Patent attributes
The present invention contemplates the addition of zirconium compounds to well known ceramic ballistic materials to increase resistance to penetration by projectiles. In the preferred embodiments of the present invention, the zirconium compound that is employed consists of ZrO2 and is provided in the range of about 0.1% to about 11%, by weight, of starting material before densification. Preferred ranges of proportion of ZrO2 in the finished ceramic material are in the ranges of about 0.30% to about 0.75%, by weight, or about 8-9%, by weight. The ballistic material using the combination of SiC with low volume of sintering aid and ZrO2 raises the theoretical density of the ceramic material to between 3.225 and 3.40 g/cc, which is slightly higher than the typical 3.22 g/cc theoretical density for hot pressed fully dense SiC. The unexpected result that accrues through combining silicon carbide and zirconia consists of the creation of controlled defects in the finished ceramic that increase the surface area that is fractured during a ballistic event, enhancing spreading of the forces imposed on the ceramic material by a projectile and, as a result, the ability of the ballistic material to withstand higher forces while resisting penetration.
