Newly Developed Vacuum Differential Pressure Casting of Thin-Walled Complicated Al Castings

摘要

The VDPC process described has the following advantages:· The principle of the process was rational and the self-designed unit was reliable.· Because the mold was set in an evacuated chamber, the risk of entrapped gas appeared to be greatly reduced prior to mold filling.· The surface of the melt in the crucible was protected by inert gas and clean metal was drawn from the center of the melting furnace, which could result in defect-free casting during filling of the mold.· The casting soundness was significantly elevated due to solidification under applied pressure, which led to improvement in tensile strength and elongation higher than that of vacuum suction casting by 25 percent and 100 percent respectively.Based on the above mentioned advantages, the vacuum differential pressure casting process appears to be an excellent opportunity to produce highly qualified thin walled complicated casting of up to 1mm section thickness. It is also superior in many respects to gravity pouring and vacuum suction casting.