Zirconia ceramic structural parts have excellent performance, light structure, good electrical insulation performance, low thermal expansion coefficient, non-magnetic, non-conductive, high speed, low noise, high-temperature resistance, wear resistance, acid, alkali, and salt corrosion. Non-toxic, dimensional stability at high temperature, etc.

Working under harsh lubrication conditions, it has excellent dry running performance, which can just make up for the various deficiencies of metal materials, so it has been widely used in the automotive industry.

In recent years, scientists in the international special ceramics field have developed a large number of zirconia ceramic parts for automobiles after arduous experiments and research, which are summarized as follows:

1. Zirconia ceramic structure sensor

Zirconia ceramics have sensitive electrical performance parameters, and their excellent high-temperature resistance is used as induction heating tubes, refractory materials, and heating elements.

Zirconia ceramic oxygen sensor, as a component for purifying exhaust gas, is used to measure the O2 concentration in automobile exhaust, and then feedback the measured value to the engine air supply and fuel supply system to keep the fuel in a fully burned state. The mechanical performance is very superior during use, which can reduce the heat generated by friction.

2. Zirconia ceramic valve heater

Zirconia has three crystal forms: monoclinic, tetragonal, and cubic crystal phases. At room temperature, zirconia only appears as a monoclinic phase, it transforms into a tetragonal phase when heated to about 1100°C, and transforms into a cubic phase when heated to a higher temperature.

Due to the large volume change when the monoclinic phase changes to the tetragonal phase, and the large volume change in the opposite direction during cooling, it is easy to cause product cracking, which limits the application of pure zirconia in high-temperature fields.

But after adding a stabilizer (generally yttrium oxide is used), the tetragonal phase can be stabilized at room temperature, so there will be no volume change after heating, which greatly expands the application range of zirconia.

In order to make the engine burn completely when starting, inhale air in the engine. The side is equipped with a heating device, that is, a valve heater, to heat the suction air, so that the fuel evaporates and mixes completely. During suction heating, in order to control the temperature and improve the reliability of the device, the barium titanate ceramic PTC zirconia ceramic (thermistor) is used as the valve heater. With the use of ceramic valve heaters, the engine is in a complete combustion state as soon as it starts, so as to achieve the effects of improving thermal efficiency, saving energy, and purifying exhaust.

3. Zirconia ceramic engine

Partially stabilized zirconia ceramics not only have a mechanical strength of 100kg/mm2 but also have a lower thermal conductivity than other materials, only -0.04/cms. In terms of gas turbine engines, in order to achieve the same fuel cost as diesel engines, the inlet temperature of the turbine must be as high as 1350℃ for cars. Zirconia ceramics can endure 50-60℃/S rapid cold and rapid heat for a long time; due to strong mechanical performance, failure The rate is usually below 10-5. In the future, ceramic engines may be made of silicon nitride combined with silicon carbide ceramics or partially stabilized zirconia ceramic materials.

4. Zirconia ceramic sensing element

The car shock absorber is a smart shock absorber that has been successfully developed by using the positive piezoelectric effect, inverse piezoelectric effect, and electrostrictive effect of special zirconia ceramics. This kind of smart shock absorber has the function of recognizing the road surface and being able to adjust itself. It can minimize the vibration of the car on rough roads and make passengers feel comfortable.

In addition to the above four, many devices, parts, and small devices used in automobiles are also made of zirconia ceramics. Such as electronic buzzer, ultrasonic vibrator, heat-absorbing glass, photocell, oil plug ring, oil-water seal, etc. These zirconia ceramic parts have good adhesion to metals and other materials, can be mass-produced, and are inexpensive, and are easy to form industrialized operations. Looking forward to future automotive zirconia ceramic products, broad market demand will be formed.