The deformation of B4C particle in the B4C/2024Al composites after high velocity impact

• Nano-crystallinity was observed in the Al matrix after impact.
• The plastic deformation in B4C particle was observed after impact.
• The crystal boundary in B4C particle was the type of high-angle.

In the present work, B4C/2024Al composites with volume fraction of 45% were prepared by a pressure infiltration method. The microstructure of the crater bottom of B4C/2024Al composite after impact was characterized by transmission electron microscope (TEM), which indicated that recovery and dynamic recrystallization generated in Al matrix, and the grain size distribution was about from dozens of nanometer to 200 nm. Furthermore, the plastic deformation was observed in B4C ceramic, which led to the transformation from monocrystal to polycrystal ceramic grains. The boundary observed in this work was high-angle grain boundary and the two grains at the boundary had an orientation difference of 30°.