MA956 (Fe-Cr-Al) alloy powder was high-energy ball milled with various amount of yttria contents (1,2,3, and 4 wt.%) to fabricate an oxide dispersion strengthened alloy. The milled powders were then consolidated using hot press sintering at 1150°C. The surface morphology and crystal structure of MA956 powder during the high-energy milling depending on the yttria contents was investigated using particle size analysis, X-ray diffraction, and scanning electron microscopy. The microstructural analysis of sintered alloy was performed using transmission electron microscopy and energy dispersive spectroscopy to evaluate the dispersion behavior of yttrium oxide. The results showed that, as yttria contents increased, the oxide particles became finer and are uniformly distributed during the high-energy milling. However, after the sintering, the oxide particles were coarsened with more than 3 wt.% of yttria addition.

In this study, Ni(OH) 2 was synthesized by the continuous reaction by the Taylor fluid flow and compared with those prepared from the conventional batch type reaction. The nickel powders were synthesized by reduction of Ni(OH) 2 in an aqueous solution with hydrazine hydrate acting as the reductant. And then the characteristics of the nickel powder according to the synthesis method were compared. The average particle size of the synthesized Ni(OH) 2 using Taylor reactor was generally decreased about 1.5~2.5 times more than the batch reaction. The nickel powders prepared by the batch reaction highly agglomerated with non-uniform particles. In the Taylor reaction, the agglomeration of particles was broken and uniform nickel powder was produced.