Microstructural Evolution and Deformation Mechanisms of In Situ TiC Reinforced Ti‐6Al‐4V Composites during High‐Temperature Hot Compression

Abstract

Deformation processing is a key strategy to improve the strength‐ductility of metal matrixcomposites. Herein, TiC/TC4 composites are spark plasma sintered usingreinforcement precursors of reduced graphene oxide to reinforce TC4 matrix. Inorder to investigate the hot deformation behaviors and mechanisms of TiC/TC4 composites, the composites are hot compressed over temperature range of 870–1070 °C and strain range of 0.001–10 s−1. The results indicate that the optimal processing window of hot deformation ismainly within the temperature range of 890–970 °C and the strain rate range of 0.01–0.1 s−1. The flow instability of TiC/TC4 composites occurs in the temperature range of 890–930 and 1000–1060 °C at the strain rate range from 0.1 to 10 s−1. The thermal deformation mechanism of TiC/TC4 composites in the processingwindow region involves continuous dynamic recrystallization and discontinuous dynamic recrystallization. TiC can effectively hinder thedislocation motion, leading to the generation of high‐density dislocationsaround TiC. Consequently, this promotes sub‐grains formation and rotation,facilitating CDRX. Meanwhile, TiC particle induces high‐angle grain boundarymigration and provides more nucleation sites for recrystallized grains. These findings enhance understanding the role of hot deformation behaviors of Ti compositesand provide insights into their deformation processing.