Low pressure casting is to place the casting mold in a closed holding furnace, and the cavity is connected to the molten metal in the furnace through a riser. In operation, pressurized air is added to the furnace and molten metal flows from the standpipe into the cavity. After the molten metal solidifies, the compressed air in the furnace is released, and the unsolidified metal flows back into the furnace from the riser.

Many parts are manufactured using low-pressure casting techniques, such as aluminum wheels and blades in torque converter cores. The casting obtained has a dense structure and good mechanical properties. The yield of this method is high, the same as that of gravity casting, and the yield is70% to 80%. High production efficiency. The production efficiency of the die casting process of the same product is three times that of gravity casting. And the surface is smooth and clean, which can reduce the machining allowance.

StartproceedWhen low pressure casting, please check the mold first. After the end of the production cycle, when the paint fails or the surface is uneven, it needs to be polished with a grinding wheel. Then clean the aluminum shavings of the ejector rod and clean the exhaust plug, and then bake the mold, the working temperature is (360±10)℃, so the mold should be baked to the working temperature before work.

Heat the low dieAt 300°C, apply the paint, and the paint must be uniform and free from sagging. This can prevent aluminum alloy from corroding the cavity and prolong the life of the mold. It can also prevent aluminum alloy from adhering to the cavity or parting surface, so that production can be carried out continuously and quickly. It can also make the cavity have a layer of heat insulation layer, protect the organization, make the molten metal flow into the cavity easily and smoothly, reduce the flow resistance of molten aluminum, and improve the filling performance of molten metal.

Then set the core and set the low pressure casting process parameters. The process parameters of low pressure casting are mainly the temperature of aluminum water, the pressure speed and pressure setting of the equipment. These three factors will affect the quality of the casting. If the setting is not good, it will cause defects such as sticky sand, insufficient pouring and blockage. Therefore, parameter setting is very important for casting.

Compared with traditional gravity casting, low-pressure casting can greatly increase the output of castings and have high working efficiency. Due to the crystallization under pressure, the structure of the casting is compact and the tensile strength can reachMore than 200MPa. However, low-pressure casting has higher requirements for equipment, molds and processes, and you need to be extra careful when casting.