Effect of scanning strategy during selective laser melting on surface topography, porosity, and microstructure of additively manufactured Ti-6Al-4V

Research output: Contribution to journalJournal articleResearchpeer-review

71 Downloads (Pure)

Abstract

The effect of the scanning strategy during selective laser melting (SLM) of Ti-6Al-4V was investigated. An optimized cellular scan strategy (island scan modeled) was compared to a simple cellular scan strategy (island scan stripes) and a simple antiparallel line scanning strategy (line scan). Surface texture was investigated by optical three-dimensional (3D) surface measurements, which when combined with light optical microscopy (LOM), revealed deflections caused by the thermal stresses during the build process. Elevated edges caused by the edge-effect dominate the surface texture of all investigated specimens. The scanning strategy determines the surface texture, and the lowest surface roughness was obtained by the line scan strategy. Porosity was investigated with X-ray computed tomography-imaging. Mainly spherical porosity was observed for the line scan and island scan modeled specimens, while the island scan stripes strategy showed more lack-of-fusion defects and a higher total porosity amount. Microstructure was investigated with LOM and scanning electron microscopy (SEM). The microstructure in Ti-6Al-4V was largely martensitic α' and prior β grains. The morphology is different for the various scan strategies, and decomposition of α' into lamellar α/β was observed in the bottom part of the island scan specimen. Accordingly, the hardness decreased in the decomposed part of the specimen.
Original languageEnglish
Article number5554
JournalApplied Sciences
Volume9
Issue number24
Number of pages19
ISSN2076-3417
DOIs
Publication statusPublished - 2019

Keywords

  • SLM
  • Selective laser melting
  • Powder bed fusion
  • Ti-6Al-4V
  • Scanning strategy
  • Porosity
  • Microstructure
  • Surface topography

Fingerprint Dive into the research topics of 'Effect of scanning strategy during selective laser melting on surface topography, porosity, and microstructure of additively manufactured Ti-6Al-4V'. Together they form a unique fingerprint.

Cite this