The effect of grain size diversity on the flow stress of nanocrystalline metals by finite-element modelling

The results of finite-element modelling of the effect of grain size uniformity on the flow stress of nanocrystalline metals are reported. The results gave a clear evidence of grain size effect and the reverse Hall–Petch relationship, which is a consequence of macroscopic strain being preferentially accumulated at grain boundaries. They also show the importance of grain size distribution on the flow stress of polycrystals. In fact, K values for the polycrystalline aggregate decrease with increasing grain size diversity.