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The phase relationships in the system K2O · AL2O3-Al2O3 between 1200 and 1700° C have been experimentally established. The homogeneity range of potassium -alumina is limited by the 83 and 91 mol % Al2O3 compositions. The eutectic point between the K2O-Al2O3 and -alumina was found to be at 1450° at about 62 mol % Al2O3 composition. An X-ray diffraction pattern analysis of potassium -alumina is shown. 相似文献
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The BaO · 2B2O3–La2O3 · 3B2O3 join of the ternary system BaO–La2O3–B2O3 is studied using differential thermal analysis, x-ray diffraction, and density measurements. The join is shown to be pseudobinary, with eutectic phase relations. In the composition range 5–99.8 mol % La2O3 · 3B2O3, glassy materials are obtained, which seems to be associated with the existence of the congruently melting compound BaO · La2O3 · 5B2O3. 相似文献
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《Materials Letters》2004,58(22-23):2810-2814
Wettability is the most significant phenomenon in SiC liquid phase sintering. The wetting of Y2O3/Al2O3 and Sm2O3/Al2O3 on SiC was analysed by the “Sessil drop” method. The wetting of liquid on solid during liquid phase sintering is very important. The behaviour of the additive on the SiC plate was observed using an imaging system with a CCD camera, and the contact angle measurements were analysed by Qwin Leica software. The samples were cut transversally and characterized by scanning electron microscopy and X-ray spectrometry (SEM/EDS). The wetting was found to be strongly influenced by the temperature; the SiC/additive contact angle decreased with increasing temperature. The YA and SA additives presented low contact angle values, indicating their good wetting on SiC in the argon atmosphere. The contact angle could not be measured when the test was performed in the nitrogen atmosphere because bubbles formed in the liquid during the test. The best atmosphere for this sintering was found to be argon, which allows uniform spreading. 相似文献
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Bi2O3-Y2O3体系中纳米δ-Bi2O3相的生成规律研究 总被引:1,自引:1,他引:0
以分析纯的Bi(NO3)3·5H2O和Y (NO3)3*6H2O作为原料,经反向滴定法化学共沉淀、干燥和430℃焙烧后获得(75mol%Bi2O3+25mol%Y2O3)纳米复合粉体,粉体平均粒度30nm以下;通过常压反应烧结工艺制备了纳米Bi2O3-Y2O3快离子导体,对烧结过程中高导电相(纳米δ-Bi2O3)的形成规律研究结果表明烧结初期以固溶反应为主,后期以晶粒长大为主,晶粒生长规律符合(D-D0)2=K·t抛物线方程;用模式识别技术对δ-Bi2O3相生成的工艺条件进行了优化. 相似文献
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Rie Ihara Yasuhiko Benino Takumi Fujiwara 《Science and Technology of Advanced Materials》2013,14(2):138-142
Some ternary Gd2O3–Bi2O3–B2O3 glasses are prepared, and crystallization behavior and second harmonic intensity are examined to develop new non-linear optical crystallized glasses. The glasses with Gd2O3 contents of 8–14 mol% have large densities of over 6 g/cm3 and large refractive indices of ~ 1.9. Transparent surface crystallized glasses consisting of two kinds of crystalline phases with different morphologies, i.e. plate shape and needle shape crystals, are fabricated by heat-treatment at temperatures between glass transition and crystallization temperatures. From second harmonic generation microscope observations, micro-Raman scattering spectra and XRD analyses, plate shape crystals are determined to be non-linear optical GdxBi1KxBO3 and needle shape crystals are Bi3B5O12 having no second-order optical non-linearity. Since crystallized glasses consisting of GdxBi1KxBO3 crystals exhibit relatively strong SHGs, they have a high potential for application to light control devices. 相似文献
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《Science and Technology of Advanced Materials》2005,6(2):138-142
Some ternary Gd2O3–Bi2O3–B2O3 glasses are prepared, and crystallization behavior and second harmonic intensity are examined to develop new non-linear optical crystallized glasses. The glasses with Gd2O3 contents of 8–14 mol% have large densities of over 6 g/cm3 and large refractive indices of ∼1.9. Transparent surface crystallized glasses consisting of two kinds of crystalline phases with different morphologies, i.e. plate shape and needle shape crystals, are fabricated by heat-treatment at temperatures between glass transition and crystallization temperatures. From second harmonic generation microscope observations, micro-Raman scattering spectra and XRD analyses, plate shape crystals are determined to be non-linear optical GdxBi1−xBO3 and needle shape crystals are Bi3B5O12 having no second-order optical non-linearity. Since crystallized glasses consisting of GdxBi1−xBO3 crystals exhibit relatively strong SHGs, they have a high potential for application to light control devices. 相似文献
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玻璃陶瓷属于一类多晶陶瓷材料.通过调整玻璃基质和晶相组成可以制备出具有良好的力学、热学、电学和光学性能的玻璃陶瓷材料.采用传统的熔融和退火技术制备出含B2O3-Al2O3-SiO2-Li2O-K2O组分的硼铝硅玻璃,并通过成核和长晶工艺最终制备出透明玻璃陶瓷.配合料在铂金坩埚中于1450℃下熔融2h,然后经两步热处理制度控制晶核的生成和晶粒的长大.采用差热分析技术确定成核和长晶温度.采用X射线衍射技术对不同热处理制度下的玻璃陶瓷样品进行分析,以确定最佳成核和长晶条件.采用扫描电子显微镜分析玻璃陶瓷形态,晶粒尺寸及其在残余玻璃相中的分布.采用UV-Vis-Nir分光光度计测定玻璃陶瓷样品的透过率. 相似文献
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研究了Sm2O3掺杂的bi2O3-ZnO-Nb2O5(BZN)基陶瓷(Bi1.5-xSmxZn0.5)(Zn0.5Nb1.5)O7(O≤x≤0.6,BSZN),的结构及介电性能.结果表明纯BZN陶瓷的结构为立方焦绿石单相;当Sm2O3掺杂量较少(O<x≤0.5)时,样品的相结构仍然保持立方焦绿石单相;随着Sm2O3掺杂量的进一步增加(x≥0.6),样品出现其它相.同时,试样的介电性能随结构的变化而呈现有规律的变化. 相似文献
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研究了应用于阳极支撑型的中温固体氧化物燃料电池(ITSOFC)密封的SrO-La2O3-Al2O3-B2O3-SiO2体系微晶玻璃不同组分的线膨胀率,结果表明当微晶玻璃粉组成SrCO3 28.14%(摩尔分数),La2O3 21.17%(摩尔分数),Al2O3 7.22%(摩尔分数),H2BO3 41.72%(摩尔分数),SiO2 1.76%(摩尔分数)(SLABS3) 时,最符合ITSOFC密封要求.差热分析结果表明SLABS3的玻璃转变温度在670℃~760℃之间,结晶温度在813~840℃之间,玻璃软化点约在900℃,XRD测试表明微晶玻璃与Ni-La0.3Ce0.7O1.85(Ni-LDC)阳极化学相容性好,将微晶玻璃和Ni-LDC在850℃烧结100h后,SEM观察界面粘附性好,EPMA测试界面的元素含量结果表明,虽然阳极的Ce会向微晶玻璃扩散10μm的深度,但观察不到微晶玻璃的元素向Ni-LDC扩散现象.用SLABS3密封模拟电池,测试开路电压结果表明SLABS3的密封效果和稳定性良好. 相似文献
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Chauhan Sumit Bala Rajni Gaur Sanjay Rani Saroj 《Journal of Materials Science: Materials in Electronics》2022,33(29):22835-22850
Journal of Materials Science: Materials in Electronics - The quaternary glass system has a composition of 30Li2O·20PbO·xBi2O3·(50-x)B2O3 (where x?=?0, 10, 20, 30, and... 相似文献
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本文利用扫描电子显微镜(SEM)、透射电子显微镜(TEM)和X射线能量色散谱(EDAX)等结构分析技术,研究了施主(Bi3+)和受主(Fe3)掺杂对BaTiO3陶瓷晶粒生长及晶界等微观结构的影响.研究结果表明:施主掺杂抑制晶粒生长,受主掺杂则促进晶粒生长;受主(Fe3+)掺杂导致部分晶粒中出现壳-芯结构和包晶结构特证,EDAX微区分析证实,壳-芯结构和包晶结构的形成都与Fe3+的偏析有关. 相似文献
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本文研究了共掺Er3 +/Yb3 +P2 O3 -B2 O3 -Al2 O3 -SrO -BaO玻璃的能量转移过程。实验中制备了高掺杂Yb3 +离子的双掺Er3 +/Yb3 +的磷酸盐玻璃样品。在Er3 +/Yb3 +掺杂比率 >1 :1 8(mol% )时 ,观测到了基于Yb3 +离子至Er3 +离子能量转移下Er3 +( 4 I13 / 2 →4I15 / 2 )的增强发射和Yb3 +( 2 F7/ 2 →2 F5 / 2 )发射的减弱 ,当Yb3 +离子掺杂浓度超过 2 .1× 1 0 2 1ions/cm3 时 (Er3 +/Yb3 +≤ 1 :1 8,mol% ) ,由于Yb3 +离子的自淬灭效应 ,Er3 +离子的发射强度降低。实验中得到了Yb3 +离子的最佳掺杂浓度为1 .74× 1 0 2 1ions/cm3 相似文献
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《Science and Technology of Advanced Materials》2001,2(1):67-71
There are two eutectic reactions in the Al2O3-rich portion of the Al2O3–Y2O3 pseudo-binary system; one is the equilibrium Al2O3–YAG eutectic reaction at 1826°C, and the other is the metastable Al2O3–YAP eutectic reaction at 1702°C. Selection of the Al2O3–YAG and the Al2O3–YAP eutectics was examined in terms of cooling rate, nucleation temperature and maximum melt temperature. When the melt was cooled from 2100°C at any cooling rate, it always nucleated below the Al2O3–YAP eutectic temperature, therefore the Al2O3–YAP eutectic was selected. The Al2O3–YAG eutectic was selected when the melt was cooled from 1900°C at a cooling rate of less than 1 K s−1. The selection of the two eutectic systems was determined by the nucleation temperature, although the maximum holding temperature of the melt and the cooling rate significantly affected the nucleation temperature. The structure of the melt, such as coordination of oxygen and chemical order when being heated to 2100°C may affect the nucleation behavior. 相似文献
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T. N. Kol''tsova 《Inorganic Materials》2001,37(11):1175-1177
Under ordinary conditions, yttrium tungstate exists in the form of the trihydrate Y2W3O12· 3H2O and has a monoclinic structure (sp. gr. P2/m; a= 14.308 Å, b= 4.354 Å, c= 12.430 Å, = 119.78°). The dehydration Y2W3O12· 3H2O Y2W3O12occurs at 142°C. 相似文献
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