Effect of atomic structure on migration characteristic and solute segregation of ordered domain interfaces formed in Ni75AlxV25−x
(1. State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi’an 710072, China;
2. Northwest Institute for Nonferrous Metal Research, Xi’an 710016, China)
2. Northwest Institute for Nonferrous Metal Research, Xi’an 710016, China)
Abstract: Based on the microscopic phase-field model, ordered domain interfaces formed between D022 (Ni3V) phases along [001] direction in Ni75AlxV25−x alloys were simulated, and the effects of atomic structure on the migration characteristic and solute segregation of interfaces were studied. It is found that the migration ability is related to the atomic structure of interfaces, and three kinds of interfaces can migrate except the interface (001)//(002) which has the characteristic of L12 (Ni3Al) structure. V atoms jump to the nearest neighbor site and substitute for Ni, and vice versa. Because of the site selectivity behaviors of jumping atoms, the number of jumping atoms during the migration is the least and the jumping distance of atoms is the shortest among all possible modes, and the atomic structures of interfaces are unchanged before and after the migration. The preferences and degree of segregation or depletion of alloy elements are also related to the atomic structure of interface.
Key words: atomic migration characteristic; solute segregation; site selectivity; microscopic phase-field; ordered domain interface