Effect of the argon/monomer flow-rate ratio on the flowability trend of PECVD-processed micropowder

Plasma-enhanced chemical vapor deposition of non-continuous coatings on the surface of micropowders can reduce the interparticle van der Waals forces and consequently improve the powder flowability. A quasi-Arrhenius relation holds between flowability improvement and energy delivered per mass of plasma monomer W/FM. This work reports the flowability trend of graphite micropowder processed with organosilicon glow-discharge plasma at high levels of energy per monomer mass (~ 10-100 MJ/kg). A critical energy level is found, above which the argon/monomer flow-rate ratio becomes a significant additional parameter influencing the deposition process. A revised empirical quasi-Arrhenius relation is proposed to take into account this effect.