Preparation and characterization of Zircaloy 4-Tantalum alloys for application in corrosive media

Two Zircaloy 4-Ta alloys (14 and 55 wt.% Ta) were produced by arc-melting. The alloys were hot-rolled at 900 °C and heat-treated under argon atmosphere for 100 h at 700 °C. The alloys were analyzed by scanning electron microscopy and X-ray diffractometry. The microstructure of both rolled and heat-treated alloys is constituted of (β Zr,Ta)-II Ta-rich precipitates dispersed in a (α Zr) matrix. Corrosion tests performed in boiling concentrated H2SO4 solutions showed that the Zircaloy 4-Ta alloys are more corrosion resistant than Zircaloy 4 and that the corrosion resistance increases with increasing Ta content.

► Arc-melted, hot rolled (900 °C) and heat-treated (700 °C) Zircaloy 4 - 14 and 55 wt.% Ta alloys were produced. ► Their microstructure is constituted of (β Zr,Ta)-II Ta-rich precipitates dispersed in a (α Zr) matrix. ► Both Zircaloy 4-Ta alloys are more corrosion resistant than Zircaloy 4 in boiling H2SO4 solutions. ► Their corrosion resistance increases with increasing Ta content.