Application of Be-Free Zr-Based Amorphous Sputter Coatings as a Brazing Filler Metal in CANDU® Fuel Bundle Manufacture

Abstract

Amorphous sputter coatings of Be-free multi-component Zr-based alloys were applied as a novel brazing filler metal for Zircaloy-4 brazing. By applying the homogeneous and amorphous-structured layers coated by sputtering the crystalline targets, the highly reliable joints were obtained with the formation of predominantly grown alpha-Zr grains owing to a complete isothermal solidification, exhibiting high tensile and fatigue strengths as well as excellent corrosion resistance, which were comparable to those of Zircaloy-4 base metal. The present investigation showed that Be-free and Zr-based mult-component amorphous sputter coatings can offer great potential for brazing Zr alloys and manufacturing fuel rods in CANDU® fuel bundle system.