Aluminum die casting is a manufacturing process to make complex, precise, defined, smooth, and textured-surfaced aluminum parts with a thin wall section. It is a popular option for automotive, telecom, and products. Also, it is often used to manufacture lighting, hydraulic and electrical components.
It was accomplished by using high-pressure equipment to force molten aluminium into a mold form. Aluminum die-casting enables the production of many die-cast parts in a short period. It is less expensive than alternative casting techniques.
This post will explain to you the fundamentals of the die-cast aluminium process.
Aluminium Die-Casting Process
The aluminum die-casting process maintains permanent strength at very high temperatures, requiring cold-chamber machines. The pressure requirements for cold chamber castings are typically higher than those for hot chamber die castings. Heat aluminum alloy ingots to extremely high temperatures and are entirely molten. Inject the liquid aluminum into the cavity of a steel matrix under high pressure, also known as a mold. Above is an example of a mold for car parts. The mold is in two halves, and after the molten aluminum has solidified, they are separated to reveal the cast aluminum part.
Precisely cast aluminum with a smooth surface and often does not require machining. Because of steel molds, the casting process can repeate tens of thousands of times until it is broken. That is why aluminium die-casting can be the best choice for mass manufacturing aluminum parts.
Advantages of Aluminium Die Casting
Die casting aluminium has various advantages, making it the ideal option for producing aluminium parts. Aluminum items are light in weight but strong in strength. Aluminum die casting produces lightweight products while maintaining strength.
- For starters, it can build highly complicated structures that neither extrusion nor machining can. The manufacture of sophisticated automotive parts such as transmissions and engine blocks is a prime illustration of this. Other processes cannot consistently deliver these parts’ complexity and tight tolerances.
- Aluminum die-cast parts are corrosion-resistant, highly conductive, and have a good stiffness and strength-to-weight ratio. Aluminum casting has numerous surface treatment possibilities. Another significant benefit of the aluminium die casting method is its dimensional stability.
- The aluminium die-casting process is based on rapid production, which enables tens of thousands of die-cast parts to be manufactured much more quickly and cost-effectively than alternative casting methods.
- Furthermore, they are versatile and can be used in almost any business. Without the need for machining, aluminium casting can make everything from electrical components to automotive gearboxes and clutch housings for automobiles.
A380, A390, A360, A413, CC401, B390, ADC-12, and ADC-1 are some of the most common aluminium alloys we use for die casting. The key consideration when selecting an alloy is its intended use.
- A360 has high corrosion resistance and pressure tightness. When melted, it possesses a high degree of fluidity. This alloy is a good choice for 5G communication boxes, vehicle controller shells, automobile oil pans, and other similar applications.
- B390 is for applications such as automotive engine blocks. It has excellent wear resistance and hardness despite having the lowest ductility of all cast alloys.
- A383 (ADC12) is the most often used metal for numerous die-castings manufactured worldwide. It is cost-efficient and facilitates manufacturing processes.
- Alloy A380 has a good balance of casting and product qualities and is the most typically specified alloy for casting a wide range of products.
- A380 alloy is for various applications, including power tools, household furnishings, chassis for electronic equipment, gearbox cases, engine mounts, and many others.
- A390 alloy has a high hardness and excellent wear resistance. As a result, they are suitable for applications such as automotive engine blocks.
Properties of Aluminum Alloy
Aluminium alloy has a wide range of sophisticated chemical and mechanical properties. They are very corrosion-resistant and have excellent heat dissipation characteristics strength-to-weight ratio. Also, these characteristics enable mechanical engineers to build aluminium die-cast parts with a high degree of flexibility.
Some of the properties are as follows:
- Excellent stiffness
- High strength-to-weight ratio
- Good finishing features
- Good machinability
- Resistance to corrosion
- Excellent thermal conductivity
- Electrical conductivity is very high.
- Complete recyclability
Finishing Options for Casting Parts
Die casting aluminium parts often have an excellent surface finish, and require little or no machining. Sanding, sandblasting, and orbital sanding can smooth off a rough surface or other parts’ flaws. Shot peening is a cold working method frequently used on die-cast aluminium to improve fatigue resistance.
Other forms of process, such as drill tapping, can also be made to the parts after casting. A protective coating, such as a powder coat, can also be applied to the die-cast part.
Some of the most popular surface finishes for aluminium casting parts are the following.
Anodizing die-cast aluminium is a cost-effective way to make items corrosion-resistant and long-lasting.
It generates a layer of Al2O3 (aluminum oxide) film on the surface of aluminium and aluminium alloys using electrochemical principles. This oxide coating has unique properties, including protection, ornamentation, insulation, and abrasion resistance.
It is commonly used to minimize corrosion and impart an appealing metallic hue to machined aluminium parts. Anodizing is a scratch-resistant finish that is also a natural electrical insulator and one of the most lasting.
Powder coat is a popular surface treatment process for aluminium die-casting products. It is applied to the workpiece’s surface using powder spraying equipment. The powder is uniformly absorbed on the surface of the workpiece by static electricity, forming a powdery coating; the powdery coating is baked at a high temperature. It cures flat and transforms into the final coating with various effects. You will also get a large range of colors, textures, and gloss levels.
Chem film is another common surface treatment for aluminium die casting. It can be applied in various ways, including spray, dipping process, brush, and so on. The sole distinction is that it is electrically conductive.
Applications of Aluminium Casting Parts
The remarkable benefits of aluminium alloy are used in a variety of applications. For instance, they play a crucial role in the construction and automobile industries. Research estimates that the market for aluminium casting will be worth 51 billion US dollars in 2021. New applications will be created, and more industries will join the community.
Here are a few typical uses for die casting in aluminium alloy.
Aluminum is used in window frames, roof overhangs, and other construction. Die-cast aluminium components are used in big constructions, including commercial buildings and bridges.
These high-strength aluminium casting parts can be found in various automotive applications. They are everywhere, from engines to body parts. Oil pumps, water pump housings, connections, transmission parts, and a wide range of brackets are examples of aluminium cast parts used in automotive manufacturing. Aluminum cast parts’ durability and reliability have made them indispensable in auto design advancements and advances.
Over the last two decades, aluminium die-cast parts have played a significant role in producing those electronic consumer devices. Die-cast aluminium alloy plays a vital role in this growth, from smartphones to 5G network housing.
Aluminum alloy is used in the furniture business to make various home and workplace furniture. Because aluminium has a high strength-to-weight ratio and is resistant to corrosion, they are relatively cheaper.
There are more and more chairs made with die-cast aluminum. Besides, many important furniture parts are made of aluminum, such as door locks, hinges, knobs, and other aluminum fittings.
As a lightweight and impact-resistant alloy, aluminum die-casting materials are used for various parts of an aircraft. For example, aircraft engine piston heads, cargo loader housings, fuel system parts, aircraft distributor cap housings, lighting fixture parts, and electronic housings.
Aluminum cast lighting generates lightweight lights. Aluminum cast light fixtures are great for outdoor use due to their corrosion resistance. The use of cast aluminium in manufacturing light fixtures is both cost-effective and time efficient.
Aluminum Die Casting Design
Aluminum Die Casting Design
When designing the part to be cast, a few considerations must be kept in mind.
First, the mould needs to be made such that it can separate and release the solidified metal component. A separation line must be considered in the initial phases of die design since it designates the point at which the two sides of the mould separate. Before committing to a final design, the designer should consider the parting line—the line dividing two halves—.
The Location of Injection Point
Another important consideration is the location of injection points. The die can be designed with several injection points in cases when the molten metal would otherwise solidify before reaching every crevice in the die. It can also help if cavities are included in the design; you can surround them with aluminum and still have the part come off when the mold is separated.
You must also take part’s wall thickness into account. Thanks to current technological advancements, there are typically no standards for a minimum wall thickness. Still, we should always aim to maintain a consistent wall thickness across the part because metal flows and solidifies more effectively with consistent thickness. Therefore, casting integrity and quality is significantly superior.
Die-cast aluminium parts typically have wall thicknesses ranging from 0.787 inches (2.0 mm) to 0.1737 inches (3.5 mm). The alloy, part size, and application of your die-cast parts influence this. However, there may be an exception to the maximum, and minimum wall thickness for small and large aluminium die castings. If you have any questions, you can contact RpProto.
When aluminum die casting begins to cool and solidify, it will shrink to some extent. It is unavoidable. Thicker sections are more prone to shrinkage, which causes internal pores to form.
As a result, the designer must make the necessary changes to the product design to allow for shrinkage. Such spots must be locally cooled by improving the die design.
How to Reduce Casting Shrinkage
To reduce shrinkage in aluminium die-cast parts, the designer should avoid large/thick sections in your design. If possible, redesign them with thinner sections. Adding flat or vertical ribs to the walls can improve feeding characteristics and reduce shrinkage. Squeeze pins can be used to reduce shrinkage porosity in a specific area.
The aluminium alloy die-casting process is a low-cost manufacturing method. The costs are determined by a variety of factors. The first is the cost of initial tooling. The tooling costs for this process range from $5,000 to $85,000, raising the overall cost of the die-casting process. However, because die casting is a repetitive process, high-volume production becomes more cost-effective. Second, the accurate cost of die casting is determined by the size of the mould as well as the cross-sectional complexity of the product specifications.
RpProto – Aluminum Die-casting Service Provider
RpProto provides precise custom aluminium die casting services with fast turnaround. Aluminum parts of various dimensions can be manufactured.
We have industry-experienced staff and engineers to complete your project according to your specifications. We will provide you with the best and most affordable service, from prototyping to mass production.
For your aluminium die-cast parts, we can achieve tolerances of up to 0.004 (0.1 mm). We manufacture your die-cast parts in accordance with industry standards.
RpProto can help you in the following ways:
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Die casting is the most cost-effective process if you are dealing with a large quantity. RpProto aluminum die-casting services include professional die design and manufacturing with excellent quality control and consistent properties. We also provide e-plating, and powder coating finishes for the casting parts.
Aluminium Casting FAQs
One of the most cost-effective metal die-casting processes is aluminium casting. Aluminium is significantly less expensive than stainless steel and slightly more expensive than carbon steel. Though die-casting tooling takes longer, a single mould can produce thousands of units. The more you produce, the lower your unit price becomes.
Die casting is a type of automated casting. It takes time to make the mould. However, the mould can quickly solidify aluminium alloy. And because it is an automated process, the machine can produce many units without stopping. As a result, die casting is a quick process, especially when producing a large number of parts.
The primary distinction between die casting and sand casting is the material used to create the mould. A mould made of aluminium alloy is used in aluminium casting. Sand casting, on the other hand, employs a sand mould.
Sand casting can handle more complicated designs. Die casting, on the other hand, provides greater dimensional accuracy and speed.
Another significant distinction is that sand casting produces thicker walls, whereas die casting produces thinner walls. As a result, sand casting is not suitable for small parts.
Die casting is ideal for large-scale production, such as when thousands of parts are required. Sand casting, on the other hand, is ideal for small-scale production, such as 100-150 units.