Soda lime玻璃材料中失效波形成和传播研究

为了研究冲击载荷作用下Soda lime玻璃材料中失效波的形成和传播,通过轻气炮加载平板撞击实验,采用双螺旋锰铜压阻传感器,在一发实验中同时测量4种不同厚度试件背面与有机玻璃背板间界面处的纵向应力时程曲线,根据测量结果得到试件中失效波的传播轨迹。通过改变碰撞速度,对不同加载条件下的失效波形成和传播规律进行了研究,结果表明,Soda lime玻璃材料在冲击作用下产生失效波所需的延迟时间随冲击载荷的增加而减小,失效波传播速度随冲击载荷的增加而增加。最后采用弹性微裂纹统计模型描述冲击载荷作用下Soda lime玻璃的破坏机制,并将模型嵌入LS-DYNA有限元程序中,模拟试件在不同加载条件下的平板碰撞,所得横向应力和自由面粒子速度曲线均可用于表征失效波破坏现象。根据数值模拟结果分析失效波的传播轨迹,与实验测量结果符合较好。

金刚石切削Soda-lime玻璃中的刀具磨损及其对工件表面粗糙度的影响

金刚石切削加工光学玻璃时,工件表面粗糙度与刀具磨损直接相关,为研究切削距离递增下的金刚石刀具磨损及其对工件加工表面粗糙度的影响,进行了Soda-lime玻璃金刚石切削的刀具磨损试验,并对刀具磨损形貌、后刀面磨损带的材料成份、工件的表面形貌及粗糙度进行了检测.结果表明:切削距离递增下的金刚石刀具前刀面磨损表现为平滑且均匀的月牙洼磨损,后刀面磨损表现为磨损带逐渐增大,且磨损带内有沿切削方向的微沟槽产生;切削距离未达到150 m时,工件表面粗糙度Rq、Ra及Rmax值始终低于32、25及300 nm,切削距离超过150 m后,工件表面粗糙度显著增大.机械摩擦作用、热化学作用及磨料磨损作用为导致金刚石刀具磨损的主要原因.

Tool Wear and Its Effect on Surface Roughness in Diamond Cutting of Glass Soda-lime

For the technology of diamond cutting of optical glass, the high tool wear rate is a main reason for hindering the practical application of this technology. Many researches on diamond tool wear in glass cutting rest on wear phenomenon describing simply without analyzing the genesis of wear phenomenon and interpreting the formation process of tool wear in mechanics. For in depth understanding of the tool wear and its effect on surface roughness in diamond cutting of glass, experiments of diamond turning with cutting distance increasing gradually are carried out on soda-lime glass. The wear morphology of rake face and flank face, the corresponding surface features of workpiece and the surface roughness, and the material compositions of flank wear area are detected. Experimental results indicate that the flank wear is predominant in diamond cutting glass and the flank wear land is characterized by micro-grooves, some smooth crater on the rake face is also seen. The surface roughness begins to increase rapidly, when the cutting mode changes from ductile to brittle for the aggravation of tool wear with the cutting distance over 150 m. The main mechanisms of inducing tool wear in diamond cutting of glass are diffusion, mechanical friction, thermo-chemical action and abrasive wear. The proposed research makes analysis and research from wear mechanism on the tool wear and its effect on surface roughness in diamond cutting of glass, and provides theoretical basis for minimizing the tool wear in diamond cutting brittle materials, such as optical glass.

Modeling and Evaluating of Surface Roughness Prediction in Micro-grinding on Soda-lime Glass Considering Tool Characterization

The current research of micro-grinding mainly focuses on the optimal processing technology for different materials. However, the material removal mechanism in micro-grinding is the base of achieving high quality processing surface. Therefore, a novel method for predicting surface roughness in micro-grinding of hard brittle materials considering micro-grinding tool grains protrusion topography is proposed in this paper. The differences of material removal mechanism between convention grinding process and micro-grinding process are analyzed. Topography characterization has been done on micro-grinding tools which are fabricated by electroplating. Models of grain density generation and grain interval are built, and new predicting model of micro-grinding surface roughness is developed. In order to verify the precision and application effect of the surface roughness prediction model proposed, a micro-grinding orthogonally experiment on soda-lime glass is designed and conducted. A series of micro-machining surfaces which are 78 nm to 0.98 ~tm roughness of brittle material is achieved. It is found that experimental roughness results and the predicting roughness data have an evident coincidence, and the component variable of describing the size effects in predicting model is calculated to be 1.5x 107 by reverse method based on the experimental results. The proposed model builds a set of distribution to consider grains distribution densities in different protrusion heights. Finally, the characterization of micro-grinding tools which are used in the experiment has been done based on the distribution set. It is concluded that there is a significant coincidence between surface prediction data from the proposed model and measurements from experiment results. Therefore, the effectiveness of the model is demonstrated. This paper proposes a novel method for predicting surface roughness in micro-grinding of hard brittle materials considering micro-grinding tool grains protrusion topography, which would provide significant research theory and experimental reference of material removal mechanism in micro-grinding of soda-lime glass.

Alkali desilicated coal fly ash as substitute of bauxite in lime-soda sintering process for aluminum production

By desilication treatment,the Al2O3/SiO2 molar ratio of coal fly ash could be improved to the range of 1.63-2.0.The desilicated coal fly ash(DSCFA)was enriched in alumina extraction.A processing technology was developed for alumina extraction from the DSCFA with the lime sintering process.Ca/(SiO2+TiO2)molar ratio,and NaO/Al2O3 molar ratio,sintering time,and temperature were the most significant parameters impacting on the aluminum extraction efficiency.The optima aluminum extraction efficiency was obtained under conditions of Ca/(SiO2+TiO2)molar ratio of 2.0,NaO/Al2O3 molar ratio of 0.98,and sintering at 1 200 ℃for 60 min.Astandard industrial dissolution method was used under conditions of caustic ratio(αk=n(NaO)/n(Al2O3)of 2.0,Al2O3 concentration of 50 g/L,sodium hydroxide concentration(Nk)of 60.78 g/L,Na2CO3 concentration of 10 g/L,temperature of 85℃, and dissolution duration of 10 min.The final aluminum extraction efficiency was 90%.

Investigation of Optical and Luminescence Properties of Soda Lime Borate Glasses Doped with Sm^(3+) Ion

This paper was to investigate the optical and luminescence properties of Sm^(3+) doped SLB glasses by a melt quenching technique. The optical and luminescence properties of the prepared glass samples were investigated via absorption and photoluminescence spectra, respectively. The related physical and optical parameters were also calculated. From optical absorption measurements, the transition ~6H_(5/2) → ~6P_(3/2) at 403 nm has a higher spectral intensity and is a hypersensitive transition. From photoluminescence spectra, four prominent emission spectra appear. The most intense band is located at ~4G_(5/2) →~6H_(9/2)(599 nm), which is the characteristic emission range of Sm^(3+) ions with the reddish orange color. The experimental decay time of the ~4G_(5/2) level of Sm^(3+) SLB glasses was determined. The decay time decreases from 1.367 to 0.333 ms with increasing the content of Sm^(3+). The color coordinates(x, y) of the prepared glasses passes through the reddish-orange region in the CIE 1931 diagram and are suitable for orange LEDs, optoelectronics, and solidstate lighting. The further investigation on the optimization of the dopant content in the SLB glasses was suggested.

Model of Diffusion of Sulfur in Soda-lime-silicate Glass:An Experimental and Comparative Study

The diffusion property of sulfur on the soda-lime-silicate float glass surface was studied by using secondary ion mass spectroscopy（SIMS）.According to the Fick＇s Second Law,two models of diffusion of sulfur on the glass surface were built.When the diffusion of sulfate（S^6＋） is considered uniquely,the concentration-depth profile of sulfur can not be fitted very well,especially on the top surfaces of the air side and tin side of float glass.So the diffusion of sulfide（S^2-） on the profile of sulfur can not be ignored.The concentration-depth profile of sulfur on both sides of glass can be fitted more exactly when both S^6＋ and S^2- are considerd.Based on the above-mentioned fitting results,it is concluded that the diffusion coefficents of S^6＋ and S^2- of tin side are larger than those of the air side.Moreover,the diffusion coefficents are related to the contacted medium.

熔铸耐火材料抗盖板玻璃熔体侵蚀行为研究

本文以熔铸耐火材料为研究对象进行抗盖板玻璃熔体侵蚀试验,采用化学分析、岩相分析和电子显微镜能谱分析等测试分析方法,对比研究钠钙玻璃熔体、高铝玻璃熔体和锂铝玻璃熔体对熔铸耐火材料的侵蚀行为。结果表明,玻璃熔体中的碱金属离子向耐火材料中的玻璃相扩散,导致玻璃相黏度降低,同时耐火材料中刚玉相溶解,斜锆石分散,主体结构遭到破坏,并形成界面层。界面层内存在富铝含锆的玻璃相,由于高铝玻璃和锂铝玻璃氧化铝含量高,表面张力大,界面层内的玻璃相聚集在试样周围且扩散慢,从而阻止了侵蚀的发展。玻璃熔体的侵蚀速率为钠钙玻璃熔体>高铝玻璃熔体>锂铝玻璃熔体。

化学沉淀法处理含^(90)Sr-^(90)Y闪烁废液的研究

在对放射源的检验中需要使用液体闪烁计数器对其表面污染及泄漏指标进行测量,检验过程会产生含有^(90)Sr-^(90)Y的闪烁废液,该废液同时具有有机物与放射性物质两种属性,不易进行处理,成为亟待解决的问题。国内外对放射性有机废液的处理进行了诸多研究,虽得到一些解决方案,但都存在一定局限性,并不适用于放射源检验产生的闪烁废液的处理。本工作借助闪烁液能够与一定量水互溶的特性,采用多种化学沉淀法尝试对^(90)Sr-^(90)Y进行沉淀,分析了影响因素,并通过过滤将放射性沉淀与过滤后的闪烁液分离,实现对含有^(90)Sr-^(90)Y的闪烁废液进行去污及减容的目的,提出了一种处理放射性闪烁废液的新思路。

钠钙玻璃的单磨粒变切深划擦表面完整性实验

以玻璃为代表的硬脆材料由于其高硬度、高脆性等特点,使其在加工过程中极易出现凹坑、脆性破碎及表面/亚表面裂纹等损伤,严重影响其使用性能和表面完整性。从单磨粒变切深划擦实验着手,研究在单磨粒划擦过程中速度变化对钠钙玻璃表面裂纹生成与扩展以及表面完整性的影响。结果表明:单磨粒变切深划擦实验能够实现磨削过程中的划擦、耕犁、切削3个阶段,且随着划擦速度增加,钠钙玻璃发生脆-塑转换的临界深度增加,划痕形貌及划痕边缘光滑度提升。

钠钙双碱法脱硫工艺改进探讨

为提高碳素企业烟气脱硫效率,降低企业环境投入成本,本文基于钠钙双碱脱硫的原理,分析实际应用中存在反应池容积小,过度添加NaOH等问题,提出装置提升为“三级反应池+清水池”,且建议吸收液pH保持在为8~9范围。

氨碱法纯碱生产中对电石渣的循环利用探讨

青海盐湖镁业有限公司充分利用当地资源,建成集生态、环保、节能、减排为一体的循环经济产业链,处于物料循环利用尾端的纯碱厂,利用各分厂的产品及废物变废为宝生产纯碱,试生产阶段在整个物料循环未建起来的情况下介绍了电石法PVC厂的电石渣在纯碱厂的局部循环利用,改变了石灰窑以石灰定产的限制,即增加了纯碱产量,又为后续整个物料的循环利用奠定的一定的基础。

基于电渗析的煤化工废水深度处理研究

为解决煤化工废水深度处理与回用中工艺流程长、处理成本高等问题,以某厂焦化废水为原水,通过分析原水中的成分,制定出一套基于电渗析的节能、低成本煤化工废水深度处理技术。针对废水水质,对唐山废水电渗析脱盐,工作电压为10 V时,具有适宜的脱盐速度、能耗以及COD脱除率,电流效率为89.2%,相应能耗1.03 kW·h/kg,料室COD下降到42 mg/L。通过核算,本工艺处理每吨水的成本约1元,比反渗透的处理费用有较大下降。

中国铝资源与高铝粉煤灰提取氧化铝研究进展

针对中国铝土矿资源不足的状况,利用高铝粉煤灰生产氧化铝不仅有望缓解铝资源的不足,而且可减少粉煤灰对大气、水体的污染和大量土地资源的占用。高铝粉煤灰提取氧化铝技术主要包括酸法、碱法和酸碱联合法。采用碱法提取氧化铝技术,具有对设备腐蚀性小,与现有氧化铝生产设备相容性好,对水体和空气不产生二次污染等优势。与石灰石烧结法和预脱硅-碱石灰烧结法等代表性碱法技术相比,采用预脱硅-低钙烧结法制备氧化铝技术,处理物料总量、一次性资源消耗量和CO2排放量,分别减少22.1%～52.4%、24.6%～52.0%、20.0%～66.2%;综合耗能降低16.4%～36.3%;剩余硅钙固体排放量减少27.5%～71.5%。因此,预脱硅-低钙烧结法技术在物耗、能耗、环境相容性和产品方案等方面均有明显优势,符合高效节能和清洁生产的要求,有望实现高铝粉煤灰生产氧化铝的完全资源化利用。

应用裂纹控制法的钠钙玻璃YAG激光切割技术

针对目前对玻璃切割质量越来越高的需求,应用裂纹控制法进行了连续YAG激光切割钠钙玻璃的试验,分析了激光功率、激光扫描速度、激光光斑大小对切割质量的影响规律,得到了YAG激光切割钠钙玻璃平板的最佳切割参数。同时利用光学显微镜照片研究了玻璃切口表面的质量,对比了激光切割与机械法切割得到的玻璃切口质量,结果表明:采用裂纹控制法的玻璃YAG激光切割技术可以得到很好的切口质量,应用于高质量玻璃的加工。文中还进行了多层玻璃、管状玻璃以及平板玻璃曲线轨迹的YAG激光切割试验,为YAG激光切割玻璃的进一步应用提供了技术基础。

浮法超薄玻璃化学钢化及性能研究

本文研究高铝超薄浮法玻璃与浮法钠钙硅玻璃的化学钢化过程。用全自动化学钢化玻璃表面应力测试仪、万能试验机和数显显微维氏硬度计分别测试了样品的表面应力、应力层深度、抗折强度和显微硬度。结果表明:在一定的温度下,随着离子交换时间的增加,高铝超薄玻璃与浮法钠钙硅玻璃的表面应力、抗折强度、显微硬度均出现先增加再到减小的趋势,应力层深度则随着时间的增加而加深。在同样的离子交换制度下,高铝玻璃化学钢化后的力学性能优于钠钙硅玻璃。同时,以浮法工艺生产的玻璃锡面的表面应力小于非锡面的应力,应力层深度也相对小于非锡面的深度。

密闭救援空间内碱石灰去除二氧化碳效率影响因素分析

在矿用救生舱、载人航天器等有人应急生存或作业的有限空间内长时间生存,去除人体代谢产生的二氧化碳是保障人员生存的重要措施。碱石灰相比于其他吸附药剂具有吸附稳定性高、技术成熟、价格合理等特点,作为密闭救援空间空气净化的吸附药剂具有无可替代的优点。但是救生舱等密闭救援空间由于受到灾变后特殊条件(外部动力中断及体积等因素)限定,要求碱石灰具有较高的吸附率和吸附速率。通过对市场粒径、组分、产品吸附率等条件的筛选,共选出6种碱石灰进行了不同组分、不同厚度、不同风速、不同温度及湿度下的吸附率影响因素试验,得到了碱石灰对二氧化碳吸附的最佳配比及在密闭救援空间内工作的最佳方式和最佳使用条件。结果表明:碱石灰在救生舱等密闭救援空间内使用条件、优化其成分配比、开发相关环境控制与生命保障技术装备提供了必要的数据支持及理论参考。

还原气氛中碱石灰与高铁铝土矿间的作用机理

针对高铁铝土矿的综合利用难题,研究了保温过程中碱石灰同高铁铝土矿以及纯碱和石灰之间的相互作用机理.试验表明,在还原气氛中,原矿中的赤铁矿几乎全部被还原为单质铁,但只有少部分氧化铝转化为铝酸钠,其余仍以铝硅酸钠和刚玉形式存在,造成氧化铝和氧化钠的溶出率偏低.这是由于CaO活性较低,不能完全置换出铝硅酸钠中的Na2O和Al2O3.由于低活性石灰的稀释作用,在体系中的相对含量降低,纯碱与高铁铝土矿之间的相互作用减弱.

陶瓷材料压痕韧性的统计性质

采用直接压痕法测定了钠钙硅酸盐玻璃和一种ＴｉＣ 颗粒增强Ａｌ２Ｏ３复合材料的断裂韧性．研究表明，在同一压痕压制荷载下测得的同一种材料的压痕韧性呈现出较大离散性，可以采用Ｗｅｉｂｕｌｌ分布加以较好地描述．对两种材料的试验数据的对比分析指出，压痕韧性测试值的离散性反映了材料显微结构的不均匀性对材料局部裂纹扩展阻力的影响．基于这一分析，本文建议采用直接压痕法测定材料断裂韧性时，应尽可能增大试验量，从而对压痕韧性测试结果的统计性质作出完整描述．

钠钙玻璃板激光热应力切割过程的有限元仿真

为了使脆性材料板的激光热应力切割得以完成并提高切割质量,提出了一种切割过程的仿真方法.利用有限元法分析玻璃板在激光扫描过程中的瞬态热传导,求得瞬态温度场.按热弹性平面应力理论分析热应力场,并采用最大切向应力准则和节点松弛法模拟板材的开裂.通过该仿真方法分析了钠钙玻璃板的切割过程,根据所导致的温度最高值和板材的开裂情况,研究了激光功率和激光扫描速度这两个关键参数对切割的影响,并给出了可完成连续切割的参数范围.仿真结果表明,该方法可以对激光功率和扫描速度等激光参数进行优化调节,从而改善切割的质量.