THREE-STAGE RELATIONSHIP BETWEEN FLOW STRESS AND DYNAMIC GRAIN SIZE IN TITANIUM IN A WIDE TEMPERATURE INTERVAL A. Belyakov, S. Zherebtsov * , G. Salishchev Belgorod State University, 85 Pobeda str, Belgorod, 308015 Russia Abstract. The relationship, D -N , between the flow stress () and the size (D) of deformation- induced grains has been established for commercial-purity titanium in the interval 77-1123 K. The relationship has three parts with different grain size exponent (N). The N values of 0.83, 0.38, 0.95 were obtained in the intervals of low stresses (hot deformation), moderate stresses (warm deformation) and high stresses (cold deformation), respectively. The changes in the values of N were suggested to be associated with different mechanisms of microstructure evolution. Keywords: Titanium alloys; Bulk deformation; Dynamic recrystallization; Nanostructured materials, Grain refinement 1. Introduction The microstructural control during plastic deformation is of considerable importance in the thermo-mechanical processing of the structural metallic materials because of desirable properties of the products. The microstructure evolution during hot/warm plastic working is generally discussed in terms of dynamic recrystallization (DRX) [1]. The characteristic stress- strain curves and new grains evolved during DRX have been studied in detail as a function of temperature-strain rate conditions, which can be represented by the Zener-Hollomon parameter Z [1], ) / exp( RT Q Z    , (1) * Corresponding author. Phone:+7 (4722) 585416, E-mail address: ser_z@mail.ru or zherebtsov@bsu.edu.ru (S. Zherebtsov) *Manuscript Click here to view linked References