Atlas of Casting Defects
Negative
Smooth, dished surface depression
varies
Heavy sections or thick flat surfaces
N/A
Cavitation
Visual inspection, overlay of straight edge or customary dimensional inspection tools
Heavy section of wax pattern shrinks as it cools. The vacuum created during cooling causes the surface to cavitate or dish inward.
| Area | Possible Cause | Potential Correction |
|---|---|---|
| Other (Wax Tool Design) | Feed runner freezing prematurely |
Increase size or add runner to affected section |
| Wax | Incorrect wax injection parameters |
Reduce wax temperature, increase injection time, increase injection pressure |
| Wax | Missing wax chill |
Create wax chill to reduce the volume of injected wax in the area of sink/cavitation |
| Wax | Hot wax chill |
Allow time for the wax chill to cool to room temperature before inserting in the wax injection die |