Improving the surface quality of additive manufactured polyamide parts using conventional treatment methods

Additive manufacturing processes have progressed in years past from not only being prototyping methods to also being end-product manufacturing methods. However, there are many challenges hindering higher industrial adoption rates of additive manufacturing such as low surface quality of the manufactured parts. Post-process surface treatment methods can play a key role in addressing this challenge. In this work, three mechanical methods were applied to selective laser-sintered polyamide 12 (PA12) parts with the aim of improving the surface quality. The effects of the methods regarding the surface integrity characteristics were evaluated. The results show improved surface roughness across all three methods: from initial Ra of 7.09 μm to 0.055 μm Ra, 0.28 μm Ra and 0.45 μm Ra by grinding, diamond turning and milling on the surfaces oriented upwards during fabrication respectively. Across the three methods, surface hardness was slightly reduced: with a maximum reduction of 2.5% by diamond turning.