What is Die Cast aluminum? A Comprehensive Guide

aluminum die casting plant

Die cast aluminum has many applications in the modern world thanks to its exceptional qualities, such as low weight, corrosion resistance, and outstanding dimensional stability. This guide explains why die casting is great for making parts using aluminum alloys and the industries that use it most.

What is Die Cast Aluminum?

Die cast aluminum is aluminum produced with the die-casting process. It means using a die (or a mold) to form metal parts while utilizing high mold-filling pressures.

Aluminum is lightweight, resists corrosion, and has good strength and dimensional stability. On the other hand, die casting creates complex parts quickly and with great accuracy.

These combinations make aluminum parts made by die-casting applicable in many industries, from automotive and construction to consumer goods and electronics.

According to a recent Precedence Research report, the die-cast aluminum market will expand at a CAGR of 5.82% from 2024 to 2032. This growth is attributable to the excellent properties of the material and the process characteristics.

The casting process and the die structure illustrated
The casting process and the die structure illustrated
Resource: https://www.sciencedirect.com

Aluminum Die Casting Process

The aluminum die-casting process is one of the most used metal forming techniques today, owing to its ability to make complex shapes with smooth surfaces and other qualities like high tolerance levels.

It uses the cold chamber process to prevent the high temperature of molten metal from causing damage. It also uses high pressures to fill the mold with molten metal. Here’s what happens:

  • Aluminum ingots are heated to very high temperatures until they melt
  • The liquid metal is then transferred to the casting equipment containing the die
  • A robotic arm pours the metal into the casting machine while a plunger forces it into the mold cavity
  • Upon cooling, the melt solidifies, taking the mold’s shape
  • An ejection system removes the cast part from the mold
  • From here, the cast part goes through a checking process
  • Later, it goes to the trimming stage where it’s deburred
  • Gating and other structures from the casting process are also removed
  • Later, the parts are tested and inspected for quality and finished as required

The casting produces high-quality surfaces that do not often require applying a finish. But when necessary, it may be considered. The mold used to cast the alloys is typically steel.

Because it’s hardened steel, the mold can have many casting cycles before it needs replacing, making the process suitable for high-volume production runs.

Die Casting Aluminum Alloys

Manufacturers use several aluminum alloys. Each alloy presents specific characteristics that anyone considering the material must understand. They include the following:

  • A383
  • A380
  • A390
  • A360
  • A413
  • 413
  • ALSi9Cu3
  • ALSi10Mg
  • ALSi-12
  • And K-alloy


The application determines the desired mechanical and other properties when selecting aluminum alloys for die casting. Some alloys perform better than others, impacting product performance and durability.

Porosity detection in a cast aluminum product
Porosity detection in a cast aluminum product
Resource: https://www.mdpi.com

Is Die Cast Aluminum Strong?

It is. It is. Compared to other manufacturing methods, the process creates parts with great strength and dimensional stability. The strength level depends on the type of alloy used to cast the part: some are stronger than others.

For parts with thin walls, manufacturers employ various methods to add strength to the walls, such as using ribs and bossing. Other measures include using best practices to prevent porosity and those that increase parts density.

Die Cast Aluminum Material Properties

Various mechanical and other properties characterize the alloys used to cast parts. These qualities offer many benefits across different industries, including the following:

  • Low weight
  • Outstanding thermal conductivity
  • High electrical conductivity
  • Smooth finish characteristics
  • Ability to excellently resist corrosion
  • Exceptional strength-to-weight ratio
  • The material can withstand high temperatures
  • The parts are highly recyclable
  • Ability to block electromagnetic waves (EMI shielding)
Die-casting aluminum produces smooth-surfaced components
Die-casting aluminum produces smooth-surfaced components
Resource: https://www.researchgate.net

Die Cast Aluminum Surface Finish Options

After casting, the parts may need finishing to enhance their visual appeal or make them resistant to environmental damage. Three options exist when it comes to surface finishing. They’re powder coating, film coating, and anodizing.

Powder Coating

A thermoplastic or thermoset powder is melted on the part surface and left to dry. The process may also involve dipping heated parts in the powder. The process produces a finish that protects against scratching and fading or wears over time. You can use custom colors, which gives greater flexibility and durability.

Conversion Coating

This surface finishing method is also called Chem Film coating. The part is dipped in a chemical solution or sprayed with a film to coat it and make it more pleasing and durable. The coat may also be applied using a brush. A

Anodizing


Anodizing is an electrochemical process introducing a non-conductive oxide layer on the surface. In addition to protecting against corrosion and wear, it also preps the surface for other coatings like paint.

Die cast aluminum parts
Die cast aluminum parts
Resource: https://www.researchgate.net

Die Cast Aluminum Parts Applications

The application of die cast aluminum parts cuts across all major industries. Here’s a list of these industries and how they benefit from components produced using the casting process.

Automotive

The process makes lighter components that suit modern vehicle weight reduction requirements for fuel efficiency. They include cylinder heads, transmission parts like gearbox covers, and various structural elements. These parts do not rust, allowing manufacturers to ensure durability.

Electronics

The electronic industry uses die-cast aluminum components due to their low weight, corrosion resistance properties, thermal conductivity, and other properties like blocking EM radiation. Parts manufactured using this method include enclosures, transformers, power supplies, heat sinks, EMI shields, etc.

Construction

In the construction industry, the application involves making parts like window frames, partitions, and various interior fittings. On a larger scale, castings form part of buildings like roofs and structures such as bridges. The castings also find significant use in the construction of skyscrapers.

Medical

Due to its lightweight nature and ability to resist corrosion, the material fits applications in the medical sector— and the casting method creates intricate parts that can also block electromagnetic waves. You’ll usually find products of this process used in MRI scanners, ultrasound equipment, and other medical devices.

Aerospace

Aerospace unique requirements include reduced weight, dimensional accuracy and stability, heat dissipation, and intricate designs. The casting process and material perfectly fit the bill and are typically employed in manufacturing parts for air and spacecraft applications.

Conclusion

Die-cast aluminum makes high-quality parts that offer many benefits, including reduced weight, thermally and electrically conductive, and structural stability. Its use cuts across many industries, notably the automotive and construction sectors. We hope this guide has given you the information you need to understand the material and where to use it.

Table of Contents

Contact Us
Scroll to Top
Contact Us