Papers by Keyword: Antiphase Domain Boundary

Abstract: Kinetics of order-disorder transition at antiphase domain boundary (APDB) formed between DO₂₂ (Ni₃V) phases during stress aging was investigated using microscopic phase field model. The results demonstrated that whether order-disorder transition happens or not depends on the atomic structure of the APDB. Accompanied with the depletion of V and enrichment of Ni and Al, order-disorder transition happened at the APDB (001)//(002). Whereas at the APDB {100}·1⁄2[100], which remains ordered with temporal evolution, Ni and Al enrich and V depletes. Composition evolution of APDB with order-disorder transition favors the nucleation of the L1₂ and disordered phase. Some of the grains grew bigger while the others disappeared, accompanying the formation of disordered phase layer during order-disorder transition of APDBs, and the order-disorder transition of APDBs can be considered as accompanying process of coarsening of ordered domain phases and growth of disordered phases.

Abstract: The order-disorder transition at antiphase domain boundary (APDB) between DO22 (Ni3V) phases is investigated using the microscopic phase-field model. After the formation of ordered APDB, the order-disorder transition at APDB is happened, and the ordered APDB transforms into a thin disordered phase layer. Accompanied with the enrichment of Ni and Al at the disordered APDB, the second phase L12 nucleates at the order-disorder interface between DO22 phases and grows along the disordered phase layer. The order-disorder transition at the ordered APDB makes the nucleation and growth of the second phase L12 much easier and faster. The disordered phase caused by the order-disorder transition at the APDB can be considered as the transient phase during the precipitation process of L12 phase.

Abstract: Based on the microscopic phase-field model, the precipitation process of Ni75Al4.3V20.7 alloy at 1190K is simulated, and the kinetics of order-disorder transition at antiphase domain boundary (APDB) formed between DO22 (Ni3V) phases is investigated. After the ordered APDB formed by the impingement of growing DO22 (Ni3V) domains, the order-disorder transition at APDB is happened. Accompanied with the enrichment of Ni and Al at the APDB, the ordered APDB transforms into a thin disordered phase layer. The second phase L12 nucleates at the order-disorder interface between DO22 and disordered phases, and grows along the disorder phase layer quickly. The order-disorder transition at the ordered APDB accelerates the nucleation and growth of L12 phase at the APDB. The disordered phase caused by the order-disordered transition can be considered the transient phase during the precipitation process of L12 phase.