Features of the order-disorder phase transition during the ordering of Ni4Mo and Ni4W alloys with D1a superstructure

Klopotov, Anatoly A.; Potekaev, Aleksandr I.; Marchenko, Ekaterina S.; Popov, Andrey A.; Kozireva, R. A.; Fedorischeva, Marina V.

Features of the order-disorder phase transition during the ordering of Ni4Mo and Ni4W alloys with D1a superstructure

Klopotov, Anatoly A., Potekaev, Aleksandr I., Marchenko, Ekaterina S., Popov, Andrey A., Kozireva, R. A., Fedorischeva, Marina V.

Дата публикации: 2018

Дата публикации в реестре: 2020-03-03T20:02:22Z

Аннотация:

Results are presented from studying atomic long-range order in Ni4Mo and Ni4W alloys via X-ray diffraction analysis. The phase transitions in these alloys are confirmed to be of the D1a → A1 type. The temperature dependences of the long-range order parameters are found to be similar in Ni4Mo and Ni4W alloys. The difference between their properties is due to different characters of the order–disorder phase transition. A transition from the single-phase state with D1a superstructure to single-phase А1 through the diphase (D1a → A1) region occurs in the Ni4Mo alloy. A more complex D1a → (A1 + δ) peritectoid transformation takes place in the Ni4W alloy. It is shown that an order parameter equal to unity can be obtained in Ni4Mo alloy through long-term ordering annealing, while such long-range order in Ni4W alloy (ηmax = 0.9) is impossible to obtain by annealing.

Ключевые слова:
фазовые переходы, никелевые сплавы, дальний порядок

Тип: статьи в журналах

Источник: Bulletin of the Russian Academy of Sciences: Physics. 2018. Vol. 82, № 7. P. 867-869