Effect of cohesion on structure of powder layers in additive manufacturing

Producing a consistent layer quality for different raw-materials is a challenge for powder-based additive manufacturing. Interparticle cohesion plays a key role on the powder spreading process. In this work, we characterise the structure of deposited layers in the powder-base additive manufacturing process by numerical simulations using the discrete element method. The effect of particle cohesion on the quality of powder layers is evaluated. It is found that higher interparticle cohesion lead to poor spreadability, with more heterogeneous powder layer structure and enhances particle size segregation in the powder layer. We also compare the powder layer quality deposited on a smooth substrate with that on a powder layer. Deposition on a powder layer leads to inferior layer quality of powder layer with higher heterogeneity and higher particle size segregation effects. Graphical abstract: [Figure not available: see fulltext.].