Deformation and fracture behavior of steel projectiles impacting AD95 ceramic targets-experimental investigation

The deformation and failure behaviors of soft and hard steel projectiles and ceramic targets during normal impact at different velocities were investigated experimentally. Impact tests were conducted with light gas guns over a range of velocities from 100 to1000 m/s. The projectile and target, including fragments, were recovered after each test. Experimental results show that, with the impact velocity increasing, for the soft projectiles, the deformation and fracture modes were mushrooming, shear cracking, petaling and fragmentation (with relatively large fragments and lower number), respectively, while for the hard projectiles there are three deformation and fracture modes: mushrooming, shearing cracking and fragmentation (with very small fragments and large number). Velocity ranges were identified for each failure mode. In all tests, projectiles were rebounded and did not fully penetrate the ceramic targets. However, as a function of the velocity, the failure mode of ceramic target changed. At low impact velocity, only radial cracks formed. As impact velocity increased, circumferential cracks could be seen. A conical region of was ejected from the rear of the ceramic target when the velocity reached 400 m/s or above. The portion of the target affected by the conical ejected region took on two separate forms: front surface intact at lower velocity and perforated at higher velocity. At the higher impact velocities, the fragment size in the ceramic cone is smaller and more of a uniform distribution. No obvious difference in the damage to the ceramic target is seen with projectiles having different hardness but impacting at the same velocity range.