J. Mater. Sci. Technol. ›› 2023, Vol. 158: 180-193.DOI: 10.1016/j.jmst.2023.01.059

• Research article • Previous Articles     Next Articles

Additive manufacturing of high-strength Inconel 718 alloy through the addition of Ti2AlC MAX particles

Yu Konga,b, Kaiyuan Penga,b, Haihong Huanga,b,*   

  1. aSchool of Mechanical Engineering, Hefei University of Technology, Hefei 230009, China;
    bKey Laboratory of Green Design and Manufacturing of Mechanical Industry, Hefei University of Technology, Hefei 230009, China
  • Received:2022-11-28 Revised:2023-01-25 Accepted:2023-01-25 Published:2023-09-20 Online:2023-09-15
  • Contact: *School of Mechanical Engineering, Hefei University of Technology, Hefei 230009, China. E-mail address:huanghaihong@hfut.edu.cn (H. Huang)

Abstract: Decreasing the content of detrimental Laves phase in additively manufactured Inconel 718 alloy is highly essential. In the present study, we introduce a novel approach to effectively suppress the precipitation of Laves phase. By ex-situ incorporation of Ti2AlC MAX particles, Ti2AlC/Inconel 718 composites with Ti2AlC volume fractions of 5% and 10% are successfully fabricated using the directed energy deposition (DED) technique. In comparison to the Inconel 718 alloy, the 10 vol.% Ti2AlC/Inconel 718 composite exhibits 70.9% higher yield strength, 39.1% higher ultimate tensile strength, and 61.4% higher hardness. A detailed microstructure examination confirms that the detrimental Laves phase, which is abundantly present in the inter-dendritic region, is replaced by in-situ formed (Nb,Ti)(C,N) and γ' particles with average diameters of 1.12 μm and 10 nm, respectively. Through non-equilibrium solidification process simulation, the suppression of Laves phase, in-situ formation of multi-scale precipitates, and the microstructural evolution due to Ti2AlC addition are illustrated at the mechanistic level. Conclusively, a theoretical model of Ti2AlC/Inconel 718 composite is developed to reveal its underlying strengthening mechanism. It is indicated that Ti2AlC/Inconel 718 composites possess the capability to be a next-generation high-end nickel-based alloy.

Key words: Additive manufacturing, Inconel 718, Max phase, Microstructure, Mechanical properties