Clad Titanium-Base Dispersions Containing Boron

This study was undertaken to evaluate Zircaloy-2 clad titanium-base dispersions containing enriched boron or enriched titanium diboride as possible control materials. Results of corrosion tests of the nonirradiated dispersions indicated that cladding with a corrosion resistant material was necessary. Roll bonding Zircaloy-2 cladding to titanium-base dispersions was shown to be feasible through a study of the integrity, corrosion resistance, and bend properties of the clad dispersions. Clad separation and excessive swelling were noted in the samples of clad titanium-base dispersions containing 5 w/o enriched boron which were irradiated for long exposures. The clad 34 w/o enriched titanium diboride dispersion irradiated to nearly the same exposures showed no visual evidence of clad cracking or excessive swelling. Metallographic examination after irradiation, which was confined to the 5 w/o enriched boron dispersion, revealed internal cracking and bond line damage with the severity of damage increasing with increasing irradiation exposure.