Pros and Cons of Die Casting

Page 1: A look at the History
Page 2: Latest Developments
Page 3: The Casting Process in China
Page 4: Pros and Cons of Die Casting
Page 5: Type of Die Cast Products
Page 6: Informative ChinaSavvy Videos

This part of our six part article looks into the details surrounding both the pros and cons of the metal die casting process.

The Pros associated with this specific metal casting process includes:

  • It is an economical process that can be applied to produce a wide range of complex products and components.
  • The process can be fully automated and achieve a rapid production rate. Full automation is frequently used for high volume applications.
  • Components can be specifically developed to have a long service life, close tolerances as well as dimensional accuracy. It typically delivers 0.005 for the first inch and 0.002 for each additional inch, but this does depend on the type of material used in the process. Post machining can be minimised or eliminated entirely with products having a fine surface finish and smooth cast surface in the range of 0.04 and 0.10 rms freely reachable.
  • Casting tensile strengths can be up to 415 megapascals or 60 ksi.
  • The need of secondary machining can be reduced, and sometimes even eliminated, because inserts (such as threaded inserts, high strength bearing surfaces and heating elements) can be cast in.
  • Components produced can have thinner walls (ranging down to an approximate of 0.030 inches) compared to components produced using sand casting or permanent mold casting. Achieving these thin walls does however require a careful mould design and great, detailed attention to the selection of the material used and casting machine operating parameters.
  • Mold tools can be repeatedly reused, frequently being able to deliver up to 100 00 operating cycles. This does however mean that molds need the proper management and maintenance. In some cases, tools are designed with replaceable elements in areas where high wear occurs.

The Cons associated with the die casting process are as follows:

  • The main con, or disadvantage, associated with this particular casting process is its high capital cost. Compared to most casting processes, the casting equipment needed, the dies used and the related components needed for the process, is very costly. In order to make die casting an economically viable option, a high production volume is required.
  • Currently, the process is limited to include high-fluidity metals. The casting weights are also require to be between 30 grams (1 oz.) and 10 kilograms (20 lb.), but has gone up to 32 kilograms in the latest development and evolution of the process. New developments within the process are seeking ways to remove these limitations by filling the die cavity with a metal in the semi-plastic state.
  • Within the standard casting process, the final casting will have a small amount of porosity. This porosity prevents welding or heat treating as the heat causes the gas caught inside the pores to expand. This, in turn, causes micro-cracks inside of the part and the exfoliation of the part’s surface.

As with all metal casting processes, the advantages of the process must outweigh the disadvantages in order to make it an effective and economically viable option.

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