Nano ZrO2 particles in nanocrystalline Fe-14Cr-1.5Zr alloy powders

Here we report on the formation of nano ZrO2 particles in Fe-14Cr-1.5Zr alloy powders synthesized by mechanical alloying. The nano ZrO2 particles were found uniformly dispersed in the ferritic matrix powders with an average size of about 3.7 nm, which rendered the alloy powders so stable that it retained nanocrystalline structure after annealing at 900 °C for 1 h. The ZrO2 nanoparticles have a tetragonal crystal structure and the following orientation relationship with the matrix: (0 0 2)ZrO2//(0 0 2)Matrix and [0 1 0]ZrO2//[1 2 0]Matrix. The size and dispersion of the ZrO2 particles are comparable to those of Y-Ti-O enriched oxides reported in irradiation-resistant ODS alloys. This suggests a potential application of the new alloy powders for nuclear energy applications.