The characteristics and application of zirconia powder
Zirconia ceramics is a new type of high-tech ceramics. In addition to its high strength, hardness, high temperature resistance, acid and alkali corrosion resistance and high chemical stability, it also has the characteristics of scratch resistance, no signal shielding, and excellent heat dissipation performance. , At the same time, it has strong machinability and good appearance effect, and is suitable for mass production.
1 High melting point
The melting point of zirconia is 2715°C. The higher melting point and chemical inertness make zirconia a good refractory material.
2 High hardness and good wear resistance
Zirconia ceramics have greater hardness and better wear resistance. From the specific data, the Mohs hardness of zirconia ceramics is about 8.5, which is very close to the Mohs hardness of sapphire 9, while the Mohs hardness of polycarbonate is only 3.0, the Mohs hardness of tempered glass is 5.5, and the Mohs hardness of aluminum-magnesium alloy The Mohs hardness of Corning glass is 6.0, and the Mohs hardness of Corning glass is 7.
3 Relatively high strength and toughness
Zirconia ceramics have high strength (up to 1500MPa). Although there is a big gap in toughness compared with some metals, compared with other ceramic materials, zirconia ceramics are considered to be the best in the “ceramic circle” (1-35MPa .m1/2).
4 Low thermal conductivity, low coefficient of expansion
The thermal conductivity of zirconia is the lowest among common ceramic materials (1.6-2.03W/(m.k)), and its thermal expansion coefficient is close to that of metal. Therefore, zirconia ceramics are suitable for structural ceramic materials, such as zirconia ceramic mobile phone appearance structural parts.
5 Good electrical performance
The dielectric constant of zirconia is 3 times that of sapphire, the signal is more sensitive, and it is more suitable for fingerprint recognition patches, etc. From the perspective of shielding effectiveness, zirconia ceramics, as a non-metallic material, have no shielding effect on electromagnetic signals, and will not affect the internal antenna layout at all, and can be easily integrated to adapt to the 5G era.
Zirconia ceramics are widely used in modern industry and life. Let’s briefly introduce its main applications.
1 Mobile phones and other 3C electronics fields
Zirconia ceramics have no signal shielding, are resistant to falling, wear and folding, and at the same time have a warm and jade-like appearance and a good hand feel. They are widely used in 3C electronics such as mobile phones. Mainly used as mobile phone backplane and other mobile phone structural parts.
2 Smart wear field
Compared with metal, zirconia ceramics have better wear resistance, smooth surface, good texture, and no oxidation. Well-known brands such as the famous Swiss “Radar” brand, Apple, and Chanel have launched high-end ceramic watches.
3 Optical communication field
At present, ceramic ferrules and sleeves are widely used in optical fiber connector connectors. The ceramic ferrule made of high-strength and high-toughness ceramics can not only meet the high-precision requirements, but also have a long service life and very low insertion loss and return loss.
4 Biomedical field
Due to high strength, high toughness, corrosion resistance, wear resistance and good biocompatibility, zirconia ceramic materials are most commonly used in the field of biomedicine as dental restoration materials and surgical knives.
5 Automotive field
The thermal conductivity of zirconia ceramics is small, and the thermal expansion coefficient is relatively large, so the components used to make the engine combustion chamber have good heat insulation, and at the same time, they are closer to metal materials in terms of thermal expansion. It can be used as cylinder head bottom plate, cylinder liner, piston crown, valve seat ring, etc. However, due to the harsh working conditions of the engine, the strength of ceramic components changes greatly at high temperatures, so there is still a long way to go before commercial application.
6 Jewelry field
High-precision ceramics and precious metal alloy powder are mixed and fired, and finally integrated into jewelry design after several precise and strict procedures and multiple machine polishing. This ceramic is not only light and wear-resistant, but also has anti-sensitivity properties and is comfortable to wear.
7 Daily life
Ceramics have the characteristics of high temperature resistance, corrosion resistance, oxidation resistance, high strength, wear resistance, and natural antibacterial properties, and can be used as porcelain bowls and spoons, vases, ceramic knives, etc.
8 Other fields
Zirconia ceramics have good mechanical properties, and are wear-resistant and corrosion-resistant. They can be used as ceramic bearings and can also be made into ceramic knives.