Sofia, D;
Chirone, R;
Lettieri, P;
Barletta, D;
Poletto, M;
(2018)
Selective laser sintering of ceramic powders with bimodal particle size distribution.
Chemical Engineering Research and Design
, 136
pp. 536-547.
10.1016/j.cherd.2018.06.008.
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Abstract
This paper addresses the possibility of carrying out Selective laser sintering (SLS) using powders obtained as mixtures of particles of different size. The beam source used in the experiments was a CO2 laser tube with a nominal power of 40W. The materials used were model Glass beads and a real ceramic material characterized by irregular shape of the particles. Bimodal distributed powders were generated by mixing samples characterized by different narrow particle size distributions. Single layer sintered specimens were obtained with a laser scanning speed of 50 mm/s and 8W beam. The sintered specimens were studied by means of microphotography and were characterized in terms of bulk density and tensile strength.Results show that the strength of the sintered specimen is significantly dependent upon the amount of fines in the powder mixture, in spite of the limited effects on the specimen thickness and density. In particular, the highest strength of the sintered material are observed with the highest fraction of fines in the originating powder mixture. In order to estimate the value of the forces between particles of different size produced by the sintering action, the model developed by Liu et al. (2017), based on the Rumpf (1958) approach, was purposely adapted. The application of the model revealed that in our process conditions the connection between large and fines particles is significantly weaker than the force between particles of the same size. The model also indicates that the strength of the sintered materials from mixtures can potentially increase up to values significantly higher than those of the materials sintered starting from the unimodal powder components.
| Type: | Article |
|---|---|
| Title: | Selective laser sintering of ceramic powders with bimodal particle size distribution |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1016/j.cherd.2018.06.008 |
| Publisher version: | https://doi.org/10.1016/j.cherd.2018.06.008 |
| Language: | English |
| Additional information: | This version is the author accepted manuscript. For information on re-use, please refer to the publisher’s terms and conditions. |
| Keywords: | Laser sintering; powder distribution; Morphology analyses |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Engineering Science UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Engineering Science > Dept of Chemical Engineering |
| URI: | https://discovery.ucl.ac.uk/id/eprint/10050415 |
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