Effect of twin boundary on the initial yield behavior of magnesium nanopillars under compression: molecular dynamics simulations

Nanotwinned Mg nanopillars under uniaxial compression were investigated by molecular dynamics simulations. The simulation results indicate that more TBs and less TBs are recommended to introduce for obtaining Mg nanopillars being of higher compressive yield strength. The pre-built TBs restrains the nucleation of new twins, and subsequently causes the increase of the yield strength. The initial yield behavior of nanotwinned Mg nanopillars with TBs was found to be twinning nucleation, and the nucleation mechanism is a shuffling mechanism. The introduction of TBs bring sources of dislocations into Mg nanopillars and subsequently causes the decrease of yield strength.