Military New Materials Industry - Special Ceramic Materials

New military materials include superalloys, carbon fibers and special ceramic materials.

Among them, compared with conventional materials, special ceramic materials have huge advantages: its density is only 1/4 to 1/3 of the high temperature metal alloy, high strength, wear resistance, has good high temperature resistance, high temperature creep resistance, can be applied in aviation, military and industrial fields, especially in the aerospace engine hot end parts have advantages.

1) aero engine field: It is the ideal material for the development of high thrust-to-weight ratio aero engine, which is expected to replace superalloy;

2) Aerospace field: can be used for rocket engine thermal structural parts, aircraft thermal protection system, etc.

3) Automotive industry: improve vehicle performance and reduce body weight;

4) Nuclear power: can be used for nuclear high-temperature components and nuclear fuel cladding materials;

5) Weapons: for the barrel.

Used to improve the efficiency of turbine engines

Ceramics are resistant to high temperatures, and ceramic matrix composites and ceramic thermal barrier coatings can be used to increase the efficiency of turbine engines. Ceramics can operate at temperatures above 1100℃ with little or no cooling, and ceramic matrix composites are 30 to 50 percent lighter than currently used metal alloys. When both the composite burner liner and turbine blades are coated with ceramic, the operating temperature can be raised to 1650℃ and the components can be protected in the combustion environment. Multicomponent ceramic coatings based on hafnium oxide were tested continuously for 300 hours at 1650℃.

Used for aircraft engine and aircraft brake disc

For aeroengines, increasing the temperature of turbine front gas is the main technical way to increase engine thrust. However, the current temperature of turbine front gas has gradually approached the melting point of superalloy itself, and there is little room for temperature rise. Therefore, alternative materials are needed. Ceramic matrix composites have high temperature resistance and can be used for hot-end components. The results show that ceramic matrix composites can increase the gas temperature of turbine front by more than 300K. At the same time, the density of ceramic matrix composite material is small, which is conducive to engine weight reduction. As the civil aviation industry continues to pursue greater fuel efficiency, GE expects the use of ceramic matrix composites in aviation to grow tenfold over the next decade. Compared with the previous generation of carbon ceramic brake disc, the static friction coefficient is increased by 1-2 times, the wet friction performance attenuation is reduced by more than 60%, the wear rate is reduced by more than 50%, and the service life is increased by 1-2 times. The production cycle is reduced by 2/3, the production cost is reduced by 1/3, the energy consumption is reduced by 2/3, and the cost performance is increased by 2-3 times. At present, it is the only material found in the world that can not attenuate the physical properties in the high temperature environment of 1500℃. After the promotion and application, it can save about 300 million yuan for the cost of China's civil aircraft every year.

Used for rocket engine thermal structure components

Ceramic matrix composites can be used in rocket engines. Ceramic matrix composite is an ideal thermal structure material for liquid rocket engine because of its high heat shock resistance, high chemical stability to liquid propellant, high temperature resistance compared with metal materials, and high creep resistance.

Used information electronic devices

Military ceramic capacitors are in high demand. Electronic ceramics in addition to being widely used in the civilian field, with the acceleration of information technology of weapons and equipment, such as ceramic capacitors such as electronic ceramics in the military field is increasing demand, especially the chip multi-layer ceramic capacitor (MLCC, market share of more than 90%), and the military market has higher quality requirements for capacitors. The market size of China's military ceramic capacitors has maintained a growth of more than 10% over the years.

Ceramic materials and ceramic matrix composites are used in armor

Such as body armor, warplanes and armored vehicles protective layer. Body armor is mainly composed of jacket and bullet-proof layer two parts, bullet-proof layer can absorb the kinetic energy of the warhead or shrapnel, low speed warhead or shrapnel has obvious protective effect, in the control of a certain depression can reduce the damage to the human chest, abdomen. Hot-pressed boron carbide and silicon carbide ceramic matrix composites can be used to create robust anti-attack helmet decks. China is the world's three largest manufacturer of body armor, in the international market, the price of body armor in our country is about 500 US dollars, while the price of body armor in other countries is about 800 US dollars, in terms of manufacturing costs, our country has advantages.

Compared with traditional materials such as plastics and metals, advanced ceramic materials have the advantages of light weight, high temperature resistance, high hardness, friction resistance, corrosion resistance, small friction coefficient and special conductivity. Commonly used ceramic sheet materials are titanium diboride, boron carbide, silicon carbide, alumina and so on. It is widely used in lightweight and durable body armor against medium-caliber guns. Hot pressed boron carbide and silicon carbide ceramics can optimize the structural combination of composite materials to create strong armor plates resistant to multiple impacts.