Effects of order and disorder on the defect evolution of NiFe binary alloys from atomistic simulations

Abstract

The effects of the ordered and disordered arrangements of elements on radiation-induced defects production and evolution in NiFe alloys were investigated through atomistic simulations. Results present a sluggish evolution of the overall microstructure in ordered L10 NiFe. Although the disordered phase has fewer Frankel pair accumulation in cascade simulation attributed to the low thermal conductivity reduced by the intrinsic chemical disorder, the difference is negligible when PKA energy increases because of the direct formation of clusters. Interstitial diffusion is restricted in the ordered phase, where Ni and Fe layers are alternately arranged. This condition delays interstitials accumulation and leads to the formation of more Shockley partial loops rather than Frank loops which favor in the disordered phase. The higher stacking fault energy in the ordered phase renders it difficult to form stacking fault tetrahedra