Heat Treatment Effect on the Behavior of Oxide Particles in Mechanically Alloyed Oxide Dispersion Strengthened Powders

Abstract

Nano-scale crystalline Fe-10Cr-1Mo-5Y(2)O(3) powders are prepared though mechanically alloying. To evaluate the formation stage of nano-sized oxide particles, the microstructural examinations were evaluated using in-situ TEM and XRD. The structural change mechanism and morphologic evolution of the oxide particle in mechanically alloyed Fe-10Cr-1Mo-5Y(2)O(3) powders can be explained as follows. The results show that the mechanically alloyed powder is characterized by ultrafine grains and high dislocation density, which facilitate the dispersion of oxide particles. Detailed in-situ TEM results show that nano-sized precipitates are present in the matrix during heating. It was concluded that the starting Y2O3 are decreased in crystallite size, and have a deformed structure as Y-rich oxide particles by high energy milling. The oxide particles are dispersed in a matrix during mechanical alloying, and crystallization of nano-sized oxide particles was exhibited during the heat-treatment process.