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Page 16 of 20                      Gesch et al. J. Mater. Inf. 2025, 5, 42  https://dx.doi.org/10.20517/jmi.2025.23

                 5
               10 ) is slightly higher than that achieved with 60 training frames, it comes at the cost of reduced predicting
               accuracy for microstructure evolution in latent space. Thus, we estimate the optimal computational gain of
                                                                   5
               our accelerated framework to be approximately 3.35 × 10  for Ostwald ripening, which represents a
               significant speedup compared to high-fidelity phase-field simulations.


               Furthermore, integrating SVM models into our accelerated phase-field framework improves the overall
               efficiency. For instance, once the framework is established for any four fields, SVM models can be employed
               to predict the latent dynamic features of the remaining field. Subsequently, these predicted latent
               representations can be reconstructed into the original 2D microstructure using the well-trained
               autoencoder. In this way, there is no need to develop an LSTM model for the remaining field, thereby
               significantly improving the overall computational efficiency of the accelerated phase-field framework.


               Limitations and future work
               The accelerated framework demonstrates the feasibility of expediting the phase-field simulations for
               coupled microstructural evolution. Through the analysis of microstructure prediction performance, we
               found that autoencoder-based LSTM models exhibit high accuracy and efficiency in forecasting the
               microstructure evolution within the latent space. However, there are several limitations of this accelerated
               framework that should be acknowledged. First, as shown in Figure 7, the autoencoder sometimes has
               trouble recreating the 2D microstructures of the η fields from the latent space. This limitation is likely due to
               the relatively simple microstructure patterns presented in the η fields compared to the c field, as well as the
               limited size of microstructure database (200 simulations), which may be insufficient for training a robust
               autoencoder-based neural network. The second limitation is that LSTM models are heavily dependent on
               the number of time frames used for their training, as these models demonstrate lower performance when
               trained with a smaller number of time steps [Figure 4]. Thus, enhancing the predictive performance of
               LSTM models with fewer number of time frames is crucial for improving the overall efficiency of the
               accelerated phase-field framework.


               It is worthy to note that an interesting direction for accelerating Ostwald ripening is the development of
                                                                 [51]
               physics-informed models, such as PSDMs based on U-Net . This approach is motivated by recent studies
               which demonstrate that the PSDMs can achieve very high accuracy in predicting the microstructural
               evolution with low prediction error and reduced error accumulation during autoregressive predictions .
                                                                                                       [39]
               According to a review article by Dingreville et al., the accelerated framework developed for Ostwald
               ripening falls in the category of LDM formulation, as the microstructure evolution is predicted within the
                         [39]
               latent space . Since LDMs typically scale better with smaller dataset , we anticipate the accelerated
                                                                             [39]
               framework will outperform the PSDMs in modeling Owstwald ripening. Yet, as the size of database
               increased or microstructural features become more complex, PSDMs are expected to outperform LDMs in
               predictive performance for coupled microstructure evolution.

               Although the accelerated framework developed in this study is for 2D Ostwald ripening problem, it is
               anticipated  that  this  framework  can  be  easily  extended  to  the  3D  systems.  This  is  because  the
               microstructural features in both 2D and 3D cases always share similar evolutionary behaviors, which
               indicates that the key features in latent space demonstrate similar variations, making it easier for machine-
               learning models to capture them. Additionally, our accelerated framework is applicable to the more
               complex, coupled phase-field problems by incorporating various physical coupling interactions between
               various fields, such as elastic strain, component diffusion heterogeneity, and inhomogeneous interface
               energy. Once the new microstructural database is developed, the accelerated framework can be readily
               retrained to capture the new microstructural features in latent representations and predict their evolution
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