What is High Pressure Die Casting?

Have you ever wondered how to manufacture complex automotive components? For example, engine blocks, transmissions, or suspensions. High pressure die casting is a common manufacturing process. Whether it’s a large automotive component or a lightweight tool used in the medical field, it can be manufactured using high pressure die casting.

With this article, you can learn more specific information about the process. It will introduce you to the high-pressure die casting method, how it works, and its benefits. This will allow you to see for yourself if this process is suitable for your manufacturing needs.

What is High Pressure Die Casting?

In high pressure die casting, liquid metal is poured into a mold. The metal is then allowed to solidify to create the desired part. The molten metal is usually pressed into the mold cavity under high pressure and held in place by a powerful press. When the liquid metal has solidified, the mold is opened to remove it. After pushing the completed casting out, the mold is locked again for the next production run. The two steel blocks that make up the high-pressure die casting mold are the ends of the mold cavities, which are used to create the desired product.

The Origin of High Pressure Die Casting

So, what is die casting? The die casting process was first introduced to the printing industry in the mid-19th century. Keys for printing presses were made by pouring a mixture of lead and tin into a steel mold. Later, the process became known in many other fields as well. When die casting, a wide variety of products can be made using different-shaped dies.

After 1914, different materials such as zinc and aluminum alloys began to be used in the manufacturing process. Today, these materials are still commonly used in the industry. In addition, in modern times, more and more industries are using the metal die casting process.

How Does High Pressure Die Casting Work?

Mold preparation, injection, ejection, and post-cast processing are the four main steps in high-pressure casting. Methods may need to be altered to accommodate different products. Some of these modifications include vacuum die casting, slow filler die casting, semi-solid state metal working (SSM), etc. The following are general steps that usually need to be taken:

Making the Mold

Before starting to make parts, the die casting mold needs to be cleaned to remove any dirt or dust. The inside of the mold is then greased. This will keep the temperature of the mold stable and make it easier to remove the finished product.

Injection

The molten metal is poured into the pressure injection chamber and then the liquid metal is injected into the mold. There are two different ways of filling the process. One is injection in a hot chamber and the other is injection in a cold chamber.

Hot chamber injection

In this method, the injection device is placed directly into the furnace. The molten metal passes through the injection plunger into the nozzle and then into the mold. Metals such as zinc, magnesium, and lead can be processed in this way. This process is also commonly referred to as hot chamber die casting.

Cold Chamber Injection

With this method, liquid metal can be poured by hand or machine into a cold chamber sleeve. A hydraulic plunger is then pushed all the way into the sleeve. The liquid metal is pushed through the plunger into the mold and the port is closed. When solidification is complete, the plunger is removed and the mold is opened, then the part is removed. Solids with high melting points such as magnesium, aluminum, and brass can be used in this method. Additionally, the cold chamber process can use either horizontal or vertical injection.

In both methods, the injection process takes place under high pressure. The pressure is usually maintained between 1,500 and 25,000 PSI. In order to achieve solidification, the mold must be completely sealed and held at this high pressure. In addition, any gases trapped in the mold are compressed, which aids in the cooling shrinkage during solidification.

Component Dismantling

Once it has been determined that all the molten metal has solidified, the cavity can be removed from the mold. The cavity can be opened using an ejector bar. Ejector bars are usually located at the moveable end of the mold. They push the solidified casting out of the cavity.

Trimming

In the final step of high pressure die casting, excess material is removed from the casting and the mold. Trimming molds, saws or other tools can be used in the trimming process. In addition, the metal scrap can be recycled and reused later in the production process.

Advantages of High Pressure Die Casting

Many different types of businesses use high pressure die casting. This is because high pressure die casting has many advantages over other manufacturing processes. See some of the advantages below:

Higher Productivity

High-pressure casting has a higher productivity than low-pressure casting or gravity casting. When high pressure is used, liquid metal can be injected quickly, which increases productivity. This allows the process to be used to manufacture high-volume production items.

Producing High Quality Parts

In addition to this, high pressure casting produces high-quality parts with precise dimensions and smooth surfaces. These high-precision products do not require additional finishing steps. And these steps can cost extra time and money. In addition, another advantage of high pressure die casting parts is that they are very homogeneous and have optimal mechanical properties.

Thin-walled Products

Since the high-pressure die casting process maintains a constant high pressure during the production process. As a result, this process can produce very thin cross-sections. This is not possible with other casting processes. Depending on your needs and the dimensions of the part, you can obtain wall thicknesses of less than 0.40 mm.

Thin walls help to reduce the weight of the product. It is also possible to add inserts (also known as “co-cast” parts), such as screws and gaskets, to the product while casting. This helps reduce the number of parts that need to be assembled.

Realization of Complex Designs

Different mold forms can be used in the die casting process. If the mold shape is flexible, complex parts can be made during the casting process. This helps in assembling complex systems.

Robust Molds

The molds used in the die casting process have a long service life. They can therefore be used repeatedly in different production processes. This reduces the cost of each batch of die cast products.

Application of High Pressure Die Casting

Due to the extremely high quality of the products manufactured by high pressure die casting. Therefore, the process has been widely used in many different industries.

Automotive Industry

High-pressure die casting can be used to manufacture different automotive structural parts from aluminum and magnesium. It can manufacture structural parts such as engine blocks, transmission housings, oil sumps, engine mounts, and cross members.

Medical Business

In the medical field, it is also often used to manufacture small, lightweight surgical tools. In addition, the high-pressure hold-down process is used to manufacture medical devices, high-yield imaging equipment, infusion pumps, and more.

Aerospace Industry

This die casting process is very popular in the aerospace industry. This is because it can produce complex designs and is easy to automate. Engine components for spacecraft are made from aluminum, zinc, and magnesium alloys.

To Summarize

Choosing the right manufacturing process for your product is very important. At Yonglihao Machinery, we have a group of professional engineers with extensive die casting experience. Our team of professionals can provide you with better advice and answer any questions you may have.

In addition, Yonglihao Machinery has advanced equipment and rich production experience. Therefore, we can produce high quality products for you in a short time. You can rest assured that we will provide you with the best products at market-competitive prices.