Cast Aluminum: Everything You Need to Know

Cast aluminum is a specific aluminum that is formed by casting technique. There is a wide application of cast aluminum due to its lightweight yet good strength. Cast aluminum could be seen in both daily life and industrial applications, such as cast aluminum cookware, cast aluminum chair legs, cast aluminum pumps, and more.

As a professional casting company, CFS Foundry can produce custom cast aluminum parts following your drawing’s specifications. There are several aluminum casting processes available at our foundry, including aluminum die casting, aluminum gravity casting and aluminum sand casting. Each casting process has its special advantages, and we can recommend a best suitable casting process according to the design of the aluminum part.

What is Cast Aluminum?

What is Cast Aluminum

Cast aluminum refers to aluminum that has been heated to its melting point before pouring it into molds for specific shapes or forms. The casting process involves heating aluminum until its melting point has been reached, then pouring it in an appropriate mold where it cools and solidifies to produce desired forms or shapes. After casting, post operations such as trimming and surface grinding are performed to achieve net shape castings.

Benefits of Cast Aluminum

Cast aluminum, particularly from manufacturers like CFS Foundry, offers a range of benefits for various applications. Here’s a closer look at the advantages of cast aluminum:

Complex Design Capability

Cast aluminum has its ability to creat parts into complex shapes, no matter how intricate the design is. For its excellent fluidity of aluminum alloys, thet can fill mold cavities completely, and an exact solid cast piece is formed after solidification. CFS Foundry can produce cast aluminum parts with accurate dimensions and close tolerances, which might be difficult to achieve by machining or forging process.

Lightweight Yet Strong

Aluminum is known for its high strength-to-weight ratio. Parts made from cast aluminum can provide the required strength for great working performace, while maintaning light weig

ht part. This is not available when parts made from other casting materials such as cast steel or cast iron. This benefit makes cast aluminum a good application especially for automotive and aerospace industries.

Excellent Corrosion Resistance

When exposed to atmospheric conditions, aluminum can naturally form an oxide layer, this protects it against corrosion. So, after casting, cast aluminum parts have excellent corrosion resistance, which make them an ideal choice in harsh or corrosive environments, like marine applications or outdoor furniture. If there is a higher requirement, cast aluminum parts could be further anodized or powder painted to improve its enchace its corrosion resistance capacity.

Faster Speed of Production

The casting process of aluminum parts is always faster than other manufacturing process, such as machining or welding fabrication process. As most of the aluminum casting processes are automated, once the molds are prepared, the production process of cast aluminum parts is very fast. Cast aluminum can provide shorter lead times while high quality products.

Cost-effectiveness for Manufacturing

Even with an intial investment in mold, due to the great production speed and less material waste, the cost per cast aluminum part is very economical. Besides, cast aluminum has the ability to creat a simple piece in complex shapes, and reduce or remove the need for post machining, which lower the production cost in further step.

The Casting Processes for Aluminum

Everything You Need to Know About Cast Aluminum

At CFS Foundry, there are several processes to cast aluminum into various shapes. Each casting process has its own capabilties and advantages. Here is an overview of the main manufacturing processes for casting aluminum parts:

1. Low / High Pressure Die Casting

Low Pressure Die Casting (LPDC) is the casting process that can produce cast aluminum parts at low pressure, typically between 20 psi and 100 psi. In this process, aluminum is melted and then tranferred into a mold under low pressure until the aluminum solidifies. Cast aluminum parts made from this process can achieve good dimensional accuracy even in medium to high volumes. It is particularly suitable for making cast aluminum parts in thicker wall thickness.

High Pressure Die Casting (HPDC), as its name implies, creats cast caluminum parts at high pressure, typically between 10,000 and 15,000 psi. In this process, molten aluminum is injected into a mold under high pressure fastly. By high pressure die casting, thin-walled cast aluminum parts with complex shapes could be made. Besides, it also allows for high volume production. The strength of cast aluminum made in this process is the best among all the aluminum casting processes.

2. Gravity Die Casting

Gravity Die Casting, sometimes referred to as permanent mold casting, involves pouring molten aluminum into metal molds using gravity for permanent cast aluminum production. Molds made of steel or cast iron typically can support useable multiple cycles, which make gravity die casting an economical medium-to-high volume production method. Cast aluminum parts made from this process can achieve improved mechanical properties and finer surface finishes than sand casting method.

3. Sand Casting

As one of the most versatile casting processes available today, sand casting is not limited to make cast steel and cast iron parts, it can creat cast aluminum parts as well. Cast aluminum parts with intricate geometries are usually made in sand casting process, which is challenging by other casting methods. Aluminum sand casting process involves creating a mold from sand mixture, then pouring molten aluminum into it for solification. Next, the mold is broken away to take out the finished cast aluminum part. This process prpvides flexibility on mold design, so it supports both small and large cast aluminum parts with intricate shapes. While the surface is rougher when compared with die casting process.

Common Cast Aluminum Alloys

What is Cast Aluminum

Because of the excellent mechanical properties and casting ability, cast aluminum is widely used by many industries. At Foundry, we have the capability to produce cast aluminum parts in different alloys, including A356, A360, A380, A383. They have unique chemical compositions, each alloy shows district advantages for different applications.

A356 Aluminum Alloy

A356 aluminum alloy is the most common material in aluminum gravity casting. The T6 heat treatment can further improve its strength and will be helpful for machining operation. The main chemical elements of A356 alloy include aluminum, magnesium (0.02-0.45%), silicon (6.5-7.5%) and other elements. Due to its good castability, welding ability and corrosion resistance, it is widely used in aluminum gravity casting process to creat parts with high strength and ductility. A356 castings are widely used in automotive and aerospace applications, as well as other industries.

A360 Aluminum Alloy

The A360 aluminum alloy mainlt consists of elements like aluminum, magnesium (0.4-0.6%), silicon (9-10%) and copper (6%). These compositions increases its strength and corrosion resistance when compared to other metals. A360 can offer good pressure tightness, which is critical for fluid-handling components. The excellent castability of A360 and its aesthetic surface finish makes it a good choice for casting housings, connectors and complex automotive components.

A380 Aluminum Alloy

A380 is a widely used cast aluminum alloy that contains aluminum, silicon (7.5-9.5%), copper (3-4%) and other elements such as iron, nickel and zinc. It is a versatile die casting material due to its high thermal conductivity and fluidity. CFS Foundry can cast A380 aluminum parts where strength and durability are needed, such as automotive components, electronic devices, lighting components and engine brackets.

A383 Aluminum Alloy (ADC12)

A383, also known as ADC12, is also a common die cast aluminum alloy. Its composition differences can improve its casting characteristics when compared with A380 alloy. This alloy includes elements like copper, silicon, and aluminum (9.5-11.5%). CFS Foundry usually uses A383 aluminum alloy for casting production because its good balance between castingability, mechanical properties and thermal conductivity. A383 is well suited for die casting production with thin walls, high precision. Examples of A383 cast aluminum parts are gearboxes and pumps.

How To Select a Right Casting Process for Aluminum?

When selecting a right casting process for aluminum parts, it is necessary to evaluate both the usage of the part and the material properties of cast aluminum alloy. CFS Foundry suggests to consider the manufaturing process from several factors in below, and we can also recommend the best process for you based on your design.

Design Complexity

The complexity and detail of any design play an essential part in selecting an optimal casting process. High-pressure die casting specialises in producing parts with intricate geometries and tight tolerances, making it ideal for creating aluminum parts with fine details and high accuracy. So, when the cast aluminum parts have a high requirement on dimensional accuracy and surface finish, high pressure die casting is the best choice for high volume production. For simpler or thicker designed parts, gravity die casting or sand casting may offer more cost effective solutions. Besides, sand casting is also suitable for large cast aluminum parts in small volume production.

Production Volume

Production volumes is also a necessary consideration factor for cast aluminum parts production. For high-pressure die casting, it is only cost effective for high volume production runs due to its high investment on the mold cost. Of course, it is worth to mention that the production efficiency is also very high. Medium volume projects might consider gravity die casting. While for low and prototype runs, sand casting may offer advantages due to reduced tooling costs, although its per-unit costs are higher.

Material Properties and Performance

For its superior strength-to-weight ratio and corrosion resistance of aluminum alloys, they are widely used in casting production. Casting process will further affect the properties. For example, high pressure die casting creates denser microstructures which enhance mechanical properties but increase porosity. Gravity die casting provides excellent material integrity which makes this approach ideal for moderate strength applications. While sand casting produces coarser microstructures which may result in parts with lower mechanical properties than expected – it is therefore vital that we clearly establish any performance expectations before choosing this form of casting as our final solution!

Surface Finish

The surface finish is also an important factor to consider when selecting an aluminum casting process. High pressure die casting can provide the finest surface quality of cast aluminum parts, and less or no machining is needed after casting. Low pressure die casting sand gravity die casting also offer good surface finish after fine blasting. While sand casting often provides rougher surface finish, which usually need further machining to achieve higher surface finish.

Cost Considerations

Cost factor could not be ignored when selecting a casting process for aluminum parts. High pressure die casting has the advantages of speed, precision and surface finish, but it requires a high tooling investment, and is more ideal for large orders. Gravity die casing and low pressure die casting offer lower tooling cost, but its unit cost is relatively higher. Sand casting is a most econimical selection for low volume production, while its unit cost per part is the highest when compared with other casting processes, and additional machining operation is usually required for closer tolerances or higher surface finish.

Cast Aluminum vs. Forged Aluminum

The fundamental difference between Cast and forged aluminum is easy to understand: Cast aluminum is the aluminum that was melted in a furnace and poured into a mold. Forged aluminum is when the metal is worked in the solid form with the help of specific tools. These two manufacturing processes will yield two materials with very different properties.

Aluminum has a wide range of uses across every major industry, however, it is often difficult to decide which grade is best suited to a specific application. The challenge becomes greater when comparing not only between alloys but also between cast and forged aluminum. Both are fundamentally aluminum alloys which often have the same alloying elements but in different compositions and quantities. However, the applications and material properties vary widely between the two.

Examples of Cast Aluminum Products

Cast Aluminum Products

You may be surprised to find out that many of the commercial products you come in contact with every day may be using cast aluminum parts and components or even be made entirely from cast aluminum.

Car Parts

Due to the amazing strength and light weight of cast aluminum parts, it is very popular in the production of car parts. For example, safety-critical parts like airbag housings or seat-belt retractor spools are made with diecast aluminum. In addition, steering knuckles, which support the wheel bearing, are made with this material. This is an essential part of a vehicle’s suspension, so the lightweight material helps to reduce the overall weight of the car without compromising strength or performance.

Lighting Parts

Due to the light weight and good corrosion resistance of cast aluminum, it is always used as the casting alloy for various lighting parts. Cast aluminum lighting parts could be designed and produced by either gravity die casting or high pressure die casting process.

Medical Devices

Many medical devices are also made from cast aluminum, not only due to the strength but also due to its heat resistance. Some of the more common medical equipment you may see made from this metal is parts for various pumps, surgical tools, components for monitors, and even gearboxes for hospital beds.

Firearms

Another popular application for die casting is the production of firearms. While many popular firearms may have plastic components, there are still a number of parts that are created from die-cast metals. Some of these parts may include triggers, trigger guards, trigger safetys, and much more.

Cast Aluminum Cookware

For decades, cast aluminum cookware (flater beater, dough hook, etc)  has been a vital tool in a well-stocked home kitchen. The versatile product is perfectly suited for cooking on the stovetop and baking in the over. It is dishwasher safe, making for a quick and easy clean up. Despite some ridiculous reports, it is safe to use for cooking and poses no health risks at all.

If you’re looking for pots and pans made from this material, the good news is they’re everywhere. You can find brand-new sets on the websites of major retailers. If a more classic style is what you are after, you can even find vintage cast cookware on eBay.

Cast Aluminum Patio Furniture

When you think about investing in patio furniture you want something attractive, durable, and low-maintenance. If you also want an outdoor ensemble that’s available in a variety of styles, finishes, and colors, cast aluminum patio furniture including cast aluminum chair legs may provide you with an ideal setting to enjoy entertaining and relaxing with family and friends.

Work With CFS Foundry for Your Cast Aluminum Project

Whether you’re sourcing aluminum die casting or aluminum gravity casting process for your project, CFS Foundry can help you with your next cast aluminum project. We’ve provided high-quality aluminum casting and machining services to a wide variety of industries for more than 30 years. Contact us today to request a quote for your cast aluminum project.

1 thought on “Cast Aluminum: Everything You Need to Know

  1. Dear CFS Team,

    we are looking to produce our parts through casting to reduce our machining and cost as well.
    let me know if you can support us.
    regards

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