Selective Laser Sintering/Melting (SLS/SLM) are additive manufacturing (AM) technologies. Objects are produced by spreading successive layers of powder material and solidifying selected parts by sintering/melting them with a laser. The focus of this study is the powder spreading process for which the powder characteristics plays a major role for the powder layer quality, that in turn, influences the final product properties. The spreading process of a characteristic, frequently used, Ti-6Al-4V powder is simulated in MercuryDPM, using a discrete particle model. A parameter study varying cohesion, sliding and rolling friction allows us to quantify the influence of these powder properties on the layer characteristics, such as density and uniformity. The layer characteristics were obtained by coarse-graining, which generates grid-free continuum fields, e.g., density from discrete data. The density and homogeneity of the powder layer decreased with the increase of interparticle friction, leading to non-uniform layer, higher porosity, and dragged particles causing defects in the powder bed. However, the larger interparticle friction led to a rather good bed. In addition, the sliding friction had a little effect on the layer uniformity, but a large effect on particle segregation, whereas the rolling friction had a larger effect on layer uniformity. Further investigations will focus on additional parametric studies, experimental validation, the effect of humidity and spreading tool design evaluation.
|Number of pages||12|
|Publication status||Published - 2019|
|Event||8th International Conference on Discrete Element Methods, DEM 2019: MS-03: Open-source development - University of Twente, Waaier building, Enschede, Netherlands|
Duration: 21 Jul 2019 → 26 Jul 2019
Conference number: 8
|Conference||8th International Conference on Discrete Element Methods, DEM 2019|
|Abbreviated title||DEM 2019|
|Period||21/07/19 → 26/07/19|
- Additive manufacturing
- Discrete particle simulation
- Powder layer quality
- Selective laser melting
- Spreading process
Shaheen, M. Y., Thornton, A. R., Luding, S., & Weinhart, T. (2019). Discrete particle simulation of the spreading process in additive manufacturing. Paper presented at 8th International Conference on Discrete Element Methods, DEM 2019, Enschede, Netherlands.