Differences in ballistic performance induced by building direction of additively manufactured 316L stainless steel cylindrical projectiles

This paper evaluates the anisotropic mechanical and ballistic properties of additively manufactured (AM) 316L stainless steel fabricated by selective laser melting (SLM) technology. Vertically printed (AM-V) specimens exhibited worse static tensile strength and superior dynamic compression strength than horizontally printed (AM-H) ones, revealing significant anisotropy. Unlike previous studies focusing on the quasi-static properties of AM-V materials (Xue et al., 2023), this work examines anisotropy under dynamic conditions and their influence on ballistic performance. The ballistic performance of the AM-V projectiles is 43.3 % better than that of the AM-H projectiles under the same conditions. The mechanism of the difference in ballistic performance of AM projectiles due to directionality was revealed by microstructural investigations. The AM-V projectile has a dense internal structure after impact, while many cracks and hole defects are observed inside the AM-H projectile. Moreover, the numerical simulation was conducted based on the modified Johnson-Cook (MJC) model. The ballistic limit velocity, residual projectile morphology, and mass loss of the projectiles are relatively consistent with the test results.