Dynamics of short fiber/polymer composite particles in paving process of additive manufacturing

Abstract The dynamic behaviors of short fiber/polymer composite powders in powder paving process of additive manufacturing are investigated by discrete element method simulations. Two typical forms of powder paving, counter-rolling and scraping, are performed with mixed carbon fibers/polyamide12 powders. It is found that the compaction of the mixed powders in the counter-rolling form powder paving is stronger than that in the scraping form. With the same paving speed and layer thickness, the powder layer obtained from the counter-rolling form powder paving is denser. For both forms of powder paving, the powder layer density decreases with the increasing of the paving speed. Finally, the increase of the fiber length will reduce the spreadability of the mixed powders, and hence decreases the packing density of the powder layer. The negative effect of the fiber length is relatively weak in the counter-rolling form powder paving due to the compaction of the roller.