What is High-Pressure Casting (HPDC)?

 Die casting is the process of producing metal parts by forcing molten metal into a machined mold cavity under high pressure. The die casting method is ideal for applications that require a large amount of small and medium-sized parts. It requires details, surface quality, and shape stability. Almost all molded parts are made of non-ferrous metals, especially zinc and aluminium. The variety of die-casting has made it one of the most mass-produced processes in the metallurgy industry.

How does the high-pressure casting process work?

The high-pressure horizontal casting machine makes sure the mold is completely closed. This is classified according to the amount of clamping force that can be applied. For Italpresse Gauss machines it goes from 550 tons to 5700 tons.

 

 

 

 

Depending on the metal used, the injection unit filling the mold can be a hot chamber or a cold chamber. In hot chamber die casting, the metal is held in a die casting machine. Then the metal is brought into the chamber and the mold by the deed of the inoculation piston. These divisions of the apparatus are always getting in touch with the molten metal.

In the cold room process, the metal is first melted in another furnace and transferred to a holding furnace. Then it is poured into the filling chamber and injected into the mold. Italpresse Gauss offers a wide range of high-pressure cold chamber casters.

Advantages of the high-pressure casting process

High-pressure casting technology can produce very large Die Cast Aluminum Alloys part at high volume and high speed.

The high-pressure casting process can also produce thin-walled components and castings, as well as various types of parts such as screws and linings.

Application

Cold chamber high pressure die casting technology is ideal for manufacturing a wide range of automotive aluminium and magnesium components.

They were widely used in other industries to manufacture application components ranging from the simplest (lighting components) to the most demanding (aerospace engine components).

Advantages of die casting:

1.  Good product quality

The dimensional accuracy of casting is high, generally equivalent to 6-7, up to 4.

Good surface finish, generally equivalent to 5-8.

It has high strength and hardness, generally 25 to 30% higher than sand mold casting, but the dispersion rate is reduced by about 70%.

The size is stable, and the compatibility is good.

It can press-mould thin and complex molded products. For example, current zinc alloy castings have a minimum wall thickness of 0.3 mm.

2.  High production efficiency

The die casting type has a long life and is a die casting type. Alloy die castings with a life of hundreds of thousands or millions. Easy to machine and automate.

3.  Excellent economic results

Due to the exact size of the die casting parts, the surface is shiny and clean. Generally, they are not mechanically processed and used directly, or the amount of processing is small. It improves the metal utilization rate and reduces a large number of processing equipment and working time. The casting price is simple. Composite Aluminum Die Casting can be used for other metallic or non-metallic materials.

While die casting has many advantages, it also has some drawbacks that have not yet been addressed. 

Critical Points in Die Casting Components

There are rules to consider when designing products or components in a die casting. Applying these tips will result in a design that is logical, efficient, and cost-saving.

To optimize the process and successfully avoid critical points in cast iron pressure of foundry components, it is important to know material reactions at each phase.

The geometry of the parting line

When the organization of the separation line, which is given by the design of the component. The Aluminum Die Casting Supplier must consider the position and length available for the liquid metal to flow into the cavity. It is also important to remember that an adequate entrance area will be needed and if the length of the entrance is restricted. It will have to be thick with the possible consequence of trimming problems. To overcome these problems, the solution might be to change the geometry of the component.

Relations section

It is better to develop the components with a fairly constant cutting thickness. However, in actual production, exceptions to this rule are possible, if the Aluminum Die Casting Manufacturer is experienced and knows how to do that.

Angles

Tilt angles could be useful to prevent the casting from sticking to the moving part of the moving mold.

Ribs

Strengthening an Aluminium Gravity Die Casting piece without thickening is possible with the ribs, which must be rounded, mixed and arranged to join the adjacent sections.

Flat surfaces

Smooth or flat surfaces are the widest design feature from zinc molding to production. There are many ways to make a more attractive product, and at the same time to reduce the cost of production. Collaboration between designers and the zinc die casting supplier, in a co-design activity, could help achieve the goals without wasting resources.

Fillets and mixes

Sharp corners can be avoided by using fillets, as these have a reinforcing effect. It is common practice in die casting to use a fillet with a minimum radius of 1.6 mm at the inner edges. A slight radius at the outer corners is an effective measure to decrease expenses.

The lettering

If letters are required, designers should use raised letters, rather than printed letters. Embossed letters allow to limit costs and minimize risks in terms of mold erosion.

Inserts

Depositing the inserts inside the dies or molds slows down the process times, for this reason, today the inserts are used less than in the past. Although it can also save you machining costs.

Best achievable linear tolerances

It is very important to work closely with the die inclination in the ongoing co-design activity. During the casting process, the linear tolerance band dies by 0.1% of the dimension and a level is allowed of confidence eight standard deviations. This dimension can be achieved only when the component geometry is favourable to consistent shrinkage without distortion after ejection from the die.

Design to avoid local matrix overheating

Designers must develop products or components to pay attention to problems caused by die overheating, which can lead to surface porosity, drag marks and cracks.

Design to avoid moving cores

Complex three-dimensional shapes are achieved through the use of moving nuclei, which slide into the matrix. If designers can achieve sufficient effect without moving cores, this will be a cost-saving action.