Analysis of the interaction products in U(Mo,X)/Al and U(Mo,X)/Al(Si) diffusion couples, with X = Cr, Ti, Zr

Abstract In the framework of the development of a low 235 U enriched nuclear fuel for material testing reactors, γ-U(Mo)/Al based materials are considered as the most interesting prospect. In the process to optimize their composition, addition to both γ-U(Mo) and Al have been proposed. In this paper, the crystallographic composition of Interaction Layers (ILs) in γ-U(Mo,X)/Al and γ-U(Mo,X)/AlSi7 diffusion couples, with X = Cr, Ti, Zr, heat-treated at 600 °C for 2 h, were studied by micro-X-ray diffraction (μ-XRD). When compared to the U(Mo)/Al and U(Mo)/Al(Si) reference systems, all investigated systems involving either Al or Al(Si) as counterparts show interaction products composed of similar phases and related sequences of phase formation. Only relative thicknesses of sub-layers and relative fractions of intermediate phases are correlated with the nature of the X element in the γ-U(Mo,X) alloy. More generally this work shows that γ-U(Mo)/Al and γ-U(Mo)/Al(Si) ILs are now robustly described down to the micrometer scale.