The microstructures and mechanical properties of nanocrystalline Li₂SiO₃: molecular dynamics simulations

The microstructures and mechanical properties of nanocrystalline Li₂SiO₃ have been investigated via molecular dynamics calculations. The results indicate that the mean atomic mass densities of nanostructured Li₂SiO₃ with different mean grain size are slightly lower than that of ordinary crystal Li₂SiO₃. Interestingly, a significant anti-Hall-Petch effect between yield stress and average grain size is observed in the tensile deformation simulation of the samples. In fact, the curve changes linearly until the strain reaches approximately 0.016-0.018. Next, when the strain is between 0.27 and 0.38, the stress of the sample has a small peak in the plastic flow region. Then, all the samples will begin to fracture at a strain of about 0.39-0.41. Moreover, due to the influence of grain boundary sliding and grain rotation, there are a few dislocations in the samples with the small average grain sizes, highlighting the strong influence of the mechanical properties on the overall tensile deformation of the samples.