SiC—Al2O3基复相陶瓷的N2—HIP研究

通过对热压ＳｉＣ－Ａｌ２Ｏ３复合材料进行了Ｎ２－ＨＩＰ后处理，制备得到Ｓｉ３Ｎ４－ＡｌＮ＝ＳｉＣ－Ａｌ２Ｏ３梯度材料，经Ｎ２－ＨＩＰ处理后，材料抗弯强度提高３５％－９５％，并得到经强度达１０３０ＭＰａ的ＳｉｅＮ４－ＡｌＮ／ＳｉＣｐ－ＳｉＣＷ－Ａｌ２Ｏ３复合材料。     

Si_3N_4-Al_2O_3-ZrO_2系陶瓷表面氧化层组成的EPMA分析

利用ＥＰＭＡ和ＸＲＤ的分析方法，研究了Ｓｉ＿３Ｎ＿４－Ａｌ＿２Ｏ＿３－ＺｒＯ＿２系陶瓷材料表面氧化层组成。结果表明，Ｓｉ＿３Ｎ＿４－Ａｌ＿２Ｏ＿３－ＺｒＯ＿２系陶瓷材料表面氧化层是由方石英相、ＺｒＳｉＯ＿４相和含有Ａｌ＿２Ｏ＿３、ＣａＯ等的ＳｉＯ＿２玻璃相所组成，其中ＳｉＯ＿２玻璃相中Ａｌ＿２Ｏ＿３、ＣａＯ等的含量，随着氧化时间的增加而逐渐增加。     

利用表面形成Si_2N_2O层提高Si_3N_4陶瓷材料抗氧化性能

根据对Ｓｉ－Ｎ－Ｏ系统相图的分析，首次在Ｓｉ３Ｎ４陶瓷材料表面形成Ｓｉ２Ｎ２Ｏ抗氧化层。其方法是利用Ｓｏｌ－Ｇｅｌ在Ｓｉ３Ｎ４陶瓷的表面涂上一层ＳｉＯ２（其中含有１０％的Ａｉ２Ｏ３）涂层后，在Ｎ２气氛中，并有Ｓｉ３Ｎ４粉末和ＳｉＯ２粉末存在的条件下，于１２７３～１６７３Ｋ的温度下进行热处理。用ＸＲＤ和ＸＰＳ分析验证了Ｓｉ２Ｎ２Ｏ（和／或Ｏ’－Ｓｉａｌｏｎ）层的存在。由于形成了Ｓｉ２Ｎ２Ｏ（和／或Ｏ’－Ｓｉａｌｏｎ）层，Ｓｉ３Ｎ４陶瓷材料在１５７３Ｋ的温度下氧化１００ｈ后，氧化增量从原来的０．４２ｍｇ／ｃｍ２降低到０．２４ｍｇ／ｃｍ２。     

无机盐先驱体溶胶—凝胶法制备50%Al2O3—50%ZrO2结晶复相陶瓷

采用无机盐先驱体，溶胶－凝胶法制备出超细５０％Ａｌ２Ｏ３－５０％ＺｒＯ２复合粉体，ＢＥＴ法测得其比表面积达２２７．４ｍ＾２／ｇ。复合粉体经热压烧结得到具有互渗结构的结晶复相陶瓷，其Ａｌ２Ｏ３晶粒约１００ｍｍ，ＺｒＯ２晶粒约０．６μｍ。     

助烧剂Y2O3对ZrO2（Y—TZP）—Si3N4系统中ZrO2相组成的影响

本文研究了助烧剂Ｙ２Ｏ３对ＧＰＳＺｒＯ２（３ｍｏｌ％Ｙ－ＴＺＰ）－Ｓｉ３Ｎ４系统中ＺｒＯ２相结构的影响。研究结果表明：ＺｒＯ２（Ｙ－ＴＺＰ）－Ｓｉ３Ｎ４系统中不添加Ｙ２Ｏ３助烧剂,ＺｒＯ２相组成主要以ｍ－ＺｒＯ２形式存在,并有少量氮稳定ＺｒＯ２;ＺｒＯ２（Ｙ－ＴＺＰ）－Ｓｉ３Ｎ４系统中添加５ｗｔ％Ｙ２Ｏ３助烧剂,ＺｒＯ２相组成为ｃ－ＺｒＯ２、不能相变的过稳定ｔ－ＺｒＯ２。     

陶瓷复合体的抗热冲击性能研究

由陶瓷复合材料的抗热冲击实验，证明添加Ｗ（ＺｒＯ２）＝２０％时可使Ａｌ２Ｏ３复合陶瓷的热震温度达到３７０℃，如何添加Ｖ（ＳｉＣｗ）＝２０％可使Ａｌ２Ｏ３复合材料的热震温度达到４３０℃，使Ｓｉ３Ｎ４复合材料的热震温度达到６５０℃；如果采用Ｖ（ＳｉＣｗ）＝２０％，同时添加Ａｌ２Ｏ３，Ｙ２Ｏ３等活性剂，由于强化晶界的作用，可使Ｓｉ３Ｎ４复合材料的热震温度达到７００～７５０℃，还对各添加剂使陶瓷材料抗热冲     

金—钼酸盐—丁基罗丹明B体系显色反应研究

研究了在高氯酸和聚乙烯醇（ＰＶＡ）存在下，金与钼酸盐和丁基罗丹明Ｂ（ＢＲＢ）的显色反应。其适宜条件ＣＨＣｌＯ４＝１．５ｍｏｌ／Ｌ，ＣＭｏＯ２－４＝９．１×１０－４ｍｏｌ／Ｌ，ＣＢＲＢ＝３．８×１０－５ｍｏｌ／Ｌ及０．０８％ＰＶＡ。金钼杂多酸—丁基罗丹明Ｂ离子缔合物的最大吸收位于５７０ｎｍ，表观摩尔吸光系数为３．３６×１０６Ｌ·ｍｏｌ－１·ｃｍ－１，金量在０～４０μｇ／Ｌ范围内服从比尔定律，测定极限（Ｓ／Ｎ＝３）０．９０μｇ／Ｌ（ｎ＝１０），对于２８μｇＡｕ（Ⅲ）／Ｌ测定的相对标准偏差２．１％（ｎ＝７）。缔合物至少可稳定５ｈ，摩尔比Ａｕ∶ＢＲＢ＝１∶３。考察了４４种共存离子的影响，大多数常见离子不干扰，用活性炭分离富集金，对砂矿和炭粉中金的测定，结果满意。     

Si3N4—MgAl2O4—Al2O3系材料无压烧结的研究

本文对Ｓｉ３Ｎ４－ＭｇＡｌ２Ｏ４－Ａｌ２Ｏ３系复合材料的无压烧结进行了研究，讨论了Ａｌ２Ｏ３含量对材料性能的影响及烧结工艺对材料性能和显微结构的相互关系。实验表明：两段法烧结可以得到性能良好的Ｓｉ３Ｎ４－ＭｇＡｌ２Ｏ４－Ａｌ２Ｏ３复合材料。     

KTa0.55Nb0.45O3薄膜的介电和铁电及热释电性能研究

在ＢＴ／Ｐｔ／Ｔｉ／ＳｉＯ２／Ｓｉ衬底上用溶胶－凝胶法制备了ＫＴａ０．５５Ｎｂ０．４５Ｏ３（ＫＴＮ）薄膜,０．５μｍＫＴＮ－０．０８μｍＢＴ薄膜在２５℃,１．０ｋＨｚ时,其εｒ＝１１１４,ｔａｎδ＝２．５％;１２℃时,其中Ｐｒ＝２．１μＣ／ｃｍ＾２,Ｐｓ＝４．２μｃ／ｃｍ＾２,Ｅｃ＝５．８ｋＶ／ｃｍ,０．５μｍ厚ＫＴＮ膜的Ｃｕｒｉｅ温度为３５℃;１．０ＫＨｚ时,ＫＴＮ膜的εｒ＝１４１２,估算ＫＴＮ     

无压烧结合成O＇－Sialon

探讨了Ｏ＇－Ｓｉａｌｏｎ的合成工艺及配方选择；研究了Ａｌ２Ｏ３在Ｓｉ２Ｎ２Ｏ中的固溶状况及添加剂Ｙ２Ｏ３和烧结液相的特点对Ｏ＇－Ｓｔａｌｏｎ中Ａｌ２Ｏ３固溶度的影响．结果表明；无压烧结合成Ｏ＇－Ｓｉａｌｏｎ的工艺应选用ＳｉＣ粉料作为埋粉，通Ｎ２保护；Ｘ＝０．３为Ｏ＇－Ｓｉａｌｏｎ固溶极限的配方；Ｙ２Ｏ３的加入量增多有利于Ｋ１ｃ值的提高；Ｋ１ｃ在Ｘ＝０．３～０．４时达到最大值；配料时应避开靠近低共熔点处（Ｘ＝０．２）的配方，因其试样力学性能较差．     

钕-铝系稀土色料的研制

通过钕-铝系列色料合成实验,分析不同配比及不同矿化剂等对色料呈色效果的影响,确定最佳工艺方法。对实验结果进行XRD及色度分析,确定其主晶相为钕酸铝,试样的明度均在70以上,色彩鲜艳亮丽。     

Phase equilibrium in binary La2O3-Dy2O3 and ternary CeO2-La2O3-Dy2O3 systems

Cerium oxide doped with oxides of rare earth elements is a multifunctional material, a wide range of uses which is associated with its unique physicochemical properties. Phase diagrams of multicomponent systems are the physicochemical basis for the creation of new materials with improved characteristics.In this work, phase equilibria in ternary CeO₂–La₂O₃–Dy₂O₃ and binary La₂O₃–Dy₂O₃ systems in the whole concentration range were studied. No new phases have been identified in these systems. An isothermal section of the phase diagram of the CeO₂–La₂O₃–Dy₂O₃ system at a temperature of 1500 °С is constructed. No new phases have been detected in the system. It was found that in the studied ternary system solid solutions are formed on the basis of (F) modification of CeO₂ with structure of fluorite type, monoclinic (B), cubic (C) and hexagonal (A) modifications of Ln₂O₃.In the La₂O₃–Dy₂O₃ binary system (1500–1100 °С) three types of solid solutions are formed: based on hexagonal modification A-La₂O₃, monoclinic modification B-Dy₂O₃ and cubic modification C-Dy₂O₃ separated by two-phase fields (A+B) and (B+C), respectively. The boundaries of the regions of homogeneity of solid solutions based on A-La₂O₃ are determined by compositions containing 35–40, 20–25, 15–20 mol% Dy₂O₃ at 1500, 1250, 1100 °C, respectively. From the obtained data it follows that the solubility of Dy₂O₃ in the hexagonal modification of lanthanum oxide is 39 mol% at 1500 °C, 23 mol. % at 1250 °C and 16 mol% at 1100 °C. The limits of existence of solid solutions based on monoclinic B-modification are determined by compositions containing 30–35, 65–60 (1250 °С), 35–40, 55–60 (1100 °С) 40–45, 70–75 (1500 °C) mol% Dy₂O₃.In the studied system, with a decrease in temperature from 1500° to 1100°C, there is a decrease in the solubility of La₂O₃ in the crystal lattice of cubic solid solutions of C-type from 16 to 10 mol%.     

Na2O-Al2O3-Fe2O3系烧结过程中铝、铁的反应行为

以Al2O3, Fe2O3和Na2CO3为原料,对Na2O-Al2O3-Fe2O3系烧结过程中的反应行为进行了详细研究. 基于溶出率与时间、温度的关系,证明Na2O×Al2O3和Na2O×Fe2O3的生成反应动力学都服从Zhuralev-Lesokin-Tempelman模型,表观活化能分别为186.59和80.92 kJ/mol,表明Na2O×Fe2O3比Na2O×Al2O3在动力学上更易形成;Al2O3易与Na2O×Fe2O3反应形成Na2O×Al2O3和Fe2O3,在1273 K烧结30 min,所得熟料Al2O3溶出率达98.51%;Fe2O3对Na2O×Al2O3的形成有双重作用,在1273 K下可加速Na2O×Al2O3的形成,超过1323 K,促使Na2O×Al2O3分解成Na2O和b-Al2O3,且随着温度升高或时间延长,分解程度增高,从而导致熟料中Al2O3溶出率显著降低.     

Polycrystalline In2O3 and In2O3/Y2O3 photoanodes

Single crystal In₂O₃ shows promise as a photoanode for the decomposition of water. Because of various difficulties in the preparation of the single crystal material, two simple techniques were developed for the preparation of polycrystalline In₂O₃ anodes. One method involves the thermal decomposition of the nitrate while the other utilizes the chemical vapour deposition technique. Voltammograms and photoresponse spectra of these anodes are compared to the single crystal material. Among other observations, it is noted that the quantum efficiencies of the thermally decomposed films are comparable to the single crystal material. It is also shown that the on-set potential can be shifted to more negative values by forming the mixed oxide In₂O₃/Y₂O₃.     

Properties of RO-Y2O3-Al2O3-SiO2 glasses

The coefficient of linear expansion, glass-transition temperature, temperature at the orset of deformation (strain point), density. Young modulus, microhardness, crystallizability, and contact angle are studied as a function of the composition in RO–Y₂O₃–Al₂O₃–SiO₂ (R=Ca and/or Mg) glass systems. The composition ranges for glasses (with strain point >900°C and coefficient of linear expansion of (32–45)×10^–7°C^–1) that can be used for soldering silicon-nitride ceramics were established.Translated from Steklo i Keramika, No. 12, pp. 5–7, December, 1996     

Cr2O3-Al2O3-ZrO2高铬制品

介绍了Cr2O3-Al2O3-ZrO2制品的组成及各组成的作用、烧成气氛、制品的显微结构特征和性能指标.着重论述了影响制品性能的烧成工艺和以电熔、烧结两种Cr2O3颗粒生产的Cr2O3-Al2O3-ZrO2制品的显微结构差异,表明在还原气氛下烧成的Cr2O3-Al2O3-ZrO2制品性能优良,而采用电熔Cr2O3料生产的Cr2O3-Al2O3-ZrO2制品性能优于使用烧结Cr2O3料生产的.     

CaO-SiO2-Al2O3-Fe2O3-SO3多元体系高温相变研究

实验采用石灰石、砂岩、粉煤灰和低品位铝矾土等工业原料,制备C3S相和C4A3S-相共存的水泥熟料;利用DSC-TG、高温XRD、岩相等方法对CaO-SiO2-Al2O3-Fe2O3-SO3多元体系烧制过程中高温相变进行分析,获得C4A3S-相和C3S相的变化规律,为利用废渣制备低碳排放的水泥熟料提供了理论支持.     

Fe2O3-MnO-Cr2O3-La2O3系统紫色颜料的制备及表征

采用溶胶均匀共沉淀法于低温下合成了含少量稀土氧化物La2O3的紫色颜料，并采用颜色测定、SEM、XRD等手段对颜料的颜色、检度及结晶构造等进行了表征。     

含Y2O3的锂铝硅系统微晶玻璃

The rare earth oxide Y2O3 was added to the system Li2O—Al2O3—SiO2 glass—ceramics and the effects of Y2O3 on the properties of melting, crystallizing, microstruoture as well as thermal expansion coefficient of the glass was studied by DTA, SEM and XRD. The results indicate that, adding YZO3 to Li2O—Al2O3—SiO2 systems glass could increase the viscosity of glass melt, in6rease the melting temperature and the crystallization temperature of glass,increase the volume fraction of crystals while the crystal types are not changed, and the coefficient of thermal expansion of glass-ceramics decreases with the increasing of Y2O3 content.     

2,2,3-三氯-3-苯基-3-(3-甲基苯甲酰基)丙腈的合成研究

以苯甲酰氯、四氯化碳、间甲基苯甲酰氰为原料,合成了标题化合物。重点考察了氰化过程中不同原料配比、反应温度、时间、溶剂和催化剂用量对收率的影响。实验结果表明,其最佳反应条件为:n(1,1,2-三氯-2-苯基乙烯)∶n(3-甲基苯甲酰氰)=1∶1.2,二氯甲烷为反应溶剂,3 mmol催化剂三乙胺,室温反应5 h,总收率达80.6%。