Solution Synthesis of Co-Ni-W-Based ODS Alloy Powder

Low-temperature combustion synthesis was utilized to prepare Co-Ni-W-based oxide dispersion strengthened (ODS) alloy powder. The influence of the U/Co and C/Co ratios on the morphology and specific surface area of the combusted powder was investigated. Particle size, phase constituents, and element distribution of the resulting Co-Ni-W-based ODS alloy powder were characterized. The results indicate that insufficient urea induced no autocombustion reaction, while excess urea and glucose inhibited the combustion reaction. The optimized contents of urea and glucose were around U/Co = 1.2 and C/Co = 1.5, and the specific surface area of the powder reached 43.5 m²/g. The lamellar Co-Ni-W-based ODS alloy powder with particle sizes of 1-21 μm was the soft agglomeration of a high population of nanosized (65 nm) particles. These nanoparticles grew from 65 to 260 nm in the reduction temperature range of 700-900 °C. Homogeneous distribution of Co, Ni, W, and Y in the Co-Ni-W-based ODS alloy powder was achieved.