Электронный каталог

Статья

Samadov, S.F.
Gamma-Induced Porosity Reduction and Self-Healing in W–Ni Alloys: Evidence from Multi-Technique Characterization / S.F.Samadov, N.V.M.Trung, M.N.Nasrabadi, A.A.Sidorin, M.N.Mirzayev, T.Vershinina, O.S.Orlov, N.V.Tiep, A.S.Abiyev, [a.o.]. – Text : electronic // Journal of Alloys and Compounds. – 2025. – Vol. 1049. – P. 185389. – URL: https://doi.org/10.1016/j.jallcom.2025.185389. – Bibliogr.: 89.

In this work, powder metallurgy tungsten–nickel (W–Ni) alloys were exposed to gamma irradiation in the absorbed dose range of 620–3566 kGy to investigate defect evolution, phase stability, and porosity reorganization. A multi-technique approach—combining X-ray diffraction (XRD), positron annihilation lifetime spectroscopy (PALS), Doppler broadening spectroscopy (DBS), Raman spectroscopy, electron momentum distribution (EMD) analysis, and atomistic simulations—was employed. XRD results revealed progressive dissolution of the WNi&sub(4) phase accompanied by expansion of the W matrix lattice. PALS analysis demonstrated the transformation of large open-volume defects (*t&sub(2) ≈ 433 ps, I&sub(2) = 5 %) into smaller vacancy clusters (*t&sub(2) ≈ 250 ps, I&sub(2) = 47 %), confirming irradiation-induced porosity healing. A critical reorganization threshold was identified at 1239 kGy, where defect redistribution, microstrain relaxation, and vibrational mode shifts coincided. Raman spectroscopy detected dose-dependent hardening and softening of W–O and W––O bonds. DBS and EMD analyses confirmed enhanced vacancy recombination under irradiation. Atomistic simulations indicated that most primary knock-on atoms undergo recombination rather than forming stable Frenkel pairs, while density functional theory calculations linked the final defect state predominantly to Ni vacancies. These findings demonstrate that gamma irradiation simultaneously activates phase dissolution, defect restructuring, and pore closure, proving to be an effective processing route for improving lattice homogeneity, densification, and radiation resistance in W–Ni alloys, with direct relevance to nuclear and aerospace applications.



Спец.(статьи,препринты) = С 349.1 - Действие излучения на материалы$
Спец.(статьи,препринты) = С 342 в - Прохождение гамма-квантов через вещество. Эффект Мессбауэра. Волны в периодических средах и средах типа Фибоначи
Спец.(статьи,препринты) = С 350 а - Трансмутация ядерных отходов$
ОИЯИ = ОИЯИ (JINR)2025