Vacuum modeling is a physical modeling method. It combines vacuum technology with sand vowin.cn/' target='_blank'>mold casting. The cavity surface and back of the sand vowin.cn/' target='_blank'>mold are sealed by plastic film, and negative pressure is generated by vacuum pumping to cause the inside and outside of the sand mold. The pressure difference causes the mold sand to be tightly formed. After placing the sand core, closing the mold, and casting, after waiting for the casting to solidify, the negative pressure is released or the air extraction is stopped, and the mold sand collapses to obtain the casting. According to the current application field, it can be divided into vacuum sealing model (V method) and solid vacuum casting (FV method).
Vacuum casting is an advanced die-casting process that eliminates or significantly reduces the pores and dissolved gases in the die-casting part by removing the gas in the die-casting mold cavity during the die-casting process, thereby improving the mechanical properties and surface quality of the die-casting part. Vacuum casting is generally divided into two forms: vacuum suction casting and vacuum die casting.
Vacuum suction casting is to insert the mold gate into the molten metal, and the mold is evacuated to make the mold cavity under negative pressure. Under the action of negative pressure, the molten metal rises along the gate and fills the mold, solidifying and forming, so as to obtain castings.
Vacuum die casting is a process for die casting after establishing a certain degree of vacuum in the die casting mold cavity.
Advantages of vacuum casting:
1. Eliminate or reduce the pores inside the die casting, improve the mechanical properties and surface quality of the die casting, and improve the plating performance;
2. To reduce the back pressure of the cavity, lower specific pressure and alloys with poor casting properties can be used, and it is possible to die-cast larger castings with small machines;
3. The filling conditions are improved and thinner castings can be die-casted.