Definition
Molten metal solidified before completely filling the mold cavity, leaving rounded, incomplete edges and missing sections.
Engineering Explanation
As the metal loses superheat during pouring, its fluidity drops. If the liquidus is reached before the last cavity regions fill — typically thin sections farthest from the gate — solidification halts the flow and the casting is left incomplete.
Likely Root Causes
- Low pouring temperature
- Poor metal fluidity
- Undersized gate restricting flow
- Very thin casting sections
Industrial Impact
Misruns render parts non-functional and are usually scrapped, driving up cost per good casting and disrupting production schedules on thin-walled components.
Recommended Corrective Action
Raise the pouring temperature to restore superheat and enlarge the gate so the cavity fills before solidification begins.
- Maintain pouring temperature above the recommended superheat window
- Design generous gates and runners for thin sections
- Pour promptly to minimise heat loss in the ladle
Best Manufacturing Practice
Use solidification-time modelling to confirm the thinnest sections fill before the metal reaches its liquidus temperature.