When undertaking an aluminum die-casting project, one of the first decisions to make is choosing the most suitable process. Equally important is selecting the appropriate alloy to use, as it will greatly influence both the casting process and the final product’s characteristics.

This decision should be approached with careful consideration to ensure an informed choice. In this article, we will explore the essential characteristics to look for when selecting an alloy for the die-casting process. Additionally, we will delve into the common applications where aluminum die casting is widely utilized.

What are the Different Properties of Aluminum Die-Casting Alloys?

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When determining the most suitable aluminum alloy for your application, there are several characteristics that need to be considered. These alloy characteristics are based on guidelines provided by the North American Die Casting Association and can be categorized into two groups.

The first category comprises alloy characteristics that significantly impact the manufacturing process, while the second category encompasses essential characteristics of the final product. The following considerations are of utmost importance.

Alloy Properties That Can Affect the Casting Process

The casting alloy that you choose will greatly affect numerous aspects of the process, for instance, if the alloy is prone to defect and if the alloy is easy to work with.

Solidification Cracking

Solidification cracking, also known as hot cracking, is a common defect in aluminum alloys that can result in surface-level cracks or internal tears.

This casting defect is typically caused by internal stress and strain that can occur during the solidification process, particularly as the cast shrinks. It is important to note that certain aluminum alloys are more susceptible to hot cracking than others, making it a crucial factor to consider when making your selection.

Die Soldering

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This is another typical defect of aluminum die casting which can likely occur when the cast sticks to the walls of the die, making it hard to eject the casting product. As a result, both the die and the cast could get damaged. That is why it is important to choose alloys that contain high anti-soldering properties.

Although there are other factors that could be crucial to your process, these two are the greatest concern when it comes to the process of die-casting various aluminum alloys. While selecting an easy-to-cast alloy can lower your production cost, you should also think about its effects on the final product.

Alloy Properties That Can Affect the Final Product

Generally, the most important properties to consider in an aluminum alloy are its mechanical characteristics, including hardness, ductility, and strength.

These fundamental properties have a significant impact on your decision. However, there are other important qualities to consider as well. These include:

Wear Resistance

One important characteristic to consider in aluminum alloys is wear resistance, which can vary among different alloys. This property is crucial for applications where the object will be subjected to constant friction. Additionally, thermal and electrical conductivity may also play a significant role in certain applications.

Corrosion Resistance

While corrosion resistance is a common attribute of aluminum, it can still vary between different alloys. It is important to consider this characteristic based on the specific environmental conditions to which your casting will be exposed.

Machinability and Surface Treatments

After the casting process is complete, the finished product often requires surface treatments or further shaping. Fortunately, some alloys are more suitable for post-casting activities and treatments compared to others.

This is an important factor to consider when selecting an alloy. Popular surface treatments for die-cast aluminum parts include electroplating, anodizing, powder coating, polishing, and painting. In addition, standard procedures for post-cast products include machining, cold and hot working, and welding.

Most Used Aluminum Alloys for Casting

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Here, we are going to give you some of the commonly used aluminum alloys for die casting. The most popular aluminum alloys for die casting according to the NADCA are the 3xx.x series, then succeeded by the 4xx.x series.

While the alloys that are less popular are the 5xx.x and 2xx.x series, nevertheless, they are still useful for certain applications. The following shows the common applications of each aluminum alloy.

  • A360 is used for irrigation system parts, instrument cases, hinges, and outboard motor parts.
  • A380 is excellent for making lawnmower housings, gear cases, and workbench vises as well as any other hand tools.
  • 383 is great for power tools, furniture, appliances, cylinder head covers, and engine brackets.
  • B390 is commonly used for brake cylinders, manifolds, blocks, and pistons, as well as cylinder heads for internal combustion engines.
  • A413 would be ideal for creating streetlamp housings, dental equipment, and outboard motor pistons.
  • 518 should be used when making marine and aircraft hardware fittings, conveyor parts, and architectural castings.

Which Alloy is More Suitable for Your Project?

Keep in mind that there is no single alloy that is suitable for every application. Therefore, it is important to carefully consider the important aspects of your project. While the A380 is the most widely used aluminum alloy on the market, it may not be the best choice for all applications due to its lower corrosion resistance. The suitability of an alloy will depend on the specific requirements of your final product.

An excellent alternative to consider is the A360 alloy, which excels in corrosion resistance. Although it can be more challenging to cast, there are methods to overcome these difficulties in various circumstances. Therefore, the A360 is highly recommended, especially for industrial applications where corrosion resistance is a critical factor.

By identifying which properties are most important for your specific needs, you can determine the aluminum alloy that is best suited for your application.

Why Are Die-Casting Products So in Demand?

Undoubtedly, the die-casting process has revolutionized the metal casting industry, attracting manufacturers with its efficiency and cost-effectiveness. As a result, major industries are now widely adopting die-casting for their production needs.

Die-cast parts have proven to be excellent replacements for various materials, offering high-quality components with exceptional strength at an affordable cost. This allows manufacturers to create outstanding products for their clients while staying within budget.

What Are the Industries That Depend on Die Casting?

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For thousands of years, metal casting methods have played a crucial role in various industries, relying on rigorous and costly techniques. However, the manufacturing industry has been revolutionized with the advent of die-casting technology.

Today, die-casting products are ubiquitous, and their presence can often go unnoticed. Nearly every industry depends on die-casting for the production of essential components. Key sectors such as aerospace, automotive, medical devices, consumer electronics, construction, defense, marine, telecommunications, and many more heavily rely on die-casting products.

At SEI Castings, we specialize in manufacturing a wide range of customized aluminum die-casting parts, from enclosures to various components tailored to different industries. We are committed to delivering precise and high-quality products to meet your specific needs. For more information, please feel free to contact us at sales@seimw.com.