Dry press forming: The dry press forming technology of alumina ceramics is limited to objects with a simple shape and an inner wall thickness of more than 1 mm and a length to diameter ratio of not more than 4:1. The forming method is uniaxial or bidirectional. There are two types of presses, hydraulic type and mechanical type, which can be semi-automatic or fully automatic molding. The maximum pressure of the press is 200Mpa. The output can reach 15-50 pieces per minute. Due to the uniform stroke pressure of the hydraulic press, the height of the pressed parts is different when the powder filling is different.
The amount of pressure applied by the mechanical press varies with how much the powder is filled, which can easily lead to differences in dimensional shrinkage after sintering and affect product quality. Therefore, the uniform distribution of powder particles during dry pressing is very important for mold filling. The accuracy of the filling amount has a great influence on the dimensional accuracy control of the manufactured alumina ceramic parts. Powder particles larger than 60μm and between 60 and 200 mesh can obtain the maximum free-flow effect and obtain the best pressure molding effect.
