Glasses and ceramics

Glasses and ceramics are the most important class of armour materials. The ceramics, in particular, make very effective disruptors. However, they are very brittle in nature and different design rules need to be applied when constructing ceramic-composite armour systems. In this powerful chapter, key properties and drivers are reported, as well as the complex array of energy-absorbing mechanisms and failure modes. The constitution of both the traditional glasses and the more advanced transparent crystalline ceramics are covered, including a new review of the alternative systems (Sapphire, AlONs and Spinels), manufacturing methods and their respective ballistic performance. The higher-performing opaque ceramics are also well covered and two important families introduced: reaction sintering/bonding of silicon carbide and a newly-developed method of producing cost-effective, ballistically-efficient, boron carbide using a combination of Viscous Plastic Processing (VPP) and Pressureless Sintering (PS). The application of such materials to body armour systems is fully described and the effects of material choice and methods of construction upon ballistic performance is well covered.