Homogeneous dispersion of yttrium oxide particles in nickel-based superalloy by high pressure homogenizing and ball milling method

An optimum route to fabricate the Ni-based superalloy with homogeneous dispersion of Y₂o₃ particles is investigated. Ni-based oDS powder was prepared by high-energy ball milling of gas-atomized alloy powders and Y₂o₃ particles treated with a high-pressure homogenizer. Decrease in particle size and improvement of dispersion stability were observed by high-pressure homogenization of as-received Y₂o₃ particles, presumably by the powerful cavitation forces and by collisions of the particles. Microstructural analysis for the ball-milled powder mixtures reveal that Ni-based oDS powders prepared from high-pressure homogenization of Y₂o₃ particles exhibited more fine and uniform distribution of Ni and Y elements compared to the as-received powder. These results suggested that high-pressure homogenization process is useful for producing Ni-based superalloy with homogeneously dispersed oxide particles.