Long-term oxidation behavior of in situ synthesized SiC particulate-reinforced MoSi2 matrix composites at 900℃
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摘要: 研究了不同體積分數原位合成SiC顆粒增強MoSi2基復合材料在900℃空氣中1000 h的長期氧化行為.復合材料氧化1000 h后，均未發生pest現象.6種材料都表現出優異的氧化抗力，原位合成的復合材料的氧化抗力好于傳統的通過熱壓商用MoSi2粉末和SiC粉末混合物制備的復合材料（外加復合材料）.復合材料氧化膜表層為連續致密的α-SiO2（α-石英），下層為Mo5Si3，復合材料的氧化過程不僅是O2與MoSi2的作用，SiC也同時發生了氧化.材料900℃下發生硅的選擇性氧化，正是這種硅的選擇性氧化在MoSi2的表面自發形成一層致密的SiO2保護膜，使材料表現出優異的長期氧化抗力.Abstract: MoSi2 intermetallic is well known as one of the most promising compounds used as structural components due to its high melting point, relatively low density, excellent oxidation resistance, and good strength at high temperatures. Unfortunately, MoSi2 has poor toughness at low temperatures and low creep strength at elevated temperatures. Especially, MoSi2 alloy usually exhibits severe "pest oxidation" at low temperatures of between 400 and 900℃. These problems limit the applications of MoSi2 alloys. The main methods to solve these problems are alloying and compounding. Unfortunately, so far, the problem of low-temperature oxidation resistance of MoSi2 has not been completely solved, and its composite materials are reinforced using external means. In a previous work, SiC particle-reinforced MoSi2 matrix composites were prepared by an in situ synthesis technique, and the microstructures and the mechanical behaviors at room temperature and high temperature were systematically studied. In this work, the long-term oxidation behavior of in situ synthesized SiC particulate-reinforced MoSi2 matrix composites with different volume fractions and occurring at 900℃ for 1000 h was investigated. The composites are not observed to disintegrate (pest) after oxidation for 1000 h. The oxidation resistances of six kinds of materials appear excellent. The composite synthesized by in situ possesses higher oxidation resistance than the traditional composite, which is fabricated by hot-pressing the mixture of commercial powders of MoSi2 and SiC. The surface of scales consists of α-SiO2 (α-quartz), and the subsurface is composed of Mo5Si3. The oxidation of the composites is conducted not only between MoSi2 and O2, but also SiC is oxidized. Selective oxidation of Si completely takes place at 900℃. This selective oxidation results in the spontaneously formation of a layer of dense SiO2 protective scale on the MoSi2 surface, making the material exhibit excellent long-term oxidation resistance.
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Key words:
- composite /
- MoSi2 /
- SiC particulate reinforcement /
- in situ synthesis /
- oxidation behavior at low temperature /
- pest
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圖 1 6種材料樣品在900 ℃氧化1000 h的動力學曲線及局部放大圖. (a)氧化0~1000 h；(b)氧化0~100 h的放大圖；(c)氧化0~20 h的放大圖
Figure 1. Oxidation kinetics curves of samples at 900 ℃: (a) for 1000 h; (b) enlarged views of 0-100 h; (c) enlarged views of 0-20 h
圖 2 試樣氧化膜表面X射線光電子窄掃描譜圖(濺射3 min、厚度1.8 nm). (a) Si2p; (b) Mo3d; (c) O1s
Figure 2. XPS narrow spectra of the oxide scale surfaces of samples after sputtering for 3 min with the sputtered thickness of 1.8 nm: (a)Si2p; (b) Mo3d; (c) O1s
圖 4 6個樣品氧化1000 h后表面的宏觀形貌
Figure 4. Macro surface morphologies of samples oxidized for 1000 h
圖 5 6個樣品氧化1000 h后氧化膜表面的掃描電鏡形貌. (a) MoSiC10；(b) MoSiC20；(c) MoSiC30；(d) MoSiC45；(e) WS；(f) MS
Figure 5. SEM surface morphologies of samples oxidized for 1000 h: (a) MoSiC10; (b) MoSiC20; (c) MoSiC30; (d) MoSiC45; (e) WS; (f) MS
圖 6 Mo-Si-O系中可能化合物在不同溫度及氧分壓下的化學穩定性[22]
Figure 6. Chemical stability of possible compounds in Mo-Si-O system at different temperatures and oxygen partial pressures
圖 7 原位合成SiC顆粒增強MoSi2基復合材料900 ℃氧化機理示意圖
Figure 7. Schematic drawing of the oxidation mechanism of in situ synthesized SiC particulate reinforced MoSi2 matrix composites at 900 ℃
表 1 樣品X射線光電子能譜分析結果(濺射3 min、厚度1.8 nm)
Table 1. XPS analytical results of samples after sputtering for 3 min with the sputtered thickness of 1.8 nm
樣品 元素 結合能/eV 對應相 原子分數/% Mo3d — — 0.45 MS Si2p 103.8 SiO2 30.15 O1s 533.5 SiO2 69.40 Mo3d — — 0.10 MoSiC20 Si2p 103.8 SiO2 28.58 O1s 533.5 SiO2 71.34 Mo3d — — 0.20 MoSiC30 Si2p 103.8 SiO2 27.79 O1s 533.5 SiO2 72.01 
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參考文獻
[1] Fitzer E, Benesovsky F. Molybdenum disilicide as high-temperature material//Proceedings of 2nd Plansee Seminar. Vienna, 1955: 79 [2] Chou T C, Nieh T G. New observations of MoSi2 pest at 500℃. Scripta Metall Mater, 1992, 26(10): 1637 doi: 10.1016/0956-716X(92)90270-O [3] McKamey C G, Tortorelli P F, DeVan J H, et al. A study of pest oxidation in polycrystalline MoSi2. J Mater Res, 1992, 7(10): 2747 doi: 10.1557/JMR.1992.2747 [4] Westbrook J H, Wood D L. "PEST" degradation in beryllides, silicides, aluminides and related compounds. J Nucl Mater, 1964, 12(2): 208 doi: 10.1016/0022-3115(64)90142-4 [5] Chen J X, Li C H, Fu Z, et al. Low temperature oxidation behavior of a MoSi2-based material. Mater Sci Eng A, 1999, 261(1-2): 239 doi: 10.1016/S0921-5093(98)01071-5 [6] Kuchino J, Kurokawa K, Shibayama T, et al. Effect of microstructure on oxidation resistance of MoSi2 fabricated by spark plasma sintering. Vacuum, 2004, 73(3-4): 623 doi: 10.1016/j.vacuum.2003.12.081 [7] Arreguín-Zavala J, Turenne S, Martel A, et al. Microwave sintering of MoSi2-Mo5Si3 to promote a final nanometer-scale microstructure and suppressing of pesting phenomenon. Mater Charact, 2012, 68: 117 doi: 10.1016/j.matchar.2012.03.014 [8] Dasgupta T, Umarji A M. Improved ductility and oxidation resistance in Nb and Al co-substituted MoSi2. Intermetallics, 2008, 16(6): 739 doi: 10.1016/j.intermet.2008.01.006 [9] Potanin A Y, Pogozhev Y S, Levashov E A, et al. Kinetics and oxidation mechanism of MoSi2-MoB ceramics in the 600-1200℃ temperature range. Ceram Int, 2017, 43(13): 10478 doi: 10.1016/j.ceramint.2017.05.093 [10] Zhou H M, Liu G Q, Xiao L R, et al. Low temperature oxidation behavior of MoSi2 composites strengthened and toughened by Si3N4 particles and SiC whiskers. J Inorg Mater, 2009, 24(5): 929 https://www.cnki.com.cn/Article/CJFDTOTAL-WGCL200905012.htm周宏明, 柳公器, 肖來榮, 等. Si3N4顆粒及SiC晶須強韌化MoSi2復合材料的低溫氧化行為. 無機材料學報, 2009, 24(5): 929 https://www.cnki.com.cn/Article/CJFDTOTAL-WGCL200905012.htm [11] Feng P Z, Wang X H, He Y Q, et al. Effect of high-temperature preoxidation treatment on the low-temperature oxidation behavior of a MoSi2-based composite at 500℃. J Alloys Compd, 2009, 473(1-2): 185 doi: 10.1016/j.jallcom.2008.06.032 [12] Taleghani P R, Bakhshi S R, Erfanmanesh M, et al. Improvement of MoSi2 oxidation resistance via boron addition: fabrication of MoB/MoSi2 composite by mechanical alloying and subsequent reactive sintering. Powder Technol, 2014, 254: 241 doi: 10.1016/j.powtec.2014.01.034 [13] Wen S H, Zhou C G, Sha J B. Improvement of oxidation resistance of a Mo-62Si-5B (at. %) alloy at 1250℃ and 1350℃ via an in situ pre-formed SiO2 fabricated by spark plasma sintering. Corros Sci, 2017, 127: 175 doi: 10.1016/j.corsci.2017.08.019 [14] Sun Z Q, Zhang L Q, Yang W Y, et al. A Method of the Preparation of In Situ Silicon Carbide Particulates Reinforced Molybdenum Disilicide Matrix Composites: China Patent CN01141978.4. 2002-04-17孫祖慶, 張來啟, 楊王玥, 等. 一種制備碳化硅顆粒增強二硅化鉬基復合材料的原位復合方法: 中國專利CN01141978.4. 2002-04-17 [15] Zhang L Q, Sun Z Q, Zhang Y, et al. Microstructure and mechanical properties of in situ SiC particulates reinforced MoSi2 matrix composite. Acta Metall Sin, 2001, 37(3): 325 doi: 10.3321/j.issn:0412-1961.2001.03.022張來啟, 孫祖慶, 張躍, 等. 原位SiC顆粒增強MoSi2基復合材料的顯微組織和力學性能. 金屬學報, 2001, 37(3): 325 doi: 10.3321/j.issn:0412-1961.2001.03.022 [16] Fu X W, Yang W Y, Zhang L Q, et al. High temperature creep behavior of in situ synthesized MoSi2-30%SiC composite. Acta Metall Sin, 2002, 38(7): 731 doi: 10.3321/j.issn:0412-1961.2002.07.013傅曉偉, 楊王玥, 張來啟, 等. 原位合成MoSi2-30%SiC復合材料高溫蠕變行為. 金屬學報, 2002, 38(7): 731 doi: 10.3321/j.issn:0412-1961.2002.07.013 [17] Zhang L Q, Pan K M, Duan L H, et al. Oxidation behavior of in-situ synthesized MoSi2-SiC composites at 500℃. Acta Metall Sin, 2013, 49(11): 1303 https://www.cnki.com.cn/Article/CJFDTOTAL-JSXB201311005.htm張來啟, 潘昆明, 段立輝, 等. 原位合成MoSi2-SiC復合材料在500℃的氧化行為. 金屬學報, 2013, 49(11): 1303 https://www.cnki.com.cn/Article/CJFDTOTAL-JSXB201311005.htm [18] Zhang L Q, Duan L H, Lin J P. Oxidation behavior of in-situ synthesized MoSi2-SiC composites at 700℃. Chin J Mater Res, 2015, 29(8): 561 https://www.cnki.com.cn/Article/CJFDTOTAL-CYJB201508001.htm張來啟, 段立輝, 林均品. 原位合成MoSi2-SiC復合材料700℃的氧化行為. 材料研究學報, 2015, 29(8): 561 https://www.cnki.com.cn/Article/CJFDTOTAL-CYJB201508001.htm [19] Wirkus C D, Wilder D R. High-temperature oxidation of molybdenum disilicide. J Am Ceram Soc, 1966, 49(4): 173 doi: 10.1111/j.1151-2916.1966.tb13227.x [20] Chou T C, Nieh T G. Comparative studies on the pest reactions of single-and poly-crystalline MoSi2. Scripta Metall Mater, 1992, 27(1): 19 doi: 10.1016/0956-716X(92)90312-3 [21] Meschter P J. Low-temperature oxidation of molybdenum disilicide. Metall Trans A, 1992, 23(6): 1763 doi: 10.1007/BF02804369 [22] Bartlett R W, McCamont J W, Gage P R. Structure and chemistry of oxide films thermally grown on molybdenum silicides. J Am Ceram Soc, 1965, 48(11): 551 doi: 10.1111/j.1151-2916.1965.tb14671.x -
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