Dual-doped IN939 superalloy with superior strength and high temperature oxidation resistance via Laser Powder Bed Fusion

Document Type

Article

Publication Date

6-1-2026

Abstract

A dual-doping modification of IN939 alloy is achieved via the Laser Powder Bed Fusion (LPBF) method using a micron–nano combination of Si and Y2O3. For the first time in an LPBF-processed FCC alloy, this strategy drives the dominant grain orientation from the conventional (100) texture toward a randomized orientation while retaining columnar grains, thereby reducing anisotropy without sacrificing structural integrity. Notably, while Y2O3 addition alone in Ni-based superalloys typically induces severe cracking during LPBF, the proposed dual doping approach produces completely crack-free builds, removing a major barrier to oxide dispersion strengthening in AM superalloys. The dual-doped IN939 exhibits an excellent tensile strength of 1166 MPa with 12.1% elongation, representing a balanced improvement in strength and ductility. High-temperature oxidation tests at 1200 °C reveal that it forms the thinnest yet most protective oxide scale, consisting of a Ti-enriched Cr2O3 layer and subscale Al/Si/Ti oxides, effectively preventing further oxidation. In contrast, baseline IN939 suffers from severe oxidation due to the depletion of key strengthening elements. This dual-doping approach not only enhances mechanical and oxidation performance but also offers a new pathway for developing crack-free, high-performance LPBF Ni-based superalloys for extreme environments.

Publication Source (Journal or Book title)

Materials Science and Engineering A

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