ISSN 1063-7834, Physics of the Solid State, 2012, Vol. 54, No. 4, pp. 694–698. © Pleiades Publishing, Ltd., 2012. Original Russian Text © T.N. Konkova, S.Yu. Mironov, A.V. Korznikov, M.M. Myshlyaev, 2012, published in Fizika Tverdogo Tela, 2012, Vol. 54, No. 4, pp. 652–656. 694 1. INTRODUCTION Recrystallization is one of the most fundamental processes studied in materials science. Detection and analysis of the recrystallized structure are usually per- formed using optical and transmission electron microscopy. Indirect approaches include an X-ray structural analysis, measurement of properties (for example, microhardness), and calorimetry. Funda- mental principles of recrystallization were established using these methods. Currently, in order to investigate recrystallization, the automatic analysis of electron backscattered dif- fraction (EBSD) patterns starts being actively used. This method combines the possibility to obtain the most diverse information on the structure and texture of the material under study with large statistic sam- pling of measurements [1]. This allows us to expect that EBSD will promote the research progress in this field. When analyzing the partially recrystallized struc- ture, one of the main problems in EBSD is the deter- mination of a reliable criterion allowing us to objec- tively separate the deformed and recrystallized phases. Two approaches to solve this problem are distin- guished in EBSD. One of them is based on the clear- ness and sharpness of indexed Kikuchi patterns [2], which are known to be very sensitive to lattice micros- trains. The second approach is based on the evaluation of the orientation spread within the crystallites [3–5]. The presence of the developed substructure and inter- nal stresses in strained grains usually leads to the appearance of considerable orientation gradients, which distinguish these crystals from the recrystallized structure. Both approaches are characterized by substantial disadvantages. On the one hand, the sharpness of the Kikuchi patterns can depend on many factors includ- ing the chemical composition of the material, the crystallographic orientation of the grain, and even the microscope parameters. On the other hand, the exper- imental EBSD error in determining the misorienta- tion (~2°) can be very essential when evaluating the orientation spread within the grains. In this study, we analyzed the practical applicability of these two approaches to reveal the recrystallized structure by the example of copper of M1 grade. 2. MATERIAL AND EXPERIMENTAL PROCEDURE A commercially pure copper of the M1 grade was employed as the material for the investigation. The initial hot-rolled rod was subjected to the preliminary severe “abc deformation” in the temperature range of 500–300°C and then rolled at the cryogenic tempera- ture to the degree of reduction of 93%. 1 The experi- mental details are described in [6]. It is known that copper deformed at the cryogenic temperature is 1 This work was performed in the framework of the research project for evaluating the feasibility of cryogenic deformations for production of the nanocrystalline structure in copper. METALS Detection of Recrystallized Structure by Means of Automatic Analysis of Electron Backscattered Diffraction Patterns T. N. Konkova a , S. Yu. Mironov a, b , A. V. Korznikov a , and M. M. Myshlyaev c, d a Institute for Metals Superplasticity Problems, Russian Academy of Sciences, ul. Khalturina 39, Ufa, 450001 Bashkortostan, Russia * e-mail: konkova_05@mail.ru b Department of Materials Processing, Graduate School of Engineering, Tohoku University, Aramaki-aza-Aoba 02, Aoba-ku, Sendai, Miyagi, 980-8579 Japan c Baikov Institute of Metallurgy and Materials Science, Russian Academy of Sciences, Leninskii pr. 49, Moscow, 119991 Russia d Institute of Solid State Physics, Russian Academy of Sciences, ul. Akademika Ossipyana 2, Chernogolovka, Moscow oblast, 142432 Russia Received July 19, 2011; in final form, September 6, 2011 Abstract—The possibility of applying the automatic analysis of electron backscattered diffraction (EBSD) patterns to reveal the recrystallized structure in the partially recrystallized material has been discussed. The analysis has been performed based on new experimental results. It has been shown that the EBSD method can be successfully used to investigate the recrystallization process. DOI: 10.1134/S1063783412040130