Selective laser sintering of copper filled polyamide 12: Characterization of powder properties and process behavior

Commercially available materials for selective laser sintering (SLS) include mainly semicrystalline polymers and only a few composites like polyamide 12 filled with glass beads or aluminum. Powder composites can be used for setting tailored properties. Exemplarily, mechanical properties as well as thermal or electrical conductivity can be improved. Thermally conductive SLS parts filled with copper particles have not been under investigation before. This study contains the characterization of polyamide 12 filled with copper acting as a metal filler with a high thermal conductivity. Two composites differing in the filler shapes are investigated concerning powder properties and the resulting processability. The thermal conductivity in dependence on the filler content and anisotropy is of major interest. Isotropic, spherically shaped copper fillers are compared with strongly anisotropic flakes leading to the result that a much lower content of anisotropic filler is needed to reach an increased thermal conductivity. However, the powder flowability and processability is also highly influenced by the filler shape and content. Fillers with a similar shape like the matrix powder lead to a better flowability allowing higher filler contents. POLYM. COMPOS., 40:1801–1809, 2019.