Study on Dimension Effect of Punch on Nanoimprint Process for Cu-Ni Alloy

The effects of punch size and molding mechanism on the nanoimprint process of Cu(85%)-Ni(15%) alloy were investigated by molecular dynamics method. The distribution for Cu and Ni atoms was random. In order to examine the punch size effect on nanoimprint process, three punch sizes were studied, namely: 3nm × 3nm, 6nm × 6nm and 9nm × 9nm. The results showed that it was difficult for the material to fully fill into die corner, i.e. at non-smooth geometry in the die, during final period of loading. The forming energy and force increased rapidly, because inter-atomic repulsive energy increased as formed pattern became small. It was not successfully imprinted after unloading in the case of 3nm × 3nm, due to larger spring back. Comparing to nano imprint of pure copper, the current study of nano imprint of Cu-Ni alloy presented a cyclically vibrated relationship of force and displacement showing a more complicated interaction between different kinds of atoms.