Tension/compression strength asymmetry in a simulated nanocrystalline metal

We explore asymmetries in the plastic deformation of idealized nanocrystalline nickel through static molecular simulations. We find that both the yield and flow stresses of these materials are higher in compression than in tension. This result is discussed in the context of earlier work on metallic glasses, and it is suggested that very similar atomic-level mechanisms control yield in both of these materials classes.