Ceramic powder pressing mold is to pay attention to the ceramic powder into a large special die cavity, then, that is, through the powder mold for powder pressing pressure forming method. Ceramic powder pressing mold in most cases is the film. The suppression process, the main pressure is to suppress the internal friction and external friction.
For its powder particles to a large extent that there will be internal friction and powder particles and ceramic powder mold wall appeared between the external friction phenomenon, so that to a large extent it will lead to Unevenness from the beginning of the distribution of the density of the blank, manifested in the use of one-way press from the stamping die near the part density is higher, the farther part of the density is lower.
When the ratio of the height and the diameter of the compacts on the ceramic powder pressing mold is relatively large, the difference in density between the upper and lower sides is relatively large. At this time, we should pay attention to the bidirectional pressing method. In order to make the green compact density distribution more uniform, we actually should pay attention to should adopt the mold with friction mandrel to suppress.
Preparation of magnetic materials, the magnetic field will be used to improve the magnetic suppression, which is based on the ordinary mold to add an external magnetic field, the pressure direction and the magnetic field direction is to include both parallel and vertical. There is internal friction between the particles of the ceramic powder, and external friction occurs between the powder particles and the wall of the ceramic powder, so that the density distribution of the green compact is uneven.
Ceramic powder pressing mold performance in the use of unidirectional compression, the pressure from the punch will be relatively close to the part of the density is higher, the farther part of the density will be lower. When the ratio of the height and the diameter of the ceramic powder compact is large, the difference between the density of the ceramic powder and the diameter of the ceramic powder is relatively large. In this case, in fact, it is necessary to pay attention to the bidirectional pressure.