Theory 156/Ceramic sintering/Ratio lens
Shrinkage Is Surface Against Bulk
The claim
Shrinkage is set by the ratio of surface energy to bulk modulus, so finer powders shrink more for the same density gain.
01Mechanism
Driving force for densification is excess surface area; resistance is the material's stiffness.
02Prediction
Shrinkage should track the ratio.
03Refutation
Shrinkage tracking particle size alone would remove modulus.