Additive manufacturing of strong and ductile In939+TiB2 by laser powder bed fusion

Improving the printability and high-temperature mechanical performance of high aluminum and titanium content Inconel superalloys is of interest in aerospace, automotive, and energy industries. In aerospace applications, for instance, components such as turbine blades and engine parts require exceptional strength and ductility under extreme temperatures (above 800 °C), which more common Inconel alloys such as In718 and In625 struggle to provide. Therefore, this study explores the influence of TiB₂ on the additive manufacturing of Inconel 939 superalloy (In939) by laser powder bed fusion (LPBF). TiB₂ powders with a size of approximately 1–3 μm were decorated on the surfaces of Inconel 939 alloy powders via high-speed blending. Both pure In939 and In939+TiB₂ samples were prepared by LPBF with varying laser power and scanning speed. Microstructural analysis of the as-printed specimens revealed that the TiB₂ addition to Inconel 939 eliminated crack formation under all LPBF conditions tested. Consequently, the as-printed In939+TiB₂ exhibited superior room temperature (RT) yield strength (1256 MPa) and ultimate tensile strength (1578 MPa) with reasonable tensile ductility (13–15 %) compared to the as-printed In939. Furthermore, In939+TiB₂ shows exceptional high-temperature strength, demonstrating superior performance up to 850°C in contrast to other additively manufactured and cast In939 materials in the literature. This study paves the way for sectors including aerospace, automotive, and energy to significantly enhance the performance of critical components like turbine blades and engine parts made of In939 through LPBF.