On the strengthening and embrittlement mechanisms of an additively manufactured Nickel-base superalloy

Modelling of Additive Manufacturability of Nickel-Based Superalloys for Laser Powder Bed Fusion

“…By inserting 94.4% as the one-dimensional DC solidification front and the average cellular size as 420 nm (determined in Ref. [43] ) for LPBF MAD542 superalloy, it results in an ID region of approximately 23.5 nm (slight margin of r > λ/ 2 neglected), which is consistent with the observation of the typical cellular boundary thickness ( ∼ 30 nm) for LPBF superalloy [52] . Fig.…”

“…Thus, the observed microstructure corresponds to a super-saturated γ matrix. The high suppression of γ in as-LPBF-processed materials is also reported for a wide range of γ strengthened nickel-based superalloys including IN738 [52] ,…”

A Novel γ′-Strengthened Nickel-Based Superalloy for Laser Powder Bed Fusion

“…It should be noted that IN738LC and CM247LC are two common superalloys of good interest for the LPBF process. In this study, the MAD542 was solutioning treated at 1230 • C for 2 h, the IN738LC was hot isostatic pressed at 1210 • C for 4 h (for healing the cracks), followed by solutioning heat treatment at 1120 • C for 2 h and aging at 850 • C for 24 h [34], and CM247LC was solutioning treated at 1260 • C for 2 h. It should be noted that all the three superalloys were thermal treated at the super-solvus temperature, which indicate that single γ phase region was achieved. The grains with a grain orientation spread (GOS) value less than 1 • were defined as the recrystallized grains.…”

A High-Throughput Method to Define Additive Manufacturing Process Parameters: Application to Haynes 282

“…The specimen with P 1 = 100 (sample 1 as shown in Figure 4) was chosen for the TEM study as a representative structure within the Haynes 282 optimal processing window. In a Ni-based superalloy, precipitates, Laves phases (AB 2 , where A = Mo, Nb, Ti and B = Cr, Ni, Fe) and carbides (MC, M 6 C, M 23 C 6 , where M = Mo, Cr, Ti) can form at the GBs as well as at the interdendritic regions [4,60] and decrease ductility, so the distribution of phases during LPBF processing is relevant. The bright-field (BF) scanning transmission electron microscope (STEM) micrographs in Figure 7 reveal the microstructure of the as-fabricated specimen, where the cellular dendritic microstructure with precipitates is apparent as shown in Figures 7(a) through (c).…”