Numerical design of open-porous titanium scaffolds for Powder Bed Fusion using Laser Beam (PBF-LB)

Karol Cwieka; Bartlomiej Wysocki; Jakub Skibinski; Agnieszka Chmielewska; Wojciech Swieszkowski

doi:10.1016/j.jmbbm.2023.106359

Numerical design of open-porous titanium scaffolds for Powder Bed Fusion using Laser Beam (PBF-LB)

J Mech Behav Biomed Mater. 2024 Mar:151:106359. doi: 10.1016/j.jmbbm.2023.106359. Epub 2023 Dec 29.

Authors

Karol Cwieka¹, Bartlomiej Wysocki², Jakub Skibinski³, Agnieszka Chmielewska⁴, Wojciech Swieszkowski⁵

Affiliations

¹ Faculty of Chemical and Process Engineering, Warsaw University of Technology, Ludwika Warynskiego 1, 00-645, Warsaw, Poland. Electronic address: karol.cwieka@pw.edu.pl.
² Multidisciplinary Research Center, Cardinal Stefan Wyszynski University in Warsaw, Marii Konopnickiej 1, 05-092, Dziekanow Lesny, Poland.
³ Institute of Heat Engineering, Faculty of Power and Aeronautical Engineering, Warsaw University of Technology, 21/25 Nowowiejska Street, 00-665, Warsaw, Poland.
⁴ The Department of Materials Science and Engineering, The Ohio State University, Columbus, OH, USA; Faculty of Materials Science and Engineering, Warsaw University of Technology, Woloska 141, 02-507, Warsaw, Poland.
⁵ Faculty of Materials Science and Engineering, Warsaw University of Technology, Woloska 141, 02-507, Warsaw, Poland.

PMID: 38181569
DOI: 10.1016/j.jmbbm.2023.106359

Abstract

The paper concerns the numerical design of novel three-dimensional titanium scaffolds with complex open-porous structures and desired mechanical properties for the Powder Bed Fusion using Laser Beam (PBF-LB). The 60 structures with a broad range of porosity (38-78%), strut diameters (0.70-1.15 mm), and coefficients of pore volume variation, CV(V_p), 0.35-5.35, were designed using the Laguerre-Voronoi tessellations (LVT). Their Young's moduli and Poisson's ratios were calculated using Finite Element Model (FEM) simulations. The experimental verification was performed on the representative designs additively manufactured (AM) from commercially pure titanium (CP Ti) which, after chemical polishing, were subjected to uniaxial compression tests. Scanning Electron Microscopy (SEM) observations and microtomography (μ-CT) confirmed the removal of the support structures and unmelted powder particles. PBF-LB structures after chemical polishing were in close agreement with the CAD models' dimensions having 4-12% more volume. The computational and experimental results show that elastic properties were predicted in very close agreement for the low CV(V_p), and with even 30-40% discrepancies for CV(V_p) higher than 4.0, mainly due to PBF-LB scaffold architecture drawbacks rather than CAD inaccuracy. Our research demonstrates the possibility of designing the open-porous scaffolds with pore volume diversity and tuning their elastic properties for biomedical applications.

Keywords: Finite element method; Laser powder bed fusion; Open-cell; Pore size distribution; Tessellations; Titanium scaffolds.

MeSH terms

Lasers
Porosity
Powders
Prostheses and Implants*
Titanium* / chemistry

Substances

Titanium
Powders