Anti-bullet property of encapsulated AD95 Al₂O₃ ceramic

2024Al and SiC/2024Al were used to encapsulate the AD95 Al ₂O₃ ceramics by Vacuum-high Pressure Infiltration Method. Their anti-bullet properties are not excellent with Efm of 5.17 and 4.65 respectively, and is far lower than Efm of the ceramic without encapsulation. The latter one can generate higher hydrostatic pressure between the bullet and ceramic during penetration process. However, in encapsulated targets, the ductile materials in front of the ceramic can decelerate the bullet, so the pressure between bullet and ceramic is not great enough to break the bullet. Propagated microcracks along with the bonding interface were observed in plates consisting of encapsulated Al₂O₃. These microcraks lead to the interfacial debonding between Al₂O₃ and encapsulating materials. Consequently, the anti-bullet property of the ceramic encapsulated by metal or composite is depressed. Further more, the different interface bonding conditions and fracture modes cause the discrepancy of anti-bullet property in two kinds of targets with encapsulation structure.