Characterization and Modeling of Deformation Mechanisms in Ni-Base Superalloy 718

Knowledge of process-structure-property relationships to engineer better heat treatments for laser powder bed fusion additive manufactured Inconel 718

“…6-8). This finding suggests that the coprecipitates coarsen at a slower rate than their individual monolithic phases, which is consistent with previous studies of their kinetics in wrought processes [23,31,32,75]. As discussed in section 3.2.3, optimizing the formation of coprecipitates in AM-IN718 should improve the performance at higher operating temperatures.…”

“…The g¢ unit cell size is in between that of the g matrix and g″ precipitates. Therefore, it is proposed that g¢ -matrix interfaces serve as preferential nucleation sites for g″ [28], because the lattice strain energy caused by g″ nucleating on g¢ -matrix interfaces is lower than that of g″ nucleating completely within the matrix [23,32,33]. Coprecipitates have been shown to improve mechanical responses by requiring more complex dislocation structures to induce plastic deformation [34,35].…”

Creep‐fatigue deformation characteristics and life prediction model of Inconel 718 superalloy under hybrid stress–strain‐controlled mode

“…In order to obtain optimized microstructures and mechanical properties, the material was subjected to standard heat treatment that involved the following steps: solution annealing treatment at 960 C for 1 h, first-stage aging treatment at 720 C for 8 h followed by furnace cooling at 50 C/h to 620 C, second-stage aging treatment at 620 C for 8 h and then air cooling to room temperature. The microstructure of this material is consisted of the equiaxed γ matrix, the γ 0 precipitate with a Ni 3 (Al, Ti, Nb) compound, the γ 00 precipitate with a Ni 3 Nb compound, and a small fraction of δ phase distributed at grain boundaries 13,26 as shown in Figure 1.…”

“…11 Thus, Inconel 718 has been extensively used in aircraft engines, including in the fabrication of turbine disks. 12,13 To ensure the safe operation of turbine disks, plenty of researchers are devoted to studying the deformation behavior of turbine disk materials under LCF and creepfatigue loads. After obtaining the basic deformation response of the material, many scholars have proposed various models to accurately predict the service life of the material.…”