Abstract:In order to investigate the adiabatic shear behavior and deformation mechanism of TA1 pure titanium, dynamic impact experiments were carried out using the split Hopkinson press bar (SHPB) set up based on the a TA1 pure titanium hat-shaped specimen. The microstructure after dynamic deformation was characterized using optical microscopy (OM), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and electron backscattering diffraction (EBSD) techniques. The results show that forced shear region of TA1 pure titanium hat-shaped specimen occurs the obvious adiabatic shear bands(ASB) under dynamic loading. With the strain rate increasing, the width of adiabatic shear band decreases and the length of adiabatic shear band increases, which exhibits the higher adiabatic shear sensitivity. The deformation mechanism of the center region in shear band is geometric dynamic recrystallization induced by adiabatic temperature rise and severe plastic deformation. The deformation mechanism of the transition region is dominated by dislocation slip and assisted by twin deformation, while the dislocation slip and twin deformation are both the main deformation mechanisms of the matrix.

Abstract: