Temperature-dependent mechanical and oxidation behavior of in situ formed ZrN/ZrO2-containing Si3N4-based composite |
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Authors: | Jiongjie Liu Wei Li Emmanuel Ricohermoso III Zhuihui Qiao Qingwen Dai Xingmin Liu Wenjie Xie Emanuel Ionescu Anke Weidenkaff Ralf Riedel |
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Affiliation: | 1. Institute of Materials Science, Technical University of Darmstadt, Darmstadt, Germany;2. State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou, P. R. China;3. College of Mechanical and Electrical Engineering, Nanjing University of Aeronautics & Astronautics, Nanjing, China;4. Institute of Materials Science, Technical University of Darmstadt, Darmstadt, Germany
Department Digitalization of Resources, Fraunhofer IWKS, Alzenau, Germany |
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Abstract: | In this work, Si3N4 and Zr(NO3)4 were used as raw materials to prepare ZrN/ZrO2-containing Si3N4-based ceramic composite. The processing, phase composition, and microstructure of the composite were investigated. Hardness and fracture toughness of the ceramics were evaluated via Vickers indentation in Ar at 25°C, 300°C, 600°C, and 900°C. During spark plasma sintering, Zr(NO3)4 was transformed into tetragonal ZrO2, which further reacted with Si3N4, resulting in the formation of ZrN. The introduction of ZrN enhanced the high-temperature mechanical properties of the composite, and its hardness and fracture toughness reached 13.4 GPa and 6.1 MPa·m1/2 at 900°C, respectively. The oxidation experiment was carried out in air at 1000°C, 1300°C, and 1500°C for 5 h. It was shown that high-temperature oxidation promoted the formation and growth of porous oxide layers. The microstructure and phase composition of the formed oxide layers were investigated in detail. Finally, it was identified that the obtained composite exhibited a higher thermal diffusivity than that of monolithic Si3N4 in the temperature range of 100°C–1000°C. |
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Keywords: | mechanical properties oxidation silicon nitride thermal properties zirconia |
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