Effect of Y₂O₃ 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