TY - JOUR
T1 - Microstructure and compressive properties of 3D-extrusion-printed, aluminized cobalt-based superalloy microlattices
AU - Park, Hyeji
AU - Choe, Heeman
AU - Dunand, David C.
N1 - Funding Information:
This study was supported by the U.S. Department of Commerce , National Institute of Standards and Technology ( NIST ), as part of the Center for Hierarchical Materials Design ( CHiMaD ) at Northwestern University ( NU ) via award 70NANB14H012 . HP acknowledges support from the Basic Science Research Program ( 2019R1I1A1A01058247 ; 2018R1D1A1B07048390 ) through the National Research Foundation of Korea ( NRF ). The authors thank Dr. C.E. Campbell (NIST) for useful discussions concerning the Co–Ni–W phase diagram, and Prof. Ramille N. Shah and Dr. Adam E. Jakus for providing equipment and training on the ink fabrication and printing of the samples used in the work, and numerous useful discussions.
Publisher Copyright:
© 2021 Elsevier B.V.
PY - 2021/5/20
Y1 - 2021/5/20
N2 - Cobalt-based superalloy microlattices with γ/γ′ microstructure are manufactured by combining two additive methods: ink-extrusion 3D-printing and pack-cementation surface alloying. First, a microlattice green structure is 3D-printed at ambient temperature from inks comprised of Co3O4, NiO, and WO3 powders, an elastomeric binder and solvents. Organic removal followed by oxide reduction under Ar-5% H2, sintering and homogenization at 1250 °C lead to a metallic microlattice with dense struts with uniform γ (fcc)-Co–22Ni–8W (at.%) composition. Second, aluminum is deposited on the strut surfaces via pack-cementation at 1000 °C, diffused at 1300 °C through the strut volume to achieve a uniform composition (Co–20Ni–6W–10Al or Co–18Ni–5W–13Al, at.%), and precipitated during aging at 900 °C as γ′ precipitates within the γ matrix. The compressive strength, ductility and energy absorption of these γ/γ′ Co-based precipitation-strengthened microlattices is measured at ambient temperatures for two aging time (16 and 65 h) and found to be much superior to those of an unalloyed Co microlattice.
AB - Cobalt-based superalloy microlattices with γ/γ′ microstructure are manufactured by combining two additive methods: ink-extrusion 3D-printing and pack-cementation surface alloying. First, a microlattice green structure is 3D-printed at ambient temperature from inks comprised of Co3O4, NiO, and WO3 powders, an elastomeric binder and solvents. Organic removal followed by oxide reduction under Ar-5% H2, sintering and homogenization at 1250 °C lead to a metallic microlattice with dense struts with uniform γ (fcc)-Co–22Ni–8W (at.%) composition. Second, aluminum is deposited on the strut surfaces via pack-cementation at 1000 °C, diffused at 1300 °C through the strut volume to achieve a uniform composition (Co–20Ni–6W–10Al or Co–18Ni–5W–13Al, at.%), and precipitated during aging at 900 °C as γ′ precipitates within the γ matrix. The compressive strength, ductility and energy absorption of these γ/γ′ Co-based precipitation-strengthened microlattices is measured at ambient temperatures for two aging time (16 and 65 h) and found to be much superior to those of an unalloyed Co microlattice.
KW - 3D-printing
KW - Co-based superalloy
KW - High-temperature application
KW - Microlattice architecture
KW - Pack-cementation
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U2 - 10.1016/j.msea.2021.141262
DO - 10.1016/j.msea.2021.141262
M3 - Article
AN - SCOPUS:85105299457
SN - 0921-5093
VL - 815
JO - Materials Science & Engineering A: Structural Materials: Properties, Microstructure and Processing
JF - Materials Science & Engineering A: Structural Materials: Properties, Microstructure and Processing
M1 - 141262
ER -