Microstructure and oxidation resistance of spark plasma sintered Yttria-Zirconia ODS steels

In this experiment, the effect of Y2O3 and ZrO2 additions on the microstructure and cyclic oxidation resistance of 17-Cr ODS steel containing Al consolidated using spark plasma sintering method were studied. In addition, density, porosity and hardness were also observed. Four compositions of ferritic steels as Fe-17Cr-3.5Al-Ti-Y ('FP'), Fe-17Cr-3.5Al-Ti-Y-0.4Y(2)O(3) ('FY'), Fe-17Cr-3.5Al-Ti-Y-0.4ZrO(2) ('FZ'), and Fe-17Cr-3.5Al-Ti-Y-0.2Y(2)O(3)-0.2ZrO(2) ('FYZ') were prepared by mechanical alloying and followed by sintering at 1000 degrees C. Microstructure characteristics were observed for different aspect, viz. elemental distribution, composition, and phase identification. Cyclic oxidation tests were carried out at 800 degrees C for 8 cycles. The results show that ZrO2 addition suppresses the formation of Y-Al-O clustering and promotes the formation of Y-Zr-O clustering and the enhancement of oxidation resistance of the alloy. However, in some condition it also has a deleterious effect on crack resistance. In contrast, the addition of Y2O3 decreases the oxidation resistance but increases the hardness.