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A Design Study in Aluminum Castings - GM Cylinder Block                                          

Lost Foam Casting

All of the aluminum blocks and heads in this family of engines are produced by using the "lost foam casting" process

The lost foam casting process uses a expanded polystyrene replica of the part being cast. 
  • The coated replica/pattern is placed in a flask and loose sand is placed around the pattern and shaken into its voids. 
  • Molten aluminum is then poured through a foam sprue, or funnel, into the sand where the hot metal melts and displaces the foam of the pattern. 
  • The metal cools in the shape of the part. 

Unlike conventional sand casting, the lost foam process allows more complex and detailed passages and other features to be cast directly into the part.   The lost foam process:

  • Forms complex internal passages and features without cores.

  • Reduces part mass with near net shape capability.

  • Eliminates parting lines.

  • Reduces machining operations and costs.

  • Provides for tight tolerances in critical areas and features.


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Last Modified:August, 2004 by STG

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