In this article, we will define squeeze casting and discuss the factors that influence its quality. Take a look at the discussion below.
Squeeze casting is a method of casting that combines casting and forging. Molten metal is poured into the die mold (metal mold) and allowed to solidify (almost freeze) before being forged by pressing it against the surface of the mold. Pressure applied to semi-solid metal can change the melting point of the alloy, aiming to increase the speed of solidification in castings and reduce shrinkage porosity.
Metal liquid volume, pouring temperature, die mold temperature, pouring time, pressure limit, pressing duration, and lubrication are all factors that affect the quality of the cast as a result of squeeze casting.
Factors that affect squeeze casting quality
The volume of metal liquid (melt volume)
The volume of metal liquid is adjusted to the capacity of the print cavity, so control is required to ensure that the liquid does not exceed the print cavity capacity, as this will affect the quality of the results.
The temperature of the casting
This temperature is determined by the alloy and the shape of the casting. The pouring temperature must be regulated during the pouring process because it has a significant impact on the casting’s quality.
Misrun defects are caused by pouring temperatures that are too low. What exactly is a misrun defect? Misrun defects occur when the metal liquid does not fill the mold cavity due to premature metal freezing.
In pouring it needs to be done quickly but still consider the weight, thickness of the casting and cast material to determine the right pouring time.
The temperature of the tool / die mold
Normal temperatures range from 190°C to 315°C. This temperature range can be reduced for casting products with a relatively thick cross-section. To allow for adequate clearance or ventilation between the two, the punch temperature is typically set to 15°C -30°C lower than the lowest die temperature. Excessive clearance between the punch and die causes erosion on both surfaces.
Waiting Time (time delay)
The time measured from the first time the molten metal is poured into the mold cavity until the punch surface touches and begins to press against the molten metal surface is referred to as the time delay.
If the product has a complex cross-sectional shape, the molten metal takes a long time to fill the entire mold cavity. It takes enough time for the punch to strike and press against the molten metal. This is done to prevent shrinkage.
Pressure limit (pressure level)
Depending on the geometry of the component and the required mechanical properties, the normal pressure range is 50-140 MPa. However, the minimum pressure could be 40 Mpa. The most common pressure is 70 Mpa.
Pressure time
The duration of the suppression is calculated from the lowest point of the punch until the punch is lifted (the pressure is released). For cast objects weighing up to 9 kg, the typical pressing time ranges between 30-120 seconds.
Lubrication
Lubricant on the surface of the die is required for the squeeze casting process to facilitate the removal of the casting product from the mold.
This is a discussion of the definition of squeeze casting and the factors that influence the quality of the results. If you have any questions or need more information, please leave them in the comments section or contact our team directly.