Bonding mechanisms and hysteresis areas in compression cycle plots

Area of Science:

• Materials Science
• Solid Mechanics
• Powder Technology

Background:

• Previous models assumed linear hysteresis in powder compression, analogous to nonporous solids.
• This linearity was linked to plastic deformation, while quadratic relationships were associated with brittle fracture.

Purpose of the Study:

• To experimentally investigate the relationship between applied and transmitted pressure during powder compression cycles.
• To determine if plastic deformation in powders results in a linear or quadratic hysteresis area.
• To challenge existing assumptions in powder compression modeling.

Main Methods:

• Compression testing of various compounds predicted to exhibit plastic deformation.
• Measurement of transmitted pressure against applied pressure during compression cycles.
• Analysis of the hysteresis area in relation to the maximally applied pressure.

Main Results:

• Tested compounds, expected to deform plastically, exhibited a quadratic relationship between hysteresis area and maximally applied pressure.
• This contradicts the previously assumed linear relationship for plastic deformation.
• Experimental data indicates a deviation from established powder compression models.

Conclusions:

• The assumption of linear hysteresis for plastic deformation in powder compression is experimentally challenged.
• Powder compression behavior, particularly under plastic deformation, may be more complex than previously modeled.
• Further research is needed to refine models for powder compression, considering the observed quadratic relationship.