Pressure Die Casting Service

High Pressure Die casting (referred to die casting) is a metal casting process of making copies of metal parts in short cycle time by injecting molten liquid or semi-solid metal into the custom steel casting mold at a very high speed, which includes aluminium pressure casting and prototype zinc die casting. The die casting parts are formed and cooled and solidified under high pressure. The die casting mold is usually machined from a stronger steel, the process is somewhat similar to injection molding. Most die casting parts are made from zinc, copper, aluminum, magnesium, lead, tin, and lead-tin alloys and their alloys. Depending on the type of die casting, a cold chamber die casting machine or a hot chamber die casting machine is required. Die casting machine and molds are expensive, so the die casting process is generally suitable for manufacturing a large number of small and medium-sized castings, Die casting is one of the most widely used in various casting processes which has flat surface and high dimensional consistency.

High Pressure Die casting process involves injecting high pressure molten metal into a steel mold (called a die). A full high pressure die casting cycle can take from less than a few seconds for small parts to 2-3 minutes for castings over 30 pounds, which make high pressure die casting the fastest technology for producing precision non-ferrous metal parts in large quantities. The following process are typically showing how high pressure die casting work to produce a metal die casting parts. 

Clamping - Prepare and clamp the two halves of the mold/die. After cleaning and proper preparation, the two clean mold halves are greased to prevent sticking and the then the molds are closed and clamped. At this stage, a force must be applied to the mold to hold it in place as the molten metal is injected.

Injection - After transferring from the hot or cold chamber machine, the molten metal is injected into the mold by high pressure. These pressures range from 31,000 to 20,000 psi. The total injection time required for your project will depend on the length of time it takes to fill all of the cavities and channels in the mold. The exact duration of the injection time can be determined by the thermodynamic properties of the material and the wall thickness of the casting. The thicker the wall, the longer the injection time.

Cooling - Once the molten metal enters the mold cavity, the cooling process starts. The final shape of the die casting is formed when the mold cavity is fully filled and the molten metal hardens. It is important not to open the mold until it has completely cooled. This allows the casting to solidify completely. The thicker the wall, the longer the cooling time. In addition, complex mold geometries increase resistance to heat flow and require longer cooling times.

Ejection - After an adequate cooling time, the mold halves can be opened and the die cast part can be ejected from the mold cavity. Once the casting part is ejected, the mold can be closed and clamped for the next injection cycle.

Trimming - Excess material and burrs should be removed from the mold channels that solidify during the die casting process. This is done manually or with a trimming tool. The waste metal from trimming can be discarded or reused in the die casting processing.

1. Surface finish and dimension accuracy are excellent.

2. High density & strength. Die casting parts has a dense structure and high strength and hardness as the liquid metal is cooled and solidified under pressure.

3. High productivity efficiency. The die casting machine has high productivity. The filling time is extremely short and the cooling rate is extremely fast. And the lifespan of die casting mold is long, which can generally produce 60K-80K shots, sometime even as high as 100K shots.

4. Cost effective production. High material utilization. As die casting parts have the advantages of accurate size and good surface finish, they are general can assembled directly without machining, or only a small amount of machining is required, reducing a lot of processing cost. Its material usage rate is about 60%~80%, if not secondary processing, the utilization rate is about 90%. Therefore the price of die casting parts is cheap.

Metal parts with complex geometries can be made. Die casting can manufacture metal parts with complex shapes, clear contours and thin-walled deep cavities: because the molten metal is under high pressure and high speed, which maintains high flowability, which enables the acquisition of metal parts that are difficult to machine by other processes.