Abstract
Cobalt-based superalloy microlattices were created via (i) three-dimensional-extrusion printing of inks containing a suspension of Co-, Ni- and W-oxide particles, (ii) H2-reduction of the oxides and sintering to a homogenous Co-Ni-W alloy, (iii) Al pack-cementation to deposit Al on the microlattice struts, followed by Al-homogenization. The resulting Co-(18–20)Ni-(5–6)W-(10–13)Al (at.%) microlattices, with 27–30% relative density and 350 μm diameter struts, display a peak in yield strength at 750 °C, consistent with their γ/γ′ aged microstructure. Oxidation resistance is strongly improved compared to Al-free printed Co-Ni-W lattices, via the formation of an Al2O3 surface layer. However, the resulting Al depletion within the struts reduces creep resistance at 850 °C, which nevertheless remains similar to Ni-based superalloy foam, with 35% relative density.
Original language | English (US) |
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Pages (from-to) | 146-150 |
Number of pages | 5 |
Journal | Scripta Materialia |
Volume | 188 |
DOIs | |
State | Published - Nov 2020 |
Funding
This study was supported by the U.S. Department of Commerce, National Institute of Standards and Technology, as part of the Center for Hierarchical Materials Design (CHiMaD) at Northwestern University via award 70NANB14H012. HC also acknowledges support from the Korea Electric Power Corporation (Grant No.: R18XA06-41).
Keywords
- 3D-printing
- Co-based superalloy
- High-temperature characterization
- Mechanical property
- Microlattice architecture
ASJC Scopus subject areas
- General Materials Science
- Condensed Matter Physics
- Mechanics of Materials
- Mechanical Engineering
- Metals and Alloys