Journal of Powder Materials

Research Article

The Use of TiH₂ to Refine Y₂Ti₂O7 in a Nano Mo-ODS Alloy: Yuncheol Ha, Chun Woong Park, Won Hee Lee, Jongmin Byun, Young Do Kim; J Powder Mater. 2024;31(5):399-405. Published online October 31, 2024; DOI: https://doi.org/10.4150/jpm.2024.00178

Abstract PDF: Mo-ODS alloys have excellent mechanical properties, including an improved recrystallization temperature, greater strength due to dispersed oxides, and the ability to suppress grain growth at high temperatures. In ODS alloys, the dispersed Y2O3 and added Ti form Y-Ti-O complex oxides, producing finer particles than those in the initial Y2O3. The complex oxides increase high-temperature stability and improve the mechanical properties of the alloy. In particular, the use of TiH2 powder, which is more brittle than conventional Ti, can enable the distribution of finer oxides than is possible with conventional Ti powder during milling. Moreover, dehydrogenation leads to a more refined powder size in the reduction process. This study investigated the refinement of Y2Ti2O7 in a nano Mo-ODS alloy using TiH2. The alloy compositions were determined to be Mo-0.5Ti-0.5Y2O3 and Mo-1.0Ti-0.5Y2O3. The nano Mo-ODS alloys were fabricated using Ti and TiH2 to explore the effects of adding different forms of Ti. The sintered specimens were analyzed through X-ray diffraction for phase analysis, and the microstructure of the alloys was analyzed using scanning electron microscopy and transmission electron microscopy. Vickers hardness tests were conducted to determine the effect of the form of Ti added on the mechanical properties, and it was found that using TiH2 effectively improved the mechanical properties.

Search