**3.4 Boron carbide (B4C)**

Boron Carbide is a ceramic material with outstanding physical and mechanical properties such as high hardness Hugoniot elastic limit and low specific weight which makes this material good for lightweight ballistic protection. The testing of this ceramic material pointed out a very interesting parameter, which is the high value of HEL (15–20 GPa). The material exhibits an abrupt drop in strength at very high pressures and impact rates. The production of light materials for ballistic protection based on boron carbide 95–99% of the theoretical density and grain size in the range between 1.5 and 60 mm is usually done by hot pressing and sintering without pressure [35]. **Table 5** shows the physical and mechanical properties of Boron Carbide lightweight ballistic material.


### **Table 5.**

*Physical and mechanical properties of B4C ballistic materials.*

The physical and mechanical properties of B4C ballistic materials largely depend on the method of processing and raw material. The ballistic characteristic of ceramic material based on boron carbide can be reinforced by the addition of silicone or titanium to obtain better ballistic performance. Also, raw B4C matrix can be reinforced with the addition of titanium-diboride powder to produce a composite with better ballistic performance [40]. From the point of fabrication, the composite based on Boron Carbide modified by the addition of Silicon Carbide is easier to form into the complex shapes needed for torso body armor and is nearly as effective ballistically as boron carbide itself.
