Microstructure evolution during forging deformation of (TiB+TiC+Y2O3)/α-Ti composite: DRX and globularization behavior

In this work, the beta and (alpha+beta) forging deformation were conducted on (TiB + TiC + Y2O3)/alpha-Ti composite to investigate the effect of reinforcement on dynamic recrystallization and globularization behavior. During b deformation, the reinforcements not only accelerated discontinuous dynamic recrystallization by particle stimulated nucleation mechanism, but also promoted the heterogeneous nucleation of a phase thus conducted the {0001}alpha pole figure of composite more widely distributed. However, during (alpha+beta) deformation, the microstructure was characteristic of kinked alpha colonies morphology. Moreover, compared to matrix, the (TiB + TiC + Y2O3)/alpha-Ti composite depicted a more homogeneous microstructure and larger crystallography rotation both along or transverse to the alpha lamellar. The distribution of Schmid factor value indicated that the deformation behavior of matrix showed varies with the alpha colony while it was more homogeneous in composite. Reinforced with (TiB + TiC + Y2O3) reinforcements, on the one hand, the random SF value of composite conducted the incompatibility slip between adjacent alpha lamellar thus at last leaded the formation of HABs in inter-lamellar; on the other hand, the reinforcement itself could obstruct dislocation that accelerated the dynamic globularization behavior. Therefore, the (TiB + TiC + Y2O3)/alpha-Ti composite had a great advantage in optimizing microstructure especially globularization that made the composite of great application prospect. (C) 2020 Elsevier B.V. All rights reserved.