Finite Element Analysis of TV Panel Glass during Cooling

A finite element software has been used to determine the temperature history in forming a TV glass panel during hot pressing in a metal mold and the controlled cooling cycle. The temperature history is then used to calculate the stress and strain history in the glass panel. The goal of the simulation model is to predict the resulting stresses and strains due to forming and cooling that takes place during the manufacturing of the TV panel. DEFORM 3D software has been used to carry out the numeric simulation.     

Nano fountain pen manufacture of polymer lenses for nano-biochip applications

Polymer microlenses have been manufactured by delivering droplets of a monomer mixture to a glass substrate using a nano fountain pen (NFP). Subsequent UV polymerization yielded microlenses with optical properties that were controlled by varying the deposition time of the monomer solution. Using this approach, it is possible to strategically place single microlenses at predefined positions with very high accuracy, an ability which may prove very useful for nano-biochip applications, as demonstrated.     

用差示扫描量热法研究Mg65Cu25Gd10块体非晶合金的晶化动力学

通过铜模吸铸法得到Mg65Cu25Gd10块体非晶舍金，用差示扫描量热仪（DSC）研究其晶化动力学和玻璃转变行为，玻璃转变温度Tg，晶化起始温度Tx，晶化峰值温度Tp都与加热速率有关，通过Kissinger方程可以得到表面激活能，发现晶化初始激活能Ex小于峰值激活能Ep，表明形核过程比生长过程容易，讨论了此非晶舍金的玻璃形成能力，根据JMA方程非等温模型研究了晶化动力学，Avrami参数表明在不同温度下的晶化机制是不同的．     

Thermal modeling of laser-densified microlenses

A three-dimensional transient thermal modeling of laser-densified gel-silica microlenses is described. This model simulates the three-dimensional temperature distribution in a porous gel-silica glass irradiated by a CO(2) laser. The heat induced by the laser gives rise to a gradient in temperature, which creates a gradient in density and index of refraction. The laser-densified region functions as a microlens. The modeling results include a temperature distribution with time within a volume of 2 mm × 2 mm × 2 mm. The calculated temperature distributions compare well with the measured property distributions of the microlens including microhardness and the peak positions of the Si-O-Si stretching vibration mode in IR spectra across the lens.     

基于单向拉伸的glare板力学性能测试

目的 研究使用新方法制造小型大曲率glare板零件的可能性。方法 通过使用传统的模具来充液成形/普通拉深成形含有半固化玻璃纤维预浸料的glare板,成形后再进行固化。在室温下,使用单向拉伸方法分别对金属、含半固化玻璃纤维预浸料的glare板和固化之后的glare板进行力学性能测试。结果 含半固化玻璃纤维预浸料的glare板主要失效形式为金属板断裂,固化之后的glare板的主要失效形式为玻璃纤维断裂;含半固化玻璃纤维预浸料的glare板有着和金属相近的断后伸长率,具有较好的塑性,固化之后的glare板的断后伸长率远小于金属的断后伸长率,塑性极差。结论 通过使用传统的模具来充液成形/普通拉深成形含有半固化玻璃纤维预浸料的glare板,成形后再固化的方法来制造小型大曲率glare板零件是有可能的。     

Formation and properties of cadmium sulfide buffer layer for CIGS solar cells grown using hot plate bath deposition

In the present study, cadmium sulfide (CdS) thin films were deposited on different substrates [soda glass, fluoride doped tin oxide, and tin doped indium oxide (ITO) coated glass] by a hot plate method. To control the thickness and the reproducibility of the sample production, the thin films were coated at different temperatures and deposition times. The CdS thin films were heated at 400 °C in air and forming gas (FG) atmosphere to investigate the effect of the annealing temperatures. The thickness of the samples, measured by ellipsometry, could be controlled by the deposition time and temperature of the hot plate. The phase formation and structural properties of CdS thin films were studied by X-ray diffraction and scanning electron microscopy, whereas the optical properties were obtained by UV–vis spectroscopy. A hexagonal crystal structure was observed for CdS thin films and the crystallinity improved upon annealing. The structural and optical properties of CdS thin films were also enhanced by annealing at 400 °C in FG atmosphere (95 % N₂, 5 % H₂). The optical band gap was changed from 2.25 to 2.40 eV at different annealing temperatures and gas atmospheres. A higher electrical conductivity, for the sample annealed at FG, was noticed. The samples deposited on ITO and annealed in FG atmosphere showed the best structural and electrical properties compared to the other samples. CdS thin films can be widely used for application as a buffer layer for copper–indium–gallium–selenide solar cells.     

The role of capillarity in the gravitational molding of metallic glass pieces

Pieces of Pd₄₀Ni₁₀Cu₃₀P₂₀ (numbers indicate at.%) metallic glass of high surface to volume ratio are processed by gravitational casting in a mold. The influence of mold temperature on mold filling and sticking at the alloy/mold interface is investigated. Sticking is discussed with a particular emphasis on the role of wetting of the molten alloy on mold surfaces, which was assessed from sessile drop experiments performed on different mold materials. The measured mold filling time is compared with a simple analytic model.     

Case Study on Improving Bushing Reliability in Glass Fiber Manufacturing

Bushing reliability plays an important role in the glass fiber-forming process. In this study, a single three-factorial design was used to investigate the effects of three forming factors: forming throughput, glass viscosity, and forming temperature. Results show that the bushing life distribution could be approximated by a Weibull distribution. There was a negative correlation for the bushing life under forming at different throughputs, viscosities, and temperatures. There were negative correlations between bushing lives at different forming temperatures for yarn production, but in the case of fiber-reinforced plastic production, the correlation between the bushing life and the forming temperature is not significant. We recommend that the processing parameters be set to the following low levels: forming throughput 32 kg/h, glass viscosity 1192 poise, and forming temperature 1193 °C. The results of this study can be used to improve the forming process and save costs.     

Annealing effects on the Curie temperature of a Fe77Cr2B16Si5 glass

Changes in the Curie temperature of a Cr-containing FeBSi glass were studied using DSC measurements. The Curie temperature increases monotonically with annealing temperature and time and the equilibrium value is inversely proportional to the annealing temperature. A uniformly linear log (time) kinetics, as in other Fe glasses containing two metalloids, is found. Results can be explained in terms of the activation energy spectrum model.     

复杂连接块成形工艺有限元分析及模具设计

目的采用理论分析、计算机有限元分析和物理实验的方法对某复杂连接块温挤压成形技术进行研究,根据有限元分析结果设计出模具并成形该零件。方法通过调节不同的参数,对该零件的成形进行数值模拟。结果有限元分析结果表明,该零件在成形过程中等效应力应变分布不均匀,两端凸台位置较难充填。结论根据以上分析结果,在设计模具和实验的时候,提高成形温度及成形速率,优化润滑条件,降低了成形载荷,并在实验室现有的1000 t液压机上进行了物理实验。实验结果与数值模拟结果相吻合,为该零件的批量化生产提供了指导。     

Inside Front Cover: Direct Printing of 3D and Curvilinear Micrometer‐Sized Architectures into Solid Substrates with Sub‐micrometer Resolution (Adv. Mater. 15/2006)

The inside cover shows a hexagonal array of convex microlenses etched directly into glass using a reaction‐diffusion process initiated from a hydrogel stamp. The technique, reported by Grzybowski and co‐workers on p. 2004, allows for direct printing of complex microarchitectures into a variety of materials with sub‐micrometer resolution. The images were generated by longtime exposure of slowly rotating patterns. Cover design by Christopher J. Campbell.     

Silicone microlenses and interference gratings

Interference gratings, plano-convex microlenses, and spherical microlenses have been made in silicone. Lenses were fabricated by the melting method. Two substrates have been tried: glass and Teflon. The latter substrate lets us fabricate low-f-number lenses. We made spherical microlenses by placing pieces of silicone near a thermal source and studied resolution of the lenses by investigating the images they gave of a test chart. We made low-spatial-frequency gratings by recording interference patterns and studied parameters involved in the recording. A study of the profile of the gratings and lenses was done with a mechanical surface analyzer.     

Bending behavior of as-cast and annealed ZrCuNiAl bulk metallic glass

Here ZrCuNiAl bulk metallic glass samples were annealed below its glass transition temperature. The bending behaviors and thermal properties of the as-cast and the annealed samples were studied. The increase of annealing time leads to the transition from ductile to more brittle behavior during bending tests. Meanwhile, prolonging the annealing causes a gradual decrease in the free volume content. Based on free volume theory, the change in the microstructure and mechanical properties induced by annealing treatment has been interpreted in detail.     

Design of microlenses with long focal depth based on the general focal length function

A general focal length function is proposed to design microlenses with long extended focal depth and high lateral resolution. The focal performance of the designed microlenses, including the actual focal depth, the focal spot size, and the diffraction efficiency, is calculated by rigorous electromagnetic theory and the boundary-element method for several f-numbers. In contrast to conventional microlenses, the numerical results indicate that the designed microlenses can exhibit long extended focal depth and good focal performance. It is expected that the long focal length function will be widely used to design microlenses with long focal depth characteristics.     

弹体毛坯热冲拔工艺

目的设计弹体毛坯热冲拔成形工艺方案。方法将冲子压入加热后的钢坯,使钢坯在压力作用下充满模腔,压成盂形,然后套在引伸冲子通过一串直径逐渐缩小的模圈,使弹体拉长、直径减小、壁厚减薄,获得合理的弹体毛坯尺寸,生产出合格毛坯。分析弹体毛坯冲拔成形原理、温度控制、工装设计及冲拔过程中的金属流动规律,根据体积不变原理,计算出冲拔毛坯尺寸。结果通过批量试制,根据冲拔过程中常见问题的控制措施,优化了冲拔工艺参数,实现了弹体毛坯热冲拔成形。结论通过冲拔原理分析、毛坯及工装设计,形成了热冲拔设计规范,该弹体毛坯热冲拔工艺可行。     

激冷快速凝固Al-Cu共晶合金的层片失稳研究

目的 研究热处理条件下共晶层片组织的失稳机制,通过理论建模定量阐明控制层片失稳的关键因素。方法 以Al-Cu共晶合金为研究对象,采用铜模激冷的方法使合金发生激冷快速凝固,获得2个不同冷却速率下的细化共晶层片组织,进一步对所制备的样品进行不同温度及时间的退火处理。研究了退火条件下层片组织的失稳行为,进一步建立了层片失稳的理论解析模型,并基于模型,阐明了热处理条件下共晶层片失稳的机制。结果 凝固冷速为63 K/s和28 K/s的2个样品层片组织均发生了失稳,且在相同退火温度下,冷速为63 K/s的样品(初始共晶层片更细小)更易发生失稳,当退火温度及时间相同时,冷速为63 K/s的样品层片失稳程度更高。结论 在退火条件下,受瑞利不稳定性的影响,共晶层片失稳遵循由层片组织转为棒状组织、棒状组织转变为粒状组织的演变规律;层片厚度和退火温度是层片粒化的主要影响因素。     

铝诱导晶化P型非晶硅薄膜实验研究

利用PECVD设备在普通玻璃基片上沉积硼掺杂P型非晶硅薄膜,采用铝诱导晶化法（AIC）在氮气气氛保护下进行退火处理制备出P型多晶硅薄膜,研究了不同厚度的金属铝膜和热处理温度对非晶硅薄膜的微观结构、表面形貌的影响。实验结果表明：铝膜相对厚度越厚,对a—Si的晶化诱导效果则越好,在一定温度条件下,相对较厚的铝膜可以缩短a—Si晶化为polv-Si的时间,并且能使a—Si的晶化更加完整,产生尺寸较大的硅晶颗粒。在铝膜厚度相同,退火温度相同的条件下,热处理的时间越长,则晶化发生的程度越深,晶化越为彻底。     

The Effects of Casting Temperature on the Glass Formation of Zr‐Based Metallic Glasses

The glass1‐forming ability of two alloys, Zr_64.9Al_7.9Ni_10.7Cu_16.5 and Zr₄₇Cu_37.5Ag_7.5Al₈, prepared by arc‐melting a mixture of Zr, Cu, Al, Ni and Ag elements is studied as a function of casting temperature. Other processing parameters such as the alloy melt mass, and the vacuum and injection pressures during the copper‐mold‐casting process are kept constant so just the influence of the casting temperature is considered. The casting temperature determines the characteristics of the liquid melt and the cooling rate. The glass‐forming ability is discussed in terms of dissipation of pre‐exiting, metastable local‐ordering clusters that act as nucleation sites promoting crystallization, the cooling rate at high casting temperatures, and the presence of oxygen in the alloys, which is increased at high casting temperatures. It is found that the glass‐forming ranges of alloys shrink as the glass‐forming size approaches a critical value. The optimum temperatures are around 1450 K and 1550 K for Zr_64.9Al_7.9Ni_10.7Cu_16.5 and Zr₄₇Cu_37.5Ag_7.5Al₈ alloys respectively. The alloys were studied by XRD, TEM, oxygen‐level determination, and DSC.     

Optoelectronic properties of sputter-deposited Cu2O-Ag-Cu2O treated with rapid thermal annealing

Cu₂O and two types of Cu₂O-Ag-Cu₂O (CAC) multilayered thin films were deposited on glass substrates using DC-magnetron sputtering. For CAC films, the mass thickness of Ag layer was controlled at 3 nm. After deposition, some of these films were annealed using a rapid thermal annealing (RTA) system at 650 °C, in order to create embedded Ag particles. AC films were used to study the clustering effect of Ag in Ar atmosphere, as well as for forming the 2nd type of CAC film by covering another Cu₂O layer on the annealed AC structure. A UV-VIS-NIR photometer, a Hall measurement system, and a I-V measurement system were used to characterize the optical and electrical properties of these films with and without RTA. The results show that 2-dimensional Ag layer can transform into many individual particles due to its high surface tension at annealing temperature, no matter when the annealing was carried out. For CAC films, without annealing, the optical transmission and the resistivity are decreased with the inserted Ag layer. After annealing, both the transmission and resistivity are increased, possibly due to the clustering effect of Ag layer. Most importantly, it is found that the embedded Ag particles can increase the light absorption in the NIR-IR region, which can increase photo-induced current.     

7A04铝合金等温正挤压制坯工艺技术

通过对铝合金轴杆件毛坯零件的成形工艺技术研究分析,提出采用正挤压最佳成形制坯方法取代原粗车工艺。介绍了7A04铝合金等温正挤压成形工艺主要工艺条件的选择和工艺参数的确定,模具控温装置的选择和控温原理,模具结构和工作过程,以及生产中出现的质量问题和解决方法,正挤压制成的毛坯质量满足要求。