A framework to link localized cooling and properties of directed energy deposition (DED)-processed Ti-6Al-4V

Sarah J. Wolff*, Stephen Lin, Eric J. Faierson, Wing Kam Liu, Gregory J. Wagner, Jian Cao

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

140 Scopus citations

Abstract

Additive manufacturing (AM) of titanium alloys is a rapidly growing field due to an increase in design flexibility of parts. However, AM parts are highly anisotropic in material microstructure and mechanical behavior due to the change of the local processing conditions in the build-up process. This study follows a link chain model to investigate the relationships between process parameters, cooling rate, porosity and mechanical behavior. The aim of this work is to present a framework that is inspired by the three-link chain model. The framework combines theoretical, computational and experimental approaches. We demonstrate this by using an in-house thermal simulator to link predicted cooling rates with micrographs describing experimental shape descriptors to develop a relationship between solidification cooling rate and porosity geometry. Finally, representative volume elements from predicted porosity maps allow for a prediction of mechanical properties at localized areas. The capability of being able to predict mechanical behavior of titanium alloys is demonstrated for the directed energy deposition process.

Original languageEnglish (US)
Pages (from-to)106-117
Number of pages12
JournalActa Materialia
Volume132
DOIs
StatePublished - Jun 15 2017

Funding

The authors would like to thank the National Institute of Standards and Technology (NIST) for their support through award number 70NANB13H194. This work made use of the MatCI Facility which receives support from the MRSEC Program (NSF DMR-1121262) of the Materials Research Center at Northwestern University. This material is based upon work supported by the National Science Foundation Graduate Research Fellowship under Grant No. DGE-1324585. Quad City Manufacturing Laboratory built the Ti-6Al-4V components. The authors would also like to thank Olivia Schneider and Jacob Smith from Northwestern University.

Keywords

  • Anisotropy
  • Cooling rate
  • Directed energy deposition (DED)
  • Porosity
  • Titanium alloys

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Ceramics and Composites
  • Polymers and Plastics
  • Metals and Alloys

Fingerprint

Dive into the research topics of 'A framework to link localized cooling and properties of directed energy deposition (DED)-processed Ti-6Al-4V'. Together they form a unique fingerprint.

Cite this