0.1wt% Boron addition Effect on dynamic compressive mechanical properties of Ti-6Al-4V alloy

Abstract

0.1wt% Boron addition effect on dynamic compression properties of Ti-6Al-4V (Ti-64A) alloy are investigated by Split Hopkinson Pressure Bar (SHPB). In the study, and relative damage mechanism is also analyzed. The results show that, as-cast microstructure is refined due to 0.1% Boron addition and also to lower the non-uniform distribution of strain, stress or local concentration due to inharmonic deformation. As well as both dynamic strain and average dynamic flow stress is improved with a reduction of the sensitivity of adiabatic shear behavior. As deformation microstructure loaded at high strain rate with 0.1wt% boron addition, Dynamic strain and maximum absorbed energy is decrease 10%~30% compare with Ti-64A alloy. Both Ti-64A and Ti-6Al-4V-0.1B (Ti-64B), average dynamic flow stress is close. At high speed impact load, it exhibits a damage of adiabatic shear and TiB phases bear loading during fracture. Adiabatic shear band is main reason of Ti-64A and Ti-64B alloys fracture failure through the deformed specimens' microstructure observation. Adiabatic shear band formation and expansion is a precursor of material shear fracture failure. Deformation cavity can be formation between TiB phase and matrix during the deformation process, but not the main reason of material fracture failure.