Microscopic phase field simulation is performed to study antisite defect type and temporal evolution characteristic of D022-Ni3V structure in Ni75AlxV25-x ternary system.The result demonstrates that two types of antis...Microscopic phase field simulation is performed to study antisite defect type and temporal evolution characteristic of D022-Ni3V structure in Ni75AlxV25-x ternary system.The result demonstrates that two types of antisite defect VNi and NiV coexist in D022 structure;however,the amount of NiV is far greater than VNi;when precipitates transform from D022 singe phase to two phases mixture of D022 and L12 with enhanced Al:V ratio,the amount of VNi has no evident response to the secondary L12 phase,while NiV exhibits a definitely contrary variation tendency:NiV rises without L12 structure precipitating from matrix but declines with it;temporal evolution characteristic and temperature dependent antisite defect VNi,NiV are also studied in this paper:The concentrations of the both defects decline from high antistructure state to equilibrium level with elapsed time but rise with elevated temperature;the ternary alloying element aluminium atom occupies bothαandβsublattices of D022 structure with a strong site preference of substitutingαsite.展开更多
基金Supported by the National Natural Science Foundation of China(Grant Nos.50671084 and 50875217)the Doctorate Foundation of Northwestern Polytechnical University of China(Grant No.CX200806)+1 种基金the China Postdoctoral Science Founda-tion Funded Project(Grant No.20070420218)the Natural Science Foundation of Shaanxi Province of China
文摘Microscopic phase field simulation is performed to study antisite defect type and temporal evolution characteristic of D022-Ni3V structure in Ni75AlxV25-x ternary system.The result demonstrates that two types of antisite defect VNi and NiV coexist in D022 structure;however,the amount of NiV is far greater than VNi;when precipitates transform from D022 singe phase to two phases mixture of D022 and L12 with enhanced Al:V ratio,the amount of VNi has no evident response to the secondary L12 phase,while NiV exhibits a definitely contrary variation tendency:NiV rises without L12 structure precipitating from matrix but declines with it;temporal evolution characteristic and temperature dependent antisite defect VNi,NiV are also studied in this paper:The concentrations of the both defects decline from high antistructure state to equilibrium level with elapsed time but rise with elevated temperature;the ternary alloying element aluminium atom occupies bothαandβsublattices of D022 structure with a strong site preference of substitutingαsite.
