Creep behavior and microstructure evolution of titanium matrix composites reinforced with TiB, TiC and Y₂O₃

Titanium matrix composites reinforced with (TiB + TiC) and (TiB + TiC + Y₂O₃) were prepared by induction skull melting. The creep test was carried out at 650 °C and 120−160 MPa, and the microstructure evolution was characterized in detail by XRD, SEM and TEM. The results show that the microstructure of the two composites is basket-weave structure. Under the same creep condition, the composite with the addition of Y₂O₃ has lower steady-state creep rate. After creep, silicides precipitated at the α/β interface, around dissolved β phases and reinforcements, which have a strong pinning effect on the dislocation movement. Due to the stacking fault structure through TiB whisker, the size of silicides around TiB is significantly larger than that around TiC and Y₂O₃. Solute-drag creep is the main creep mechanism, and the dislocation movement is also affected by α/β interface, reinforcements and silicides.