What is The Preparation Process of Advanced Ceramic Materials?

The preparation process of Advanced ceramics mainly includes the synthesis of original powder, product molding, sintering, processing and inspection. In addition, according to the appearance characteristics of ceramic products, advanced ceramics can also be divided into advanced ceramic solid materials, advanced ceramic composite materials, advanced ceramic porous materials, etc. For the preparation of these advanced ceramic materials, the following figure shows the preparation process of advanced ceramic materials.

1. Raw materials

Generally, they are chemical reagents or industrial chemical raw materials with high purity that have been purified and processed. Sometimes relatively primary raw materials can also be used, and the purification of raw materials is carried out together with the synthesis process of the powder.

2. Powder synthesis

Powder that meets the requirements (chemical composition, phase composition, purity, particle size, fluidity, etc.) is synthesized from the starting raw materials through chemical reactions. The powder synthesis method can be mechanical crushing with particle refinement. It can also be prepared by the main method of nucleation and growth of particles in the medium, the latter is generally a chemical method. According to the different phases of chemical reactions, chemical methods can be divided into liquid phase methods, gas phase methods and solid phase methods

3. Powder adjustment

If the synthesized powder does not meet the design or subsequent process requirements, the powder needs to be adjusted. If the powder is not fine enough or contains large agglomerates, the powder needs to be ground. If it contains undesirable ionic impurities, it can be washed. Powder adjustment also includes the addition of organic additives, humidity adjustment, granulation, mud (ductile material) and slurry preparation, and kneading to make it suitable for molding.

4. Forming

Transform the dispersion system (powder, ductile material and slurry material) into a block with a certain geometric shape, volume and strength, also called a blank. Granular powders are molded by dry pressing or isostatic pressing; ductile materials are suitable for extrusion molding or injection molding; slurry materials are molded by casting.

5. Pretreatment before sintering

Since the molded body contains a certain amount of organic additives and solvents, it generally needs to be processed before sintering, that is, drying and burning off of the organic additives.

6. Sintering

Refers to the process of causing the microstructural changes of the molded body to cause its volume to shrink and its density to increase under a certain temperature and pressure. Sintering is a key step in the manufacture of ceramic materials. Through sintering, the material not only becomes dense, but also acquires considerable mechanical properties such as strength and various other functional properties.

7. Machining

Engineering Ceramics must be processed according to customer requirements before use. Due to the large shrinkage that occurs during the sintering process than green Ceramic parts, the dimensional deviation of the sintered body is on the order of millimeters or even larger, which cannot meet the fitting requirements at all, so further finishing is required.