Effect of Cu on strain-stress relationship of W bicrystal models with grain boundary from molecular dynamics simulation

The W bicrystal models with grain boundary are constructed and several percentages of W atoms are replaced by Cu atoms in the region of grain boundary to study the effect of Cu impurity atoms. Molecular dynamics simulation combined with Monte Carlo (MC) swaps reveals that Cu atoms will segregate to the W grain boundary and form clusters. As the number of copper atoms increases, the strength of grain boundaries decreases and the brittleness increases. The doping of Cu atoms is beneficial to the propagation of grain boundary cracks, and the higher the Cu atoms content, the faster the crack growth rate.