The Dynamic Recrystallization and α Texture Evolution of As-Sintered GNPs/TA15 Composites During Extrusion

During the initial extrusion stage of the as-sintered GNPs/TA15 composite, dislocations accumulated along the GNPs and grain boundaries, leading to the formation of a subgrain structure. As extrusion progressed, these subgrains underwent rotation and transformed into finer grains through dynamic recrystallization. This process resulted in significant grain refinement, with the average grain size decreasing from 3.04 μm to 1.30 μm. Concurrently, the Ti matrix adjacent to the GNPs initially flowed towards the GNPs and subsequently elongated along the extrusion direction (ED). Furthermore, the deformed α grains experienced slip along the {101¯0}⟨112¯0⟩ system, giving rise to the development of [101¯1]//ED and [202¯1]//ED α textures. This study elucidates the influence of GNPs on the microstructural evolution, particularly in terms of grain refinement and the formation of α textures, as a function of increasing extrusion ratios.