High Toughness Ceramics Containing Carbon Nanotube Reinforcement

Boron Carbide (B4C) was chosen for use as a ceramic ballistic protection system due to the beneficial combination of low density and high elastic modulus. These properties contribute to the performance characteristics of high hardness and high sonic valuethat defeats the incoming projectile. However, the brittle nature of the ceramic component limits the envelope of practical applications. Previous studies have shown a 20% increase in fracture toughness for ceramic matrix components by the addition ofcarbon nanotubes. Preliminary testing has shown that mixing conditions have a significant effect on the uniformity of the hot pressed composite. The mixing method, however, did not have a significant effect on the bulk density of the samples.The work herein proposed by NanoLab, Inc. will study the dispersion of carbon nanotubes in B4C powder and provide hot pressed test specimens for physical and mechanical property testing. Results will be used to identify samples for armor penetrationtesting. The addition of carbon nanotubes to boron carbide ceramic armor is expected to increase the fracture toughness of the composite, which will increase resistance to low speed impact defects. The result will be a more effective protection barrier for bothpersonnel and equipment. Replacement due to non-ballistic impact should also be reduced.