$30.00  2002 Acta Materialia Inc. Published by Elsevier Science Ltd. All rights reserved. doi:10.1016/S1359-6454(02)00446-9 graphic orientation of individual grains and their spatial location. Such connections between the morphology of the structural elements and their orientations can by summarized by the term microtexture. The knowledge about the microtex- ture is frequently necessary in order to describe microstructural features, as, for example, morphological/geometrical grain parameters, phase relationships or interfacial parameters and proper- ties, in a more detailed way. A categorization of the mainstream techniques used for texture measurements by diffraction can be carried out, for example, according to the used radiation—neu- trons, X-rays or electrons [2].