Abstract Scope |
The use of conventional zirconium alloys at temperatures >400°C is restricted by their poor creep and oxidation resistance. This limits the consideration of zirconium alloys for fusion and Generation IV fission plant designs operating at 500°C–1000°C. Zirconium has a physical metallurgy similar to titanium, which has seen alloying advances allowing application temperatures ~600°C. A set of alloys in the Zr-Al-Sn system, designed by analogy to near-alpha titanium alloys, were synthesised by arc melting, and processed in a sequence of homogenisation, cold rolling, recrystallisation, and ageing treatments. Electron and optical microscopy combined with diffraction showed a refined Widmanstätten microstructure reinforced by Zr₃Al precipitates, with microstructures differing with ageing times. Deformation testing using three-point bending revealed a strengthening effect by Al, but with significant changes to ductility on ageing depending on the evolution of Zr₃Al. The microstructure and properties of these alloys suggest they are promising candidates for further development. |