The effect of contact torques on porosity of cohesive powders

TL;DR

This paper investigates how contact torques, such as static rolling and torsion friction, significantly influence the porosity of cohesive powders during uniaxial compaction, with implications for nano-powder sintering.

Contribution

It demonstrates through contact dynamics simulations that contact torques have a significant and additive effect on powder porosity, a factor often overlooked in previous models.

Findings

Contact torques significantly affect porosity.

Effects of contact torques are approximately additive.

Implications for nano-powder pressure sintering.

Abstract

The porosity of uniaxially compacted cohesive powders depends on the applied stress (including gravity). The case, where these stresses are weak, is considered. The compaction results in a porosity which is a function of sliding, rolling and torsion friction. By contact dynamics simulations it is shown that the influences of contact torques (static rolling and torsion friction) on the porosity are significant and approximately additive. The relevance for nano-powder pressure sintering is discussed.