2017 | AFC ACCOMPLISHMENTS 98 FeCrAl ODS Alloy Development for Fission Platforms Principal Investigator: Sebastien Dryepondt Collaborators: Caleb Massey, Philip Edmonson and Maxim Gussev Advanced wrought and oxide dispersion strengthened (ODS) FeCrAl alloys are among the leading candidates for next generation accident tolerant fuel cladding due to their high strength and excellent oxidation behavior at temperatures up to 1450ºC.The superior mechanical strength of ODS FeCrAl alloys up to ~800ºC allows for the use of thinner cladding, thus limiting the neutronic penalty from the replace- ment of Zr-based alloys by Fe-based alloys.The ODS FeCrAl high strength comes, however, with limited ductility making the fabrication of thin tubes very challenging. Project Description: The overall project goal is to develop new low-Cr ODS FeCrAl alloys exhib- iting great oxidation resistance in steam atT>1400ºC, good mechanical strength up to at least 800ºC, superior irradia- tion resistance at 200-500ºC, and suffi- cient ductility at low temperature to allow for the production of tubes less than 500 micrometers thick. Extensive microstructure characterization, tensile testing at 20-800ºC, and steam oxida- tion testing at 1200-1450ºC of several ODS FeCrAls has led to the selection of an ODS Fe-10Cr-6Al-0.3Zr+0.3Y2O3 alloy (106ZY). Previous work on small powder quantities also revealed that careful control of the powder ball milling and extrusion steps allows for the optimization of the ODS FeCrAl microstructure and properties. In particular, increasing the extru- sion temperature decreased the alloy strength and hardness but increased the alloy ductility.The project is now focusing on the fabrication of large batches of ODS FeCrAl and the search for industrial partners to produce thin tubes. Understanding the effect of tube processing on the ODS FeCrAl microstructure is also key to optimize the final tube properties.The expected project outcome is the production of ODS FeCrAl cladding with enhanced safety margin for the current and next generation reactors. Figure 1. a) Extrusion cans, b) Cross section of the extruded bars, c) Final ODS 106ZY rods. a) and b) highlight the difference between previous small extrusions bars and the larger bars required for the production of the two rods presented in c).