Microstructure evolution and deformation mechanism with comparison of Ta-2.5 W and Cu under detonation load

The comparison of microstructure evolution of Cu and Ta-2.5 W liner during explosively formed projectile (EFP) formation was studied. The electron backscatter diffraction method (EBSD) was used to statistically characterize the microstructure of the liner before and after deformation. Both recycled EFPs show strong fiber texture and different degrees of recrystallization. The center of the recycled Cu EFP has strong and preferred orientations along the EFP axis, and the density of the texture changes with the deformation strain. Cu EFP has extensive dynamic recrystallization, up to 88%, which is considered to be a traditional dynamic recrystallization mechanism, the temperature is the main controlling factor in the refinement process. On the contrary, the recycled Ta-2.5 W EFP has a strong fiber preferred orientation, and almost no dynamic recrystallization occurs, large strain deformation is the main factor for the microstructure fragment. [Display omitted] ●Observed and simulated explosively formed projectile (EFP) by 3D method.●All recycled EFPs are refined and show strong fiber textures.●The deformation of the center is much larger than that of the surface for EFP.●Large-scale dynamic recrystallization occurred in Cu but not in Ta-2.5 W.●The elongated grains are found in Ta-2.5 W EFP while refined grains found in Cu.