Microstructure and compressive properties of 3D-extrusion-printed, aluminized cobalt-based superalloy microlattices

MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING

卷:815

Article

Park, Hyeji^1,2  Choe, Heeman¹  Dunand, David C.² 

[1] Kookmin Univ, Sch Mat Sci & Engn, Seoul 02707, South Korea

[2] Northwestern Univ, Dept Mat Sci & Engn, Evanston, IL 60208 USA

关键词: Co-based superalloy;    3D-printing;    Pack-cementation;    Microlattice architecture;    High-temperature application;   

DOI  :  10.1016/j.msea.2021.141262

来源: Elsevier

【 摘 要 】

Cobalt-based superalloy microlattices with gamma/gamma ' 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 gamma (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 gamma ' precipitates within the gamma matrix. The compressive strength, ductility and energy absorption of these gamma/gamma ' 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.

【 授权许可】

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