X-ray diffraction analysis of secondary phases in zirconium alloys before and after neutron irradiation at the MARS synchrotron radiation beamline

Then, second phase particles of the Zr-1%Nb alloy (M5®) have been analyzed before and after irradiation. For the Zr(Fe, Nb)2 Laves phase, the diffraction line disappeared after neutron irradiation. For β-Nb phases, the evolution of diffraction peaks clearly show the convolution of two phenomena: in one hand slight decreases in Nb content for native β-Nb particles and on the other hand irradiation-enhanced precipitation of nano-sized needle-like β-Nb particles. To our knowledge, this is the first time that the crystallographic unit cell, lattice parameter and Nb content of the β-Nb irradiation-enhanced precipitates have been determined using synchrotron radiation on irradiated Zr-1%Nb (M5®) alloy.