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题名	Y2O3–MgO纳米复相陶瓷的制备及其红外光学性能研究
作者	谢俊喜
文献子类	硕士
导师	毛小建
关键词	红外窗口 Infrared window 溶胶-凝胶燃烧法 sol-gel combustion Y2O3–MgO纳米复相陶瓷 Y2O3–MgO nanocomposite ceramics SPS SPS HIP HIP 低辐射率 low emissivity
其他题名	Preparation and research of infrared optical properties of Y2O3–MgO nanocomposite ceramics
英文摘要	随着红外材料制导飞行器向更快的攻击速度和更高的打击精度方向发展，现有的红外窗口材料已经无法满足应用需求。下一代红外窗口材料需要具备更高的性能要求，如更高的机械性能，更高的抗热冲击性和更低的发射率。Y2O3–MgO纳米复相陶瓷具有良好的机械性能和较低的发射率，并且在3–7 μm中红外波段内具有较高的透过率，被认为是一种很有前途的红外窗口材料。 本文采用溶胶-凝胶燃烧法合成Y2O3–MgO纳米复相粉体，研究了柠檬酸与硝酸根的比例（下文中简称c/n值）、粉末热处理温度对粉体粒径、相组成及尺寸分布的影响。研究表明c/n值的增加或是粉末热处理温度的提高都有助于粉体中游离水和碳酸盐等杂质的排除，提高粉体的质量。然后研究了粉末的吸水性、烧结方式、烧结制度对Y2O3–MgO纳米复相陶瓷显微结构、光学性能和力学性能的影响。采用SPS烧结时，升温速率为100 ℃/min，烧结温度为1100 ℃，制备得到的复相陶瓷在3–5 μm中红外波段内平均透过率达到80%以上，但是在~7 μm处产生的CO32-吸收峰无法被排除。换用Post-HIP烧结工艺，增加空气中预烧结时低温段的保温时间，优化粉体处理方法如调整c/n值或热处理温度，能够使烧结的陶瓷中CO32-吸收峰消失，2.5–6.5 μm中红外波段内透过率达到83%。另外，对Y2O3–MgO纳米复相陶瓷的热导率、弹性模量和抗弯强度等性能进行了初步探索，得到室温下热导率为14.2 w/(m?k)，弹性模量为204 Gpa，抗弯强度为250 Mpa。Y2O3–MgO纳米复相陶瓷在350 ℃时4.5 μm之前的辐射率小于0.02。; Increased mechanical strength, improved thermal shock resistance and lower emissivity are needed in the development of advanced hypersonic missiles that are faster and more accurate. Among the commonly available and durable mid-infrared materials, Y2O3–MgO nanocomposite ceramics are considered as potential materials for hypersonic infrared windows and domes because of their low emissivity, good mechanical properties, and excellent transmittance in the region of 3–7 μm In this work, a citrate–nitrate combustion method was applied to synthesize composite Y2O3–MgO nanopowders. The effects of the molar ratio of citric acid to nitrate (c/n molar ratio) and the heat treatment of the nanopowders on the microstructural size and phase distribution of the synthesized nanopowders are studied. The results indicated that the increase of c/n molar ratio or the calcined temperature of the powder contributed to the elimination of impurities such as free water and carbonate in the nanopowders, and improve the quality of the nanopowders. Then, the effects of water absorption, sintering method and sintering system on the microstructure, optical properties and mechanical properties of Y2O3–MgO nanocomposite ceramics were studied. During the SPS, when the heating rate was 100 °C/min and the sintering temperature was 1100 °C, the average transmittance of the prepared nanocomposite ceramics was more than 80% in the region of 3–5 μm, but the absorption peak at ~7 μm caused by CO32– can not be elimilated. Hence, the sintering method was changed to Post-HIP. The CO32– can be elimilated by increasing the holding time in the low-temperature stage during the air pre-sintering or optimizing the powders handling methods such as adjusting the c/n molar ratio and the calcined temperature, and so the transmittance reached 83% in the region of 2.5–6.5 μm. In addition, the thermal conductivity, elastic modulus and flexural strength of Y2O3–MgO nanocomposite ceramics were investigated. The thermal conductivity was 14.2 w/(m?k), and the elastic modulus was 204 Gpa, and the flexural strength was 250 Mpa. The emissivity of Y2O3–MgO nanocomposite ceramics before 4.5 μm at 350 ° C is less than 0.02.
学科主题	材料学
内容类型	学位论文
源URL	[http://ir.siom.ac.cn/handle/181231/30937]
专题	中国科学院上海光学精密机械研究所
作者单位	中国科学院上海光学精密机械研究所
推荐引用方式 GB/T 7714	谢俊喜. Y2O3–MgO纳米复相陶瓷的制备及其红外光学性能研究[D].

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