A creep-damage phase-field model: Predicting topological inversion in Ni-based single crystal superalloys

Fuzzy random evaluation of creep model of frozen soft soil in metro tunnel construction using artificial ground freezing technique

“…According to the uniaxial compression and uniaxial creep test results of frozen soft soil specimens in this study, the deformation trend and data were similar at different temperatures corresponding to the same stress level 35 – 38 . For example, at − 5 °C, − 10 °C, and − 15 °C, the final strains at different stress levels were as follows: With a 0.3σ c stress level, the final strains of clay were 2.49%, 2.30%, and 1.69%, respectively, those of silt were 2.60%, 2.09%, and 1.79%, respectively, and those of silty clay is 1.50%, 2.29%, and 2.20%, respectively; With a 0.5σ c stress level, the final strains of clay were 4.58%, 4.39%, and 3.79%, respectively, those of silt were 4.59%, 4.18%, and 3.60%, respectively, and those of silty clay were 3.99%, 4.30%, and 4.48%, respectively; and with a 0.7σ c stress level, the final strains of clay were 6.80%, 6.20% and 5.70%, respectively, those of silt were 6.60%, 6.30%, and 5.40%, respectively, and those of silty clay were 6.00%, 6.60%, and 6.90%, respectively.…”

Influence of Cooling Scenarios on the Evolution of Microstructures in Nickel-Based Single Crystal Superalloys

“…In some places, the precipitates fused, and the morphology became "L" type. In other places, the matrix channels become "islands", it seems that the precipitate phase surrounds the matrix phase, that is, the so-called topological structure inversion [24]. When the matrix is relatively wide, the curvature of the interface changes greatly, showing a "wavy" shape.…”

Review of γ’ Rafting Behavior in Nickel-Based Superalloys: Crystal Plasticity and Phase-Field Simulation

“…Assigning different values to different phases (for example, γ' strengthening phase and γ matrix phase in nickel-based superalloys), the interface region is implicitly given [78]. Such a method makes it possible to analyze the evolution of complex microstructures, including precipitation, dissolution, coarsening, connection, and topological inversion of γ' strengthening phases [79,80]. Additionally, the physical characteristics, i.e., the γ/γ' lattice misfit, elastic constants and dislocation densities, and the mechanical behavior, i.e., heterogeneous elasticity and plastic deformation, of superalloys can be well incorporated in the mathematical framework of the phase-field method.…”

“…However, further creep deformation may distort the stable raft structure and lead to topological inversion of γ/γ' phases, i.e., the γ' strengthening phase gradually surrounds the γ phase [94]. Incorporating damage parameters [8,19,80] and the change of misfit strain [84,95] in the phase-field models allows for the determination of the major factors contributing to the collapse and topological inversion of the γ/γ' microstructures.…”

“…The damage parameters can represent the change of the elastic constants of the γ' phase and/or the increase of the plastic shear rate during creep deformation. Some slip systems can cut into the γ' phase and distort stable raft structures [8,80] when plastic strain accumulated near the γ/γ' interface reaches a critical value. The results from the phase-field models with the variation of misfit strain reveal the decrease of misfit strain during the deformation, which makes the γ/γ' interface become semi-incoherent or incoherent.…”