Aluminum Die Casting: A Comprehensive Overview

An Overview of the Aluminum Die Casting Process

Aluminum die casting, as a crucial metal smelting and processing technique in modern industry, operates on the principle of applying pressure rather than relying on gravity, bearing similarities to injection molding. Its hallmark features are the high-pressure and high-velocity filling of the die-casting mold. The commonly used injection pressure ranges from several thousand to tens of thousands of kPa, and can even reach up to 2×105 kPa. The filling speed is approximately 10 - 50 m/s, and in some cases, it can exceed 100 m/s. The filling time is remarkably short, typically within the range of 0.01 - 0.2 s.

This process endows aluminum die casting products with a multitude of advantages. 

Firstly, in terms of product quality, the castings exhibit high dimensional accuracy, generally equivalent to grades 6 - 7, and can even attain grade 4 in certain instances. The surface finish is excellent, usually corresponding to grades 5 - 8. The strength and hardness are relatively high, with a 25 - 30% increase compared to sand casting. It is capable of die-casting complex thin-walled castings. 

For example, the minimum wall thickness of zinc alloy die castings can be as low as 0.3 mm, and that of aluminum alloy castings can reach 0.5 mm. The minimum casting hole diameter is 0.7 mm, and the minimum pitch is 0.75 mm. 

Secondly, the production efficiency is remarkable. The machine productivity is high. The domestic JⅢ3 horizontal cold chamber die-casting machine can perform 600 - 700 die-casting operations on average in eight hours, while the small hot chamber die-casting machine can achieve 3000 - 7000 die-casting operations on average in eight hours. The die-casting die has a long lifespan. A set of die-casting dies for die-casting aluminum alloy can last for hundreds of thousands or even millions of times. It is also conducive to the realization of mechanization and automation. 

Thirdly, the economic benefits are outstanding. Due to the precise dimensions and smooth surface of die-casting aluminum parts, they generally require little or no further machining, enhancing the metal utilization rate, reducing a large amount of processing equipment and labor hours. The casting price is relatively inexpensive, and it is also possible to use combined die-casting with other metals or non-metallic materials, saving assembly labor hours and metal.

Nevertheless, aluminum die casting also has some drawbacks. Owing to the high speed and unstable flow state of the liquid metal filling the mold cavity, the castings are prone to porosity and cannot be heat-treated. It is challenging to die-cast complex castings with internal concave features. When die-casting high-melting-point alloys, the lifespan of the die-casting die is relatively short. It is not suitable for small-batch production because the manufacturing cost of the die-casting die is high and the die-casting machine has high production efficiency, making small-batch production uneconomical.

Characteristics of Aluminum Die Casting Products

(I) Product Quality Superiority

The quality advantages of aluminum die casting products are highly prominent. The dimensional accuracy of the castings is high, reaching grades 6 - 7 and even grade 4 in some cases. This implies that aluminum die casting products can fulfill applications with extremely stringent dimensional accuracy requirements. Simultaneously, the surface finish is excellent, generally corresponding to grades 5 - 8, endowing the products with an exquisite appearance. The relatively high strength and hardness, which are 25 - 30% higher than those of sand casting, provide reliable assurance for the use of the products in various complex environments. Moreover, aluminum die casting can produce complex thin-walled castings. For instance, the current minimum wall thickness of zinc alloy die castings is 0.3 mm, and that of aluminum alloy castings can be up to 0.5 mm. The minimum casting hole diameter is 0.7 mm, and the minimum pitch is 0.75 mm. This capability gives aluminum die casting a unique edge in manufacturing small, precise, and structurally complex parts.

(II) Production Efficiency Advantage

The production efficiency advantage of aluminum die casting is evident. The machine productivity is high. The domestic JⅢ3 horizontal cold chamber die-casting machine can perform 600 - 700 die-casting operations on average in eight hours, while the small hot chamber die-casting machine can achieve 3000 - 7000 die-casting operations on average in eight hours. The die-casting die has a long lifespan. A set of die-casting dies for die-casting aluminum alloy can last for hundreds of thousands or even millions of times. This enables enterprises to reduce die replacement costs and enhance production continuity during the production process. At the same time, it is easy to achieve mechanization and automation, significantly reducing labor intensity and improving production efficiency, especially suitable for large-scale mass production.

(III) Economic Benefit Advantage

From the perspective of economic benefits, aluminum die casting has many merits. Firstly, the metal utilization rate is high. Since the dimensions of die-casting aluminum parts are precise, they generally require little or no further machining, reducing material waste and increasing the metal utilization rate. Secondly, the processing equipment and labor hours are few, which not only reduces production costs but also improves production efficiency. Thirdly, the casting price is relatively inexpensive, conferring a certain price advantage compared to other manufacturing processes. In addition, combined die-casting with other metals or non-metallic materials can be employed, saving assembly labor hours and metal, further enhancing economic benefits.

(IV) Product Deficiencies

However, aluminum die casting products also have some shortcomings. Firstly, due to the high speed and unstable flow state of the liquid metal filling the mold cavity, the castings are prone to porosity and cannot be heat-treated. This restricts the application of the products in some fields where heat treatment is required. Secondly, it is difficult to die-cast complex castings with internal concave features, necessitating higher technical levels and more complex die designs. Thirdly, when die-casting high-melting-point alloys, the lifespan of the die-casting die is relatively short, increasing production costs. Finally, it is not suitable for small-batch production because the manufacturing cost of the die-casting die is high and the die-casting machine has high production efficiency, making small-batch production uneconomical.

In the world of aluminum die casting, EATHU Foundry stands out as a premier choice. Despite the inherent challenges in the process like porosity and limitations with certain complex castings, our cutting-edge technology and equipment, stringent quality control, experienced team, customization options, and sustainable practices set us apart. We offer high-quality, precisely crafted aluminum die casting components, ensuring dimensional accuracy, excellent surface finish, and enhanced strength. Whether it's for automotive, aerospace, or electronics, EATHU Foundry is your trusted partner, ready to meet diverse manufacturing needs and drive innovation in the field.