Influence of Externally Applied Stresses on Kinetics of Ion Exchange in Glass

Soda-lime-silica glass canes were ion-exchanged in a bent mode in a molten KNO₃ salt bath. After ion exchange and cooling, the specimens showed asymmetry of residual stresses. Measured penetration profiles of potassium showed that the maximum diffusion occurred from the tension side, the minimum from the compression side, with the neutral side being in between. These observations support the notion that externally applied stresses can alter the average site size for cation diffusion in glass.     

单步法二元离子交换对锂铝硅玻璃化学强化的影响

以深圳市东丽华科技有限公司的GK6玻璃作为锂铝硅玻璃素片,采用不同配比的NaNO3和KNO3高钾低钠盐浴进行单步法二元离子交换实现复合压应力,并与传统二步法离子交换进行对比.利用光波导应力仪和散射光应力仪、二次离子质谱仪、中心落球与四点弯曲,分析强化玻璃应力分布、钠-锂离子交换程度和机械强度.结果表明:单次离子交换样品具有较高CS,但是DOL_0偏小,机械强度较未强化样品有显著提高,但与二次离子交换样品仍有一倍左右的差距.     

离子交换玻璃表面性质研究

针对离子交换增强玻璃稳定性问题,详细研究了由钾离子作为增强离子的玻璃表面性质.利用光学显微镜观察玻璃表面在加速风化条件下表面被侵蚀的情况,并用原子吸收光谱(AAS)研究玻璃在该加速风化条件下,表面K+偏析的情况.通过场发射扫描电子显微镜(FEGSEM)测试K+离子交换深度,用X射线光电子能谱(XPS)研究玻璃在离子交换前后表面元素含量的变化.研究表明,在加速风化条件下,离子交换增强玻璃表面较普通玻璃更容易受到侵蚀,K+离子向表面偏析明显.研究发现造成此种现象的原因是:在交换过程中,处于KNO3电解质中的玻璃表面吸附一层K+离子,形成Sterm紧密层,由于Stern层的距离只有几纳米,玻璃表面对K+的吸附力非常大,离开溶液后,表面层的活性大量K+离子依旧存在玻璃表面,致使离子交换玻璃表面稳定性降低.     

离子交换工艺对ESP玻璃的影响

使用两步离子交换法制备工程应力分布玻璃( ESP玻璃)。两步离子交换中第一步交换时间较长,第二步交换时间较短。主要研究经过不同第一步离子交换工艺制度后的ESP玻璃性能上的区别。本文对ESP玻璃测试了弯曲强度,显微硬度,K+分布状态,并根据弯曲强度,K+分布状态计算得出Weibull模量以及离子扩散系数。结果表明：第二步离子交换会降低第一步离子交换玻璃的弯曲强度,而两步离子交换后的ESP玻璃其Weibull模量有所升高。显微硬度趋势与弯曲强度趋势一致。结合抗折强度以及K+分布状态,可知第一步离子交换最佳温度为450℃,时间30 h;第二步离子交换最佳温度为400℃,时间33 min。     

离子交换纤维吸附二氢辣椒碱的动力学研究

首先采用SEM和IR方法表征了吸附二氢辣椒碱前后的ZB-2强碱性阴离子交换纤维,确定了可以吸附;然后测定了离子交换纤维吸附二氢辣椒碱的速率,确定了吸附在3 min时由液膜扩散控制转入离子交换纤维内扩散控制;最后考察了搅拌速度、溶液浓度、吸附温度和离子交换纤维直径对离子交换速率的影响,得到了离子交换纤维内扩散控制交换过程...     

化学强化过程中的离子迁移现象与规律研究

以碱铝硅玻璃为研究对象,采用多次离子交换(凯丽法),研究离子迁移与离子交换对玻璃强度的影响。结果表明:凯丽法在单次离子交换法基础上引入高温离子迁移(HTIM)工艺,易实现更深的离子交换层深度(DOL),DOL值增加140%,且具有特殊的应力分布层,抗冲击强度较传统一步法提高1倍,避免了传统离子交换法玻璃自爆的安全性风险。     

Ion Exchange of Soda-Lime Glass with Univalent Cations

Fhdeld-assisted and ordinary diffusion ion exchange of K⁺, Rb⁺hd Cs⁺, and Ag⁺ from nitrate salts with Na⁺ in soda-lime glass tubes were investigated between 700 and 735 K by application of various currents between 0 and 20.0 mA. An analysis of the field-assisted process with both a forward and a reverse field allowed calculation of the conductivity of the exchanged layer from the change of potential difference with time. Good agreement with experiment was found in both directions but anomalously high conductivities were observed in the Rb and Cs layers. Photoelastic measurements on rings sliced from the ion-exchanged tubes were used to calculate the residual stress arising from the ion exchange with the different cations. These results showed that other factors in addition to the ion size influence the magnitude of residual stress after exchange. The voltage-current relation during field-assisted ion exchange, along with the Nernst-Einstein equation, permitted calculation of the self-discussion coefficient of the exchanged cation in the exchanged layer. The self-diffusion coefficient was also estimated by applying the Nernst-Planck equation to results from unassisted ion-exchange experiments.     

银离子交换法制备光致变色玻璃的组成研究

本文应用差热分析、透射电镜、扫描电镜和X射线能谱等实验方法，研究了R2O-Al2O3-B2O3-SiO2系统玻璃组成对其分相、离子交换以及光色性能的影响规律；确定了能获得良好光色性能的最适宜玻璃组成范围。     

磷酸盐激光玻璃离子交换动力学研究

对Li2O质量分数不同的磷酸盐激光玻璃进行了离子交换实验,并研究了熔盐中K+及Na+在玻璃中的扩散动力学。使用波分散光谱(WDS)技术分析了K+及Na+在玻璃中的扩散深度,并研究了两种离子在玻璃中的离子扩散系数和扩散活化能。实验结果表明,玻璃中Li2O质量分数较高时,K+及Na+在玻璃中的扩散深度较大;混合碱效应导致离子的扩散系数降低。     

离子交换对磷酸盐玻璃表面裂纹扩展的影响

采用LiNO3和NaNO3混合熔盐在250℃对N31型磷酸盐玻璃表面进行离子交换处理,研究了小离子交换大离子对玻璃表面和亚表面裂纹的扩张作用.利用偏光显微镜、扫描电子显微镜、能谱仪对离子交换前后玻璃表面形貌和成分进行了测试,根据有限源扩散动力学和离子交换表面应力分布理论,分析了离子交换时间和H2O对裂纹扩张的影响.结果...     

Fracture of Soda-Lime Glass Tubes by Field-Assisted Ion Exchange

The field-assisted ion exchange of K⁺ and Na⁺ in soda-lime glass tubes fdled with and immersed in molten KNO₃ was Investigated. Stress distribution deduced from photoelastic measurements agrees well with that calculated from analogy to thermal stresses. Fracture was observed when a critical exchange depth was reached. The effects of tube dimension, surface condition, temperature, electric current density, current interruption, and current reversal on the critical exchange depth were studied. Calculated stresses for fracture originating on the tensile side of tubes exchanged on one side only agree with the independently measured fracture stresses of similar tubes. Fracture originating on the compressive side is believed to be related to "spalling" under biaxial compressive stresses which were frequently observed on the compressive surface.     

Stress Buildup and Relaxation During Ion Exchange Strengthening of Glass

A soda-lime-silica glass was subjected to an ordinary ion exchange treatment in molten potassium nitrate at temperatures near and substantially below the strain point of the glass. Stress profiles were measured as a function of exchange temperature and time. At all temperatures, the measurements showed rapid relaxation of the surface stress and the development of a pronounced compression maximum in a short period. A simple viscoelastic model with composition-independent parameters was used to analyze the stress profiles. Neither Maxwell's nor Michelson's relaxation expression could satisfy both characteristics of the residual stress development. Reasons for discrepancies are discussed.     

影响玻璃化学钢化盐浴活性因素的研究

研究了盐浴的失活与复活.分别选择不锈钢、银、铝和铜作为反应容器的材料,发现不锈钢和铜质容器容易受到硝酸钾和亚硝酸钾熔液的腐蚀,而银和铝则相对稳定.经过硝酸钾和亚硝酸钾钢化处理后的玻璃表面应力层厚度有很大差别.硝酸钾熔液在使用初期会暂时失去活性,失活的熔液在经过时效处理后能够复活;而使用亚硝酸钾的过程中却没有发现失去活性的现象.分析了失活机理并根据这一机理选择了活化剂.     

KOH对离子交换增强硼硅酸盐玻璃性能的影响

采用低温型离子交换法对硼硅酸盐玻璃进行增强。以掺有添加剂KOH的KNO3混合熔盐作为离子交换源,研究KOH掺入量对硼硅酸盐玻璃抗折强度、显微硬度和透过率的影响。采用扫描电子显微镜(SEM)观察离子交换后试样的表面形貌和结构。研究结果表明:KNO3熔盐中的WKOH/WKNO3为0.5时,硼硅酸盐玻璃的抗折强度和显微硬度都取得了最大值。     

K2SiO3对钠铝硅系化学钢化玻璃性能的影响

使用离子交换法制备钠铝硅系玻璃,主要研究在经过不同K_2SiO_3含量的离子交换后的玻璃在性能上的区别。本文测试了K~+、Na~+的分布情况,表面应力及应力层深度,弯曲强度,弹性模量,并计算出K~+、Na~+的离子扩散系数和K~+、Na~+的扩散活化能。结果表明:经过离子交换后,玻璃的弯曲强度和Weibull模量等性能均得到显著提高。在380℃,经过12 h的离子交换,在K_2SiO_3含量(质量分数)为2%时,K~+扩散系数为0.8411×10~(-15) m~2/s,K~+扩散活化能为140.398 0 kJ/mol;Na~+扩散系数为5.385 7×10~(-15) m ~2/s,Na~+扩散活化能为130.322 5 kJ/mol,有利于K~+、Na~+的扩散。总体上,Na~+的扩散系数远大于K~+的扩散系数,Na~+的扩散活化能小于K~+的扩散活化能。     

Luminescence Enhancement of CdS Quantum Dots in Glass by Ag+ Ion Exchange

Luminescence of CdS quantum dots (QDs) enhanced by the induction of Ag nanoparticles (NPs) in glasses was investigated. Ag⁺ ions diffused into glasses containing CdS QDs by ion exchange, then formed Ag NPs after subsequent heat treatment. Luminescence intensity of CdS QDs increased approximately three times when the ion‐exchange duration was 1 min, but was severely quenched when the duration was extended to 30 min. Increasing the amount of Ag⁺ ions increased the number of Ag NPs and decreased the average distance between Ag NPs and CdS QDs. This decrease in the average distance induced the changes of luminescence intensity.     

用二步法离子交换对手机玻璃面板进行强化和韧化

一步法离子交换对手机玻璃盖板增強,已在生产中应用,玻璃表面应力值虽然很高,但玻璃的抗冲击強度不高。两步法可以优化玻璃表面应力的分布,减少内部张应力,从而提高玻璃的抗冲击强度,而且还可以有效地利用硝酸钾熔盐。本文综述二步离子交换法所用熔融盐组成、温度制度以及玻璃表面应力分布,讨论了两步离子交换法增靱的机理。