A bio-inspired design strategy for easy powder removal in powder-bed based additive manufactured lattice structure

ABSTRACT

This study evaluates the challenges of powder removal inside surface-based lattice structures that have been fabricated by the polymer-powder-based additive manufacturing (AM) process. The natural flow adaptations of plant cells’ morphology and perforation that allow water and minerals easy transport have been bio-mimicked for ease of powder flow during post-processing powder removal. Vessel-shaped and supportless lattice structures with ventilations have been designed, followed by a Computational fluid dynamics (CFD) simulation. This is to study the fluid flow pattern and turbulence inside the lattice structures. The designed lattice structures were 3d printed with polyamide 12 (PA-12) material by HP-MJF 4200 powder bed technology. They were followed by powder removal using a pressurised air gun and computerised tomography (CT-scan) to observe the regions of trapped powder inside the lattice structures. The uni-axial compression tests were conducted to observe the effect of ventilation on the mechanical properties of the lattice structures.

KEYWORDS:

• Ventilated lattice structure
• biomimetic
• additive manufacturing
• powder bed process
• Design for Additive Manufacturing and post-processing
• 3D printing
• lattice structures
• computational fluid dynamics

Acknowledgements

The authors would like to thank Biomedical Imaging and AM Integration Team, NAR Labs, Taiwan, for providing the computerised tomography facility for research and evaluation.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was financially supported by the High-Speed 3D Printing Research Center [grant number 108P012] from the Featured Areas Research Center Program within the framework of the Higher Education Sprout Project by the Ministry of Education (MOE) Taiwan.

Notes on contributors

Saurav Verma

Saurav Verma is a PhD research scholar at the High-Speed 3D Printing Research Center (HS3DP) of National Taiwan University of Science and Technology (NTUST, Taiwan) since 2019. His research area includes design for additive manufacturing and post-processing, design and optimization for powder-bed-based additive manufacturing processes like multi jet fusion (MJF), selective laser melting (SLM) and fused filament fabrication (FFF). He has worked as a laser 3D printing consultant for the smart manufacturing projects at Foxconn Industrial Internet, Taiwan and involved with various product development projects at Taiwan Tech 3D.

Ajeet Kumar

Dr. Ajeet Kumar is currently Project Asst. Prof. at High-Speed 3D Printing Research Center (HS3DPC) of National Taiwan University of Science and Technology (NTUST, Taiwan). He does research on high-speed additive manufacturing, design for additive manufacturing and post processing, cellular lattice structure, closed cell lattice structure. In 2020, he earned his PhD in Biomimetic design and additive manufacturing of lattice structure for energy absorption application. He is also involved with various industries like Yushan Ventures, Mosaic Venture lab and Taiwan Tech 3D at various technical position for projects like 3D printing and 4D printing.

Shang-Chih Lin

Prof Shang-Chih Lin currently is the Director of High-Speed 3D Printing Research Center (HS3DPC) of National Taiwan University of Science and Technology (NTUST, Taiwan). He has served as an esteemed faculty at the Institute of Biomedical Engineering at NTUST, Taiwan since 2008. His research area is focused on 3D printing of biomedical devices (orthoses, implants, and surgical instruments), design of biomechanical experiments, bio-statistics, integration of computer-aided-design and finite element analysis, and various other projects related to biomechanics of orthopedics and dentistry. He has received several well-regarded awards like the 2011 Research Award for National Biotechnology and Innovation. He earned his PhD from the National Taiwan University.

Jeng-Ywan Jeng

Prof Jeng-Ywan Jeng currently is a Distinguished Professor in National Taiwan university of science and technology, Taiwan. His main research area is focussed on high speed additive manufacturing, digital manufacturing, laser material interaction, design for additive manufacturing, 3D printing technology. He is also founder of start-ups like T3D, Taiwan tech digital, and consultant of industries and universities such as Pouchen, Franz, Aviocast and Lunghwa University of Science and Technology. He is also independent director of GlobalWafers, ANT precision industry, ACTRON technology. He earned his PhD from The University of Liverpool, UK in 1992.