Choosing the right manufacturing process is critical to the design of any part, including aluminum components. Aluminum die casting is an excellent method for producing high-quality aluminum parts.
It produces durable, lightweight pieces with excellent tensile strength and high thermal and electrical conductivity for different industries.
Aluminum alloys have excellent mechanical properties and high dimensional stability. As a result, manufacturers employ the aluminum die-casting process to create complex structures.
In this article, you’ll learn everything you should know about aluminum die casting, including its benefits and applications. You will also learn how to choose the best aluminum casting process and effective design tips for casted parts. Let’s dive into it!
What’s Aluminum Die Casting?
Aluminum die casting is a manufacturing technique that involves completely heating and melting an aluminum bar at a high temperature. After this, you will have to force it into a pre-shaped mold cavity to form desired metal components. The primary aluminum casting processes are:
Die Casting
Die casting is a common casting method used to make a variety of aluminum parts. In this process, the aluminum must be preheated before being injected under high pressure into a die mold.
This mold is specifically designed for the product. While the injected aluminum cools off evenly, you must remove the part from the die and repeat the cycle after the die cools down.
The two processes involved in die casting include – High-pressure die casting and Low-pressure die casting. High-pressure casting, on the other hand, is best suited to aluminum alloys.
It is preferable to use the cold chamber of the casting machine in the aluminum die casting process. This is because the high molten temperature may spoil the machine if the injection mechanism is immersed as in the hot chamber method.
One of the primary benefits of die casting is its excellent electrical and thermal conductivity. Also, die casting makes strong parts resistant to heat, wear, and corrosion. It is useful for applications in the medical, aerospace, and automotive industry.
Sand Casting
Another casting technique is sand casting, which involves packing a fine sand pattern around a pattern of the desired component. The pattern is a little bigger than the final product allowing shrinkage of the aluminum as it cools.
Sand casting is frequently used by manufacturers and product designers for specialized castings, prototyping, and low-volume production runs.
Sand casting is cost-effective as you can reuse the sand multiple times. Also, it is suitable for making precision moldings of all sizes and those with complex geometric shapes. Meanwhile, due to its low dimensional accuracy, you must perform post-processing operations like trimming.
Permanent Mold Casting
This is a technique that’s very similar to die casting. However, the mechanisms used to inject the preheated aluminum alloy into the mold differ.
Permanent mold casting relies on gravity in filling the mold compared to the high or low pressure used in die casting. As a result, permanent mold casting can reduce the turbulence during the injection mold process.
In addition, you can create stronger parts with excellent surface finish and close dimensional accuracy with the permanent mold casting technique. Similarly, this process is appropriate for producing aluminum components for automotive and aerospace applications.
Considerations for Selecting the Suitable Aluminum Casting Process
Aluminum casting techniques have varying benefits and drawbacks. As a result, it is essential that you use the right one for your project to get the best results from the casting processes.
These are important factors you need to consider when trying to select the suitable casting technique for your project:
Design Complexity
The complexity of your final product will determine your choice of the casting process. Manufacturers and designers use sand casting to manufacture large and complex aluminum casting components, which is ideal for complex products. However, permanent cast molding is the go-to option for manufacturing dimensionally accurate cast aluminum products.
Speed of Production
The die-cast process employs a high-pressure injection process, making it suitable for large-scale production. Considering production speed, sand casting is the following suitable technique, leaving permanent mold casting as the third and last option of the three.
High Quantity
It is worth noting that the die-cast process is an excellent choice for producing a wide range of aluminum-cast products for a variety of industries. However, if you aim to strike a balance between tooling and high quality, sand casting and permanent mold casting are better alternatives to consider.
Prototyping
Sand casting remains an ideal process for rapid prototyping because of its low investment costs. Die casting and permanent mold casting require higher investment costs, making them unsuitable for prototyping as only a few pieces of the product are needed.
Strength and Surface Finishing
Permanent mold casting offers desired strength that matches product requirements and excellent surface finish options. Die casting and sandblasting, on the other hand, provide comparable strength, despite the fact that die casting achieves a better surface finish.
Surface Finishing Options for Die-Cast Aluminum Parts
Here are some of the surface finish options for your aluminum die casting project:
Anodizing
Anodizing is an effective surface finish option that involves decorating and enhancing the functional properties of materials such as aluminum, zinc, and magnesium. Anodizing is an electrochemical technique that makes the metal durable and resistant to corrosion and scratch.
Powder Coat
A powder coat is a distinct aesthetic finish due to its ability to conceal minor defects in the surface of die-cast parts. The surface thickness is uniform, durable, glossy, and has an excellent color consistency.
If a tough, high anti-corrosion finish capable of resisting scratches and dings is what your product needs, powder coating is the right choice. Additionally, powder coating is environmentally friendly because it makes no hazardous waste byproducts.
Chemical Film
Chem film is a widely used finishing technique for die-casted parts. You can apply chem film using different means like spray, brush, dipped process, etc. this surface finish is different from anodizing as you can apply it electrically.
Painting
Finishing options such as painting are suitable for die-cast parts because they are easy to apply and serve protective and decorative purposes. However, when designing, you must have specific special considerations concerning the type of paint finish your products need.
You must take precautions to remove contaminants such as oils from the cast surfaces. Furthermore, you can apply a conversion coating after cleaning the cast surface to ensure good adhesion of the coasting to the prepared surface.
Electroplating
Electroplating involves forming a thin metallic coating on the cast surface using an electrolytic setup. This process is an effective way of enhancing the functionality and aesthetics of various products.
Most industries use this finishing option because of its customizability and suitability for oversized products.
When you use electroplating in aluminum die casting, the die casting represents the cathode submerged in s solution containing dissolved metal ions like zinc, cadmium, etc. The dissolved metal ions form a protective layer on the surface of the die-cast when current travels through the solution.
Applications of Aluminum Die Cast Components
Some of the aluminum casting applications include the following:
Medical Industry
The medical sector depends on aluminum casts for lightweight and strength in producing surgical trays, prosthetics, etc. This industry relies on the aluminum die casting process to create specific complex and accurate geometry.
Moreso, the corrosion resistance properties of aluminum make it a suitable material for the medical sector since this medical equipment is often exposed to body fluids.
Automotive Industry
Manufacturers in the automotive industry seek to reduce the carbon footprint of vehicles produced. Hence, they use lightweight aluminum frames, engines, and body panels as it positively influences fuel economy.
Although these automotive parts are lightweight, they have uncompromised durability and strength. In addition, aluminum alloys have other environmental advantages, as you can recycle nearly all automotive aluminum scrap.
Electronics Industry
The electronic industry has risen above all others over the years thanks to die-cast aluminum. The material properties of die-cast parts have significantly influenced consumer product development.
Product designers now utilize aluminum die casting for creating electronics products, including network housing, motherboard casings, etc.
Aerospace Industry
Another industry that depends on aluminum alloys is the aerospace sector. This is because the alloys are lightweight and have impact-resistant properties.
Therefore, they are ideal for high-strength components and other complex tools. Aluminum alloys are used to make aerospace components such as cargo loading housing, airplane distributor cap housing, fuel system parts, etc.
Culinary
Die-cast aluminum has extensive uses in the culinary industry due to its corrosion resistance, durability, excellent heat conduction, and lightweight properties. In addition, the material is ideal for making cookware due to its superb dissipation properties. The aluminum casts can accumulate and disperse heat quickly.
Furniture
Aluminum alloys are used in the furniture industry to produce a variety of office and home furnishings due to its low cost, corrosion resistance, and high strength-to-weight ratio. For example, manufacturers use die-cast aluminum alloys to create a wide range furniture components such as knobs, door locks, hinges, etc.
Construction
Aluminum casting alloys are integral materials used in the construction sector. Aluminum die-cast parts that are commonly used in construction include window frames, roof superstructures, and so on. Likewise, engineers construct several large structures like commercial buildings and bridges using die-cast aluminum parts.
Considerations For Aluminum Die Cast Parts Design
These are some key factors you have to consider in your aluminum die-casting parts design to achieve the best results:
Mold Design
When designing an aluminum die casting part, this is one of the most important factors to consider. An efficient design during mold manufacturing will allow you to easily inject molten metal aluminum and eject correctly casted parts. It is worth noting, however, that every mold has a parting line. This line divides into two halves, which you must consider before completing your design.
The Location of Injection Point
The location of the injection point is the next vital factor to consider. However, if the melted aluminum has a chance of solidifying before reaching every crevice in the die, adding multiple points will help. In addition, the location of the injection point helps the cavities in the design.
Mold Wall’s Thickness
As a product designer, you must consider the thickness of your mold’s walls as it helps ensure low material wastage, rapid production, and quality products. A thin wall design can restrict the adequate flow of molten metal within the mold causing it to solidify before filling it.
In contrast, an extremely thick wall results in the wastage of material, an increase in solidification time and weight of die-cast parts, and the elimination of the speedy production cycle benefit of high-pressure die casting.
Nevertheless, using a uniformly thick wall helps to improve the integrity and quality of the casting. It ensures an outstanding metal flow and solidification of molten metal in the mold. The recommended wall thickness for aluminum castings is 0.787 to 0.1737 inches.
However, this size may change depending on the die-cast part’s size, structure, material, and application. Consequently, you can have an aluminum die casting part with a wall thickness as thin as 0.020″.
Reliable Aluminum Die Casting Services at Kemal
Kemal is your reliable custom aluminum die casting service partner in China. Our extensive manufacturing capabilities enable us to produce high-quality die-cast parts in a shorter time frame.
We have expert engineers with good years of experience to execute your project precisely to part specifications.
Enjoy high quality and cost-efficient aluminum casting services for prototypes and large-volume parts. Our facility houses automated machines and fully integrated robotic arms with state-of-the-art technology.
A combination of the advanced technology with out technical skills help us achieve quality and tolerances requirements for aluminum die-cast parts.
Conclusion
Aluminum die casting is a reliable process for creating durable and lightweight cast parts. Manufacturers prefer aluminum to other materials due to its outstanding material properties and a long list of surface finishing options.
Furthermore, you can apply the aluminum die-cast process in almost any industry and benefit from a long list of advantages.
However, there are certain factors to consider when making an aluminum cast design and choosing the suitable aluminum casting process for your project. It is important to work with a reliable die casting partner to achieve the best results. Contact us at Kemal today!
