Understanding the Various Die Casting Methods

Understanding the Various Die Casting Methods

Die casting as we all understand is a manufacturing process used for casting metal products. The process involves the introduction of molten metal into the mould cavities at very high pressures. As mentioned in the previous articles, die casting is the best process to produce metal components in bulk, without the need for secondary operations such as trimming or machining. There are two main types of precision die casting process: Hot-chamber (Hot Casting) and Cold-chamber (Cold Casting). We explain more about these two die casting process types.

Hot Chamber Die Casting

This is the most popular die casting process, and is sometimes referred to as gooseneck casting. One feature of this process is that the casting machine features a built-in melting pot that heats metal, a molten metal bath of sorts. Another feature would be the immersion of the injection mechanism’s cylinder chamber in the molten metal. Delivery of the molten metal into the mould cavity is achieved via a gooseneck feed mechanism (hence the name). Metals with low melting points and high fluidity are best suited for this process. Zinc is one of the metals used in the Hot-Chamber die casting process.

One notable advantage of this process is that direct immersion in the molten metal bath allows for quick and convenient mould injection; the downside however is an increase in the products’ susceptibility to corrosion. But when compared to the Cold-Chamber die casting process which we will explain next, this process has a higher rate of part production.

Cold Chamber Die Casting

Unlike Hot-Chamber die casting, this process eschews the immersion of the injection mechanism in the molten metal bath. The process for Cold-Chamber die casting is as follows; the metal is first melted in a furnace till it reaches molten state. It is then manually or automatically poured into the injection system. This process helps the metal avoid contact with injector chemicals (die and plunger lubricants), thus creating a metal that is more resistant to corrosion. Aluminium and its alloy types are the metals commonly used in the Cold-Chamber die casting process.

Some of the advantages that this die casting process offers are the production of solid and heavy-duty parts, the ability to attain a variety of near net shapes, and designs with multi-finishings.

Other Die Cast Methods

Apart from the above, here are some other die casting process variations:

  • Low Pressure Die Casting – This process is best suited for Aluminium products that are symmetric around an axis of rotation. Vehicle wheels and other Aluminium parts are manufactured using this process. The removal of the feeder boxes from the process ensures high casting yields.
  • Vacuum Die Casting – This process is similar to low pressure die casting, except the locations of the die cast mould and molten metal bath are reversed. The advantages of using this process include enhanced strength and low porosity to the material.
  • Squeeze Die Casting – In this process, molten metal fills an open die, which then squeezes closed, forcing the metal into the recessed portions of the die cast mould. This process creates highly dense products and is used in applications that call for fibre reinforcement.
  • Semi Solid Die Casting – This process ensures maximum density and minimum porosity of the casted material. Also known as Thixo-forming, this process gives an added advantage of better precision; it is most commonly used for non-ferrous metals such as Aluminium alloys.

Choose EKO for Your Die Casting Needs

Based on your industry and the applications required, EKO Industries can help you determine the best die casting process for your project. As a top die casting company, we perform our high-pressure aluminium and zinc die casting services in-house, and we encourage you to contact us today to discuss your project and discover how our expertise can benefit your business.

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