Microstructure and geometry effects on the compressive behavior of LPBF-manufactured inconel 718 honeycomb structures
This work discusses the combined effect of the microstructure and geometry on the deformation modes and energy-absorbing characteristics of laser powder bed fusion (LPBF)-manufactured Inconel 718 (IN718) hexagonal honeycomb structures tested under quasi-static compression. Three different geometries...
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| Format: | Article |
| Language: | English |
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Elsevier
2023-05-01
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| Series: | Journal of Materials Research and Technology |
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| Online Access: | http://www.sciencedirect.com/science/article/pii/S2238785423005574 |
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| author | George Z. Voyiadjis Reem Abo Znemah Paul Wood |
| author_facet | George Z. Voyiadjis Reem Abo Znemah Paul Wood |
| author_sort | George Z. Voyiadjis |
| collection | DOAJ |
| description | This work discusses the combined effect of the microstructure and geometry on the deformation modes and energy-absorbing characteristics of laser powder bed fusion (LPBF)-manufactured Inconel 718 (IN718) hexagonal honeycomb structures tested under quasi-static compression. Three different geometries of the hexagonal cells, varying only in the cell wall thickness (0.4, 0.6 and 0.8 mm) were manufactured using LPBF. Electron backscatter diffraction (EBSD) imaging of the three studied geometries revealed three distinct zones of grain morphologies and textures across the 0.6 and 0.8 mm cell walls and only two zones and higher overall <001> texture across the 0.4 mm cell walls. Miniature tensile tests were performed on 0.4 and 0.8 mm thick tensile samples to evaluate the thickness and orientation effects on the parent material behavior. Each hexagonal geometry was loaded in three different directions resulting in nine study sets. Exhibiting monotonically increasing plateau stress and specific energy absorbed (SEA) in addition to the high SEA/plateau stress ratios, LPBF-manufactured IN718 hexagonal honeycomb structures were demonstrated to be a viable candidate for additively-manufactured (AMed) metallic lattice structures in energy absorption applications. The reduction in the cell wall thickness influenced the instability failure mechanism for the in-plane load direction X1 but no pronounced effect was observed for the in-plane direction X2. As a result of the coupled change of the material properties with the variation in the cell wall thickness, a non-normalized anisotropic form of the Gibson-Ashby model for stochastic foams was proposed to characterize the honeycomb-structure mechanical properties. The findings of this paper more generally provide useful insights into optimizing the design of metallic AMed lattice structures. |
| first_indexed | 2024-03-13T04:10:12Z |
| format | Article |
| id | doaj.art-2b378e4523e2479da3a84946877841a2 |
| institution | Directory Open Access Journal |
| issn | 2238-7854 |
| language | English |
| last_indexed | 2024-03-13T04:10:12Z |
| publishDate | 2023-05-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Journal of Materials Research and Technology |
| spelling | doaj.art-2b378e4523e2479da3a84946877841a22023-06-21T06:55:51ZengElsevierJournal of Materials Research and Technology2238-78542023-05-012415621578Microstructure and geometry effects on the compressive behavior of LPBF-manufactured inconel 718 honeycomb structuresGeorge Z. Voyiadjis0Reem Abo Znemah1Paul Wood2Computational Solid Mechanics Laboratory, Department of Civil and Environmental Engineering, Louisiana State University, Baton Rouge, LA, 70803, USA; Corresponding author.Computational Solid Mechanics Laboratory, Department of Civil and Environmental Engineering, Louisiana State University, Baton Rouge, LA, 70803, USAInstitute of Innovation in Sustainable Engineering (IISE), College of Science and Engineering, University of Derby, Derby, GB, DE221, UKThis work discusses the combined effect of the microstructure and geometry on the deformation modes and energy-absorbing characteristics of laser powder bed fusion (LPBF)-manufactured Inconel 718 (IN718) hexagonal honeycomb structures tested under quasi-static compression. Three different geometries of the hexagonal cells, varying only in the cell wall thickness (0.4, 0.6 and 0.8 mm) were manufactured using LPBF. Electron backscatter diffraction (EBSD) imaging of the three studied geometries revealed three distinct zones of grain morphologies and textures across the 0.6 and 0.8 mm cell walls and only two zones and higher overall <001> texture across the 0.4 mm cell walls. Miniature tensile tests were performed on 0.4 and 0.8 mm thick tensile samples to evaluate the thickness and orientation effects on the parent material behavior. Each hexagonal geometry was loaded in three different directions resulting in nine study sets. Exhibiting monotonically increasing plateau stress and specific energy absorbed (SEA) in addition to the high SEA/plateau stress ratios, LPBF-manufactured IN718 hexagonal honeycomb structures were demonstrated to be a viable candidate for additively-manufactured (AMed) metallic lattice structures in energy absorption applications. The reduction in the cell wall thickness influenced the instability failure mechanism for the in-plane load direction X1 but no pronounced effect was observed for the in-plane direction X2. As a result of the coupled change of the material properties with the variation in the cell wall thickness, a non-normalized anisotropic form of the Gibson-Ashby model for stochastic foams was proposed to characterize the honeycomb-structure mechanical properties. The findings of this paper more generally provide useful insights into optimizing the design of metallic AMed lattice structures.http://www.sciencedirect.com/science/article/pii/S2238785423005574Cellular structuresLattice structuresHoneycombIN718 LPBF MicrostructureAdditive manufacturingMiniature tensile test |
| spellingShingle | George Z. Voyiadjis Reem Abo Znemah Paul Wood Microstructure and geometry effects on the compressive behavior of LPBF-manufactured inconel 718 honeycomb structures Journal of Materials Research and Technology Cellular structures Lattice structures Honeycomb IN718 LPBF Microstructure Additive manufacturing Miniature tensile test |
| title | Microstructure and geometry effects on the compressive behavior of LPBF-manufactured inconel 718 honeycomb structures |
| title_full | Microstructure and geometry effects on the compressive behavior of LPBF-manufactured inconel 718 honeycomb structures |
| title_fullStr | Microstructure and geometry effects on the compressive behavior of LPBF-manufactured inconel 718 honeycomb structures |
| title_full_unstemmed | Microstructure and geometry effects on the compressive behavior of LPBF-manufactured inconel 718 honeycomb structures |
| title_short | Microstructure and geometry effects on the compressive behavior of LPBF-manufactured inconel 718 honeycomb structures |
| title_sort | microstructure and geometry effects on the compressive behavior of lpbf manufactured inconel 718 honeycomb structures |
| topic | Cellular structures Lattice structures Honeycomb IN718 LPBF Microstructure Additive manufacturing Miniature tensile test |
| url | http://www.sciencedirect.com/science/article/pii/S2238785423005574 |
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