Understanding The Link Between Process Parameters, Microstructure And Mechanical Properties Of Laser Sintered Pa12 Parts Through X-ray Computed Tomography

• Main Authors: Kruth, Jean-pierre, Dewulf, Wim, Pavan, Michele, Craeghs, Tom, Puyvelde, Peter Van
• Other Authors: Proceedings of the 2nd International Conference on Progress in Additive Manufacturing (Pro-AM 2016)
• Format: Conference or Workshop Item
• Language: English
• Published: 2016
• Subjects: X-ray Computed Tomography; Laser Sintering
• Online Access: https://hdl.handle.net/10356/84382; http://hdl.handle.net/10220/41768
• Institution: Nanyang Technological University

Laser Sintering is an Additive Manufacturing technique increasingly used to produce functional parts, with polyamide-12 (PA12) being by far the most processed material. It is common practice in industry to process a mix of recycled and virgin PA12 powder; however it is not yet fully understood how the Laser Sintering process parameters influence the microstructural composition for this mixture, namely the degree of crystallinity, the porosity characteristics and the distribution of the pores within the sintered parts. In this work X-ray Computed Tomography (CT) is used to investigate the porosity of tensile bars printed flatwise using a 50/50 mix of used and virgin PA12 processed with different Laser Sintering energy densities (EDs). Analysis of the pores characteristics and image processing of the CT-slices parallel to the building platform provide insights into the link between Laser Sintering process parameters, pores formation and their arrangement into the sintered polymer for different energy density levels. This information combined with the crystallinity values measured by Differential Scanning Calorimetry, gives a complete picture of the microstructure of the sintered material and its link with the resulting tensile properties.