Which term denotes a void left in cast metals due to solidification shrinkage?

Which term denotes a void left in cast metals due to solidification shrinkage?

• A. Lattice
• B. Pores
• C. Shrinkage cavity
• D. Stress

Answer: (C)

Shrinkage cavities occur when molten metal contracts as it solidifies and the mold cannot supply enough material to fill the shrinking regions. This void forms because feeding metal to the solidifying front is insufficient, leaving a cavity behind. It’s different from porosity caused by gas entrapment, which are small voids from gas or shrinkage can be connected to the atmosphere or trapped during pouring. Designers prevent shrinkage cavities by ensuring adequate feeding paths, proper gating and riser design, and controlled, directional solidification.

Shrinkage cavities occur when molten metal contracts as it solidifies and the mold cannot supply enough material to fill the shrinking regions. This void forms because feeding metal to the solidifying front is insufficient, leaving a cavity behind. It’s different from porosity caused by gas entrapment, which are small voids from gas or shrinkage can be connected to the atmosphere or trapped during pouring. Designers prevent shrinkage cavities by ensuring adequate feeding paths, proper gating and riser design, and controlled, directional solidification.