Structural Characterization and Strength Assessment of Laser Powder Bed Fusion Manufactured CM247LC Nickel Based Super Alloy

The Laser Powder Bed Fusion (LPBF) process offers the capacity to produce parts with complicated geometries that cannot be manufactured using traditional manufacturing processes. The aerospace industry is particularly interested in this capability because it may enable the creation of high-temperature structural parts with sophisticated cooling channel layouts. This would allow future gas turbines to operate at higher temperatures, resulting in higher efficiency. However, if they are to realize this promise, they must first enhance their knowledge of the influence of the LPBF process on alloy microstructures and its subsequent effect on mechanical properties. Furthermore, this study offers information on how to comprehend microstructural development and the impact it has on the mechanical characteristics of the CM247LC alloy processed by LPBF. Using the Direct Metal Laser Sintering technique based on Laser Power Bed Fusion, the CM247LC nickel-based superalloy was manufactured. When the CM247LC alloy was examined microscopically, carbides and cracks (both straight and serrated) were found. Electron Backscatter Diffraction studies revealed elongated grains in the longitudinal section and equiaxed clusters in the transverse section. Longitudinal sections have been determined to be predominantly composed of columnar grains with cells that have an average size of 0.7 µm. The γ/γ′ eutectic, as well as highly concentrated precipitates and highly concentrated dislocations, separate these cells from neighboring cells and grains. Up to 10 nm of the γ′ can be found inside the cells, despite having a diameter of up to 40 nm at the cell walls. The calculated rate of cooling during solidification is around 10 6 K/s based on the observed cell diameters. Tensile tests on samples that had just been manufactured reveal that yield strength is comparable to previous studies. High precipitate concentrations, dislocations density, fine cell structure, and γ' inside cells are interpreted as the sources of high strength in as-fabricated conditions.