Development of Nanostructured Ferritic Alloys for Advanced Fission and Fusion Energy Applications

摘要

The broad objective of this research is to develop an exciting new alloy class, that we have dubbed nanostructured ferritic alloys (NFA). NFA, alloyed with 12-14%Cr and small amounts of Ti and Y, have very high static tensile and creep strengths (up to temperatures in excess of 800℃), excellent ductility and high corrosion-oxidation resistance. NFA also promise unique resistance to radiation damage, including high helium concentrations in fusion reactor and accelerator based spallation neutron sources. The excellent properties of NFA primarily derive from a high concentration of 1-3 nm scale Y-Ti-O solute clusters, with secondary contributions from a distribution of slightly larger (> 3 nm) Y_2Ti_2O_7 oxides. NFAs are processed by ball milling metallic elemental or alloy powders (Fe, Ti, Cr) with Y_2O_3, followed by hot consolidation by HIPing or extrusion. Other high temperature thermal-mechanical processing and fabrication steps, including solid-state joining, may follow powder consolidation.