Low Pressure Die Casting

Low Pressure Die Casting

Learn more about Low Pressure Die Casting: process characteristics, applications and future development

Low pressure die casting technology

Aluminum alloys are becoming more common in house construction and casting as my country’s economy grows. Low-pressure casting is the most used process for producing aluminum. This technology is not only inexpensive but also simple to use. It’s also really straightforward. This article first discusses the fundamental concepts and characteristics of low-pressure casting of road alloys, followed by a detailed analysis of the method and future possibilities for low-pressure casting of road alloys.

Aluminum is a popular casting material used in a variety of applications including construction and casting, mechanical equipment, and creative creativity. The most popular production industry for aluminum alloys is the low-pressure casting method, which primarily refers to the process of filling and solidifying aluminum liquid under pressure. This casting technique not only increases the strength of the aluminum alloy, but it can also form various complex castings to increase metal material use.

1. Principles and features of aluminum alloy low-pressure casting.

Aluminum alloys exhibit varied physical and chemical properties as a result of their many components, and the alloy crystallization process is likewise unique. To optimize the casting process, an acceptable casting method based on the properties of the aluminum alloy must be chosen.

1.1 Principle of low pressure casting

The principle of aluminum alloy low-pressure casting is to compress dry air into a sealed container. The container is filled with aluminum liquid in advance. Under the action of gas pressure, the aluminum liquid will rise along the deep liquid tube casting and pass through the casting gate. Smoothly enters the cavity of the casting. During the casting process, the gas pressure of the liquid aluminum remains at the same level until the liquid aluminum completely solidifies. After the aluminum liquid is completely solidified, the gas pressure on the surface of the aluminum liquid can be contacted, causing the excess aluminum liquid to return to the container. The shape of the solidified aluminum liquid in the casting mold is the final required casting. Because the vessel pressure required for this process is low, it is called a low-pressure casting process.

1.2 Features of Low-Pressure Casting

Low-pressure casting is distinguished by its simple ingredients, superior casting performance, ease of casting, and the ability to easily alter the pressure and flow rate of molten aluminum during the casting process. The casting procedure can be used for different casting activities.

The container for low-pressure casting is a bottom-injection mold-filling container. The metal level in molten aluminum can be kept steady. There is no sputtering during the casting process, therefore gas or particles can be avoided. Dust conditions gradually improve both density and pass rate. Because the casting is solidified by air pressure, the shape is frequently crisper, the surface is smoother, and the mechanical qualities are high, which is advantageous for big and thin-walled castings. Furthermore, the process’s equipment needs are minimal, and automatic low-pressure casting of aluminum alloy is straightforward to implement.

Furthermore, low-pressure casting provides the advantages of smooth mold filling and accurate control of mold filling speed. This avoids the impact of the aluminum liquid in the container on the casting cavity wall, resulting in a clear outline. The casting solidifies due to air pressure. Obtain castings with higher density and better mechanical characteristics.


2 Process and development prospects of aluminum low-pressure casting


2.1 Low-pressure casting technology process

The design of low-pressure casting focuses on the design of the casting mold and the design of the cavity. According to the characteristics of low-pressure casting molds, the design process must ensure that the castings are solidified in an orderly manner and the air in the cavity can be discharged smoothly. The manufacturing of the mold cavity is mainly based on the top-down solidification characteristics of the aluminum liquid during low-pressure casting. To complete the design, the shape design of the casting should be completed from the bottom up, and finally realized through the sprue. Therefore, during the casting process, the arrangement of the casting mold and the position of the condensing rod must be reasonable. When designing the casting system, it is also necessary to prevent condensation at the pipe mouth. The upper end of the liquid riser pipe should be equipped with a heating device.

In terms of exhausting the mold, since the upper part of the low-pressure mold is often closed, it is difficult to exhaust. Once the air in the mold cavity cannot be discharged normally, the air that cannot be discharged from the mold cavity will form back pressure and hinder the container. The molten aluminum in the mold enters the mold cavity, resulting in defects such as incomplete casting and gas inclusions. Therefore, when designing the sand mold, you must use molding sand with high air permeability, and you can also use steel nails to poke a varying number of small holes on the top of the molding sand for exhaust. If metal-type materials are used, an exhaust groove can be set up at the top of the material, or an external exhaust groove can be connected to the wall. When using an external exhaust groove, the depth of the groove must be controlled.

Furthermore, because each unit area of the casting system in low-pressure casting has a feeding influence on the casting, the inscribed circle method can be utilized to design the cross-section and size of the runner. An open casting system can be employed in this process, which means that outlets for separate sprue portions are created to construct a comprehensive casting system based on the size, shape, and overall complexity of the casting. Direct casting can be utilized for general parts, but for more complex parts, multiple in-runners can be handled at the same time to save pouring time, speed up the process of aluminum liquid entering the mold cavity, and smooth out mold filling.

2.2 Prospects of low pressure casting technology

Based on the technical characteristics and practical application value of low-pressure casting, it is understood that this technology has very broad development prospects. With the rapid development of my country’s machinery construction industry, the application of low-pressure casting technology in the manufacturing field will become more and more extensive. The simplicity of the process and the rationality of the casting will also greatly improve the quality of the product, and the process has the advantage of being easy to automate. , will also be widely used in modern industrial production together with future intelligent production.


Aluminum alloy low-pressure casting technology will be widely used in various industries in the future due to its advantages of high productivity, easy operation, smooth surface of castings and tight internal structure. Therefore, vigorously promoting low-pressure casting technology is of great significance to improving the output and quality of castings in our country.If you have any questions or inquiries about aluminum die casting, please contact us!!

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