Pressure casting is a widely used process for producing metal parts in a range of sectors, from aerospace engineering to medical equipment manufacturing. Pressure casting harnesses a high-pressure injection of molten metal, forcing it into a mold of the desired shape. The result is a detailed part with a permanently consistent shape and surface quality.
The main benefit of pressure casting is its repeatability. The molten metal is forced into the mold and sets in a predetermined shape without any need for post-processing. This precision casting and finishing process makes it ideal for high-volume mass production of parts with consistent repeats across hundreds or even thousands of individual casts.
The other distinct advantage of pressure casting is its relative speed. The injection process is much quicker than traditional sand casting or die-casting, meaning speeds of up to 2000 cycles per hour are possible, depending on the material grade. This makes pressure casting well suited to high-volume production lines, where time and money can be saved on manufacturing.
The high pressure used in pressure casting also has the advantage of improving the integrity of the resulting part’s surface finish. The resulting near-net-shape eliminates many of the surface machining and finishing processes required to obtain the desired surface finish. There are four main categories of pressure casting processes available: pressure die-casting, hot chamber die-casting, cold chamber die-casting and injection molding.
The most commonly used metal alloy for pressure casting is aluminum. Aluminum is lightweight yet strong and affordable, making it ideal for auto parts, medical equipment and electronics component production. Other materials can be used too, including steel and magnesium alloys, but the pressure cast process itself generally remains the same.
The pressure casting process begins with the preparation of a metal alloy in the form of a liquid. This liquid is then forced through a sprue, or injector, into a heated chamber, where it is met by a pre-made cavity in the shape of the desired component. The metal alloy then rapidly fills the mold due to the high pressure injected, cooling very quickly and solidifying into the desired shape.
The cast component then needs to be separated from the molding material. This can be done using an automated system or manually depending on the scope of the project and the complexity of the component. Once removed from the mold material, the component is ready for use after minor finishing or polishing procedures.
Pressure casting is a versatile manufacturing process with a wide range of applications. It can be used to produce complex and intricate components which need a consistent and repeatable surface finish. It offers the advantages of higher speeds and more efficiency compared to traditional sand casting, making it ideal for high-volume production runs. With a wide range of alloys available to use, pressure casting can provide an economical solution for many different sectors.
