Interaction between Time Dependent Exposure Strategies and Part Positioning within Selective Laser Melting Process of Plastics
DOI:
https://doi.org/10.3991/ijes.v3i1.4286Abstract
The selective laser melting of polymer powder is, for rapid prototyping applications, a well-established technology, although a lack in basic process knowledge occurs. Considering demands of series production the selective laser melting technique of polymers is faced with various challenges concerning processable material systems, process strategies and part properties. Consequently, basic research is necessary to understand and optimize processes to shift from rapid prototyping to rapid manufacturing of small lot sized series. Based on basic research the high potential of selective laser melting for the production of complex parts without any tools can be opened up. For the derivation of part quality increasing process strategies, knowledge about interactions between sub-processes of selective laser melting and resulting part properties is necessary. The selective laser melting of polymers consists of three major sub-processes: Powder coating, energy input, material consolidation. According to the interaction of sub-processes, resulting temperature fields during the selective laser melting process determine the part properties by changing micro structural pore number and distribution. Beneath absolute temperatures the time-dependency of the thermal fields also influences the porosity of molten parts. Present process strategies tend to decrease building time by increasing scanning speed and laser power. Although the absolute energy input into the material is constant for increasing scanning speed and laser power in the same ratio, time dependent material effects are neglected. The heating rate is a combined parameter derived from absolute temperature and time. Within the paper the authors analyze the basic interactions between different heating rates and part properties (e. g. mechanical strengths). Furthermore, the part positioning is taken into account. Due to the part positioning within the building chamber different shapes of cross sections appear even for equal part geometries. The authors estimate an interaction between exposed cross section and applied speed of energy input, due to heat accumulating effects. Therefore specimens produced with different heating rates are analyzed with imaging technologies as well as mechanical tests. Based on the done basic investigations new heating rate dependent process strategies can be established considering time dependent material behavior.
Downloads
Published
How to Cite
Issue
Section
License
The submitting author warrants that the submission is original and that she/he is the author of the submission together with the named co-authors; to the extend the submission incorporates text passages, figures, data or other material from the work of others, the submitting author has obtained any necessary permission.
Articles in this journal are published under the Creative Commons Attribution Licence (CC-BY What does this mean?). This is to get more legal certainty about what readers can do with published articles, and thus a wider dissemination and archiving, which in turn makes publishing with this journal more valuable for you, the authors.
By submitting an article the author grants to this journal the non-exclusive right to publish it. The author retains the copyright and the publishing rights for his article without any restrictions.
This journal has been awarded the SPARC Europe Seal for Open Access Journals (What's this?)