Stability of Ti-, Y-and O-enriched particles in a MA/ODS ferritic alloy

摘要

Mechanical-alloying (MA) of fine pre-alloyed metal and Y_2O_3 powders has been shown to produce oxide dispersion-strengthened (ODS) ferritic alloys with dramatically improved high temperature mechanical properties. Previous atom probe studies have revealed that the improved high temperature mechanical properties are correlated with the presence of ultrastable 4-nm-diameter Ti-, Y- and O-enriched particles and significant enrichments of Cr, W, Ti, Y, O, C and B in the vicinity of dislocations [1,2]. These particles were stable during creep experiments for at least 4,000 h at 850 °C and 14,500 h at 800 °C. In this study, the stability of these clusters at significantly higher temperatures of up to 1300 °C was examined.