硼硅酸盐浮法玻璃平衡厚度和抛光时间的研究

通过自制锡槽模拟硼硅酸盐浮法玻璃在不同温度下的抛光过程,测量静置平衡厚度的变化,用原子力显微镜(AFM)研究1250℃时抛光效果随时间的变化规律。结果表明,硼硅酸盐浮法玻璃的平衡厚度比钠钙硅浮法玻璃的平衡厚度大,并且平衡厚度随着温度的升高而减小,1250℃时的平衡厚度大约为7.11mm,1200℃时的平衡厚度大约为7.36mm。硼硅酸盐玻璃1250℃时在锡液上停留3min就能达到理想的抛光效果。     

Oxidation of Steel 30KhGSA in Borosilicate Melt Containing Iron Oxides

The kinetic specifics of the oxidation of alloyed steel under a protective layer containing iron oxide are considered. The dependence of the steel oxidation rate on the concentration of Fe₂O₃ in the melt is experimentally determined.     

Vanadium in Borosilicate Glass

Understanding the role of V₂O₅ within borosilicate glass matrices is important for the development of novel matrices toward immobilization of sulfate containing high‐level nuclear wastes. Present investigation shows, within sodium barium borosilicate glass matrix V₂O₅ can be homogeneously added up to 5 mol% and beyond which it separates out into three phases, for example, (i) silica (ii) Barium (Ba) – Vanadium (V) oxide, and (iii) glass matrix. ²⁹Si MAS NMR (Nuclear Magnetic Resonance) studies of the samples show that below 5 mol% V₂O₅ addition, silicate network is dominantly constituted of Q² and Q³ structural units, whereas above this, the network gets more polymerized through formation of Q³ and Q⁴ units. In case of borate network, ¹¹B MAS NMR investigations revealed that the concentration of BO₄ [(0B, 4Si)] unit increases gradually up to 5 mol% and then it decreases at the cost of BO₄ [(1B, 3Si)], BO₃ (symmetric) and BO₃ (asymmetric) units. Micro‐Raman analyses of the samples showed that with additions of V₂O₅ in diluted concentrations, amorphous silicate network remained unaltered, whereas some amplification in signals corresponding to ring‐type metaborate and VO₅ units exists. It is therefore apparent from both MAS‐NMR and micro‐Raman studies that with V₂O₅ additions within the solubility limit (≤5 mol%), borate network gets depolymerized leading to decrease in hardness from an average value of 5.0–4.2 GPa.     

Actinide Valences in Borosilicate Glass

Optical and Mössbauer spectra show that actinide ions are incorporated in a borosilicate glass matrix as U(VI), Np(IV), P(IV), and Am(III). Uranium was reduced by graphite to U(V) and U(IV), but Pu(IV) remained unchanged. It is inferred from their valences that Np, Pu, and Am are part of the borosilicate network and U is probably a network-modifier.     

硼硅玻璃管道的应用

介绍硼硅玻璃管道的性能、特点和应用情况;阐述其安装方法及其注意事项。     

高硼硅酸盐玻璃的技术管理

根据高硼硅酸盐玻璃的特性,阐述了高硼硅酸盐玻璃在生产实践的全过程中,影响玻璃产品质量的原料选用、配合料制备工艺、熔制工艺等环节的各种因素,控制要求和采取的各种调整方法等一系列技术管理措施.     

硼硅酸盐泡沫玻璃研究

以C和Sb2O3组合作为发泡剂,通过粉末烧结发泡工艺制备了硼硅酸盐泡沫玻璃,采用SEM观察了试样的微观结构形貌,并研究了试样的耐酸腐蚀性能.结果表明:当发泡剂C的质量分数为0.9%、Sb2O3的质量分数为8.1%时,在1200 ℃、保温30 min条件下,可以制备出平均孔径为0.2～1.0 mm、气孔分布较均匀的硼硅酸盐泡沫玻璃.试样中气孔结构主要与气泡内的气体压力、玻璃的表面张力和粘度有关.将试样浸泡在0.1 mol/L的稀硫酸中做耐酸腐蚀性实验,60 d内试样的质量先有微量增加后保持不变,这主要是由于稀硫酸进入试样的气孔结构中后形成了一层保护膜,从而阻碍了进一步的侵蚀.     

Conditions for Transformation and Equilibrium of Iron Oxides in Glass Melting

It is demonstrated that transformations of iron oxides in glass melting occur mainly in the solid phase. The ratio between the two forms of iron oxides in a glass melt is determined by the melt temperature. Achieving an equilibrium with the gaseous medium requires a long time due to high melt viscosity and low diffusion coefficients. To ensure high service parameters in products, one needs stability of raw material compositions and melting process parameters, including diathermancy of the melt.     

Chemical Durability of Lanthanum-Enriched Borosilicate Glass

The role of lanthanum in the alteration kinetics at different degrees of reaction progress was investigated at 90°C and pH 7 by complementary chemical (SIMS), morphological (SAXS), and structural (NMR, Raman, and EXAFS spectroscopy) approaches. In the first step of alteration, the forward dissolution rate diminishes with the addition of lanthanum, resembling to the behavior previously observed for zirconium. Over longer alteration time, the glasses with the highest lanthanum concentrations reach silicon saturation more slowly, but unlike zirconium, do not result in larger quantities of altered glass. Lanthanum is entirely retained in the alteration layer and is uniformly distributed; it undergoes hydrolysis and recondensation mechanisms, and its coordination number increases from 6 to 9 during leaching. Reconstruction of the alteration layer occurred more slowly at higher REE concentrations, with a slowdown in repolymerization of the silicate network and structuring of its porosity.     

Structure of Rhenium-Containing Sodium Borosilicate Glass

A series of sodium borosilicate glasses were synthesized with KReO₄ or Re₂O₇, to 10,000 ppm (1 mass%) target Re, to assess effects of large concentrations of rhenium on glass structure and fto estimate solubility of ⁹⁹Tc, a radioactive component in low active waste nuclear glasses. Rhenium was used as a surrogate for ⁹⁹Tc for laboratory testing, due to similarities in chemistry, ionic size, and redox. Magic angle spinning nuclear magnetic resonance, Fourier transform infrared spectroscopy, and Raman spectroscopy were performed to characterize the glasses. Si was coordinated in Q² and Q³ units, Al was four-coordinated, and B was mostly three-coordinated. The rhenium additions did not have significant effects on the glass structure up to approximately 3000 ppm Re by mass, the maximum concentration that remained dissolved in glass. Rhenium likely exists in isolated anions in the interstices of the glass network, as evidenced by polarized Raman spectrum of the Re glass in the absence of sulfate. Analogous to in similar glasses, is a network modifier and above solubility forms alkali salt phases on the surface and in the bulk. Comparisons of phase separation and crystallization in containing borosilicate glasses can also be made to containing glasses.     

中国3.3高硼硅玻璃管发展历程

近20年来中国的太阳能利用量始终保持世界第一。介绍我国膨胀系数3.3的硼硅玻璃发展过程,全玻璃真空太阳能集热管的产能变化和技术革新情况,同时总结了太阳能热利用过程中的经验和教训。     

锂辉石在中性硼硅玻璃中的应用研究

以锂辉石中的Li2O等量替代中性硼硅玻璃(简称5.0医药玻璃)化学组成中的Na2O和B2O3,研究Li2O对工艺性能和节能减排的影响。研究结果表明:Li2O具有较好的助熔效果,可以显著降低玻璃高、低温黏度特征点所对应的温度;当0.20%～0.30%(质量分数)Li2O替代Na2O时,5.0医药玻璃拉管工艺性能达到最好,0.20%Li2O替代B2O3时,其拉管工艺性能最好。因此,锂辉石对中性硼硅玻璃具有显著的节能减排效果,并能显著提高其拉管工艺性能。     

Dissolution and Separation of Ruthenium in Borosilicate Glass

The behavior of ruthenium oxide (RuO₂) in aluminoborosilicate glass used for the stabilization of nuclear waste was investigated. It was found that 0.025 mass% RuO₂ dissolved as Ru⁴⁺ in the glass at 1400°C, which caused the glass to turn yellow. When the RuO₂ amount was 0.05 mass%, needle-shaped crystals formed in the glass during slow cooling. If the added amount exceeded 0.1 mass% and the cooling rate was slow, it separated rapidly and the glass became pale after cooling. No dissolution of ruthenium was detectable after melting at 1200°C.     

硼硅酸盐玻璃与钠钙硅玻璃浮法成型的对比研究

总结了浮法成型工艺的特点,介绍了浮法工艺对普通钠钙硅玻璃的要求,在此基础上提出从玻璃的熔化和成型温度要求,粘度-温度曲线要求,析晶温度上限要求等几个方面探讨耐热高强硼硅酸盐平板玻璃浮法成型的要求.     

Decomposition of Ruthenium Oxides in Lead Borosilicate Glass

Behaviors of apparent phase changes of Ru-containing oxides in lead borosilicate glass at high temperature have been investigated using X-ray diffraction and transmission electron microscopy in application to thick-film resistors. During firing of thick films containing Ru oxide powder and lead borosilicate glass frits, apparent phase changes of Ru oxides have been found to occur both ways between ruthenium dioxide and lead ruthenate pyrochlore via decomposition of one phase in glass and subsequent formation of the other. The formation of pyrochlore occurs in a lead-rich form, Pb₂(Ru_{2− x} Pb _x )O_6.5, whereas the formation of RuO₂ is characterized by a platelike morphology instead of initial globular morphology. A general tendency is observed that RuO₂ is stable in low-PbO glass compositions and at high temperatures, while Pb₂(Ru_{2− x} Pb _x )O_6.5 is stable in high-PbO glass compositions and at low temperatures, with the implication that the stability of these phases is dictated by the chemical activity of PbO in the glass melt.     

中国3.3高硼硅玻璃管发展历程(续)

正2.2硼硅玻璃3.3管发展历程2.2.1西方长期对我国禁运的高技术基础材料硼硅玻璃3.3是美国康宁公司20世纪初发明的优质玻璃,以商品名称Pyrex销售。其性能十分优越,在化学、生物学、微电子学等现代科学中广泛应用。由于生产难度大,仅有极少数企业能够生产。产品价格高,且高度垄断、技术严格保密。硼硅玻璃3.3是制造原子武器、生物武器、化学武器和科研、教学用高科技材料。自20世纪50年代以来西方国家将其列为禁运物资对我国封锁近半个世纪。     

Effect of Oxidation on Single-Fiber Pullout Interfacial Shear Stresses in a Silicon Carbide–Borosilicate Glass System

The debonding, τ_d, and frictional, τ_f, interfacial shear strengths between 140-μm diameter SiC (with a 1-μm C-rich coating in which SiC particles are embedded) monofilaments and borosilicate glass were measured using the single-fiber pullout method as a function of postfabrication heat treatments [5 h at temperatures between 200° and 525°C] in 4% H₂–96% Ar and air. The debonding shear stress remained virtually unchanged after extended H₂ anneals. In air, however, τ_d, was found to initially increase and then subsequently decrease with increasing postfabrication heat treatment temperature. The initial increase in τ_d is due to enhanced bonding between the fiber and the borosilicate matrix as a result of the oxidation of the SiC particles embedded in the outermost carbon layer coating. At temperatures greater than about 450°C, oxidation of the C layer results in the severe degradation of the interfacial shear strengths.     

Dielectric Loss of Microstructurally Anisotropic Borosilicate Glass

Dhdelectric characteristics were determined for a microstructurally anisotropic borosilicate glass prepared by uniaxiallhd stretching phase-separated glass rods. The specimen showed a dielectric loss peak caused by the inhomogeneous microstructure; its magnitude varied with the orientation of the specimen with respect to the electric field direction. The results are in agreement with Sillars' theory.