Microstructure-topology relationship effects on the quasi-static and dynamic behavior of additively manufactured lattice structures

Kavan Hazeli, Behzad Bahrami Babamiri, Joseph Indeck, Andrew Minor, Hesam Askari

Research output: Contribution to journalArticlepeer-review

33 Scopus citations

Abstract

This study demonstrates a relationship between manufacturing variables including design topology and post-processing heat treatment on the porosity distribution, quasi-static, and dynamic behavior of additively manufactured lattice structures (AMLS). Lattice structures were manufactured out of Inconel 718 using selective laser melting technique with four different topologies. The effect of heat treatment on the porosity size and distribution was examined using X-ray computed tomography for as-built (AB), stress relieved (SR), and hot isostatic pressed (HIP) plus solution aged (SA) heat-treatment conditions. It was noticed that reduction of porosity in the as-built samples, as a result of SR, was greater compared the porosity reduction due to the subsequent HIP plus SA. Quasi-static and dynamic loading was conducted and it was found that the deformation trends of each topology were independent of the strain rate. It was also found that the stress relieving heat treatment process enhances the quasi-static and dynamic flow stress after yielding. However, further heat-treating, including HIP and SA, for the same topology were not as effective as the initial SR process. Furthermore, the validity of digital image correlation in measuring average global strain and the validity of using a Kolsky bar for measuring dynamic mechanical behavior of AMLS are discussed.

Original languageEnglish (US)
Article number107826
JournalMaterials and Design
Volume176
DOIs
StatePublished - Aug 15 2019
Externally publishedYes

Keywords

  • Additive manufacturing
  • Lattice structure
  • Porosity
  • Strain rate effect
  • X-ray computed tomography

ASJC Scopus subject areas

  • Materials Science(all)
  • Mechanics of Materials
  • Mechanical Engineering

Fingerprint

Dive into the research topics of 'Microstructure-topology relationship effects on the quasi-static and dynamic behavior of additively manufactured lattice structures'. Together they form a unique fingerprint.

Cite this