A numerical study on the packing quality of fibre/polymer composite powder for powder bed fusion additive manufacturing

Abstract

A discrete element model has been developed to simulate the packing process of fibre/polymer composite powder for powder bed fusion additive manufacturing. The geometric shapes of polymer powder particles and fibres are represented by multi-sphere particles and individual cylinders with round ends, respectively. The numerical model can help to understand the flow dynamics of composite powder particles and the formation mechanisms of voids in powder packing processes. The numerical model has been utilised to analyse the effects of packing parameters on the packing quality of the powder bed. The simulation results suggest that the increase of the powder layer thickness is beneficial to the increase in the packing density and the decrease in the surface roughness of the powder bed. A high roller spreading velocity degrades the packing quality of the powder bed. Furthermore, a small number of fibres in the composite powder particles are in favour of the packing quality, but a further increase in the fibre number reduces it.

Keywords

• additive manufacturing
• discrete element method
• pa12
• glass fibres
• packing density
• surface roughness