If your project design requires an aluminum part, it is crucial to determine the manufacturing process to utilize to produce it.  Among the numerous methods for forming aluminum and alloys, aluminum die casting is one of the most prevalent options that designers and industrial companies can avail of.

What is Aluminum Die Casting?

Aluminum die casting is the most preferred method for many automotive, telecommunications, and industrial products.  It’s typically the process of choice to yield electrical, lighting, and hydraulic components.

The metal-forming process allows the creation of complex aluminum parts.  Significantly high temperatures heat aluminum alloy ingots to the point that they are entirely molten.

Under high pressure, liquid aluminum is injected into the cavity of a steel die, also known as the mold.  Made of two parts, the die is separated after the molten aluminum has solidified.  This reveals the cast aluminum part.

The aluminum product is the outcome.  It was precisely shaped with a smooth surface. Usually, it requires minimal to no machining processes.  The steel dies or molds are sturdy, so the process can be repeated numerous times before it deteriorates.  Hence, aluminum die casting becomes ideal for the high-volume production and duplication of various aluminum parts.

You will learn more about the aluminum die-casting process in this article.  Keep reading if you need help deciding if it is the right option for your project and application.

What’s Good About Aluminum Die Casting?

The process delivers many benefits over other metal-forming methods. It might be the most appropriate option to create your required aluminum parts.

Its ability to produce highly complex shapes is one of its vital properties.  You will find that neither extrusion nor machining can proficiently create the form you need.  Should you use other processes, you won’t be able to consistently achieve the tight tolerances and complexity necessary for these pieces.  An example would be the production of complex automotive parts, such as transmissions and engine blocks.

Seldom requiring additional processes such as machining, another advantage of die-casting aluminum is to give its resulting products textured or smooth surfaces.  Plus, it also can accommodate and form both large and small parts.

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Top Things to Consider in Design

When designing the part to be cast, take into consideration the following factors:

To bring out the solidified aluminum part, the mold must be fashioned to separate. The parting line, which marks the division of the two halves, should be considered in the early stages of die design.

Another crucial consideration is the injection points to ensure that you reach every crevice in your design.  There can be several injection points.  Situate these points in your design to adequately form the cavities, especially the small ones.  When the molten metal solidifies, you know you have reached every crevice and included all your product’s cavities.  You can also surround them with aluminum.  The part will come off when the mold is taken apart.

The thickness of the part’s walls should also be well-thought.  There are no standard guidelines for a minimum or maximum wall thickness.  Nonetheless, having a consistent thickness for the walls is ideal.  With recent advancements, it is possible to achieve consistency.

What are the Differences between Aluminum Die Casting versus Other Casting Methods?

Two standard alternative casting processes are green sand and permanent mold.  Instead of a steel die, green sand processes utilize wet sand to function as the mold for the cast.  It makes a less expensive option than aluminum die casting and permanent mold.

On the other hand, permanent mold castings do not use injection.  It gravity-pours the molten aluminum into the mold.  Because of this process, permanent mold castings produce potentially stronger casts.

Compared to the other two processes above, aluminum die casting delivers better tolerances and a better finish on its products’ surfaces.  You get to save on expenses as this ability often eliminates the need for consequent surface treatment.

Would You Need Machining and Finishing?

Typically, die-cast aluminum parts require minimal to no machining.  There are other options for surface finishing.  Although die casting produces an excellent surface finish, its outcome can still have imperfections.  A typical example is the metal seams where the die separates.  These rough surfaces and other defects can be improved by sanding, orbital sanding, or sandblasting.

The cold working process of shot peening is typically employed to improve fatigue resistance.  Sometimes, a protective or decorative coating is applied to the finished part.  An example is the powder coat.  Other modifications can be used after casting, such as drill tapping, which adds threading if your product needs screws.

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What Are the Most Prevalent Aluminum Die Casting Alloys?

The most commonly used aluminum alloys for die casting are 383, A360, A380, A413, B390, and CC401.  Choose the appropriate alloy to use in the process, depending on your application.  The following are the usual choices:

  • A360:  This alloy possesses perfect fluidity when molten.  It has excellent corrosion resistance and pressure tightness.
  • B390:  An alloy most often used in automotive engine blocks application, it has the lowest ductility of all cast alloys.  It offers outstanding wear resistance and high hardness.
  • A380:  Considered the jack-of-all-trades among the alloys, it delivers a good combination of casting and product properties.  Manufacturing companies prevalently utilize this alloy for casting a wide range of products.

Final Word About Aluminum Die Casting

Picking the metal-forming process will be based on your budget, the application of your aluminum part, and the quantity of the parts you need.  Die-casting aluminum can be hefty in costs, but it’s worth it, especially if your design is complex and requires many components.

SEI specializes in manufacturing custom, standard, high-quality, and precision aluminum die-cast products.  We are open to working with your Engineering Department so we can reduce your expenditures by custom designing the required die-cast components of your projects.  In addition, we also provide coating and powder coating finishes for your castings if needed.

SEI Castings offer custom castings, enclosures, metal finishing, and waveguide components.  For more information about our products and how we can customize your requirements for your project, call us at sales@seimw.com.