Raw Material Treatment Before Forming of Zirconia Ceramics

The purpose of processing zirconia ceramic raw materials is to adjust and improve the physical and chemical properties of zirconia ceramics, so that zirconia ceramics can meet the requirements of subsequent processes and product performance. What are the specific details?

In general, zirconia ceramic raw material powder must undergo some treatments before use, such as calcination, crushing, sorting, and purification.

The purpose of processing zirconia ceramic raw materials is to adjust and improve the physical and chemical properties of zirconia ceramics, so that zirconia ceramics can meet the requirements of subsequent processes and product performance. What are the specific details?

1. Zirconia ceramic raw materials mixing

When preparing special ceramics, two or more raw materials are often used for mixing. Sometimes even if zirconia ceramics is a raw material, some trace additives must be added and mixed.

The quality of the mixture will directly affect the performance of the finished product. When the density and composition ratio of the mixed materials are very different or the characteristics of the materials are very special, the difficulty of mixing will increase.

2. Zirconia ceramic plasticization

The so-called plasticization refers to a process in which a plasticizer is added to a zirconia ceramic material to make the material plastic. Generally, plasticizers are added only when forgiving materials that are difficult to suppress.

In the powder metallurgy industry, plasticizers are usually called binders, and they are mixed with lubricants as forming agents.

3. Zirconia ceramic granulation

In order to obtain good sintering performance and improve the final performance of zirconia ceramics, usually, the very fine raw material powder must be selected.

However, the finer the raw material powder, the worse the fluidity, which is not conducive to automatic pressing, and the powder cannot evenly fill every corner of the mold.

Because the powder is too fine, the density of loose accumulation is small, and the mold volume is large, it is usually necessary to granulate before molding.

4. The calcination of zirconia ceramic raw materials

The main purpose of calcining zirconia ceramic raw materials is:

a. Remove volatile impurities, chemically bound, and physically adsorbed moisture, gas, and organic matter. Thereby improving the purity of zirconia ceramic raw materials;

b. Densify the raw material particles of zirconia ceramics and make their crystals grow, so as to reduce the shrinkage of zirconia ceramics in the subsequent sintering process and improve the qualification rate of zirconia ceramics;

c. Complete the crystal form transformation of the zirconia ceramic with the same crystal form to form a stable crystal phase.