An Investigation of the Stability of Y 2 O 3 and Sintering Behavior of Fe-Based ODS Particles Prepared by High Energy Ball Milling

Abstract Fe-based oxide dispersion strengthened (ODS) powders were produced by high energy ball milling, fol-lowed by spark plasma sintering (SPS) for consolidation. The mixed powders of 84Fe-14Cr-2Y 2 O 3 (wt%) weremechanically milled for 10 and 90 mins, and then consolidated at different temperatures (900~1100 o C). Mechani-cally-Alloyed (MAed) particles were examined by means of cross-sectional images using scanning electron micros-copy (SEM). Both mechanical alloying and sintering behavior was investigated by X-ray diffraction (XRD) and highresolution transmission electron microscopy (HR-TEM). To confirm the thermal behavior of Y 2 O 3 , a replica methodwas applied after the SPS process. From the SEM observation, MAed powders milled for 10 min showed a lamellastructure consisting of rich regions of Fe and Cr, while both regions were fully alloyed after 90 min. The results ofsintering behavior clearly indicate that as the SPS temperature increased, micro-sized defects decreased and the den-sity of consolidated ODS alloys increased. TEM images revealed that precipitates smaller than 50 nm consisted ofYCrO