First, after the pressure is maintained, the mold must be opened to take out the precision casting product, so the time from the end of injection to the opening of the die-casting mold is called the mold opening time. Opening the mold in sufficient time can make the precision casting have a certain strength in the mold. If the opening time and the ejection time are inconsistent, the product will deform and crack. If the opening time is too short, the casting will be demoulded when the strength is relatively low, which will also cause the casting to deform.

Second, during the die-casting process, liquid metal enters the die-casting cavity and fills the cavity. The time required during this period is called the filling time by the precision foundry. The filling time depends on the size and complexity of the casting. Generally, the filling time of simple castings is very fast.

Third, the length of the holding time depends on the material and wall thickness of the precision casting. If it is a casting with a high melting point, a wide crystallization temperature range, and a thick wall, the holding time will be longer; if it is a casting with a small crystallization range and thin wall thickness, the holding time will be shorter; when holding the pressure, the precision casting manufacturer must also control the holding time. Pressure time. If the holding time is insufficient, it is easy to cause shrinkage defects in the casting. However, if the holding time is too long, it will not play a very important role. On the contrary, it will make it difficult to cut off the leftover material of the vertical die casting machine, so controlling the holding time is also a key point.