Beyond the orthogonal: On the influence of build orientation on fatigue crack growth in SLM Ti-6Al-4V

Calvin Rans*, Jef Michielssen, Megan Walker, Wandong Wang, Ludmila ’t Hoen-Velterop

*Corresponding author for this work

Research output: Contribution to journalArticleScientificpeer-review

31 Citations (Scopus)
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A challenge in developing an in-depth understanding of the crack growth resistance of Additively Manufactured materials is the fact that their mechanical properties have been shown to be both process and part-geometry dependent. Up to now, no studies have investigated the influence of off-axis (beyond the three orthogonal build orientations) orientations on the fatigue crack growth behaviour of selective laser melted Ti-6Al-4V. Furthermore, the widespread use of compact tension specimens for investigating the material behaviour generates data more suitable for plane-strain conditions, rather than the plane-stress state which is more applicable to many lightweight aerospace structures. To address this gap in knowledge, a comprehensive study was carried out to investigate the influence of off-axis build direction in thin SLM Ti-6Al-4V plates, with a focus on the influence of columnar grain orientation on the fatigue crack growth behaviour. It was found that although a macroscopic columnar grain structure is visible on the specimens, it had no discernible influence on the crack growth resistance when the specimen had undergone a stress relieving or HIP heat treatment.

Original languageEnglish
Pages (from-to)344-354
Number of pages11
JournalInternational Journal of Fatigue
Publication statusPublished - 1 Nov 2018


  • Additive manufacturing
  • Anisotropy
  • Fatigue crack growth
  • Selective laser melting
  • Titanium

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