Two modes of grain boundary pinning by coherent precipitates

We propose a two-mechanism theory to estimate the pinning effect of coherent precipitates on grain-boundary (GB) migration in grain growth, taking into account the important effect of elastic misfit strain at the coherent interface. Depending on the relative importance of the elastic and the GB contributions to the total free energy, Zener type stabilization or a novel elastic energy induced stabilization may occur. It is found that the pinning is most effective in the crossover region between these two mechanisms. A phase-field-crystal model is used to numerically validate the theory. Relevant experiments and potential impacts on alloy design are also discussed.

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