Fabrication of a finegrain composite material based on the Al2O3-SiO2-ZrO2 system

The effect of the composition and the method of treatment of mullite-zircon powder on the kinetics of the densification, the strength, and the microstructure of the sintered material is described. It is shown that a fine-grain material with minimum porosity can be obtained based on kaolin by combining the sol-gel method and conventional powder technology with preliminary dry activation of the powder. Translated from Ogneupory i Tekhnicheskaya Keramika, No. 2, pp. 6–8, February, 2000.     

溶胶-凝胶法制备Al2O3-ZrO2-SiO2复合薄膜

本文采用溶胶-凝胶法以异丙醇铝、正硅酸乙酯和氧氯化锆为原料，HNO3为催化剂，PVA为成膜助剂，在多孔陶瓷管上制得了Al2O3-ZrO2-SiO2复合薄膜。研究了组分配比对溶胶性质的影响，结果表明Al2O3：ZrO2：SiO2在8：1：2～12：1：2之间时可得到性能符合要求的溶胶。通过扫描电镜可观察到膜的孔径为2～5μm，且膜与基底结合良好。     

High-strength,translucent glass-ceramics in the system MgO-ZnO-Al2O3-SiO2-ZrO2

In a MgO/Al₂O₃/SiO₂/ZrO₂ glass-ceramic MgO was substituted by equimolar ZnO concentrations. The effect of this substitution on the crystallization behavior, the microstructure and the mechanical properties of the glass-ceramics was studied. The crystal phases and the microstructure were analysed by X-ray diffraction and scanning electron microscopy. Tetragonal ZrO₂, a high-/low-quartz solid solution (high-/low-QSS) and spinel/gahnite were observed in the entire bulk of the glass-ceramics. Additionally, indialite or cristobalite are detected at the surface of some glass-ceramics. The substitution of small ZnO concentrations induces an increasing low-QSS concentration and hence higher microhardness and Young’s modulus. By contrast, higher ZnO concentrations lead to a liquid/liquid phase separation in the glass. Moreover, spinel/gahnite is the main crystal phase and the concentration of the low-QSS is smaller in theses glass-ceramics which also do not show as good mechanical properties. However, the biaxial flexural strength of the glass-ceramics is not notably affected by the ZnO concentration.     

A strong ceramic in the Al2O3-ZrO2-Y2O3 system

Conclusions A highly dense ceramic based on the eutectic composition of the Al₂O₃-ZrO₂ system was obtained using 3 mole % Y₂O₃ addition. The ceramic has a fine-grained structure and high hardness and strength.Translated from Ogneupory, No. 2, pp. 8–10, February, 1987.     

Al2O3-SiO2-TiO2-ZrO2复合陶瓷膜的制备与表征

采用Sol-Gel法制备出掺杂SiO2,TiO2及ZrO2改性的γ-Al2O3膜,并通过SEM,EPMA,AFM等测试手段对膜结构和性能进行表征.探讨了制膜工艺条件对膜性能及结构的影响.制备的Al2O3复合膜膜厚为1～2μm,结构均匀无缺陷.     

Al2O3-SiO2-ZrO2-TiO2溶胶的制备与研究复合

以硝酸铝、正硅酸乙酯、氧氯化锆、钛酸丁酯为前驱体，水和无水乙醇为溶剂，用溶胶-凝胶法制备适合涂膜的复合溶胶。     

Sintering of compositions in the system Al2O3-Cr2O3-SiO2

The sintering behaviour of refractory compositions in the system Al₂O₃-Cr₂O₃-SiO₂ was studied. The conditions for densification, the mechanism of densification and the reactions during sintering were investigated. Powders of Al₂O₃, Cr₂O₃, mullite and SiO₂ were used as a starting material and were sintered in compacted form under different conditions at 1300 to 1550°C. A dense body was obtained by heating in a carbon powder bed at temperatures around 1500°C. The microstructure of the body was skeleton-like and contained rectangular crystals of (Cr, Al)₂O₃ s.s., which appeared to be desirable for an improvement of the thermal shock resistance.     

Phase diagram of the system Al2O3-SiO2

Phase diagrams of the system Al₂O₃ - SiO₂ as presented in the domestic and foreign literature are analyzed. The congruent and incongruent states of mullite, liquation in the solid phase, and the structures of mullite and sillimanite are discussed.Translated from Ogneupory, No. 8, pp. 11 – 14, August, 1995.A lecture delivered to metallurgists and silicate producers at the Ural State Engineering University.     

溶胶-凝胶法制备Al2O3-SiO2-ZrO2复合膜的成膜工艺研究

用溶胶-凝胶法制得了稳定透明的Al2O3-SiO2-ZrO2复合溶胶,并采用浸渍法镀膜工艺制备了复合膜。对该成膜工艺的研究表明,合理地控制焙烧条件,进行多次浸渍-干燥-焙烧过程,添加成膜助剂,选择浸渍时间是提高成膜质量的重要因素。对于添加PVA后的溶胶,当浸渍时间为16～36秒,经过四次涂膜后,采用1～3℃/min的升温速率,可获得较理想的复合膜。     

Sol-Gel法制备Al2O3-SiO2-TiO2-ZrO2复合陶瓷膜的研究

将Sol-Gel法应用于无机膜的制备,成功的研制出一种新型的膜面平整、膜厚均匀且无宏观缺陷的Al2O3-SiO2-TiO2-ZrO2复合陶瓷膜,复合膜含有γ-Al2O3、SiO2、TiO2、ZrO2和Al2SiO5等晶相,改变体系组成含量,晶相组成和含量随之变化,从而引起膜的显微结构的变化。利用XRD、SEM、AFM、EPMA等测试手段重点研究了膜的表面形貌和显微结构,并分析了添加剂、热处理方式等对膜的表面形貌和显微结构影响。     

Mullite and mullitelike compounds in the Al2O3-SiO2 system

Conclusions The congruence or incongruence of mullite's melting is not finally explained, and requires further study; apparently, it depends on the conditions in which the experiments are carried out, and also on the presence of stabilizing impurities in the lattice of the mullite and the partial pressure of the oxygen.The phase diagram for A1₂O₃-SiO₂ system contains only one compound — mullite, of the composition 3Al₂O₃·2SiO₂, with a completely ordered lattice. Solid solutions having a mullitelike structure can be obtained in the compositional range from Al₂O₃·SiO₂ to 2Al₂O₃· SiO₂ with the use of special additives.Translated from Ogneupory, No. 1, pp. 23–27, January, 1984.     

Al2O3-ZrO2系无收缩的致密陶瓷

研究了利用无机原料以反应烧结法合成Al2O3-ZrO2系无收缩的陶瓷的可能性。为使收缩率达到零,作为活性反应组分,除了ZrAl3金属间相之外,还利用了超细铝粉,后者是采用导线通过电爆破法制取的。查明,由于加入15%金属铝,使试样的几何尺寸变化几乎为零,此时制取的试样的气孔率<1.5%,强度达750MPa。     

TiO2 在Al2 O3 -SiO2 系耐火材料中的作用

阐述了TiO2在Al2O3-SiO2系耐火材料,特别是高铝矾土中的分布和存在方式,并通过分析Al2O3-SiO2系耐火原料的煅烧过程和Al2O3-SiO2系制品的使用过程中TiO2、Al2O3和SiO2三者之间的化学反应,介绍了TiO2对Al2O3-SiO2系耐火材料结构和性能的影响。     

铝镁浇注料钢包衬渣线部位Al_2O_3-ZrO_2-SiO_2系陶瓷保护涂层的研究

以铝镁浇注料钢包衬为母体，主要研究渣线部位预防性Ａｌ２Ｏ３－ＺｒＯ２－ＳｉＯ２系陶瓷保护涂层作用机理，以期钢包各部位寿命同步，进而提高其寿命节材降耗。通过试验，取得了可喜的进展。     

结合剂对Al2O3-SiO2系浇注料性能的影响

研究了水玻璃、磷酸二氢铝、硫酸铝及磷酸二氢铝+硫酸铝复合结合剂对Al2O3-SiO2系浇注料强度和热震稳定性的影响.利用X射线衍射、红外光谱(IR)等分析手段,对磷酸二氢铝和磷酸二氢铝+硫酸铝复合结合剂的作用机理进行了探讨.认为磷酸二氢铝和磷酸二氢铝+硫酸铝复合结合剂能使材料获得较高的抗热震性和强度.     

液相法制备棒状Al2O3及Al2O3-ZrO2陶瓷复合粉体

采用二乙三胺五乙酸（DTPA）为配合剂,以简易的液相法合成出微纳米纤维状Al和Al-Zr前体,煅烧处理制备了棒状α-Al₂O₃和Al₂O₃-ZrO₂复合陶瓷粉体。同时研究了DPTA∶Al³⁺质量比、反应温度与时间对陶瓷粉体形态的影响。利用X射线衍射（XRD）、热分析（TG/DSC）以及扫描电子显微镜（SEM）对粉体进行了表征。结果表明：较高的DTPA∶Al³⁺质量比以及较长的反应时间有利于制备高长径比的纤维棒状Al和Al-Zr配合物前体。合成纳米纤维状α-Al₂O₃和Al₂O₃-ZrO₂前体的最优条件是反应温度60℃,反应时间5.5h,DTPA∶Al³⁺比例为1.2∶1。相应地,该前体煅烧后可以制备出棒状α-Al₂O₃和Al₂O₃-ZrO₂复合陶瓷粉体。     

Al2O3-SiO2质材料抗Al2O3附着的研究

通过实验和热力学分析确认了Al2O3-SiO2质浸入式水口内衬材料的组成对Al2O3附着量的影响.在Al2O3-SiO2质材料中,以Al2 O3-3Al2O3@2SiO2的抗Al2O3附着效果最好,故认为使用不合C的Al2O3-3Al2O3@2SiO2材料制作防止Al2O3堵塞的浸入式水口内衬是可行的.     

Eutectic structure evolution of Al2O3-ZrO2-Y2O3 system for potential hybrid solar cell application

Abstract

Ternary Al₂O₃-ZrO₂-Y₂O₃ samples with a eutectic composition were prepared by slow cooling. The microstructural evolution was observed with X-ray diffraction (XRD), scanning electron microscopy (SEM).

The SEM observation of the ternary samples agreed with the XRD with a completion of crystallisation by slow cooling. The target materials commonly have ‘cantaloupe skin’ microstructures as shown in the previous studies by Han et al. The nanocomposite may have experienced different cooling rates with two different microstructures, near the surface having experienced optimal conditions for the eutectic reaction during their cooling and thus formed the eutectic microstructure, near the centre having experienced a slower cooling rate. The crystallised eutectic ternary Al₂O₃-ZrO₂-Y₂O₃ system had three different phases with a 3Y₂O₃-5Al₂O₃ (yttrium-aluminium garnet phase), an alumina phase formed by the eutectic reaction, and a solid solution of ZrO₂ and Y₂O₃.