Detailed explanation of the working of low pressure casting machine

　　In a low-pressure Casting Machine, dry compressed air is introduced into a sealed crucible (or sealed tank). Under the action of gas pressure, the molten metal enters the sprue 3 along the riser and rises, then smoothly enters the mold through the inner sprue, maintaining the gas pressure on the liquid level in the crucible until the casting is completely solidified. Then the gas pressure on the liquid surface is released, the unsolidified metal in the riser flows back to the crucible, the mold is opened again, and the casting is taken out. Differential pressure casting is based on low pressure casting. Cover the mold with a tight-fitting lid and simultaneously introduce compressed air into the crucible and lid. The pressure in the crucible is slightly higher, so that the molten metal in the crucible is filled into the Casting mold through the riser under the action of the pressure difference, and crystallizes under the pressure. It is a combination of low pressure casting and pressure crystallization.

　　Before using the low-pressure casting machine, the machine must be lubricated to maintain normal use of the parts. It is also necessary to clean the Gravity Casting Machine to avoid abnormal operation of the gravity casting machine due to excessive dust. All components of the low-pressure casting machine should be checked regularly. If serious damage or wear is found, they should be replaced in time to avoid affecting normal production.

 

　　The aluminum liquid in the raw material furnace of the low-pressure casting machine must also be processed regularly. Slag and oxygen removal in the furnace must be done well, and the alumina on the furnace surface must also be cleaned regularly. During the use of the gravity casting machine, the low-pressure casting machine must be inspected and maintained every day. This can not only ensure the stability of the mechanical equipment during use, but also identify potential hazards of the machine during the maintenance process.

 

　　Frequently Asked Questions in Aluminum Alloy Gravity Casting

 

　　1.（1）The aluminum liquid was not stirred sufficiently before pouring and the temperature was too high during pouring.

；（2）The coating is uneven and may be too thick.

 

　　Treatment method:

1.Before pouring, the aluminum liquid should be fully stirred evenly and the pouring temperature should be appropriately lowered.

2.Appropriately reduce the wall thickness of the casting to shorten the solidification speed of the coating.

 

　　2.（1）Mold temperature is too low and exhaust is poor；（2）If the pouring speed is too slow, there may be problems such as continuity, unreasonable planning of the pouring system, and too few gates；（3）The planned wall thickness of the casting was too small and the corners may be short but necessary.

 

       Treatment method:

1.Move the mold temperature and properly set up ventilation slots or exhaust plugs to ensure smooth exhaust;

2.Proper moving pores.

 

　　3.（1）The pouring speed is too fast and the pouring temperature is too high；(2)The exhaust is not smooth and the exhaust volume may be too large;（3）Melting temperature is too high.

 

　　Treatment method:

1.Reduce the pouring speed and the pouring temperature appropriately to ensure smooth pouring;

2.Control the exhaust volume to make it appropriate;

3.Strictly control the melting temperature to prevent excessive temperature.