Physical processes of tableting.

Shear deformation was shown to occur during the decompression of large compacts made by nonisostatic compression. Some materials undergo fracture when these shear stresses are developed. Other materials withstand these stresses but fracture upon ejection when the stress concentrations at the edge of the die are large. Failure to fracture seems to be related to the ability to relieve stresses by plastic deformation. A test was devised to measure this property, called the brittle fracture propensity.