Sintering mode of zirconia ceramics Application of zirconia ceramics

Zirconia ceramics sounds like a very tall ceramic product, white and yellow or gray with impurities. It has the characteristics of high boiling point and high hardness. It is an insulator at room temperature and conducts electricity at high temperature. Bian Xiao also knows little about zirconia ceramics. I consulted the relevant literature and learned some knowledge about it. Now I share it with you.

First, the sintering method of zirconia ceramics

1, electric field sintering:

When the zirconia ceramic body is sintered under the action of DC electric field, some ferroelectric zirconia ceramics with high Curie point, such as lithium niobate zirconia ceramics, are applied with DC electric field at both ends of the ceramic body at its sintering temperature, and after cooling to below Curie point (Te- 12 10℃), the electric field is removed, thus obtaining piezoelectric zirconia ceramic samples.

2. Activation and hot pressing sintering:

Hot-pressing is an efficient hot-pressing technology, which can obtain high-density ceramic materials at lower temperature, lower pressure and shorter time by using the activated state of reactants in decomposition reaction or phase change process. Electronic zirconia ceramics such as barium titanate, lead zirconate titanate and ferrite are made by hot pressing through the decomposition reaction of hydroxide and oxide; High density beryllium oxide, thorium oxide and zirconia ceramics were prepared by hot pressing through carbonate decomposition reaction.

3, activation sintering:

Its principle is to use some physical or chemical methods to make the atoms or molecules of reactants in a high energy state before or during sintering. Using the instability of this high energy state, it is easy to release energy and become a low energy state. As a new process of intensified sintering, it is also called reactive sintering or intensified sintering.

Second, the application of zirconia ceramics

1. Among structural ceramics, zirconia ceramics are widely used in the field of structural ceramics because of its high toughness, high bending strength, high wear resistance, excellent thermal insulation performance and thermal expansion coefficient close to that of steel. It mainly includes: Y-TZP grinding balls, dispersed grinding media, nozzles, ball valve seats, zirconia molds, miniature fan shafts, optical fiber pins, optical fiber sleeves, wire drawing molds and cutting tools, wear-resistant tools, clothing buttons, watch cases and watchbands, bracelets and pendants, ball bearings, light golf clubs and other normal-temperature wear-resistant parts. Clothing button picture

2. In terms of functional ceramics, its excellent high temperature resistance can be used as induction heating pipes, refractories and heating elements. Zirconia ceramics have sensitive electrical properties and are mainly used in oxygen sensors, solid oxide fuel cells, SOFC (SOFC) and high temperature heaters. ZrO2 has a high refractive index (n-2 1 22).

3. Add some coloring elements (V2O5, MoO3, Fe2O3, etc.). ) ultrafine zirconia powder can make it a colorful and translucent polycrystalline ZrO2 material, which shines like a natural gem and can be made into various decorations. In addition, zirconia is also widely used in thermal barrier coatings, catalyst carriers, medical care, refractories, textiles and other fields.

The above is some knowledge of zirconia that Bian Xiao learned, and I hope it can help everyone, because Bian Xiao is also a novice to zirconia ceramics, and his understanding is not very deep. If you need to know more about zirconia ceramics, you need to collect relevant knowledge about zirconia ceramics.