Influence of thermal exposure on compressive creep behavior and dynamic recrystallization of (TiB+TiC+Y2O3)/α-Ti composite.

The influence of thermal exposure on the compressive creep behavior of (TiB + TiC + Y 2 O 3)/α-Ti composites and the matrix alloy at different conditions was studied. The results showed that the α-Ti lamellae coarsened and β-Ti laths dissolved into pieces after thermal exposure. After compressive creep, there occurred significant dynamic recrystallization, which is characterized by fine equiaxed grains. Discontinuous dynamic recrystallization is the main recrystallization mechanism, while continuous dynamic recrystallization is the minor mechanism. The increase in creep temperature will increase the possibility of continuous dynamic recrystallization. The occurrence of dynamic recrystallization will significantly soften the titanium matrix, thereby increasing creep strain. The improved compressive creep resistance after thermal exposure comes from the precipitated silicides and stacking faults. During the compressive creep process, the size and quantity of silicides increase, and the S1 type silicides introduced by thermal exposure have a strong pinning effect on dislocations. Serious dislocation pile-ups have formed around the stacking faults. The stacking faults distributed inside α-Ti lamellae will suppress β-Ti dissolution, improving the interface stability and effectively reducing creep rate. • The reasons for the enhanced creep properties by thermal exposure were analyzed. • Dynamic recrystallization mechanism during compression process was discussed. • The response of silicides and stacking faults to creep and DRX were revealed. [ABSTRACT FROM AUTHOR]