Evolution of dislocation density and character in hot rolled titanium determined by X-ray diffraction I.C. Dragomir a, T , D.S. Li a , G.A. Castello-Branco b,c , H. Garmestani a , R.L. Snyder a , G. Ribarik d , T. Ungar d a School of Materials Science and Engineering, Georgia Institute of Technology, 771 Ferst Drive, N.W., Atlanta, GA 30332-0245, United States b Department of Mechanical Engineering, Florida State University, Tallahassee, FL 32310, United States c Centro Federal de Educacao Tecnologica, CSF-RJ, Rio de Janeiro, RJ 22710, Brazil d Department of General Physics, Eo ¨tvo ¨s University Budapest, H-1518, P.O.B. 32, Budapest, Hungary Received 3 January 2005; accepted 1 March 2005 Abstract X-ray Peak Profile Analysis was employed to determine the evolution dislocation density and dislocations type in hot rolled commercially pure titanium specimens. It was found that ha i dislocation type is dominating the deformation mechanism at all rolling reduction levels studied here. A good agreement was found between the texture evolution and changes in dislocation slip system activity during the deformation process. D 2005 Elsevier Inc. All rights reserved. Keywords: a-Titanium; X-ray line broadening; Dislocations; Burgers Vector Population; Texture 1. Introduction Titanium and titanium alloys are used in a wide variety of aerospace, energy and biomedical applica- tions, since they have very attractive properties, such as high specific strength, elastic modulus and fracture toughness. These properties are highly dependent on the materials microstructure, i.e. texture, dislocation density, dislocation slip system activity. Therefore in order to be able to predict features of the materials and also to design materials with certain properties, a fundamental understanding of the deformation proc- ess in terms of microstructural parameters is critical [1]. The microstructural details can be obtained by using direct methods, such as transmission electron microscopy (TEM) techniques or by indirect meth- ods, such as X-ray diffraction (XRD) or neutrons techniques. TEM methods reveal microstructural information over very small areas of the samples, which in turn raise issues of how representative are 1044-5803/$ - see front matter D 2005 Elsevier Inc. All rights reserved. doi:10.1016/j.matchar.2005.03.002 T Corresponding author. Tel./fax: +1 404 385 6718. E-mail address: iuliana.cernatescu@mse.gatech.edu (I.C. Dragomir). Materials Characterization 55 (2005) 66 – 74