Improving accuracy of overhanging structures for selective laser melting through reliability characterization of single track formation on thick powder beds

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Abstract

Repeatability and reproducibility of parts produced by selective laser melting is a standing issue, and coupled with a lack of standardized quality control presents a major hindrance towards maturing of selective laser melting as an industrial scale process. Consequently, numerical process modelling has been adopted towards improving the predictability of the outputs from the selective laser melting process. Establishing the reliability of the process, however, is still a challenge, especially in components having overhanging structures.In this paper, a systematic approach towards establishing reliability of overhanging structure production by selective laser melting has been adopted. A calibrated, fast, multiscale thermal model is used to simulate the single track formation on a thick powder bed. Single tracks are manufactured on a thick powder bed using same processing parameters, but at different locations in a powder bed and in different laser scanning directions. The difference in melt track widths and depths captures the effect of changes in incident beam power distribution due to location and processing direction. The experimental results are used in combination with numerical model, and subjected to uncertainty and reliability analysis. Cumulative probability distribution functions obtained for melt track widths and depths are found to be coherent with observed experimental values. The technique is subsequently extended for reliability characterization of single layers produced on a thick powder bed without support structures, by determining cumulative probability distribution functions for average layer thickness, sample density and thermal homogeneity.
Original languageEnglish
Title of host publicationProceedings of SPIE
EditorsBo Gu, Henry Helvajian, Alberto Piqué
Number of pages14
Volume9738
PublisherSPIE - International Society for Optical Engineering
Publication date2016
Article number97381B
DOIs
Publication statusPublished - 2016
EventLaser 3D Manufacturing III - San Francisco, California, United States
Duration: 13 Feb 201613 Feb 2016

Conference

ConferenceLaser 3D Manufacturing III
CountryUnited States
CitySan Francisco, California
Period13/02/201613/02/2016
SeriesS P I E - International Society for Optical Engineering. Proceedings
Volume 9738
ISSN0277-786X

Keywords

  • Selective laser melting
  • Overhanging structures
  • Single track formation
  • Regression analysis
  • Monte Carlo simulations
  • Reliability estimation
  • Uncertainty characterization

Cite this

Mohanty, S., & Hattel, J. H. (2016). Improving accuracy of overhanging structures for selective laser melting through reliability characterization of single track formation on thick powder beds. In B. Gu, H. Helvajian, & A. Piqué (Eds.), Proceedings of SPIE (Vol. 9738). [97381B] SPIE - International Society for Optical Engineering. S P I E - International Society for Optical Engineering. Proceedings, Vol.. 9738 https://doi.org/10.1117/12.2212621