Migration of He atoms and growth of He bubbles in high angle twist grain boundaries(HAGBs)in tungsten(W)are investigated by atomic simulation method.The energy and free volume(FV)of grain boundary(GB)are affected by t...Migration of He atoms and growth of He bubbles in high angle twist grain boundaries(HAGBs)in tungsten(W)are investigated by atomic simulation method.The energy and free volume(FV)of grain boundary(GB)are affected by the density and structure of dislocation patterns in GB.The migration energy of the He atom between the neighboring trapping sites depends on free volume along the migration path at grain boundary.The region of grain boundary around the He bubble forms an ordered crystal structure when He bubble grows at certain grain boundaries.The He atoms aggregate on the grain boundary plane to form a plate-shape configuration.Furthermore,high grain boundary energy(GBE)results in a large volume of He bubble.Thus,the nucleation and growth of He bubbles in twist grain boundaries depend on the energy of grain boundary,the dislocation patterns and the free volume related migration path on the grain boundary plane.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11305136,11675230,11375242,and U1832112)
文摘Migration of He atoms and growth of He bubbles in high angle twist grain boundaries(HAGBs)in tungsten(W)are investigated by atomic simulation method.The energy and free volume(FV)of grain boundary(GB)are affected by the density and structure of dislocation patterns in GB.The migration energy of the He atom between the neighboring trapping sites depends on free volume along the migration path at grain boundary.The region of grain boundary around the He bubble forms an ordered crystal structure when He bubble grows at certain grain boundaries.The He atoms aggregate on the grain boundary plane to form a plate-shape configuration.Furthermore,high grain boundary energy(GBE)results in a large volume of He bubble.Thus,the nucleation and growth of He bubbles in twist grain boundaries depend on the energy of grain boundary,the dislocation patterns and the free volume related migration path on the grain boundary plane.
