Understanding the Laser Sintering of Polymers at Microscale Level by Using X-Ray Computed Tomography

Literature reports on many cases where X-ray Computed Tomography (CT) has been used to measure the porosity of laser sintered (LS) polymeric parts, in order to characterize the process parameters’ influence on their density. However, this approach implies to perform a CT scan for each parameter set being assessed, making the evaluation very costly and time consuming. Moreover, this approach does not provide useful information about the coalescence steps of the process and the local variation of the powder packing density which happen at the microscale level, namely at dimensions comparable to the layer thickness used during the process. This work presents a new CT-based approach which allows to assess at the microscale the variation of the sintering conditions for several scanning strategies at the same time. The study focuses on PA12 powder, but the proposed approach is general and can potentially be applied to every laser sinterable polymeric powder.Mechanical Engineerin