Theory 021/Materials Processing
Porosity Is a Gradient Ratio
The claim
Casting porosity is set by the ratio of thermal gradient to solidification rate rather than by either alone.
01The mechanism
The ratio sets the mushy zone length; a long zone traps feeding paths and produces shrinkage porosity.
02Predictions
- P1Porosity should collapse onto the ratio.
- P2Fast solidification with a shallow gradient should still be porous.
03Refutation
Porosity tracking solidification rate alone would remove the ratio.