Thermomechanical characteristics of the low activation materials chromium and Cr·5Fe·1Y2O3 alloy

Recent results of studies of basic physical and mechanical properties of sintered high purity chromium and a sintered Cr·5Fe·1Y2O3 alloy are presented. The materials were investigated in the temperature range from room temperature to 900°C and characterized by tensile testing, measurements of thermal diffusivity, thermal expansion, and heat capacity, complemented by metallography and fractography. The results are discussed with regard to transient thermal loading faced by first wall structures. In order to overcome the problem of brittleness and lack of ductility at low temperatures, preliminary results on the effect of microstructure refinement by severe plastic deformation are presented. These results indicate that the strength of pure chromium can be appreciably increased, and the brittleness may be reduced.