The role of node fillet, unit-cell size and strut orientation on the fatigue strength of Ti-6Al-4V lattice materials additively manufactured via laser powder bed fusion

•Manufacturing-induced geometrical defects occur in L-PBF lattice structures.•Build direction markedly affects the morphology and the defects of struts.•Fatigue strength can be enhanced by build direction and junction geometry.•The build direction governs whether fatigue failure occurs at the struts...

Full description

Saved in:
Bibliographic Details
Published in:International journal of fatigue 2021-01, Vol.142, p.105946, Article 105946
Main Authors: Dallago, M., Raghavendra, S., Luchin, V., Zappini, G., Pasini, D., Benedetti, M.
Format: Article
Language:English
Subjects:
Additive Manufacturing
Defects
Fatigue
Laser Powder Bed Fusion
Lattice materials
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:•Manufacturing-induced geometrical defects occur in L-PBF lattice structures.•Build direction markedly affects the morphology and the defects of struts.•Fatigue strength can be enhanced by build direction and junction geometry.•The build direction governs whether fatigue failure occurs at the struts or the nodes. Laser Powder Bed Fusion (L-PBF) provides ample freedom to fabricate lattice materials with tailored micro-architecture. Nevertheless, small-scale structures often suffer from a wide range of morphological defects, which impact the macro-scale mechanical properties. In this work, prominent morphological factors including geometric irregularities (surface notches and cross-section deviation), node geometry and printing direction are assessed for four batches of L-PBF Ti-6Al-4 V cubic lattice specimens, and their fatigue behavior compared. The results show that smoothing the strut fillets at their node remarkably improves the S-N curves and that the printing direction impacts both the fatigue strength and the failure behavior.
ISSN:0142-1123
1879-3452
DOI:10.1016/j.ijfatigue.2020.105946