Quantitative determination of anti-structured defects applied to alloys of a wide chemical range

Anti-structured defects bridge atom migration among heterogeneous sublattices facilitating diffusion but could also result in the collapse of ordered structure. Component distribution Ni₇₅ Al_xV_25-x alloys are investigated using a microscopic phase field model to illuminate relations between anti-structured defects and composition, precipitate order, precipitate type, and phase stability. The Ni₇₅ Al_xV_25-x alloys undergo single Ni₃ V (stage I), dual Ni₃ Al and Ni₃ V (stage Ⅱ with Ni₃ V prior; and stage Ⅲ with Ni₃ Al prior), and single Ni₃ Al (stage IV) with enhanced aluminum level. For Ni₃ V phase, anti-structured defects (V_Ni1, Ni_V, except V_Ni2) and substitution defects (Al_Ni1, Al_Ni2, Al_V) exhibit a positive correlation to aluminum in stage I, the positive trend becomes to negative correlation or smooth during stage Ⅱ. For Ni₃ Al phase, anti-structured defects (Al_Ni, Ni_Al) and substitution defects (V_Ni, V_Al) have a positive correlation to aluminum in stage Ⅱ, but Ni_Al goes down since stage Ⅲ and lasts to stage IV. V_Ni and V_Al fluctuate when Ni₃ Al precipitates prior, but go down drastically in stage IV. Precipitate type conversion of single Ni₃ V/dual (Ni₃ V+Ni₃ Al) affects Ni₃ V defects, while dual (Ni₃ V+Ni₃ Al)/single Ni₃ Al has little effect on Ni₃ Al defects. Precipitate order swap occurred in the dual phase region affects on Ni₃ Al defects but not on Ni₃ V.