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ZrO2对Li2O-Al2O3-B2O3微晶玻璃析晶行为及微波介电性能的影响 认领 引用
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作者 倪宇博 陈志斌 +8 位作者 曾广 罗琼 陈巧 刘佳 李文俊 邹澳琪 王静 田培静 韩建军 《硅酸盐通报》 CAS 北大核心 2026年第3期835-844,共10页
随着5G技术的推进,微波和毫米波频段器件对高性能介电材料的需求日益增长。本文以Li2O-Al2O3-B2O3(LAB)体系微晶玻璃为研究对象,采用低温共烧法制备了能在超低温下烧结致密且具有优异微波介电性能的微晶玻璃,并研究了外... 随着5G技术的推进,微波和毫米波频段器件对高性能介电材料的需求日益增长。本文以Li2O-Al2O3-B2O3(LAB)体系微晶玻璃为研究对象,采用低温共烧法制备了能在超低温下烧结致密且具有优异微波介电性能的微晶玻璃,并研究了外加ZrO2对LAB微晶玻璃析晶行为及微波介电性能的影响。结果表明:当ZrO2掺量从0.2%(摩尔分数,下同)增至0.8%时,LAB微晶玻璃主晶相为LiBO2,析出晶体种类和数量基本没有变化。微晶玻璃Avrami指数n为3.05~3.89,表明该体系的晶体生长机制主要为体析晶,ZrO2的引入降低了微晶玻璃的析晶活化能。随着ZrO2掺量的增加,LAB微晶玻璃显微结构中气孔增多,体积密度也因此而降低。当外加0.2%ZrO2时,Z1微晶玻璃在650℃下烧结7 h具备良好的微波介电性能,微波相对介电常数εr=7.5,品质因素Q×f=16958 GHz,该微晶玻璃是一种良好的超低温共烧陶瓷(ULTCC)候选材料。 展开更多
关键词 Li2O-Al2O3-B2O3微晶玻璃 超低温共烧陶瓷 ZrO2 微波介电性能 析晶活化能 微观结构
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Structure and mechanical properties of ZrO_2-mullite nano-ceramics in SiO_2-Al_2O_3-ZrO_2 system 认领 引用 被引量:6
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作者 梁叔全 谭小平 +1 位作者 李少强 唐艳 《Journal of Central South University of Technology》 2007年第1期1-6,共6页
ZrO2-mullite nano-ceramics were fabricated by in-situ controlled crystallizing from SiO2-Al2O3-ZrO2 amorphous bulk. The thermal transformation sequences of the SiO2-Al2O3-ZrO2 amorphous bulk were investigated by X-ray... ZrO2-mullite nano-ceramics were fabricated by in-situ controlled crystallizing from SiO2-Al2O3-ZrO2 amorphous bulk. The thermal transformation sequences of the SiO2-Al2O3-ZrO2 amorphous bulk were investigated by X-ray diffraction, infrared spectrum, scanning electron microscope and differential scanning calorimetric. And the mechanical properties of the nano-ceramics were studied. The results show that the bulks are still in amorphous state at 900 ℃ and the t-ZrO2 forms at about 950 ℃ with a faint spinel-like phase which changes into mullite on further heating. ZrO2 and mullite become major phases at 1 100 ℃ and an amount of m-ZrO2 occur at the same time. The sample heated at 950 ℃ for 2 h and then at 1 100 ℃ for 1 h shows very dense and homogenous microstructure with ball-like grains in size of 20-50 nm. With the increase of crystallization temperature up to 1 350 ℃, the grains grow quickly and some grow into lath-shaped grains with major diameter of 5 μm. After two-step treatment the highest micro-hardness, flexural strength and fracture toughness of the samples are 13.72 GPa, 520 MPa and 5.13 MPa·m1/2, respectively. 展开更多
关键词 SiO2-Al2O3-ZrO2 system amorphous bulk heat treatment structural change mechanical properties
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Effect of nucleating agents on microstructure and mechanical properties of SiO_2-Al_2O_3-ZrO_2 glass-ceramics 认领 引用 被引量:2
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作者 余丽萍 肖汉宁 胡鹏飞 《Journal of Central South University of Technology》 2005年第5期507-510,共4页
SiO2-Al2O3-ZrO2 glasses with different nucleating agents were crystallized under special processing schedule. The microstructure and mechanical properties of the glass-ceramics in SiO2-Al2O3-ZrO2 system were investiga... SiO2-Al2O3-ZrO2 glasses with different nucleating agents were crystallized under special processing schedule. The microstructure and mechanical properties of the glass-ceramics in SiO2-Al2O3-ZrO2 system were investigated by differential scanning calorimetry, scanning electron microscopy, X-ray diffraction and three-point bending method. The results show that ZrO2 is not an effective nucleating agent in SiO2-Al2O3-ZrO2 system, while TiO2 is effective for the separation of spinel, and P2O5 facilitates solubility of ZrO2 in glass and crystallization. The main crystalline phases of the glass-ceramics are spinel, anorthite and tetragonal zirconia. With the increase of ZrO2 content in the glass, glass-ceramics show higher bending strength (120MPa) than others. 展开更多
关键词 glass-ceramics SiO2-Al2O3-ZrO2 system microstructure mechanical property
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Na2O-Al2O3-SiO2微晶玻璃的研究进展 认领 引用
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作者 赵志龙 田雪洁 +3 位作者 周泽云 韩金龙 赵志永 田英良 《玻璃搪瓷与眼镜》 CAS 2025年第8期47-55,共9页
在Na2O-Al2O3-SiO2(NAS)微晶玻璃中,常见晶相除了霞石晶体(NaAlSiO4),还包含一些不含碱金属氧化物的晶相,这类晶相一定程度上可提高NAS微晶玻璃的力学性能,使其在光学、齿科、信息等领域具有潜在的应用价值。本文简要阐... 在Na2O-Al2O3-SiO2(NAS)微晶玻璃中,常见晶相除了霞石晶体(NaAlSiO4),还包含一些不含碱金属氧化物的晶相,这类晶相一定程度上可提高NAS微晶玻璃的力学性能,使其在光学、齿科、信息等领域具有潜在的应用价值。本文简要阐述了NAS微晶玻璃的研究进展,介绍了NAS微晶玻璃的主晶相和其他衍生晶相的结构,探讨了玻璃的网络形成体、网络修饰体和晶核剂对NAS微晶玻璃析晶行为及性能的影响。最后,展望了NAS微晶玻璃的应用方向。本文对今后NAS微晶玻璃的研究具有一定的参考价值。 展开更多
关键词 钠铝硅微晶玻璃 网络形成体 网络修饰体 晶核剂 钠霞石
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THE STRUCTURE AND PROPERTIES OF Li_2O-Al_2O_3-SiO_2LOW EXPANSION GLASS CERAMICS CONTAINING B_2O_3 认领 引用 被引量:8
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作者 XIAO Jing LI Hong CHENG Jinshu Wuhan University of Technology Wuhan University of Metallurgy 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 1999年第1期41-45,共5页
Through measuring the coefficient of linear expansion, the structure and properties of the Li2O-Al2O3-SiO2 low expansion glass ceramics containing B2O3 are studied by JR and XRD. It is shoutn that the IR method is eff... Through measuring the coefficient of linear expansion, the structure and properties of the Li2O-Al2O3-SiO2 low expansion glass ceramics containing B2O3 are studied by JR and XRD. It is shoutn that the IR method is efficient in the study of the glass-ceramics structure. There is a " Boron abnormality" in the system which has an important influence on the properties of the glass-ceramics. 展开更多
关键词 boron abnormality Li2O-Al2O3-SiO2 system glass ceramics
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B2O3对Li2O-ZnO-Al2O3-SiO2微晶玻璃结构与析晶行为的影响 认领 引用
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作者 温中源 李路瑶 +1 位作者 王静 韩建军 《硅酸盐通报》 CAS 北大核心 2025年第12期4546-4556,4591,共11页
透明微晶玻璃因优异的光学性能与力学性能被广泛用于智能终端和穿戴领域,其性能与玻璃相中纳米晶的种类、含量、尺寸、分布等紧密相关。通过熔融-热处理法制备了Li2O-ZnO-Al2O3-SiO2(LZAS)透明微晶玻璃,研究了B2O3含... 透明微晶玻璃因优异的光学性能与力学性能被广泛用于智能终端和穿戴领域,其性能与玻璃相中纳米晶的种类、含量、尺寸、分布等紧密相关。通过熔融-热处理法制备了Li2O-ZnO-Al2O3-SiO2(LZAS)透明微晶玻璃,研究了B2O3含量对玻璃结构演化、析晶行为及性能的影响。结果表明,随着玻璃中B2O3含量从1%(摩尔分数,下同)增加到5%,玻璃内的[BO4]逐渐向[BO3]转变,并在B2O3含量为3%~5%时,[BO3]比例稳定在约49%。B2O3含量为1%~3%的玻璃在760℃晶化后倾向于表面析晶,B2O3含量不低于4%的玻璃在780℃晶化后,微晶玻璃内部析出分布均匀的球形晶体,增加B2O3含量降低了体析晶所需的晶化温度。其中,含4%B2O3的玻璃经760℃晶化后制得的微晶玻璃样品的透过率为65%,维氏硬度达到(6.77±0.07) GPa,弯曲强度为(172.7±8.1) MPa。 展开更多
关键词 B2O3 微晶玻璃 Li2O-ZnO-Al2O3-SiO2 β-石英固溶体 析晶动力学 维氏硬度
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Mechanical properties and plasma erosion resistance of BN_p/Al_2O_3-SiO_2 composite ceramics 认领 引用 被引量:5
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作者 段小明 贾德昌 +5 位作者 周玉 杨治华 王玉金 任凤琴 于达仁 丁永杰 《Journal of Central South University》 SCIE EI CAS 2013年第6期1462-1468,共7页
BNp/Al2O3-SiO2 system ceramic matrix composites with different volume fractions (10%-60%) of hexagonal BN particulates (BNp) were prepared by hot-press sintering technique. Phase components, microstructure, mechan... BNp/Al2O3-SiO2 system ceramic matrix composites with different volume fractions (10%-60%) of hexagonal BN particulates (BNp) were prepared by hot-press sintering technique. Phase components, microstructure, mechanical properties and plasma erosion resistance were also investigated. With the increase of h-BNp content, relative density and Vickers' hardness of the composite ceramics decrease, while the flexural strength, elastic modulus and fracture toughness increase and then decrease. The plasma erosion resistance linearly deteriorated with the increase of BNp content which is mainly determined by the density, crystal structure and atomic number of the elements. 展开更多
关键词 BNp/Al2O3-SiO2 composite ceramics microstructures mechanical properties plasma erosion resistance
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Sintering,crystallization and dielectric properties of CaO-B_2O_3-SiO_2 system glass ceramics 认领 引用 被引量:3
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作者 戴斌 朱海奎 +2 位作者 周洪庆 许贵军 岳振星 《Journal of Central South University》 SCIE EI CAS 2012年第8期2101-2106,共6页
CaO-B203-SiO2 (CBS) glass powders are prepared by conventional glass melting method at different melting temperatures whose properties and microstructures are characterized by X-ray diffraction (XRD) and scanning ... CaO-B203-SiO2 (CBS) glass powders are prepared by conventional glass melting method at different melting temperatures whose properties and microstructures are characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). It is found that there are SiO2 and some unknown phases in CBS glass melting liquid from 1 300 ℃ to 1 500 ℃ and the amount of these phases decreases with the increase of the melting temperature. The CBS glass melted at 1 450 ℃ could be sintered from 830 ℃ to 930 ℃ and the bulk densities of the samples are all higher than 2.4 g/cm^3. From the points of the properties and energy conservation, the melting temperature of 1 450 ℃ is the optimal melting temperature. The glass ceramic sintered at 850 ℃ exhibits better dielectric properties: er=6.33, tan6=2.2×10^-3 at 10 GHz, and the major phases of the samples are CaSiO3, CaB2O4 and SiO2. 展开更多
关键词 glass ceramics CaO-B2O3-SiO2 sintering dielectric properties microstructure
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Si3N4/Si2N2O相界面结合力及结构特征 认领 引用
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作者 包嘉鑫 王卫国 +1 位作者 陈松 罗旭 《材料科学与工程学报》 CAS CSCD 北大核心 2026年第1期75-83,共9页
氮化硅陶瓷材料具有优良的综合性能,已在装备制造业和国防建设等领域得到应用。进一步提高氮化硅的力学性能,需深入了解相界面结构及特性,为高性能氮化硅陶瓷材料的研究和开发提供重要的理论基础。本研究通过透射电子显微镜观察了热等... 氮化硅陶瓷材料具有优良的综合性能,已在装备制造业和国防建设等领域得到应用。进一步提高氮化硅的力学性能,需深入了解相界面结构及特性,为高性能氮化硅陶瓷材料的研究和开发提供重要的理论基础。本研究通过透射电子显微镜观察了热等静压烧结的氮化硅陶瓷的Si3N4/Si2N2O相界面,构建了Si3N4/Si2N2O多种相界面模型。利用近列匹配和面重合阵点密度方法分析了Si3N4/Si2N2O相界面的结构特征,并利用分子动力学模拟计算了Si3N4/Si2N2O相界面的拉伸性能。研究结果表明,发育良好的Si2N2O晶粒与Si3N4晶粒结合紧密,界面处原子匹配有序,面重合原子密度较高,其位向关系为[0001]//[001],(1010)//(010);具有(1010)//(010)匹配特征的Si3N4/Si2N2O相界面的分离功高于其他相界面,所能承受的拉伸应力也高于其它相界面。以上结果表明,具有(1010)//(010)匹配特征的Si3N4/Si2N2O界面是一类低能稳定的相界面,增加此类相界面将有益于改善氮化硅陶瓷材料的力学性能。 展开更多
关键词 Si3N4陶瓷 Si2N2O 相界面 结合力
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The fluorescence and thermoluminescence characteristics of α-Al_2O_3:C ceramics 认领 引用 被引量:3
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作者 张斌 陆神洲 +1 位作者 张浩佳 杨秋红 《Chinese Physics B》 SCIE EI CAS 2010年第7期581-584,共4页
This paper reports that polycrystalline (α-Al2O3:C ceramics are fabricated by conventional ceramics process. The excitation, emission spectra, thermoluminescence (TL) and optical stimulated luminescence (OSL) ... This paper reports that polycrystalline (α-Al2O3:C ceramics are fabricated by conventional ceramics process. The excitation, emission spectra, thermoluminescence (TL) and optical stimulated luminescence (OSL) of α-Al2O3:C polycrystalline ceramics are investigated. There exists 410nm maximum emission peak which is caused by recombination of an electron with F+ centre to produce an excited F centre. The samples show three clear TL glow peaks at 405, 493 and 610 K. The attenuation constant of exponentially decaying fast component (τ1) and slow component(τ2) of OSL curve are 8.43s and 41.73s, respectively. Those fluorescence and thermoluminescence characteristics are similar with α-Al2O3:C crystal. 展开更多
关键词 α-Al2O3:C ceramics thermoluminescence optical stimulated luminescence
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Studies on the Structure and Properties of Multiphase Al_2O_3 Abrasion-resistant Ceramics 认领 引用 被引量:3
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作者 WU Ren-Ping YU Yan RUAN Yu-Zhong 《Chinese Journal of Structural Chemistry》 SCIE CAS 北大核心 2006年第7期805-810,共6页
The Al2O3 abrasion-resistant ceramics is successfully prepared by using waste aluminum sludge as the main raw material with the addition of a little clay, talc and barium carbonate. The crystal structure and microstru... The Al2O3 abrasion-resistant ceramics is successfully prepared by using waste aluminum sludge as the main raw material with the addition of a little clay, talc and barium carbonate. The crystal structure and microstructure of ceramic are characterized by means of XRD, SEM, etc., and the physical and mechanical properties are also tested. The results show that besides the phase of corundum, a little mullite, Mg-Al spinel and hyalophane phases also exist in the product. These phases are produced via reaction in-situ, which can inhibit the overgrowth of Al2O3 grain in grain boundary, and improve the integral property of the material. 展开更多
关键词 Al2O3 ceramic crystal structure property in-situ synthesis
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Dual-band LTCC antenna based on 0.95Zn_2SiO_4-0.05CaTiO_3 ceramics for GPS/UMTS applications 认领 引用
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作者 窦刚 李玉霞 郭梅 《Chinese Physics B》 SCIE EI CAS CSCD 2015年第10期572-575,共4页
In this paper, we present a compact low-temperature co-fired ceramic(LTCC) dual-band antenna by using the electromagnetic coupling effect concept for global positioning system(GPS) and universal mobile telecommuni... In this paper, we present a compact low-temperature co-fired ceramic(LTCC) dual-band antenna by using the electromagnetic coupling effect concept for global positioning system(GPS) and universal mobile telecommunication system(UMTS) applications. The overall dimension of the antenna is 8.6 mm × 13.0 mm × 1.1 mm. It consists of double meander lines and a via hole line. The top meander line operates at the upper band, and the bottom radiating patch is designed for the lower band. The via-hole line is employed to connect the double meander lines. Because of the effect of the coupled line,total dimension of the proposed antenna is greatly reduced. With the 2.5: voltage standing wave ratio(VSWR) impedance bandwidth definition, the lower and upper bands have the bandwidths of 110 MHz and 150 MHz, respectively. The proposed antenna is successfully designed, simulated, and analyzed by a high frequency structure simulator(HFSS). And the antenna is manufactured by using the 0.95Zn2SiO4-0.05 CaTiO3ceramics(εr = 7.1, tanδ = 0.00038) that is prepared by ourselves. The results show that the antenna is compact, efficient, and of near omnidirectional radiation pattern. 展开更多
关键词 low-temperature co-fired ceramic compact antenna microwave dielectric Zn2SiO4-CaTiO3
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微纳米添加剂α-Al2O3在表面涂层领域的应用现状及市场前景 认领 引用
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作者 伏建康 杨茂盏 +2 位作者 冉长荣 郭太雄 张千峰 《材料科学》 2025年第3期468-475,共8页
微纳米α-Al2O3是一种重要的功能材料,因其优异的硬度、耐磨性、耐腐蚀性和高热稳定性,在表面涂层领域得到了广泛应用。随着微纳米技术的发展,微纳米级α-Al2O3作为添加剂在各涂层体系中的应用得到了深入研究,显示出其能够显著改善涂层... 微纳米α-Al2O3是一种重要的功能材料,因其优异的硬度、耐磨性、耐腐蚀性和高热稳定性,在表面涂层领域得到了广泛应用。随着微纳米技术的发展,微纳米级α-Al2O3作为添加剂在各涂层体系中的应用得到了深入研究,显示出其能够显著改善涂层性能的潜力。微纳米α-Al2O3颗粒具有较大的比表面积和表面活性,能够增强涂层的机械性能,如硬度和耐磨性,同时提高涂层的耐腐蚀性和耐高温性能。微纳米α-Al2O3也是一种极优良的改性材料,其与有机硅烷、树脂等材料复合改性,既能大幅提升转化膜的应用效果,对其稳定性和耐候性也有较大的促进作用。在金属表面涂层、陶瓷涂层以及复合材料涂层中,微纳米α-Al2O3添加剂被广泛用于提高涂层的使用寿命和稳定性。此外,它在电子器件、航天航空和汽车工业等高技术领域也展现了广阔的应用前景。未来,随着表面技术的发展,微纳米α-Al2O3无铬钝化领域的市场应用将大幅增长,与其他功能性材料的协同作用和复合材料开发也将成为研究的重点。Micro-nano α-Al2O3 is an important functional material, because of its excellent hardness, wear resistance, corrosion resistance and high thermal stability, has been widely used in the field of surface coating. With the development of micro-nano technology, the application of micro-nano α-Al2O3 as an additive in various coating systems has been deeply studied, showing its potential to significantly improve coating properties. Micro-nano α-Al2O3 particles have a large specific surface area and surface activity, which can enhance the mechanical properties of the coating, such as hardness and wear resistance, while improving the corrosion resistance and high temperature resistance of the coating. Micro-nano α-Al2O3 is also an excellent modified material, and its composite modification with organosilane, resin and other materials can greatly improve the application effect of conversion film, and also has a greater role in promoting its stability and weather resistance. In metal surface coatings, ceramic coatings and composite coatings, micro-nano α-Al2O3 additives are widely used to improve the service life and stability of coatings. In addition, it also shows broad application prospects in high-tech fields such as electronic devices, aerospace and automotive industries. In the future, with the development of surface technology, the market application of micro-nano α-Al2O3 chromium-free passivation will grow significantly, and the synergy with other functional materials and the development of composite materials will also become the focus of research. 展开更多
关键词 纳米α-Al2O3 无铬钝化涂层 陶瓷膜 表面硬度 耐蚀性
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Preparation and properties of Ba_3Zn_ZCo2-ZFe24O41/SiO_2 microcrystalline glass ceramics 认领 引用
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作者 张海军 贾晓林 +1 位作者 姚熹 张良莹 《中国有色金属学会会刊:英文版》 2004年第1期170-174,共5页
Ba 3Zn Z Co 2 Z Fe 24 O 41 /SiO 2 ( Z varies from 0.0 to 1.2 in step of 0.4) microcrystalline glass ceramics were prepared by citrate sol gel process at 1 200 ℃ in the system of BaO Fe 2O 3 CoO ZnO SiO 2. The samples... Ba 3Zn Z Co 2 Z Fe 24 O 41 /SiO 2 ( Z varies from 0.0 to 1.2 in step of 0.4) microcrystalline glass ceramics were prepared by citrate sol gel process at 1 200 ℃ in the system of BaO Fe 2O 3 CoO ZnO SiO 2. The samples were characterized by X ray diffraction (XRD) and scanning electron microscopy (SEM). The complex dielectric constant and complex permeability of Ba 3Zn Z Co 2 Z Fe 24 O 41 /SiO 2 microcrystalline glass ceramics were measured in the range of 0.16.0 GHz by transmissioneflection coaxial line method. The natural resonance phenomenon was observed in μ ″ spectra for all the Ba 3Zn Z Co 2 Z Fe 24 O 41 /SiO 2 microcrystalline glass ceramics, which was closely affected by the substitution of Zn 2+ ion. 展开更多
关键词 微晶玻璃陶瓷 Ba3ZnzCo2-zFe24O41/SiO2 制备 性能 XRD SEM 溶胶-凝胶
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(Y0.25Yb0.25Er0.25Lu0.25)2(Zr0.5Hf0.5)2O7: A defective fluorite structured high entropy ceramic with low thermal conductivity and close thermal expansion coefficient to Al2O3 认领 引用 被引量:25
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作者 Zifan Zhao Heng Chen +6 位作者 Huimin Xiang Fu-Zhi Dai Xiaohui Wang Wei Xu Kuang Sun Zhijian Peng Yanchun Zhou 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2020年第4期167-172,共6页
Al2O3f/Al2O3 ceramic matrix composites(CMC)are promising candidate materials of blades and combustor liners of future gas turbines in light of their higher temperature capability,higher environmental stability and oxi... Al2O3f/Al2O3 ceramic matrix composites(CMC)are promising candidate materials of blades and combustor liners of future gas turbines in light of their higher temperature capability,higher environmental stability and oxidizing-free capacity[1–3].Nevertheless,grain growth,sintering and creep deformation at high operation temperatures are still serious problems for Al2O3f/Al2O3 ceramic matrix composites,which can lead to a reduction in the strength and damage tolerance[2].Moreover,Al2O3 can be corroded by the high temperature water vapor in combustion environments and yields volatile products,such as Al(OH)3[4].Consequently,environmental barrier coatings(EBCs)are necessary for Al2O3f/Al2O3 ceramic matrix composites,which can protect Al2O3f/Al2O3 CMC from high temperature and flowing combustion gas corrosion and thus increase the high temperature capability and the service life of components. 展开更多
关键词 Al2O3f/Al2O3 ceramic matrix conductivity close thermal expansion
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Photocatalytic activity of TiO_2 supported SiO_2-Al_2O_3 aerogels prepared from industrial fly ash 认领 引用 被引量:9
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作者 王慧龙 齐慧萍 +2 位作者 魏晓娜 刘潇彧 姜文凤 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2016年第11期2025-2033,共9页
A ternary composite of TiO2 and a SiO2-Al2O3 aerogel with good photocatalytic activity was prepared by a simple sol-gel method with TiO2 nanoparticles and SiO2-Al2O3 aerogels derived from industrial fly ash.The struct... A ternary composite of TiO2 and a SiO2-Al2O3 aerogel with good photocatalytic activity was prepared by a simple sol-gel method with TiO2 nanoparticles and SiO2-Al2O3 aerogels derived from industrial fly ash.The structural features of the TiO2/SiO2-Al2O3 aerogel composite were investigated by X-ray powder diffraction,Fourier transform infrared spectroscopy,transmission electron microscopy,gas adsorption measurements and diffuse reflectance UV-visible spectroscopy.The optimal conditions for photocatalytic degradation of 2-sec-butyl-4,6-dinitrophenol(DNBP],included an initial DNBP concentration of 0.167 mmol/L at pH = 4.86 with a catalyst concentration of 6 g/L,under visible light irradiation for 5 h.A plausible mechanism is proposed for the photocatalytic degradation of DNBP.Our composite showed higher photocatalytic activity for DNBP degradation than that of pure TiO2.This indicates that this material can serve as an efficient photocatalyst for degradation of hazardous organic pollutants in wastewater. 展开更多
关键词 Titania SiO2-Al2O3 aerogel Composite photocatalyst Industrial fly ash 2-sec-butyl-4 6-dinitrophenol Wastewater treatment
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球形SiO_2-Al_2O_3的制备、结构和性能 认领 引用 被引量:15
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作者 赵振兴 夏春谷 +2 位作者 薛群基 李殿卿 刘鹏程 《物理化学学报》 SCIE CAS 北大核心 2007年第4期549-553,共5页
将Na_2SiO_3·9H_2O溶液通过强酸性阳离子树脂进行离子交换得到酸性硅溶胶,再将硅溶胶与铝溶胶及六次甲基四胺混合后采用油柱成型法制备了球形SiO_2-Al_2O_3复合氧化物.通过XRD、BET及TPD等手段对样品进行测试和表征,结果表明,600... 将Na_2SiO_3·9H_2O溶液通过强酸性阳离子树脂进行离子交换得到酸性硅溶胶,再将硅溶胶与铝溶胶及六次甲基四胺混合后采用油柱成型法制备了球形SiO_2-Al_2O_3复合氧化物.通过XRD、BET及TPD等手段对样品进行测试和表征,结果表明,600℃焙烧得到的SiO_2-Al_2O_3中SiO_2以无定型形式存在,其比表面、孔容与表面酸性随SiO_2含量的增加而提高,孔径、堆密度随SiO_2含量的提高而减小,压碎强度基本保持不变. 展开更多
关键词 球形SiO2-Al2O3复合物 油柱成型法 无定型 结构与性能
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以钢渣为原料的SiO_2-CaO-Al_2O_3系陶瓷烧结机理 认领 引用 被引量:16
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作者 艾仙斌 李宇 +2 位作者 郭大龙 赵立华 苍大强 《中南大学学报(自然科学版)》 EI CAS CSCD 北大核心 2015年第5期1583-1587,共5页
以主要化学成分为Ca O和Si O2的钢渣为原料,制备Si O2-Ca O-Al2O3系钢渣陶瓷,采用差分扫描量热仪(DSC)、X线衍射仪(XRD)、扫描电子显微镜(SEM)与热力学计算研究钢渣陶瓷烧结过程及反应机理。研究结果表明:在以钢渣-黏土-长石-石英为主... 以主要化学成分为Ca O和Si O2的钢渣为原料,制备Si O2-Ca O-Al2O3系钢渣陶瓷,采用差分扫描量热仪(DSC)、X线衍射仪(XRD)、扫描电子显微镜(SEM)与热力学计算研究钢渣陶瓷烧结过程及反应机理。研究结果表明:在以钢渣-黏土-长石-石英为主要原料的Si O2-Ca O-Al2O3体系中,钢渣陶瓷晶相以钙长石相为主;钢渣陶瓷烧结初期以扩散传质反应为主,之后形成高温液相,促进反应进行和晶体长大,并完成坯体致密化;经过湿磨的钢渣中存在大量的氢氧化钙等矿相,这些矿相在钢渣陶瓷烧结过程中能够分解产生具有很强反应活性的氧化钙,因而促进了原料间的反应和陶瓷致密化过程。 展开更多
关键词 钢渣 陶瓷 烧结机理 SiO2-CaO-Al2O3系
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CaF2对CaO-SiO2-Al2O3渣系保护渣结晶行为的影响 认领 引用 被引量:12
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作者 王哲 唐萍 +3 位作者 米晓希 胡泉 陆逸帆 文光华 《钢铁》 CAS CSCD 北大核心 2018年第7期38-44,共7页
针对CaF2对CaO-SiO2-Al2O3渣系保护渣结晶性能的影响问题,在实验室运用热丝法、X射线衍射法获得了不同CaF2质量分数下的保护渣TTT曲线以及相应温度条件下的结晶物类型。试验结果表明,该渣系保护渣低温下稳定存在的结晶物质不是传统CaO-S... 针对CaF2对CaO-SiO2-Al2O3渣系保护渣结晶性能的影响问题,在实验室运用热丝法、X射线衍射法获得了不同CaF2质量分数下的保护渣TTT曲线以及相应温度条件下的结晶物类型。试验结果表明,该渣系保护渣低温下稳定存在的结晶物质不是传统CaO-SiO2渣系的枪晶石,而为钙铝黄长石和氟化钙;随着CaF2质量分数的增加,平均结晶孕育时间减少,鼻尖点孕育时间缩短,鼻尖点处的结晶温度提高,结晶能力增强。而在CaF2质量分数增加到一定程度后,F-将从网络外体破网作用转化为有一定的成网作用,会减弱保护渣的促晶能力,结晶能力增加趋势减缓。同时,与传统CaO-SiO2渣系保护渣相比,具有更强的结晶性能。 展开更多
关键词 连铸保护渣 CaO-Si O2-Al2O3渣系 CaF2质量分数 结晶性能
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Microstructure and electrical properties of Lu_2O_3-doped ZnO-Bi_2O_3-based varistor ceramics 认领 引用 被引量:16
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作者 徐东 史小锋 +4 位作者 程晓农 杨娟 樊曰娥 袁宏明 施利毅 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS 2010年第12期2303-2308,共6页
Lu2O3-doped ZnO-Bi2O3-based varistor ceramics samples were prepared by a conventional mixed oxide route and sintered at temperatures in the range of 900-1 000°C,and the microstructures of the varistor ceramics sa... Lu2O3-doped ZnO-Bi2O3-based varistor ceramics samples were prepared by a conventional mixed oxide route and sintered at temperatures in the range of 900-1 000°C,and the microstructures of the varistor ceramics samples were characterized by X-ray diffractometry(XRD)and scanning electron microscopy(SEM);at the same time,the electrical properties and V-I characteristics of the varistor ceramics samples were investigated by a DC parameter instrument for varistors.The results show that the ZnO-Bi2O3-based varistor ceramics with 0.3%Lu2O3(molar fraction)sintered at 950°C exhibit comparatively ideal comprehensive electrical properties.The XRD analysis of the samples shows the presence of ZnO,Bi-rich,spinel Zn7Sb2O12 and Lu2O3-based phases. 展开更多
关键词 ZnO-Bi2O3 ceramics varistor rare earth electrical properties
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