Cold Shut/Non-Fill

Cold shut/non-fill presents as an incomplete fill of the shell cavity, forming a puzzle-like section in the casting with a positive-negative junction. This defect indicates that the two metal streams met, but did not merge and completely fill. This is likely due to insufficient temperatures or insufficient permeability of the shell.

The causes of this defect are evident in the shell, metal and other portions of the process. To cure these causes, R&R recommends taking the following actions.

Area

Cause

Cure

Wax

 

 

Shell

  1. Shell not permeable enough.
  2. Shell/metal was too cold.
  1. Increase shell permeability cast under controlled atmosphere or vacuum.
  2. Increase temperature of shell/metal.

Metal

  1. The mold, shell or metal were too cold.
  2. Metal was not fluid enough (low metal fluidity).
  3. Pouring practices.
  4. Heat loss,
  5. Non-laminar flow.
  1. Increase the temperature of the mold, shell or metal.
  2. Increase metal fluidity.
  3. Pour quicker, add more head pressure.
  4. Use Kaowool wrap.
  5. Use filter.

Other

  1. Improper gating (size and structure).
  1. Increase runner and gate size.

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