Influence of YH₂ nanoparticles addition on the microstructure and mechanical properties of oxide dispersion strengthened ferritic alloys

YH₂ nanoparticles of about 15-nm were prepared and used to substitute Y₂O₃ nanoparticles to produce the oxide dispersion strengthened (ODS) Fe-14Cr-3Al-0.1Ti-2W alloys. With the addition of YH₂ nanoparticles, Y₂Ti₂O₇ nanoparticles in coherent with α-Fe matrix were generated firstly in the Al-containing ODS alloys due to the reaction of YH₂ with Ti and excessive oxygen in the system. When Y₂O₃ nanoparticles were completely replaced by YH₂ nanoparticles, the dispersed oxides in the ODS alloy has the most narrow size distribution from 3 to 30-nm and a small mean size of about 9-nm. The tensile strength of the ODS alloy increased remarkably with the increasing YH₂ content. This provides a promising way to control the structure and size of the oxide nanoparticles and develop the high performance Al-containing ODS alloys. YH₂ nanoparticles are used as raw particles to substitute the conventional Y₂O₃ nanoparticles in the Al-containing ODS steels. Y₂Ti₂O₇ nanoparticles in coherent with α-Fe matrix are generated and the mean size of the oxide particles is successfully decreased. The tensile strength of the ODS steel increases with the addition of YH₂.