Application of advanced ceramic materials in automobiles

For the automotive industry, using special materials to build cars is nothing new. Manufacturers have long used materials such as carbon fiber and aluminum-magnesium to decorate avant-garde and fashionable high-performance cars.

(1) Application of ceramics in automobile engines

The new ceramics are sintered from inorganic non-metals such as silicon carbide and silicon nitride. They are more than three times stronger than alumina ceramics and can withstand temperatures above 1000°C. To reduce the fuel consumption of diesel engines by more than 30%, new ceramics are indispensable. In current gasoline engines, about 78% of the combustion energy is lost in heat energy and heat transfer. The thermal efficiency of diesel engines is 33%, which is much better than that of gasoline engines. However, more than 60% of the heat energy is still lost. Therefore, in order to reduce this part of the loss, ceramic materials with good thermal insulation properties are used to surround the combustion chamber for insulation, and then exhaust gas turbochargers and power turbines are used to recover exhaust energy. Experiments have shown that this can increase the thermal efficiency to 48%. At the same time, due to the use of new ceramics, it will become possible for diesel engines to start instantly and quickly. The turbocharger using new ceramics has better heat resistance than today's super heat-resistant alloys, but its specific gravity is only about one-third of that of metal turbines. Therefore, the new ceramic turbine can compensate for the disadvantage of low dynamic response of metal turbines.

(2) Application of special sensitive ceramics in automotive sensors

The requirements for automotive sensors are that they can be used in the harsh environment unique to automobiles (high temperature, low temperature, vibration, acceleration, humidity, noise, exhaust gas) for a long time, and should have the characteristics of small size, light weight, good reusability, and wide output range. Ceramics are heat-resistant, corrosion-resistant, wear-resistant, and have potential excellent electromagnetic and optical functions. In recent years, with the advancement of manufacturing technology, they have been fully utilized. Sensors made of sensitive ceramic materials can fully meet the above requirements.

(3) Application of ceramics in automotive brakes

Ceramic brakes are made on the basis of carbon fiber brakes. A carbon fiber brake disc is initially made of carbon fiber and resin. It is pressed into shape by a machine and then made into a ceramic brake through several processes such as heating, carbonization, heating, and cooling. The surface hardness of the carbon silicon compound of the ceramic brake is close to that of diamond. The carbon fiber structure inside the disc makes it strong, impact-resistant, and corrosion-resistant, making the disc extremely wear-resistant. At present, this type of technology is not only used in F1 racing cars, but also in super civilian sports cars.

(4) Application of ceramics in automobile shock absorbers

The shock absorber of high-end cars is an intelligent shock absorber developed by comprehensively utilizing the positive piezoelectric effect, inverse piezoelectric effect, and electrostrictive effect of sensitive ceramics. Due to the use of highly sensitive ceramic components, this shock absorber has the function of identifying the road surface and self-adjusting, which can minimize the vibration of the car caused by rough roads.

(5) Application of ceramic materials in automobile spraying technology

In recent years, the ceramic thin film spraying technology widely used in aerospace technology has begun to be applied to automobiles. The advantages of this technology are good thermal insulation, ability to withstand high temperature and high pressure, mature technology, and stable quality. In order to achieve the goal of low heat dissipation, ceramic spraying can be performed on the engine combustion chamber components, such as zirconium oxide sprayed on the piston top and zirconium oxide sprayed on the cylinder liner. The engine treated in this way can reduce heat dissipation loss, reduce the engine's own weight, reduce the engine size, and reduce fuel consumption.