Metal matrix composite with superior ductility at 800 °C: 3D printed In718+ZrB2 by laser powder bed fusion
Abstract
We investigated the microstructure and mechanical properties of ZrB2 fortified Inconel 718 (In718+ZrB2) superalloy metal matrix composite (MMC), which was produced via Laser Powder Bed Fusion (LPBF). 2 vol% ZrB2 nano powders (below 100 nm in diameter) were decorated on the surfaces of Inconel 718 alloy powders by high-speed blender. Microstructural analysis of the as-printed specimens showed that the ZrB2 decomposed during LPBF, which promoted the formation of homogeneously distributed (Zr, Ni)-based intermetallic and (Nb, Mo, Cr)-based boride nanoparticles in the matrix. The 3D printed In718+ZrB2 has remarkably lower porosity and smaller grain size compared to 3D printed In718 fabricated under the same LPBF conditions. The mechanical performance of the as-printed and heat-treated In718+ZrB2 showed significantly higher room temperature (RT) hardness, RT yield strength (σYS), and RT ultimate tensile strength (σUTS) compared to In718. High-temperature tensile tests at 800 °C showed that In718+ZrB2 has ∼10 times higher tensile ductility with higher σYS (by 10 %) and σUTS (by 8 %) than pure In718.
Declaration of competing interest The authors declare no competing interests. Acknowledgment This work was supported by Eni S.p.A. through the MIT Energy Initiative, The Scientific and Technological Research Council of Turkey (TUBITAK) under Grant No. 1059B192000941, and ARPA-E (DE-AR0001434). Furthermore, 3D printing for this project was completed using the EOS M290 at the Advanced Digital Design and Fabrication core facility at the University of Massachusetts, Amherst. WC acknowledges support by the National Science Foundation (DMR-2004429). ADO acknowledges support by NSF GRFP Award #4999143677. SK and DA acknowledge the support by Istanbul Technical University Scientific Research Projects Unit with a project (No: MUA-2021–43196) entitled “Production and Characterization of Boron Containing Metallic Nanocomposites via Additive Manufacturing”. GDS acknowledges support by the KAI-NEET and UP, KAIST, Korea.
