Effect of boron addition on formation of a fine-grained microstructure in commercially pure titanium processed by hot compression

This paper is devoted to comparative investigation of recrystallization behavior during uniaxial hot compression at 600-900 degrees C of cast commercially pure titanium (CP-Ti) modified with boron and free of boron as well as of CP-Ti in initial wrought condition. Using optical microscopy and EBSD analysis it has been revealed that the boron addition in an amount of 0.2 wt'% promoted much more uniform strain development and intensive dynamic recrystallization during hot compression in cast CP-Ti modified with boron as compared with cast CP-Ti free of boron. At the same time, hot compression led to similar fine-grained microstructures in cast CP-Ti modified with boron and wrought CP-Ti. The obtained results suggest that the boron additions to CP-Ti may reduce postcast processing steps and thus reduce the overall cost of produced fine-grained materials out of CP-Ti by means of hot working. (C) 2015 Elsevier B.V. All rights reserved.