1. Application of ceramics in automobile engines
New ceramics are sintered from inorganic non-metals such as silicon carbide and silicon nitride. Compared with the alumina ceramics used in the past, it is more than three times stronger and can withstand high temperatures of more than 1,000 degrees Celsius. The new material promotes the development of new uses in automobiles. For example: to reduce the fuel consumption of diesel engines by more than 30%, it can be said that new ceramics are indispensable materials. 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 very superior to gasoline engines. However, more than 60% of the thermal energy is still lost. Therefore, in order to reduce this loss, ceramic materials with good thermal insulation properties are used to surround the combustion chamber for heat insulation, and then an exhaust gas turbocharger and a power turbine are used to recover exhaust energy. Tests have proven 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 quickly in an instant. The turbocharger uses a new type of ceramic, which has superior heat resistance than today's super heat-resistant alloys, but its specific gravity is only about one-third of that of a metal turbine. Therefore, the new ceramic turbine can compensate for the low dynamic response of the metal turbine. Other ongoing research includes the use of new ceramics in moving parts such as piston pins and piston rings. Engine efficiency is expected to improve due to weight reduction.
2. Application of special sensitive ceramics in automotive sensors
The requirement for automotive sensors is that they can be used in the harsh environments unique to automobiles (high temperature, low temperature, vibration, acceleration, moisture, noise, exhaust gas) for a long time, and should be small and lightweight, have good reusability, and have a wide output range. Ceramics are heat-resistant, corrosion-resistant, wear-resistant and have potentially excellent electromagnetic and optical properties. They have been fully utilized with the advancement of manufacturing technology in recent years. Sensors made of sensitive ceramic materials can fully meet the above requirements.
3. Application of ceramics in automobile brakes
Ceramic brakes are based on carbon fiber brakes. A carbon fiber brake disc is initially composed of carbon fiber and resin. It is pressed into shape by a machine. It is then made into a ceramic brake through several processes such as heating, carbonization, heating, and cooling. The hardness of the carbon silicon compound surface of the ceramic brake is close to that of diamond. The disc The internal carbon fiber structure makes it strong, impact-resistant and corrosion-resistant, making the disc extremely wear-resistant. At present, this kind of technology is not only used in F1 racing cars, but also in super civilian sports cars, such as Mercedes-Benz's CL55 AMG.
4. Application of ceramics in automotive shock absorbers
The vibration damping device of luxury cars is an intelligent damper successfully 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 road surfaces.
5. Application of ceramic materials in automobile spraying technology
In recent years, ceramic film spraying technology, which is widely used in aerospace technology, has begun to be applied to automobiles. The advantages of this technology are good thermal insulation effect, ability to withstand high temperatures and high pressures, mature technology, and stable quality. In order to achieve the goal of low heat dissipation, the engine combustion chamber components can be sprayed with ceramics, such as zirconium oxide sprayed on the piston top and zirconium oxide sprayed on the cylinder liner. The engine after this treatment can reduce heat loss, reduce the weight of the engine itself, reduce the size of the engine, and reduce fuel consumption.
6. Application of smart ceramic materials in automobiles
Smart ceramic materials as a specialty ceramic product classification, which includes environmentally sensitive materials used in automotive manufacturingMaterials that can respond sensitively to environmental changes have become the focus of research in the fields of materials science and engineering.
Smart ceramic products used in automobiles include smart material systems or structures that combine functional materials, drive systems, and feedback systems. Due to its comprehensive functions, automobile products can sense and respond to changes in the external environment while driving, allowing automobile products to have many functions such as self-checking, self-testing, self-diagnosis, self-repair, and self-adaptation. At present, some functional ceramic products have intelligent functions, such as semiconductor barium titanate positive temperature coefficient thermal resistors and zinc oxide varistor. They have the functions of self-diagnosis, backup protection and self-repair for temperature and voltage, making the material itself resistant to The ability to withstand sudden changes in the environment and can be used repeatedly. Among intelligent ceramic systems, piezoelectric ceramics are the most important category. The piezoelectric smart ceramic products and material systems that have been widely used and are being developed are as follows:
Automobile shock absorber: The intelligent shock absorber developed by utilizing the forward piezoelectric effect and reverse piezoelectric effect of intelligent ceramic products has the function of identifying the road surface and self-adjusting, which can minimize the vibration caused by rough road surfaces to the car. , the entire perception and adjustment process only takes 20 seconds. In addition, shock-absorbing devices made of smart ceramic materials can also be used in fields other than automotive products, such as stable working platforms for precision machining.
Automobile smart wipers: Using the piezoresistive effect of barium titanate ceramics, smart ceramic wipers can automatically sense the amount of rain and automatically adjust the wiper to the optimal speed.
Automotive active anechoic ceramic materials: Active anechoic ceramic materials composed of piezoelectric ceramic pickups, resonators, analog voice coils and digital signal processing integrated circuits can reduce the vibration frequency of the car to below 500 Hz.
In addition, smart ceramic materials can also be used to develop smart safety systems and smart transmission systems. For example, smart ceramic components are also used in airbags. The development, research and market of modern smart ceramic materials are already in the ascendant. At the same time, its application is not limited to the automobile industry, but also has an important impact on shipbuilding, construction, machinery, home appliances, aerospace, national defense and other industrial fields, and will greatly improve various industries. The level of intelligence and automation of similar mechanical and electronic products.
In short, special ceramics are ceramic material products that are constantly being developed, but there are many issues that have yet to be solved in terms of preparation of raw materials, material evaluation and utilization technology. At present, special ceramics are not widely used in automobiles.The main reasons are: the manufacturing process is complex and demanding; because special ceramics have strict requirements on raw materials and the process is difficult to master, it is difficult to maintain uniform performance of each batch of products; the cost is high, the processability is poor, the brittleness is high, and the reliability of use is poor. However, people have every reason to believe that with the rapid development of science and technology, more special ceramics and smart ceramic products will be introduced and used in automobiles in the future automobile manufacturing industry, and they will definitely be used in automobile production. Be widely used.
