AlON透明陶瓷研究进展

透明氮氧化铝(AlON)陶瓷具有优异的光学、力学、热学综合性能,在国防和商业众多领域内具有广阔的应用前景.本文对AlON陶瓷的性能、合成方法和制备工艺、应用等方面的研究进展进行了综述,并对其未来的研究发展方向进行了展望.     

透明AION陶瓷研究现状及应用

主要介绍透明氮氧化铝（AION）陶瓷的研究进展．对AION的制备方法和应用做了综述和介绍．并对其发展前景和存在的问题作了展望与分析。     

透明AlON陶瓷材料的研究现状及进展

综述了透明AlON陶瓷材料的制备工艺、透光性影响因素、主要应用及研究现状.指出透明AlON陶瓷已经成为各国材料学科领域和军事领域竞相研究的热点,透光性能好的AlON材料的研制和开发是制约我国在该领域发展的核心技术.     

AlON透明陶瓷研究进展

作为一种具有优异光学性能的透明陶瓷材料,单相AION陶瓷在可见光和红外光范围内都具有很好的透光性,再加之优良的热学和机械性能,愈来愈受到人们的广泛关注.本文简要的介绍了AION透明陶瓷的各项性能,回顾了其研究发展过程,介绍了其制备工艺和应用,并展望了今后的透明陶瓷的研究和发展.     

透明陶瓷的研究现状及应用进展

综述了Al2O3,YAG,AlON,Y2O3,镁铝尖晶石,闪烁陶瓷,PLZT等几种具有重要应用的透明陶瓷的研究现状,分别论述了其主要性能及应用进展,并对其发展趋势进行了分析讨论.     

透明陶瓷的研究现状与发展

由于透明陶瓷具有优异性能，近年来得到广泛深入的研究，并在实际应用中取得一定突破，有可能成为替代单晶的新一代光学材料。本文重点介绍了透明陶瓷以及制备中出现的新方法和新工艺的发展趋势。     

AlON透明陶瓷的制备与性能

以碳热还原法制得的氮氧化铝(aluminum oxynitride,Al23O18N5,AlON)粉体为原料,Y2O3为烧结助剂,采用热压烧结法在1850～1950℃和15～25MPa下制备了AlON透明陶瓷。通过X射线衍射、扫描电子显微镜和红外光谱仪分析了AlON陶瓷样品的相组成、显微形貌和红外透过率。结果表明:所制备的AlON透明陶瓷样品未发现杂质相,且晶界处未见明显的玻璃相,晶粒间为直接结合。AlON陶瓷样品的体积密度为3.69g/cm3,约为其理论体积密度的99.5%,弯曲强度为304MPa,断裂韧性为2.14MPa·m1/2;3mm厚透明陶瓷样品的红外透过率达81.3%。而气孔、晶界和第二相杂质等是影响AlON陶瓷透明度的主要因素。     

透明AlON陶瓷的研究进展与展望

氮氧化铝(AlON)透明陶瓷具有强度高、硬度大、耐腐蚀、热震性好等优点,同时透波范围大、直线透过率大,因此在国防和民用众多领域具有广泛的应用前景,被美国军方评为"21世纪最重要的国防材料之一"。本文在介绍了AlON透明陶瓷国内外研究现状及AlON晶体结构和相图基础上,阐述了AlON陶瓷粉体的不同合成路线、制备及应用等方面的研究进展,并分析了现有技术困难,展望了AlON的研发方向。     

耐高温透明AlON陶瓷的研究进展与展望

透明AlON陶瓷具有良好的光学性能,是一类很有发展前景的高温透红外材料,因而也是很重要国防军事材料.本文从氮氧化铝的晶体结构出发,介绍了氮氧化铝陶瓷的制备工艺,同时综述了近年来透明AlON材料的研究进展,并对现有氮氧化铝陶瓷材料存在的问题及其未来的发展趋势作了展望.     

氧化物透明陶瓷的生产现状及性能

论述了氧化物透明陶瓷的生产现状及其主要性能,并给出了制取氧化物及其化合物透明陶瓷的有关数据。     

Transparent AlON ceramics by nitriding combustion synthesis precursors and pressureless sintering method

Fine AION powders (D₅₀ = 607 nm) with high sintering activities were synthesized by a high-efficiency solution combustion-based method, and a high-transmittance AlON ceramics can be achieved by a subsequent sintering process. Moreover, the influences of various aluminum resources (Al(NO₃)₃, AlCl₃ and Al₂(SO₄)₃) on the morphology of precursors and nitride-functionalized products have been studied in detail. Using Al(NO₃)₃ as aluminum source resulted in more active precursors and was beneficial for the preparation of ultrafine AlON powders. Then, single-phase AlON powders were obtained by calcining precursors at 1700 °C for 10 min, while residual Al₂O₃ was observed in the calcined products synthesized by other two aluminum sources. As a result, transparent AlON ceramics with high in-line transmittance of 85.9% at 2 μm were obtained. This research provides valuable reference for rapid preparation of AlON powders and transparent ceramics.     

AlON合成及致密化的研究

本文以AlN和Al2O3为原料采用无压烧结的方法制备AlON,研究了不同温度对AlON合成物相的影响,及添加剂MsO、Y2O3和CaO对其致密化的影响.通过X射线衍射仪、扫描电镜和阿基米德原理对其物相、显微结构和体积密度等性能进行表征.研究结果表明:在1700℃时AlON开始生成,随着温度升高AlON相含量越多,最佳合成温度为1800℃,当温度达到1900℃时出现多种AlON相;在1800℃时,添加剂MsO、Y2O3和CaO均能促进AlON的致密化,而添加剂CaO添加量为20wt％时,AlON致密化最佳,气孔率最小为5.43％,密度为3.14 g/cm3.     

Preparation and properties of AlON powders

Aluminum oxynitride (AlON) powders were synthesized using the raw materials of γ-Al₂O₃ and carbon black through the carbothermal reduction and nitridation process. The carbon content in the γ-Al₂O₃/C mixture and heating temperature were investigated. The AlON powders were synthesized by calcination for 2 h at 1750 °C when the carbon content in the γ-Al₂O₃/C mixture was 5.8 wt%. The particle size of powder is important to the transparency of ceramics, but the size of the synthesized powder was large. Therefore, a few methods, such as freeze-drying, ultrasonic dispersion, and liquid nitrogen ball milling, were used to reduce the particle size of powders. Among the three methods, liquid nitrogen milling had the best results.     

Transparent AlON ceramic combined with VO2 thin film for infrared and terahertz smart window

Transparent AlON ceramics are intriguing window materials with excellent mechanical strength and superb optical transparency from the near ultraviolet to the mid-infrared range. However, previous studies focused their investigations in the visible range; therefore, the application of transparent AlON ceramics to tunable windows has yet to be reported. In this work, a VO₂ thin film with a characteristic semiconductor-metal phase transition (SMT) was fabricated on a transparent AlON ceramic, which exhibited remarkable tunable switching properties in the infrared and terahertz ranges. The transparent AlON ceramic was prepared by a two-step method, which included carbothermal reduction and pressureless sintering. The resulting ceramic exhibited high transparency of over 70% in the visible-infrared range and a notable THz transmission of 64.5–73.9% at 0.1–1.5?THz. The VO₂ thin film was prepared on a transparent AlON ceramic using the sol-gel method and showed excellent optical and electric switching performance. The square resistance variance was close to four orders of magnitude, and an infrared switching ratio of over 40% was obtained. Furthermore, the combined structure showed an efficient THz switching ratio of approximately 70.9%. This study proposes a composite material combined with a transparent ceramic and a phase transition oxide and provides great insights into their application in infrared and terahertz smart windows as well as in switching devices.     

Oxidation behavior and mechanism of aluminum oxynitride (AlON) at elevated temperatures

The oxidation behavior and mechanism of aluminum oxynitride (AlON) powder exposed to air at elevated temperatures between 800°C and 1300°C was investigated by X-ray diffractometry (XRD), scanning electron microscope (SEM), electron spin resonance (ESR), nuclear magnetic resonance (NMR), and simultaneous thermogravimetry, differential thermal analysis, and mass spectrometry techniques (TG-DTA-MS). The weight of AlON gradually increases to a maximum value at 1150°C and then decreases with further heating. Meanwhile, AlON powder undergoes chemical changes, as evidenced by lattice expansion, and turns eventually into alumina. ESR spectra reveal the occurrence of lone pair electrons in the oxidized products and the intensity of corresponding resonance signal increases before disappearing with the increase in temperature. Combined with the results of NMR and TG-DTA-MS, the measured data suggest that Al-N in [AlO₃N] tetrahedron and [AlO₅N] octahedron are gradually oxidized into Al-O-N group with lone pair electrons, which causes continuous weight gain and lattice expansion. Further oxidation at higher temperatures results in alumina and N₂.