Ceramic dry press molding is also called compression molding , is a process in which granular powder is placed in a steel mold and pressed into an object of a specific shape in a press. Dry pressing method is commonly used in the production of advanced ceramic solid materials: Dry pressing method is characterized by low binder content and can be directly sintered without drying. It has simple production procedures, high efficiency, small shrinkage and automatic production. It has many advantages and can be widely used to produce various functional ceramics and electronic components in round and sheet shapes. During dry pressing,CeramicThe quality of dry pressing molding is affected by many factors.
Mold finish and fit
Dry pressing of ceramics has higher requirements on the quality of the mold: first, the hardness of the mold must meet certain requirements. Since the ceramic stabilizer particles are very fine and have poor fluidity, the mold is required to have a very high finish. If the surface treatment does not meet the requirements, it will affect the flow of the material during dry pressing, resulting in delamination. At the same time, if the mold fit is not good and the gap is large, the ceramic powder particles will escape from the mold gap during the pressing process, resulting in less dust around the mold, so the surrounding area will not be compacted during the pressing process. Because delamination occurs due to inconsistent pressure transfer, the matching requirements for the mold are higher.
Demolding method and demoulding speed
Usually the ceramic is pushed out of the mold cavity, and the ejection speed should be smooth and slow. If you are not careful, the green body will Will crack. Practice shows that the demoulding tool must remain flat when demoulding, otherwise it will produce uneven force on the green body and cause cracks. In short, dry pressing is related to the above factors. In order to form an ideal body, The above aspects must be controlled.
Pressure speed and holding time
Pressure rate and holding time of dry pressed ceramics Improper control can also lead to defects such as delamination of the zirconia body. The die should be lowered slowly. If the pressurization speed is too fast, the gas in the green body will not be easily discharged, which will cause the green body to be stratified, the surface will be dense, the medium will be loose, and bubbles will appear. If the holding time is too short, when the pressure is not transmitted to the required depth, the external force will be eliminated, so the gas in the green body will not be easily discharged, and it will be difficult to obtain a more ideal green body, which will lead to delamination, bubbles, etc. Phenomenon. At the same time, the maintenance time should be unified; otherwise it will lead to uneven product thickness and waste.
In addition, CeramicsPressure and pressurization method of dry pressing. The quality of ceramic dry pressing also has a great influence, and you should also pay attention to it when dry pressing.
