Preparation of Nano-structured 9Cr-ODS Steel by Spark Plasma Sintering and Its Microstructure Characterization

作者：Lu Chenyang; Lu Zheng; Yu Liang; Liu Chunming

来源：Rare Metal Materials and Engineering, 2016, 45(2): 454-458.

• sparking plasma sintering
• ODS steel
• Y-Ti-O clusters
• Y2Ti2O7
• Mn(Ti)Cr2O4

Ultra-fine grain 9Cr-oxide dispersion strengthened (ODS) steel was prepared by spark plasma sintering (SPS), instead of the traditional hot isostatic pressing (HIP). The microstructure and density of the SPS-ODS steel with different sintering temperatures (900, 950, 1050 degrees C) were analyzed by SEM and Archimedes Principle, respectively. The grain size and precipitates characterization of the SPS-ODS steel were analyzed by HRTEM, STEM-HAADF and EDS. The results show that 950 degrees C is the optimal SPS temperature and the relative density reaches up to 97.7%. The mixture of ultra-fine nano grains (<= 200 nm) and coarse grains (>= 1 mu m) is observed in SPS-ODS steel. High-density nano-sized Y-Ti-O clusters and Y2Ti2O7 phases are dispersed homogenously in the ODS steel. Large size spinel structured Mn(Ti)Cr2O4 precipitates (30 similar to 100 nm) are formed mainly at grain boundaries.

• 出版日期2016-2
• 单位东北大学