An Anomaly in Creep Property Dependence on Grain Size for Ultrafine Grain Nanocrystalline Nickel at Higher Creep Temperature

Abstract

In this present study, molecular dynamics simulation of creep for ultrafine grain NC Ni specimens with different grain sizes have been carried out under a constant 1 GPa applied load for various creep temperatures to study the dependence of grain growth on creep temperature and grain size during creep process and its influence on creep properties. It is observed that the extent of grain growth in ultrafine grain NC Ni during creep deformation process is more if creep in creep temperature is higher. A noteworthy anomaly, that is NC Ni with smaller grain exhibits better creep property compared to NC Ni with larger grain, is observed in case of higher creep temperatures (i.e. around or greater than 1400K).