(1. 西北工業(yè)大學 凝固技術(shù)國家重點實驗室，西安 710072；
2. 中國商用飛機有限責任公司 北京民用飛機技術(shù)研究中心，北京 100083)
摘 要: 采用微觀相場模型研究界面原子結(jié)構(gòu)和相變方向?qū)i75AlxV25-x合金中異相間有序疇界和有序/無序相界成分演化的影響。結(jié)果表明：在異相間有序疇界處，V在有序疇界的DO22相一側(cè)貧化，在有序疇界的L12相一側(cè)偏聚；Al則在有序疇界的DO22相一側(cè)偏聚，在有序疇界的L12相一側(cè)貧化。Ni在異相間可遷移有序疇界處的成分受相變方向和界面結(jié)構(gòu)的影響。在DO22相與無序相之間形成的相界處，Al和Ni偏聚，V則貧化；在L12相與無序相之間形成的相界處，Al和Ni貧化，V則偏聚。由于溶質(zhì)拖拽效應，合金元素在有序疇界處的偏聚和貧化傾向不隨有序疇界遷移改變，但程度變化。
關(guān)鍵字: Ni75AlxV25?x合金；微觀相場；有序疇界；有序/無序相界；成分偏聚
（1. State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi’an 710072, China;
2. Beijing Aeronautical Science & Technology Research Institute,
Commer）
Abstract:Microscopic phase-field model was used to study the effect of atomic structure of interfaces and phase transformation direction on the composition evolution of heterointerfaces (including ordered domain interfaces formed between L12 and DO22 phases and order-disordered interfaces) in Ni75AlxV25-x alloys. The results demonstrate that V depletes at the DO22 side and segregates at the L12 side, and Al segregates at the DO22 side and depletes at the L12 side of ordered domain interfaces formed between L12 and DO22 phases during the phase transformation L12 DO22. The composition of Ni at the ordered domain interfaces is affected by the phase transformation and atomic structure of interfaces. During the phase transformation L12→DO22, Ni segregates at the interfaces which can migrate during the phase transformation. While at the interfaces (002)D//(001)L, Ni segregates at the L12 side and depletes at the DO22 side, which is the same as the ordered domain interfaces formed between L12 and DO22 phases during the phase transformation DO22→L12. At the interface formed between DO22 and disordered phase, Ni and Al segregate and V depletes. However, at the interface formed between L12 and disordered phase, Ni and Al deplete and V segregates. The tendency of segregation or depletion of alloy elements is unchanged with the ordered domain interface because of the solute drag effect, but the degree of segregation or depletion of alloy elements is changed.
Key words: Ni75AlxV25?x alloys; microscopic phase-field; ordered domain interface; order-disordered interface; solute segregation
