Low-pressure casting: liquid metal (aluminum liquid) under the influence of small external pressure (20-80kPa), the introduction of liquid metal from the bottom of the cavity (aluminum liquid), so that liquid metal (liquid aluminum) bottom-up filling cavity , To form a casting casting method.
Low-pressure casting mold used for the metal and sand.
The casting process of low pressure casting includes the stages of liquid filling, filling, pressurizing, holding pressure, pressure relief and cooling. All stages are achieved by controlling gas pressure.
The advantages of low-pressure casting:
1. The liquid metal (liquid aluminum) is a smooth bottom-up filling mold, and the cavity flow direction and gas discharge direction, thus avoiding the liquid metal (aluminum liquid) on the wall and the core of the scouring, gas Etc., improve the quality of castings;
2. Casting solidification and shrinkage process is carried out under pressure, so the effect of shrinkage, casting high density, good mechanical properties;
3. Liquid metal (liquid aluminum) filling under pressure, increased mobility, is conducive to the production of complex thin-walled parts, to obtain a clear castings;
Defects of low-pressure casting: In the production of aluminum alloy castings, crucibles and risers long-term contact with liquid aluminum, vulnerable to erosion and scrapped; also make the liquid metal (aluminum) due to iron and deteriorated performance.
Low-pressure casting is currently mainly used for the production of aluminum alloy, such as the automobile industry automobile wheel hub, the internal combustion engine cylinder block, cylinder head and piston.