Bonding mechanisms and hysteresis areas in compression cycle plots

It was shown previously that if compression of a powder is treated in an analogous manner to the compression of a nonporous solid, a plot of the transmitted pressure versus the applied pressure should have a hysteresis area that is linear with respect to the maximally applied pressure if plastic deformation occurs. However, if brittle fracture occurs, the area should be quadratically related to the maximally applied pressure. A series of compounds expected to yield by plastic deformation was tested, and they were found to give the quadratic relationship. Thus, it is indicated experimentally that the assumption made in general in treating compression cycles may be partially invalid.