Dynamic interactions of polystyrene particles with microstructured surface manufactured by cold spray

Institute of Particle Process Engineering, University of Kaiserslautern, Germany

^* e-mail: Fabian.Krull@mv.uni-kl.de

Published online: 30 June 2017

Abstract

Dynamic interactions of particles with component surfaces often occur during production, processing and transport of granular materials. The morphology of component surfaces has a significant effect on the impact behaviour of particles. The micro processes during an impact (e.g. rebound, rolling, sliding and sticking) can be changed by microstructuring of the surface. This paper deals with the estimation of the energy dissipation processes of polystyrene particles (400 – 700 μm) impacting on a stainless steel surface. The surface was structured with stainless steel particles (mean particle size 3.5 μm) via a cold spray process. Impact experiments were performed and restitution coefficient was measured. The proportion of the energy dissipation by impact on structured surface was 3.87–10.92 times higher than the dissipation on a polished surface. The additional energy absorption can be explained by multiple particle contacts with the steel asperities and additional friction due to the indentation of these asperities in the polystyrene particles. The particle size did not show any influence on the average energy absorption by collision on the microstructured surface. Only the coefficient of variation got higher, because of the inhomogeneous particle distribution.