Deformation Behavior of Ti2AlNb-Based Alloy during Dynamic Compression

The dynamic deformation behavior of the Ti-26Al-20Nb-0.5Mo (Ti2AlNb-based) alloy is experimentally investigated from ambient temperature (AT) to 400 degrees C at a high strain rate of 2000s(-1). Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) are used to characterize the microstructural evolution during the deformation process. The results show that the flow stress of the Ti2AlNb-based alloy decreases as the deformation temperature increases. The deformation mainly occurs in the O lamellar structure, in which the B2 phase and the (2) phase play a coordinating role. Under dynamic loading, the lamellar phase break up and globularizes. Grain boundaries, dislocations, and phase interfaces act as dislocation sinks and sources during high strain rate deformation. The deformation mechanism is dominated by dislocation slip.