Antisite defect types and temporal evolution characteristics of D0_(22)-Ni_3V structure:Studied by the microscopic phase field  

作　　者：ZHANG Jing,CHEN Zheng,ZHANG MingYi,LAI QingBo,LU YanLi & WANG YongXin School of Material Science and Engineering,Northwestern Polytechnical University,Xi’an 710072,China 

出　　处：《Science China(Physics,Mechanics & Astronomy)》2009年第8期1154-1160,共7页中国科学：物理学、力学、天文学（英文版）

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);the China Postdoctoral Science Founda-tion Funded Project (Grant No. 20070420218);the Natural Science Foundation of Shaanxi Province of China

摘　　要：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 both α and β sublattices of D022 structure with a strong site preference of substituting α site.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 both α and β sublattices of D022 structure with a strong site preference of substituting α site.

关 键 词：antisite DEFECT D022-Ni3V MICROSCOPIC phase field 

分 类 号：O481[理学—固体物理]