Figure 1: SEM images of Fe-1 wt% Y2O3 samples: (a) cold press sintering; (b) hot press sintering; (c) spark plasma sintering (SPS). From Figure 1 (a) Magnified 1000 times, the grain size ranges from 10 μm to 20 μm. The structure isn’t dense enough with a considerable amount of pores. The sample demonstrated in (b) is denser. However, some vacancy defects are still obvious. The average grain size is 10 μm. The sample in (c), which was sintered by SPS, exhibits a configuration much denser compared to (a) and (b) in which there is no obvious pore. Its average grain size is 10 μm.