Low pressure casting process and advantages
Low pressure casting filling the cavity of the liquid metal under pressure, and a method to form the casting. As the pressure used is lower, so called low-pressure casting. The process (see Figure 1) is: sealing the crucible (or seal tank), dry compressed air introduced into the molten metal 2 in the role of the gas pressure rises along the rising liquid tube 4 through the gate 5, smooth enters the cavity 8, and maintain the gas pressure on the liquid surface of the crucible has been completely solidified to the casting so far. Then release the pressure of the gas on the liquid surface, so that the the the unsolidified metal flow in the open pipette crucible, and introduced by the cylinder 12 open type castings.
The unique advantages of the low-pressure casting performance in the following areas:
1. Liquid metal filling is relatively stable;
2. Casting formability, is conducive to the formation of a clear outline, smooth surface castings, more favorable for the forming of large thin-walled castings;
3. Casting of dense, high mechanical properties;
4. Improve the process, the liquid metal yield, under normal circumstances does not require riser, greatly improving the yield of liquid metal, usually up to 90% recovery rate.
In addition, good working conditions; equipment is simple, easy to implement the outstanding advantages of mechanization and automation, low pressure casting.