Ceramic hot die casting
Ceramic hot die casting is a commonly used molding method for electronic ceramics, especially alumina ceramics. Usually, the prepared wax cake is placed in a hot press barrel to be heated and melted into a slurry. Under the action of compressed air, the slurry is applied. The material is injected into the cavity through the suction port, and the pressure is released after a certain time according to the shape and size of the product, and the slurry is cooled and formed in the cavity. The body after hot die casting can be processed, for example, turning, punching, etc., and then subjected to wax removal treatment to remove paraffin in the body and increase the strength of the body. After the wax is discharged, the adsorbent on the surface is cleaned and then sintered.
The ceramic hot die casting method is also grout molding in a certain sense, but the difference is that it mixes paraffin in the billet, utilizes the heat flow characteristics of paraffin, and uses metal mold to form under pressure. The process flow is shown in the figure as below.

The ceramic hot die casting process is suitable for small and medium-sized products with complex shapes and high precision requirements, and has simple equipment, convenient operation, low labor intensity, high production efficiency, small mold wear and long service life, so it is often used in special ceramic production.  However, ceramic hot die casting also has disadvantages. For example, the process is complicated, the energy consumption is large (multiple firing is required), and the construction period is long. For a thin, large and long product, it is not suitable because it is not easy to fill the cavity.

(4) High temperature wax discharge
The green body formed by hot injection is first subjected to wax removal before firing. Otherwise, the paraffin will lose its bond and disintegrate due to melting, volatilization and burning at high temperature, and the shape cannot be maintained. The wax is buried in the loose and inert protective powder. This protective powder is also called adsorbent. It is stable at high temperature and is not easy to bond with the green body. Generally, the industrial Al203 powder is calcined. material. Although the paraffin will melt and diffuse during the heating process, the adsorbent supports the green body. When the temperature continues to rise, the paraffin wax volatilizes and burns completely, and a certain sintering occurs between the powders in the green body.

At this time, neither the reaction nor the adsorption occurs between the green body and the adsorbent, and the green body has a constant strength. Usually, the wax discharge temperature is 900 to 1100℃, depending on the nature of the blank. If the temperature is too low, there is no certain sintering between the powders, there is no certain mechanical strength, the blank is loose, and the subsequent process cannot be carried out; if the temperature is too high, until it is completely sintered, serious adhesion will occur, which is difficult to clean. The surface of the blank. After the wax is discharged, the adsorbent on the surface is cleaned and then sintered. The waxing process is shown in the figure below.

At this time, neither the reaction nor the adsorption occurs between the green body and the adsorbent, and the green body has a constant strength. Usually, the wax discharge temperature is 900 to 1100℃, depending on the nature of the blank. If the temperature is too low, there is no certain sintering between the powders, there is no certain mechanical strength, the blank is loose, and the subsequent process cannot be carried out; if the temperature is too high, until it is completely sintered, serious adhesion will occur, which is difficult to clean. The surface of the blank. After the wax is discharged, the adsorbent on the surface is cleaned and then sintered. The waxing process is shown in the figure below.

You hand us your TRUST,
We hand you our BEST.