Shape, orientation relationships and interface structure of beta-Nb nano-particles in neutron irradiated zirconium alloy

• Published in: Journal of nuclear materials Vol. 511; pp. 18 - 29
• Main Authors: Ribis, J., Doriot, S., Onimus, F.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01-12-2018; Elsevier BV; Elsevier
• Subjects: Alloy development; Atomic structure; Basal plane; Beta rays; Creep tests; Geographical variations; Heat treating; Heat treatment; High resolution; High-resolution electron microscopy; Interface structure; Irradiation; Irradiation effect; Mechanical properties; Nanoparticles; Neutron irradiation; Neutron radiation; Niobium base alloys; Nuclear Experiment; Nuclear Theory; Orientation relationships; Particle physics; Physics; Post-irradiation; Precipitates; Radiation damage; Transmission electron microscopy; Zirconium; Zirconium alloys; Zirconium base alloys; Nanoparticles; Interface structure; Irradiation effect; High-resolution electron microscopy; Zirconium alloys
• ISSN: 0022-3115; 1873-4820
• DOI: 10.1016/j.jnucmat.2018.08.042

Under neutron irradiation, radiation enhanced beta-Nb nano-precipitates develop within the α-grains of the Zr-Nb alloys. This radiation enhanced precipitation is of great interest since it may have some influence on the post-irradiation mechanical behavior of the material. In this paper the shape, the orientation relationship and the interface structure of such nano-particles are studied by means of both conventional and high-resolution transmission electron microscopy. The radiation damage was annealed out, thanks to a prior heat treatment and a creep test, in order to easily observe the beta-Nb nano-particles. The nano-particles exhibit a needle-like shape with a short thickness along the c-direction of 1.5 nm on average, a length and a width respectively of 6 nm and 3 nm, on average, in the basal plane. Using high-resolution TEM, a near Pitsch-Schrader orientation relationship is identified for a nano-particle. The interface atomic structure at various locations around the nano-particle has been accurately determined and an atomic model of the interface structure has been proposed.
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