Study of dynamic recrystallization in a Ni-based superalloy by experiments and cellular automaton model

Grain size modeling of a Ni-base superalloy using cellular automata algorithm

“…The application of CA to DRX was possible because DRX phenomena usually occur through grain boundary nucleation. DRX at first is heterogeneous and gradually become homogenous with the increase of volume of recrystallized fraction [24]. The simulated average grain size after deformation for the sample B [2] was 19 lm which is close to the measured one of 22 lm.…”

Study of Flow Softening Mechanisms of a Nickel-Based Superalloy With Δ Phase

“…Also, the variations of microstructure for several typical nickel-based superalloys are investigated by Huda et al [30], Żaba et al [31], Cheng et al [32], Yang et al [33], Zhang et al [34]. Liu et al [35,36] developed the accurate CA models to describe the dynamic and static recrystallization behaviors of GH4169 superalloy. Despite some researches focusing on the microstructural evolution and flow behaviors of some nickelbased superalloys, the flow softening behavior still need to be further investigated.…”

Dynamic recrystallisation model in precipitation-hardened superalloys as a tool for the joint design of alloys and forming processes

“…1, it constitutes an improvement over the previous model which did not take pinning by γ′ into account, since it allows to predict recrystallisation during subsolvus processing. Being fully composition-dependent through composition and phase constitution, it allows a predictive evaluation of DRX behaviour in new alloys, unlike other models that are material-specific [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24].…”

“…This may be achievable if a model is available, capable of predicting DRX features as a function of alloy compositionand hence phase constitution -as well as of processing conditions (temperature, strain rate, strain). Most models, however, provide a description of microstructural evolution using fitted parameters and are not predictive regarding the influence of composition [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24]. For instance, some authors [8][9][10][11][12][13][14] have used parameterised equations, mostly relying on or deriving from the Zener-Hollomon parameter, to describe the high temperature flow stress of different superalloys, the dependence of grain size on temperature, strain rate, and/or the evolution of the recrystallised fraction with strain.…”

“…The latter is considered as a continuous medium with averaged properties [20], or as a homogenised medium made of fractions of recrystallised and non-recrystallised grains having different properties [21]. Calculating the evolution of individual grains can also be made without a mean field approach, by simulating a large and representative set of grains by a cellular automaton [22][23][24]. Nevertheless, all the abovementioned approaches [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24] share the common feature that model parameters have to be fitted to each specific alloy, so that predictions cannot be extended to different alloy compositions unless model parameters have been fitted again.…”