Microstructure evolution of adiabatic shear band in Ti-15Mo-3Al-2.7Nb-0.2Si alloy

Using the technology of split Hopkinson Bar, the dynamic shearing experiment on Ti-15Mo-3A-2.7Nb-0.2Si titanium alloy has been done. Microstructure evolution of adiabatic shear band in Ti-15Mo-3Al-2.7Nb-0.2Si alloy subjected to dynamic loading has been studied by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). It is shown that the formation of adiabatic shear band in Ti-15Mo-3Al-2.7Nb-0.2Si titanium alloy is the result of multiplication, moving and clogging of dislocation owing to its morphology mainly made of β phase of body-centred cubic(bcc) lattice with better deformability; The course of microstructure evolution of adiabatic shear band are: elongation of grains under impressed shear stress-crushing of elongated grains-formation of fine equiaxial grains arranged at some direction; Size of the fine equiaxial grains formed in the shear band is approximately 0.2-0.4 μm.