Ni_(75)Al_xV_(25-x)合金中反相畴界有序无序化的微观相场模拟  

Microscopic phase-field study on the order-disorder transition of antiphase domain boundary in Ni_(75)Al_xV_(25-x) alloys

作　　者：张明义[1,2] 杨坤[1] 陈铮[1] 王永欣[1] 张嘉振 

机构地区：[1]西北工业大学凝固技术国家重点实验室,陕西西安710072 [2]中国商用飞机有限责任公司北京民用飞机技术研究中心,北京100083

出　　处：《材料热处理学报》2013年第1期163-169,共7页Transactions of Materials and Heat Treatment

基　　金：国家自然科学基金项目(50941020,10902086,50875217,20903075)

摘　　要：基于微观相场模型研究了Ni75AlxV25-x合金中L12-Ni3Al相间反相畴界和DO22-Ni3V相间反相畴界的有序无序化过程。结果表明,伴随着V的富集,Al和Ni的贫化,L12相间反相畴界(200)L//(200)L.1/2[001]L和(200)L//(200)L均发生有序无序化;DO22相间反相畴界是否发生有序无序化与界面结构有关,伴随着Ni和Al的富集,V的贫化,DO22相间反相畴界(001)D//(002)D处发生有序无序化,而反相畴界{100}D.1/2[100]D始终保持有序,且成分演化与(001)D//(002)D处完全相反。有序无序化过程中的反相畴界处的成分演化有利于第二相在界面处形核。反相畴界处无序相的长大伴随着部分晶粒的长大和部分晶粒的消失,反相畴界有序无序化可以视为晶粒粗化阶段的伴随过程。Kinetics of order-disorder transition at antiphase domain boundary （APDB） in Ni75AlxVV25-x alloys was investigated using microscopic phase-field model. The results demonstrate that accompanied with the enrichment of V and depletion of Ni and A1, the ordered APDBs （200） L//（200） L·1/2 [ 001 ] L and （ 200 ） L///（ 200 ） L, which are formed between L12 phases, transform into a thin disordered phase layer. Whether order-disorder transition happens or not depends on the atomic structure of the APDB formed between DO22 phases. Accompanied with the depletion of V and enrichment of Ni and A1, order-disorder transition happens at the APDB （001）D//（002）D· Whereas at the APDB {100} D·1/2 [ 100 ] D, which remains ordered with temporal evolution, V is depleted and Ni and A1 are enriched. Composition evolution of APDB is order-disorder transition favors the nucleation of the second phase. Some of the grains grow bigger while the others are disappearing during order-disorder transition of APDBs, and the order-disorder transition of APDBs can be considered as the adjoint process of coarsening process of the primary precipitate phase. The kinetics of order-disorder transition at APDB is elucidated at atomic scale, and the function of order-disorder transition at APDB during the microstructure evolution is clarified.

关 键 词：微观相场 反相畴界 有序无序化 Ni75AlxV25-x合金 粗化 

分 类 号：TG146.1[一般工业技术—材料科学与工程]