Effect of Y<inf>2</inf>O<inf>3</inf> on spark plasma sintering kinetics of nanocrystalline 9Cr-1Mo ferritic oxide dispersion-strengthened steels

Nanocrystalline mechanically alloyed powders of 9Cr-1Mo ferritic steels with and without yttria dispersoids were densified using spark plasma sintering (SPS) to near-theoretical density at a temperature of 1073 K (800 C). Studies on densification behaviour revealed that steels with dispersoids densified faster when compared to Fe-9Cr-1Mo steel. The evaluation of densification mechanisms during SPS reveals that grain boundary and lattice diffusion to be predominant at relative densities ranging from >0.7 to 0.9 in both the alloys. © 2013 The Minerals, Metals & Materials Society and ASM International.