Abstract:
Using the split Hopkinson bar system, the dynamic compression experiment on hat-shape sample of Laser Rapid Forming Ti-6Al-4V (LRF TC4) titanium alloy have been conducted under the different strike pressure. And effects of the strike pressure on the process of forming and developing of shear band in LRF TC4 alloy has been investigated by methods of optical microscope (OM), scanning electronic microscope (SEM) and transmission electron microscope (TEM). Analysis results show that the strike pressure has a great influence on the the process of forming and developing of shear band in LRF TC4 alloy.The width of shear band increases with the increasing of the strike pressure, and the flow line along the shear direction in the shear band gradually weakens. The shear band is composed of fine grains under different strike pressure. When the strike pressure is 0.065 MPa, there is no dynamic recrystallization grains found in shear band,while under another strike pressure in this study, dynamic recrystallization grains appears in the shear band and the proportion of recrystallized grains increases with the increase of strike pressure. When the pressure is 0.100 MPa, the shear band is almost composed of fine recrystallized grains. Calculation results shows that the adiabatic temperature rise in the shear band also increases with the increase of strike pressure.