Application of Alumina Ceramic Valve Plates in Automotive Engines

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Performance advantages of alumina ceramic valve disc
Aluminum oxide ceramic valve disc is a high-performance ceramic material, mainly composed of aluminum oxide (Al ₂ O3), with a content usually exceeding 99.7%. This material has the following significant performance advantages:

1. High temperature resistance performance
   -The temperature of the combustion chamber in a car engine can reach over 800 ℃, while the melting point of alumina ceramic valve plates can reach as high as 2050 ℃. At 900 ℃, its thermal expansion coefficient is only 1/5 of that of metal, which means that under high temperature conditions, the sealing surface of the valve plate will not deform due to thermal expansion, thus ensuring the sealing performance of the engine.
2. Wear resistance performance
   -The speed of turbocharged engines usually exceeds 5000rpm, and high-frequency friction between valve plates and components such as camshafts can cause rapid wear of traditional metal valve plates. The hardness of alumina ceramic valve plates reaches Mohs 9, second only to diamond. Its wear rate is 75% lower than that of metal valve plates, and its service life can be extended by 3-5 times.
3. Lightweight
   -The density of alumina ceramic material is only one-third of that of steel. The use of ceramic valve plates can reduce the overall weight of the engine by about 0.8kg, thereby reducing fuel consumption by about 0.3-0.5L per 100 kilometers. While improving fuel economy, it also conforms to the development trend of automotive lightweighting.
4. Self lubricating characteristics
   -Alumina ceramic materials have self-lubricating properties and can effectively reduce friction noise. Actual test data shows that the use of ceramic valve plates can reduce the noise of the engine at idle by 2dB (A), thereby improving driving comfort.
5. Precise sealing
   -Aluminum oxide ceramic valve plates can achieve precise sealing and reduce gas leakage. The actual test results show that the emissions of unburned HC (hydrocarbons) can be reduced by 15%, which helps vehicles meet stricter National VI B emission standards.

The Application Effect of Alumina Ceramic Valve Plates in Automotive Engines
The application of alumina ceramic valve plates has brought significant changes to the performance improvement of automotive engines:

1. Improved response speed
   -Due to the small inertia mass of ceramic valve plates, their switching response speed is 20% faster than traditional metal valve plates. This makes the valve control of the engine more precise, especially at low speeds, which can significantly improve torque output.
2. NVH performance optimization
   -NVH (Noise, Vibration, and Acoustic Roughness) performance is an important indicator for measuring the comfort of automobiles. The self-lubricating characteristics of alumina ceramic valve plates can effectively reduce the friction noise inside the engine, thereby improving the overall NVH performance of the vehicle.
3. Emission control upgrade
   -The precise sealing performance of alumina ceramic valve plates can reduce gas leakage inside the engine. This not only improves the combustion efficiency of the engine, but also significantly reduces the emissions of unburned HC, which helps cars meet increasingly strict environmental emission standards.

Applicability of Alumina Ceramic Valve Plates in Different Types of Engines
Aluminum oxide ceramic valve plates are not only suitable for traditional fuel engines, but also meet the needs of various new engines:

1. Turbocharged engine
   -The high-temperature and high-pressure environment of turbocharged engines places extremely high demands on the temperature resistance and sealing of valve plates. Aluminum oxide ceramic valve plates can withstand high temperatures of 1200 ℃ and maintain zero deformation at high temperatures, perfectly solving the problem of sealing failure of traditional metal valve plates under high temperature and pressure.
2. Hydrogen fuel cell
   -The medium of hydrogen fuel cells is corrosive, and its high-frequency motion also poses a challenge to the wear resistance of valve plates. Aluminum oxide ceramic valve plates are not only corrosion-resistant, but also have a lifespan of over a million cycles, which can meet the special needs of hydrogen fuel cells.
3. Hybrid engine
   -The frequent start stop of hybrid engines makes the wear problem of valve plates particularly prominent. The wear resistance of alumina ceramic valve plates has been increased by 4 times, which can effectively extend the service life of valve plates and reduce maintenance costs.
4. High performance racing engine
   -The maximum speed of high-performance racing engines places extremely high demands on the sealing and reliability of valve plates. The lightweight design and high reliability of alumina ceramic valve plates make them an ideal choice for high-performance racing engines.

The application of alumina ceramic valve plates in automotive engines is of great significance due to their excellent performance.