Characterization of bond strength of monolithic two metal layer systems

The in-pile performance of nuclear fuel plates is strongly influenced by the mechanical contact between fuel and cladding. Today, there is not much information available about the bond strength of two layer systems typical for monolithic fuel plates. The bond strength is considered to be a plausible indicator for the quality of the mechanical contact. Using tensile tests, the bond strength of the following material combinations were examined: fuel/cladding, fuel/diffusion barrier and diffusion barrier/cladding. Double layer foils, consisting of uranium-molybdenum alloy with 8 wt.% Mo (DU-8Mo) as fuel surrogate, Al 1050 as cladding and Ti, Nb or Zr as diffusion barrier materials were used. They were produced by sputtering. Beforehand, the behaviour of the adhesive used to mount the samples onto the specimen holders has been examined. Bond strengths of DU-8Mo on Ti and Nb larger than 70 MPa have been achieved. (author)