Isothermal deformation and spheroidization mechanism of (TiB + La2O3)/Ti composites with different initial structures

(TiB + La2O3)/Ti composites with different initial structures were obtained through designed heat treatment. The matrix was composed of lamellar α phase and acicular α phase at 920 °C, respectively. In the following deformation, the furnace cooled samples demonstrated lamellar α phase and partial spheroidized structure. Moreover, the spheroidization mechanism was similar to the boundary splitting model. The spheroidization of quenched and reheated samples occurred as complete, while high amounts of fine equiaxed grains were obtained, due to the dynamic recrystallization in the subsequent deformation. Refined lamellar microstructures could promote dynamic recrystallization.301