Effect of thickness for nanotwins on the mechanical properties of a Hastelloy

Abstract

The processes of nanoindentation on Hastelloy alloy with nanoscale twin boundary (TB) are calculated by molecular dynamics (MD). The effect of nanoscale TB’s thickness on the mechanical properties are investigated. The results show that the thickness of nanoscale TBs has obvious influence on the properties of Hastelloy alloy. The TBs obviously play the role of obstacle when the crystal lattice was destroyed by the force of indenter. Although the nanoscale twin boundaries can resist the movement to a certain extent, it does not mean that the thicker nanoscale TBs make the properties better. In these simulations, the Hall–Petch effect and the reverse Hall–Petch effect are observed, and the critical value of thickness is 25.493 A.