Under what circumstances will alumina ceramics cause wear?
Alumina ceramic structure is a very widely used product, the majority of users is its series of superior performance. However, in the actual use process, alumina ceramic structural parts will inevitably be worn, the factors causing structural wear are many, can effectively prevent the wear of alumina ceramic structural parts from these aspects.
It is understood that an important factor in the wear of alumina ceramic molds is the strong external force. During the use of the product, once it is subjected to impact force or pressure, it will lead to wear or breakage of alumina ceramic structures. Therefore, we should try to avoid collision with objects during operation to reduce damage.
Secondly, if the alumina ceramic structure is used for a long time, it will also produce a certain degree of wear, but this is a normal phenomenon, only need to replace it after excessive wear, indicating that the service life of the alumina ceramic structure has expired.
In addition, the general environmental factors will also make alumina ceramic structural parts wear, the so-called general environmental factors should be the influence of the medium in the environment, the influence of wind, the influence of temperature, etc., many times because of long-term wind erosion to make the structural parts wear.
At the same time, it may be because of the influence of impurities in the environment, no matter what factors cause the wear of alumina ceramic structural parts, it is necessary to repair and replace the parts in time, without affecting the normal operation.
Characteristics of alumina ceramics
Alumina ceramics are divided into high purity type and ordinary type two.
High purity alumina ceramic series Al2O3 content of more than 99.9% of the ceramic material, due to its sintering temperature as high as 1650-1990 ℃, transmission wavelength of 1 ~ 6μm, generally made of molten glass to replace platinum crucible; Use its light transmission and alkali metal corrosion resistance as sodium lamp tube; It can be used as integrated circuit board and high frequency insulation material in the electronics industry.
Ordinary alumina ceramics are divided into 99 porcelain, 95 porcelain, 90 porcelain, 85 porcelain and other varieties according to the Al2O3 content, and sometimes the Al2O3 content is also classified as ordinary alumina ceramics series. Among them, 99 alumina porcelain materials are used to make high temperature crucible, refractory furnace pipe and special wear-resistant materials, such as ceramic bearings, ceramic seals and water valves; 95 alumina porcelain is mainly used as corrosion resistance and wear resistance parts; The 85 porcelain is often mixed with talc to improve the electrical properties and mechanical strength, and can be sealed with molybdenum, niobium, tantalum and other metals, and some are used as electric vacuum devices.
1. High hardness
Measured by the Shanghai Institute of Silicate of the Chinese Academy of Sciences, its Rockwell hardness is HRA80-90, the hardness is second only to diamond, far more than the wear resistance of wear-resistant steel and stainless steel.
2. Excellent wear resistance
The wear resistance is 266 times that of manganese steel and 171.5 times that of high chromium cast iron. According to our customer tracking survey for more than ten years, under the same working conditions, the service life of the equipment can be extended at least ten times.
3. Light weight
Its density of 3.5g/cm3 is only half that of steel, which can greatly reduce equipment load.
Main technical indicators of alumina ceramics
Alumina ceramic content ≥92%
Density ≥ 3.6g /cm3
Rockwell hardness ≥80 HRA
Compressive strength ≥850 Mpa
Fracture toughness KΙC ≥4.8MPa·m1/2
Bending strength ≥290MPa
Thermal conductivity 20W/m.K
Thermal expansion coefficient: 7.2×10-6m/m.K
