It is generally agreed that die casting with aluminum is one of the most cost-effective and sustainable ways to create metal parts. When using aluminum, you will have to choose which aluminum casting alloys to use in the process. Here is some technical information on aluminum alloys to help you get a better sense of your alloy options and why we choose the alloys we prefer.
|Alloy Name||Benefits||Potential Drawbacks||Purposes|
|A380 Aluminum Alloy||Lightweight, very strong at high temperatures, corrosion resistant, retains dimensional stability even with complex shapes, high electrical and thermal conductivity||Used most commonly if you have budgetary concerns to consider and don’t need the highest levels of corrosion resistance or pressure tightness|
|A383 Aluminum Alloy||Offers higher strength at high temperatures and less chance of cracking under heat than the A383||Not as durable as the A380||Typically only used when you are forming intricate components and require very specific die-filling characteristics|
|A360 Aluminum Alloy||Offers higher strength at high temperatures, better ductility, and higher corrosion resistance than the A380||Harder to cast than the A380|
|ZA-8||Low Aluminum content, low melting point, and higher density than other ZA alloys||Ideal for hot-chamber die casting|
|ZA-12||Medium Aluminum content, higher melting point, and lower density than the ZA-8||Must use cold-chamber casting|
|ZA-27||The highest Aluminum content of ZA alloys in this list, highest melting point, highest strength, and lowest density||Not ideal for chrome plating, underside shrinkage can occur|
A380 Aluminum Alloy
The most popular alloy for aluminum die casting is A380. We use A380 because it has demonstrably the best combination of physical and mechanical properties for casting, including being lightweight, very strong at high temperatures and corrosion resistant. A380 is also very good at retaining dimensional stability even with complex shapes and thin walls and offers high electrical and thermal conductivity.
A383 Aluminum Alloy
Another option for die casters is to use A383 aluminum alloy. This is alloy is typically only used when you are forming intricate components and require very specific die-filling characteristics. While it doesn’t share all the properties of A380, it does offer higher strength at high temperatures with less chance of cracking under heat.
A360 Aluminum Alloy
A360 is harder to cast than A380, which is why many die casters avoid it. However, it does offer higher strength at high temperatures, better ductility, and higher corrosion resistance, so you may want to consider this alloy depending on your casting abilities and needs.
A360 vs. A380 v. A383
To summarize the differences between the three types of casting alloys as outlined above, A360 has the best pressure tightness, high-temperature strength and corrosion resistance of the three alloys.
A380 is also highly corrosion-resistant but more cost-effective and easier to work with than A360, so this is the one you would use most commonly if you have budgetary concerns to consider and don’t need the highest levels of corrosion resistance or pressure tightness.
A383 is a modified A380 alloy you would only use if you need precise die filling that you are not getting from your A380 alloy, as it is not as durable as A380.
Some applications may call for ZA, or zinc aluminum alloys, for your die casting. Originally the primary type of alloy used in gravity casting, scientists have refined this type of alloy for effective use in die casting. The three alloys that fall into this category are ZA-8, ZA-12, and ZA-27. Alloys that combine zinc and aluminum offer higher strength, lower density, better creep resistance and better wear resistance than other zinc alloys.
ZA-8 is the only hot chamber alloy of the three. It is the zinc-aluminum alloy one uses in die casting with the lowest possible aluminum content. It features an aluminum content of 8.4 percent with one percent copper. Because of the minimal aluminum content, ZA-8 has a lower melting point and higher density than other zinc-aluminum alloys. This makes it ideal for hot-chamber die casting. It’s often used for higher strength requirements that need plating.
ZA-12 has somewhat greater aluminum content than ZA-8 but less than ZA-27, so it offers a sometimes desirable mediation of zinc alloy properties. It has 11 percent aluminum and one percent copper content. It provides the best combination of castability and strength of the ZA alloys. Because of its higher melting point and lower density, if you are using ZA-12 for casting, you must use the cold-chamber method.
ZA-27 is the strongest of the three ZA alloys, but difficult to cast. It has the highest aluminum content of all the zinc-aluminum alloys we use for die casting, with an aluminum content of 27 percent and copper content of 2.2 percent. The result is a material with the highest melting point, highest strength, and lowest density.
Unlike other zinc-aluminum alloy parts, parts made with ZA-27 are typically not ideal for chrome plating. As with ZA-12, you cannot use this alloy with hot-chamber casting because of its high melting point. Underside shrinkage can be an issue in die casting for ZA-27 – so cooling rates need to be looked at carefully.
For a further comparison of these alloys check out this helpful guide:
Benefits of Choosing Aluminum for Die Casting
Die-cast aluminum properties provide multiple benefits for production, including the following:
- Metal type: Among common metal types, like iron, steel and titanium, aluminum alloys are superior for the die casting process.
- Solidification rate: The die casting processes are superior to wrought and gravity castings for alloys of similar composition.
- Machining characteristics: Alloy 380 has above-average features for machining, while Alloy 218 has the best machinability due to its high magnesium concentration. Meanwhile, Alloy 390 offers the highest silicon content.
- Surface treatment: It’s possible to apply a decorative finish or protective barrier against corrosion for aluminum die castings. Decorative finishes include painting, powder coat finishing, epoxy finishing and more. Typically, aluminum receives plating from a layer of zinc coating followed by copper-nickel or chromium plating.
- Thermal and electrical conductivity: Aluminum is highly conductive, making it an excellent solution for transferring electrical and thermal energy.
- Strength-to-weight ratio: Aluminum balances its lightweight composition with strength so that manufacturers can create lighter, durable castings.
- Recyclable: Aluminum is a fully recyclable and reusable material in production. It’s also energy efficient and a highly eco-friendly option.
Choosing the Right Alloy for Your Metal Parts
It’s not always easy to know what the right alloy is for your particular metal parts. When you call Premier Engineered Products for your metal parts casting, you get to work with experts who have been in the business for over 70 years and who can determine the ideal materials and die casting designs for your particular metal part needs.