OXIDATION BEHAVIOR OF MECHANICALLY ALLOYED CHROMIUM BASED ALLOYS

The oxidation of chromium and chromium based alloys with yttria additi ons of 0.5 to 4 wt.%. processed by mechanical alloying, was investigat ed. Additionally, the effect of milling time on the oxidation, behavio r was examined. The samples were oxidized at 950 degrees C in air. Wei ght changes, optical microscopy and SEM were utilized to characterize the oxidation behavior. Although it appeared that the presence of yttr ia reduced the oxidation rates significantly, the exact concentration of yttria was far less essential for the oxidation properties than the yttria distribution. Therefore the oxidation resistance of ODS (oxide dispersion strengthened) alloys strongly depends on the exact manufac turing process.