It is ceramic use for bulletproof plates？（一）

In people’s impression, ceramic is fragile. However, after modern technology processing, ceramics “transformed”, becoming a hard, high-strength new material, especially in the field of bulletproof materials with special physical properties, ceramics is shining, becoming a very popular bulletproof material.

①The bulletproof principle of ceramic materials

The basic principle of armor protection is to consume the energy of the projectile, slow it down, and render it harmless. Most traditional engineering materials, such as metal materials, absorb energy through the plastic deformation of the structure, while ceramic materials absorb energy through the micro-crushing process.

The energy absorption process of bulletproof ceramics can be roughly divided into three stages:

(1) Initial impact stage: The projectile impacts the ceramic surface, making the warhead blunt and absorbing energy during the process of crushing and forming small and hard fragments on the ceramic surface;

(2) Erosion stage: The blunted projectile continues to erode the fragmented area, forming a continuous layer of ceramic fragments;

(3) Deformation, cracking, and fracture stages: Finally, tensile stress is generated in the ceramic, causing it to shatter. Subsequently, the back plate deforms, and all remaining energy is absorbed by the deformation of the back plate material. During the process of projectile impact on ceramics, both projectile and ceramics are damaged.

②Requirements for material properties of bulletproof ceramics

Because of the brittleness of the ceramic itself, it is fractured when impacted by the projectile rather than plastic deformation. Under the action of tensile load, the fracture first occurs in the heterogeneous areas such as pores and grain boundaries. Therefore, in order to minimize the microscopic stress concentration, the armor ceramics should be of high quality with low porosity (up to 99% of the theoretical density value) and fine grain structure.

Properties of materials and their effects on bulletproof properties

Silicon carbide ceramic density is relatively low, high hardness, is a cost-effective structural ceramics, so it is also the most widely used bulletproof ceramics in China.
Boron carbide ceramics have the lowest density and highest hardness among these ceramics, but at the same time, their requirements for processing technology are also very high, requiring high temperature and high pressure sintering, so the cost is also the highest among these three ceramics.