About 60 years ago, the industrial application of zirconia ceramics was far from being developed. After about 1970s, large-scale research on the application of zirconia ceramics began worldwide, because it showed excellent performance in engineering applications. performance.
Zirconia ceramics are a new type of ceramics. They have very good physical and chemical properties. They have not only become a research hotspot in the scientific research field, but also have been widely used in industrial production. They are important raw materials for refractory materials, high-temperature structural materials and electronic materials. Among various metal oxide ceramic materials, zirconia has the best high temperature thermal stability and heat insulation performance, and is most suitable for ceramic coatings and high temperature refractory products.
Zirconia-based ceramic pigments using zirconia ceramics as the main raw material are important components of high-grade glazes; the thermal conductivity of zirconia is the lowest among common ceramic materials, and the thermal expansion coefficient is close to that of metal materials, becoming important Structural ceramic materials; special crystal structure makes it an important electronic material;
Zirconia ceramics become the darling of plastic ceramics due to their phase transformation and toughening characteristics; good mechanical properties and thermophysical properties make them excellent reinforcing phases in metal matrix composites.
Since Gupta first reported the tetragonal zirconia ceramic TZP, research on TZP materials has been in the ascendant. TZP ceramic is one of the materials with the highest mechanical properties at room temperature among zirconia-toughened ceramics.
Its strength and fracture toughness can be as high as 1.5 GPa and 15 MPa / m2, and its hardness, abrasion resistance and chemical resistance are also good. It is often used in harsh environments and harsh load conditions, such as wire drawing dies, bearings, Seals and replacement human bones, as well as engine piston crowns, cams in valve trains, fiberglass and tape cutters, etc.
As far as we know, zirconia ceramics have the properties of wear resistance, high temperature resistance and non-conductivity, but piezoelectric zirconia ceramic rods will cause some damage to the ceramic rods if they are not used properly at high temperature and pressure. How to use piezoelectric oxidation correctly Zirconium ceramic rods.
After the piezoelectric zirconia ceramic rod is heated in the air, a dense zirconia film is formed on the surface, which becomes an anti-oxidation protective film, which has the effect of extending the life. The greater the amount of current applied to the ceramic rod, the higher the surface temperature of the ceramic rod.
As the temperature of the ceramic rod increases, the life will be shorter, so after the furnace temperature exceeds 1600 ° C, the oxidation speed will increase and the life will be shortened. During use, care should be taken not to make the surface temperature of the ceramic rod too high.
During use, the resistance gradually increases due to the oxidation of the rod. In order to keep the furnace temperature normal, the operating voltage should be increased. When the voltage is increased to the maximum limit of the transformer used and the requirements are still not met, the furnace can be stopped to change the connection method of the rod and then continue to be used.
Do not overload ceramic rods. If the rod is broken for some reason or the rod is unevenly heated, it is partially incandescent or dark red for a period of time, which indicates that the rod body is inconsistently aging, and the resistance between the segments is too large. The furnace should be stopped for repair and replacement.
Pay attention to moisture prevention during storage. If metamorphic deliquescence is found at the end of the rod sprayed aluminum, aluminum can be sprayed again after surface treatment. If there is no aluminum spraying condition, several layers of aluminum foil can be wrapped in the aluminum spraying section of the rod for reuse.
The correct use of high temperature resistant zirconia ceramic rod is as above.