Die Casting

Die Casting: The way to go for rapid production

of aluminium and zinc alloy parts

As a Die Casting specialist, Omnidex offers a lot more than what a typical factory can do for you. From die making to production engineering and QC, we can set everything up for you. There are a lot of things to consider in a Die Casting project, and here are what we think really matter to you.

  • 1. Close connections with the top-performing Die Casting factories

We have been working with some of the best Die Casting factories in our region for many years. These factories can produce top quality products with highly accurate dimensions and tolerances. Also, you are not limited to the capacity of just one manufacturer, giving you more choice on materials and casting methods.

  • 2. Advanced simulations and engineering support

Your project is backed by our team of experienced in-house engineers. We use the very latest software to simulate molten metal flow during the Die Casting process so that we can highlight feed points and identify areas where improvements can be made. We are always ready to answer your questions concerning Die Casting and other manufacturing processes.

  • 3. Expert in die design and making

The die is the most important component in the process. Any problem in the die design may lead to inaccuracy or quality issues in the products. As an expert in Die Casting, we will provide you with the best die designs possible to ensure the success of your project.

  • 4. Top-notch Die Casting finishing

Our production offers impeccable surface finishes through detailed final cleaning and specialized painting. We also guarantee clean sprue removal and keep waste to a minimum.

  • 5. Rigorous QC standards

Issues such as flash, unfilled sections and hot tearing may occur in Die Casting. Our QC specialists will make sure the product is free of these problems, and the dimensions and properties are up to the agreed specification throughout the entire production run. Learn more about our QC process here.

Learn more about Die Casting

The Die Casting process dates back to the early 19th century when tin and lead were poured into steel molds to produce type for printing. This process is characterized by forcing molten metal under high pressure into a mold cavity. Its potential was soon exploited and today it is used in virtually every industry. 

Check out our video to learn about the steps in the Die Casting process:

There are 3 types of Die Casting methods:

  • Cold-Chamber Conventional Die Casting:

This process involves heating metal in a separate furnace, then transferring the molten metal into the casting machine. It is used for metals with a higher melting point, such as aluminum, magnesium and copper.

  • Hot-Chamber Conventional Die Casting:

Instead of using a separate furnace, metal is heated inside the casting machine. The injection mechanism involves a goose-neck machine placed inside a crucible, which can heat the metal to melting point and inject it into the die. It is typically used for metals with lower melting points such as zinc alloys. (Thanks to technology advancement, magnesium alloys can also be used.)

  • Multi-Slide Hot-Chamber Die Casting:

Multi-slide die casing uses tools with 4 perpendicular slides (in some cases up to 6 slides at angles other than 90°) to produce more complex and accurate castings. This process is used to produce small zinc alloy components at a rapid production rate (up to 4500 cycles per hour).

Die Casting Animation 

Pros and cons of Die Casting:

Pros

  • Cost effective for high volume production runs
  • Excellent dimensional accuracy and consistency
  • Rapid production rate
  • Smooth as-cast surfaces
  • Reduced need for additional machining

Cons

  • Higher initial tooling costs, not economically viable for smaller production runs
  • Materials are usually limited to non-ferrous metals
  • Part size limited by the Die Casting machine

Our Products

Magnesium die cast camera housing
Magnesium die cast camera housing
Magnesium die cast camera housing
Die cast automative part
Die cast automotive bracket
Magnesium die cast camera housing

Materials

It is best to use non-ferrous alloys such as aluminium, magnesium, zinc, brass and copper alloys for Die Casting.

Commonly used in handheld devices, electronic and telecommunication components and computer parts, aluminium die castings are not only lightweight, but also able to withstand the highest operating temperatures when compared to the other alloys.

Characteristics of aluminium alloys in Die Casting:

  1. Lightweight
  2. Able to withstand the highest operating temperatures when compared to the other alloys
  3. Good resistance to corrosion
  4. Higher electrical and thermal conductivity
  5. Low density and high dimensional stability
  6. Good strength and stiffness to weight ratio
  7. Fully recyclable
  8. Excellent EMI shielding properties
  9. Good finishing characteristics
  10. Only suitable for cold chamber machines

Aluminium alloy composition:

 

Magnesium alloys are extremely light and durable but difficult to machine. It is used to make products where lightweight and durability is necessary, such as high-end electronics and camera components. Out of all the alloys used in die casting, it is the lightest and easiest to machine.

Characteristics of magnesium alloys in Die Casting:

  1. High strength to weight ratio
  2. Very low density
  3. Excellent EMI and RFI properties
  4. High electrical and thermal conductivity
  5. Good resistance to corrosion
  6. Can withstand high operating temperatures
  7. Can be made exceptionally thin with high dimensional accuracy and stability
  8. Good finishing characteristics
  9. Suitable for both hot and cold chamber machines

Alloy AZ91D is a high-purity magnesium alloy widely used in die casting alloy. It offers an excellent combination of corrosion resistance, castability and mechanical properties. It has the following properties:

The physical properties of Magnesium AZ91D are as follows:

Zinc alloys are easiest to die cast and is a good low-cost alternative to fabricating or machining parts. It is commonly used in consumer electronics, computers, telecommunications and the automotive industry. Used in hot chamber machines, zinc alloy die castings have a smooth surface finish, allowing for plating and painting.

Characteristics of zinc alloys in Die Casting:

  1. A low-cost material
  2. Able to form very thin walls
  3. Easy to cast
  4. Offers good impact strength
  5. Fully recyclable
  6. Lower melting point (longer die life)
  7. High dimensional stability and accuracy
  8. Outstanding resistance to corrosion 
  9. High thermal conductivity
  10. High hardness and strength
  11. Can be cold formed (easy for fastening and joining parts)

Zinc alloy compositions:

Brass is an alloy containing zinc and copper. It offers a variety of aesthetically pleasing finishes, both as cast and polished. 

Characteristics of brass alloys in Die Casting:

  1. High electrical conductivity
  2. Spark resistant
  3. Fair dimensional accuracy
  4. Excellent resistance to corrosion
  5. Medium machining cost and high die cost
  6. Low finishing cost

Properties of brass:

Characteristics of copper alloys in Die Casting:

  1. Cost the most to die cast out of all alloys
  2. Offers high dimensional stability
  3. High melting point (shorter die life)
  4. High strength.
  5. High resistance to corrosion and wear
  6. Offer the highest mechanical properties compared to the other die casting alloys
  7. Require the use of a cold chamber machine

(please consult our sales department for more information)

Tolerances

Die Casting tolerances are based not only on the alloys used, but also the length, shape and location of each feature. There are several considerations when it comes to setting tolerances for a Die Casting part:

  • The shape or form of the part.
  • The wear and lifespan of the tool (may affect the long and short-term production capabilities).
  • The proximity of features within the tool.
  • How the features on the part relate to each other.

Tolerances looser than required will result in poor product quality and lifespan, whereas tolerances higher than required will result in higher scrap rate and product cost, so it is important to strike a balance between different factors and achieve tolerances that are as tight as necessary.

Therefore, it is important to highlight the functional requirements, as well as the critical dimensions and features on the part that are critical. From here we may choose the appropriate process and material to meet all these specifications and requirements.

Here is the Die Casting tolerance standards for your reference:

Choose the right material for your Die Casting project

There are many factors to consider when choosing the material for your project. Each alloy has different properties that may or may not be suitable for certain usage. Depending on your requirements, there may be several materials suitable for your project, or you may be able to get better results with another casting process. We highly recommend exploring all the options with us before making your decision.

Want to learn more about other casting processes? Check out other processes on our website.

We are always ready to help with your latest project.

Contact our Customer Service and let us know how we can help to catapult your next project to success.

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