EFFECTS OF In_2O_3 DOPING AND SINTERING TEMPERATURE ON THE ELECTRICAL PROPERTIES OF ZnO VARISTORS

ZnOvaristorshaveexcellentnon--linearcurrent--voltage(IV)characteristicsandenergyabsorptionability,makingthemvaluableasvoltagesuppressersinpowersystemsandelectroniccircuitsLlj.Thecurrentvoltagedependenceofvaristorsisdescribedbytherelation:I=C(V)"whereIisthecurrentdensity,Caconstant,Vthevoltage,andathecoefficientofnon--linearity.ThestudyresultsshowthatpureZnOgrainhasnottheelectricalconductivity.Intheprocessofitspreparation,thedefectisproducedinthegrain,andmakeitann--typesemiconductor.Thecer…     

PREPARATION AND PROPERTIES OF CRYSTAL GLASSES WITHOUT LEAD CONTENT

BaO is the most common consideration in the preparation of new crystal glass jor getting rid of lead content in the glass and ceramic mares to protect hu-man health and environment. But for keeping the glass products' properties to meet the requirements oj the traditional crystal glass, B2O3,A12O3, TiO2,SrO and ZnO etc ( at a special ratio ) had been researched with BaO to constitute a mixture to replace the lead content in the glass compositions. The results Amu that both using the mixture and adding Less lead in the hatches could make the new glass products to reach the requirement of the properties oj the common crystal glass but with less or no lead content and the corresponding poisons.     

RESEARCH AND PRODUCTION OF GLASS-CERAMIC DECORATED MATERIAL CONTAINING CHROMIUM

In this paper, the influences of catch-color agent content on glass-ceramic decorated material in the system of CaO-Al_2O_3-SiO_2 were studied. By ladder temperature furnace and sintering shrinkage curve measurement, the influence of catch-color agent content on sintering and crystallization temperature was discussed. By means of XRD, three point bending strength and density measurement, the properties of the decorated material were investigated.     

Effects of In2O3 doping and sintering temperature on the electrical properties of ZnO varistors

ZnO varistors are prepared using the 0.1–0.3 mm ZnO powders. The effects of the sintering temperature, contents of In₂O₃ doping on the non-linear properties of ZnO varistors have been investigated. The results show that this kind of ZnO powder has a high sintering activity. It is suitable for making the low voltage varistors. The V _c decreases with the increase of sintered temperature, when the In₂O₃ content is fixed (0.98%, mass fraction), and increases with the increase of In₂O₃ contents when the temperature is steady. Project supported by the Nonferrous Metals Industry Corporation of China Synopsis of the first anthor Zhao Ruirong, born in Jan. 1935, majoring in nonferrous metal metallurgy and products exploition.     

BaO-MgO-Al2O3-SiO2系统微晶玻璃的研究

以MgO-Al2O3-SiO2系统为基础玻璃组成,TiO2为晶核剂,用少量的BaO取代MgO,制备出顽辉石/堇青石基微晶玻璃.采用差热分析、X射线衍射分析、扫描电镜等测试手段研究了BaO对玻璃析晶性能和显微结构等性能的影响,并探讨了不同量的BaO取代MgO对其电导率的影响.结果表明,在1 480℃通过熔融法制备玻璃试样...     

BaO改善高钛型高炉渣起泡性能的研究

着重探讨了渣中BaO含量与钛渣起泡性能的关系,指出适宜BaO含量对改善钛渣起泡性能,对钒钛矿冶炼是很有好处的。     

碳酸根含量对碳酸羟基磷灰石形貌和热处理的影响分析

采用沉淀法制备了两种不同碳酸根〈CO3^2-）含量的纳米碳酸羟基磷灰石（nanosized carbonated hydroxyapatite,CHA）,研究了碳酸根含量对CHA晶体形貌、烧结和热稳定性的影响,用X射线衍射和透射电镜表征了样品的物相组成与形貌．结果表明：随着碳酸根含量的减小,CHA晶粒尺寸和长径比增加;CHA坯体的烧结温度和粉体的热稳定性与初始的碳酸根含量有关,含量越高,烧结温度越低,热稳定性越差．     

MC尼龙6／纳米ZnO复合材料等温结晶动力学的研究

采用原位聚合反应制备了MC尼龙6／纳米ZnO复合材料,并用差示扫描量热法（DSC）研究了MC尼龙6／纳米ZnO复合材料的等温结晶动力学。结果表明,在188～196℃时MC尼龙6及MC尼龙6／纳米ZnO复合材料结晶速率主要由成核过程控制。MC尼龙6／纳米ZnO复合材料的结晶速率G比MC尼龙6提高了0．1～0．3min^-1.研究发现,纳米ZnO的加入起到了异相成核的作用,提高了MC尼龙6的结晶速率。MC尼龙6和MC尼龙6／纳米ZnO复合材料的结晶速率G和结晶速率常数k均随结晶温度的升高而降低,半结晶时间t1/2和达到最大结晶速率的时间tmax随结晶温度的升高而缩短。但是MC尼龙6／纳米ZnO复合材料比MC尼龙6降低的幅度更大。     

Influence of ZrO2 on sintering and crystallization of CaO-Al2O3-SiO2 glass-ceramics

ZrO2 was added into CaO-Al2O3-SiO2 glass-ceramics and the effect of ZrO2 on sintering and crystallization of CaO-Al2O3-SiO2 glass ceramics was investigated. The results show that the sintering shrinkage ratio of glass particles decreases with the increase of the content of ZrO2. ZrO2 has an unfavourable effect on sintering shrinkage ratio of glass particles. The sintering shrinkage ratio of glass particles increases with the increase of sintering temperature. The increase of sintering temperature favors the decrease of the liquid phase viscosity of glass particles. ZrO2 has little effect on crystallization of main crystalline phase （β-wollastonite）. However, it promotes the crystallization at relatively low temperature.     

不同成分NASICON陶瓷的制备及其性能研究

首先采用溶胶-凝胶法合成NASICON先驱体粉末,然后利用热压和常压烧结法制备出NASICON陶瓷,着重分析了不同成分试样的晶相、致密度以及电导率等.结果表明,相对于常压烧结试样,热压烧结试样具有较高的致密度和较好的结晶性能;热压烧结试样NASI-CON(x=2.0)的离子电导率达到了2.3×10-3S.cm-1,明显高于常压烧结所得相同成分的试样;离子电导率随成分变化也有不同,当x在1.9~2.0之间时,试样的离子电导率最高,主要是由于该成分范围内试样的结晶度较高.     

Forming regularity and relation between composition and property of B2O3-BaO-ZnO glass

B2O3-BaO-ZnO glass was prepared by using conventional melt quenching technology. The forming regularity and the relationship between the composition and the property of B2O3-BaO-ZnO glass were investigated. The results show that the composition range for forming B2O3-BaO-ZnO glass is very wide, but the content of B2O3 has a limit within mole fraction of 25%-75%. When the content of B2O3 is over the limit, the melt will be divided into two phases with different compositions and structures, whereas too low content of B2O3 will result in the crystallization of the melt during the cooling process. The thermal expansion coefficient, the transition temperature and the resistivity of the glass at room temperature are (5-10)×10-6 ℃-1, 480-620 ℃ and (1.5-3.0)×1010 Ω·m, respectively.     

烧结法制MgO-SiO2-Al2O3-B2O3-KF玻璃陶瓷成分设计优化及显微析晶研究

通过烧结与水淬相结合的方法制备并系统探讨了MgO- SiO2-Al2O3-B2O3-KF玻璃陶瓷的显微析晶.研究表明:MgO-SiO2-Al2O3-B2O3-KF玻璃陶瓷的烧结收缩率与玻璃化及组分的析晶程度相关;析晶程度愈高,烧结坯愈致密;试样中成分配比愈接近云母晶体成分的原子比,玻璃陶瓷的显微析晶程度愈高;在烧结温度为1 000℃时,即开始出现析晶,到1 050℃时,析晶程度达到最高,继续提高烧结温度,显微析晶又发生重熔.     

烧结法制MgO-SiO_2-Al_2O_3-B_2O_3-KF玻璃陶瓷成分设计优化及显微析晶研究

通过烧结与水淬相结合的方法制备并系统探讨了MgO-SiO2-Al2O3-B2O3-KF玻璃陶瓷的显微析晶.研究表明：MgO-SiO2-Al2O3-B2O3-KF玻璃陶瓷的烧结收缩率与玻璃化及组分的析晶程度相关;析晶程度愈高,烧结坯愈致密;试样中成分配比愈接近云母晶体成分的原子比,玻璃陶瓷的显微析晶程度愈高;在烧结温度为1 000℃时,即开始出现析晶,到1 050℃时,析晶程度达到最高,继续提高烧结温度,显微析晶又发生重熔.     

烧结气氛对电瓷材料机械性能的影响分析

通过在电瓷坯料中外加不同量添加剂的方法，探讨了在不同气氛烧结下材料的结构及性能随组成的变化。采用X射线衍射、扫描电镜等测试技术对材料内部的晶体结构进行了分析，讨论了不同气氛下铁、钛杂质在电瓷材料中的作用机理。     

高压高温制备Sb掺杂的P型ZnO及电致发光

以ZnO和Sb_2O_3为前驱物,在5GPa、1100~1450℃条件下,制备出电学性能稳定的掺Sb的p型ZnO(记作ZnO:Sb)。其中1450℃掺杂4.6%Sb时合成了性能最好的P型ZnO:Sb,电阻率为1.6×10~(-2)Ωcm,载流子浓度为3.3×10~(20)cm~(-3),迁移率为12.1cm/V s。p型导电是由位于Zn位的Sb和两个Zn空位组成的复合受主引起的。测定了受主能级为113meV,讨论了压力对p型ZnO的形成和电性能的影响。此外,以高质量ZnO纳米线作为LED的发射层,通过将p型ZnO:Sb中的空穴注入ZnO纳米线中实现了激光发射。当注入电流达到20mA时,电致发光(EL)的功率可达到10mW。     

Ba2LaBiO6/ZnO复相材料的显微结构和电性能

采用固相烧结法制备了Ba2LaBiO6／ZnO复相材料,研究了Ba2LaBiO6／ZnO复相材料的组成和显微组织对材料电性能的影响：实验样品在较宽的温度范围内均显示了良好的NTC特性;烧结体中的相主要由六方结构的ZnO、立方结构的Ba2LaBiO6及含量很少的未知相组成,样品的平均晶粒尺寸随着材料中ZnO含量的增加有减小的趋势。在给定Ba2LaBiO6的组成下,随着材料中ZnO固溶体含量的增加,样品的室温电阻率减小,B25/125系数的值基本不变。     

掺杂Al_2O_3的ZnO陶瓷粉体的制备及表征

以硝酸锌和硝酸铝为原料 ,利用共沸法制备了Al2 O3 掺杂的ZnO陶瓷粉体 ,采用X -射线衍射 (XRD)等分析手段对所得粉体进行了表征。结果表明 ,所得Al2 O3 掺杂的ZnO陶瓷粉体为Al原子固溶在ZnO晶格中形成了固溶体 ,且此粉体分散性较好。     

掺杂Al2O3的ZnO陶瓷粉体的制备及表征

以硝酸锌和硝酸铝为原料，利用共沸法制备了Al2O3掺杂的ZnO陶瓷粉体，采用x-射线衍射(XRD)等分析手段对所得粉体进行了表征。结果表明，所得Al2O3掺杂的ZnO陶瓷粉体为刘原子固溶在ZnO晶格中形成了固溶体，且此粉体分散性较好。     

氧化钙对烧结法建筑装饰微晶玻璃烧结过程的影响

利用玻璃的烧结收缩曲线及Ｘ射线衍射分析，研究了ＣａＯ－Ａｌ２Ｏ３－ＳｉＯ２系统建筑装饰微晶玻璃的烧结动力学，并讨论了ＣａＯ含量变化对玻璃烧结的影响，结合工业化生产，确定出有利于烧结过程的最佳ＣａＯ含量范围。     

Effect of BaO addition on relative density and electric conductivity of xNi/10NiO-NiFe2O4 cermets

xNi/10NiO-NiFe₂O₄ (x=5, 10, 17) cermets and those doped with 1% BaO (mass fraction) were prepared by cold isostatic pressing at 200 MPa and sintering in nitrogen atmosphere at 1 473 K. The effects of BaO addition on relative density, microstructure and electric conductivity of cermets were investigated. The results show that relative densities of xNi/10NiO-NiFe₂O₄ cermets (x=5, 10, 17) doped with 1% BaO at 1 473 K in nitrogen atmosphere are increased by 0.49%, 1.45% and 2.99% compared with those of the undoped BaO cermets, respectively. Moreover, the electric conductivities (21.98, 28.37 and 50.10 S/cm) of xNi/10NiO-NiFe₂O₄ cermets (x=5, 10, 17) doped with 1% BaO at 1 233 K are improved compared with those (18.70, 22.79 and 39.58 S/cm) of xNi/10NiO-NiFe₂O₄ cermets (x=5, 10, 17), respectively. This indicates that perhaps the addition of BaO or formation of BaFe₂O₄ and Ba₂Fe₂O₅ has an active effect on electric conductivities of xNi/10NiO-NiFe₂O₄ (x=5, 10, 17) cermets.