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Abstract This study focused on the glass forming, crystallization, and physical properties of ZnO doped MgO-Al 2 O 3 -SiO 2 -B 2 O 3 glass-ceramics. The results show that the glass forming ability enhances first with ZnO increasing from 0 to 0.5 mol%, and then weakens with further addition of ZnO which acted as network modifier. No nucleating agent was used and the crystallization of studied glasses is controlled by a surface crystallization mechanism. The predominant phase in glass-ceramics changed from α-cordierite to spinel/gahnite as ZnO gradually replaced MgO. The phase type did not change; however, the crystallinity and grain size in glass-ceramics increased when the glasses were treated from 1030 °C to 1100 °C. The introduction of ZnO can improve the thermal, mechanical, and dielectric properties of the glass-ceramics. The results reveal a rational mechanism of glass formation, crystal precipitation, and evolution between structure and performance in the x ZnO-(20- x)MgO-20Al 2 O 3 -57SiO 2 -3B 2 O 3 (0 ≤ x ≤ 20 mol%) system. [ABSTRACT FROM AUTHOR]

• Heat transfer coefficients were identify using experimental data • Radiative effects have been included and analyzed in the identification methodology • Thermocouple position and initial temperature impact the coefficient values This paper is devoted to the identification of the heat transfer coefficient between a high temperature glass and a cast iron punch taking radiative effect into account. A 1D numerical thermal model taking the radiative effects into account has been developed to simulate the contact between a punch and a glass cylinder. It was coupled with an inverse identification methodology to determine the heat transfer coefficient using experimental data carried out in the LAMIH. First, the sensitivity of the identification of the heat transfer coefficient with respect to different parameters (initial glass temperature, thermocouple position, radiation) will be introduced. A second part will show the identification of heat transfer coefficient using experimental data taking into account radiative effects. [ABSTRACT FROM AUTHOR]

In this work, a new chalcohalide glass system, Ga 2 S 3 Sb 2 S 3 CsCl (GSSC), is reported. The glass-forming ability and the physical properties are investigated; and the potential applications of these glasses are evaluated. The glass forming ability can be remarkably improved when CsCl is added into Ga 2 S 3 Sb 2 S 3 glasses, and the compositions with more than 30% CsCl possess quite good thermal stability against crystallization. The studied GSSC glasses have transition temperatures of 217–250 °C, densities of 3.42–3.97 g/cm 3 , micro-hardness of 1.12–1.88 GPa, a transparent window of ∼0.56–13.4 μm, linear refractive indices of 1.99–2.58 @ 10 μm, nonlinear refractive indices of 1.1–11.9 × 10 −14 cm 2 /W @ 1030 nm, and zero group-velocity-dispersion wavelengths of 3.37–5.15 μm. The wide transparent window and the superior optical nonlinear property make these glasses good optical materials for infrared imaging and nonlinear photonics. [ABSTRACT FROM AUTHOR]

Ionic liquids display outstanding properties and have a wide range of potential uses. Their unique ionic and organic nature also identify them as good glass-forming materials. In this work, a series of imidazolium-based ionic liquids with varying functionalities from aliphatic to aromatic groups and a fixed bis[(trifluoromethane)sulfonyl]amide ([NTf 2 ] − ) anion are characterized using a commercial rapid scanning nanocalorimetry instrument, the Mettler Toledo Flash DSC. The limiting fictive temperature T f ′, which is equivalent to the glass transition temperature T g , is measured on heating as a function of cooling rate. The dynamic fragility is obtained for the series of ionic liquids, and using this data along with a compilation of data from the literature for a total of 50 ionic liquids reveals that aromatic structure increases fragility more than expected simply based on the change in T g . Our results provide an approach to control fragility of ionic liquids through chemical modifications to the side group. [ABSTRACT FROM AUTHOR]

• PBC lead-free glasses are prepared by traditional high temperature melting method. • The formation region of P 2 O 5 –Bi 2 O 3 –CaO ternary glass system was determined. • PBC glass has a low transition temperature and proper thermal expansion coefficient. • 60P 2 O 5 –25Bi 2 O 3 –15CaO glass has a good chemical stability and thermal stability. • 60P 2 O 5 –25Bi 2 O 3 –15CaO glass is a potential candidate for sealing material. (80-x)P 2 O 5 -xBi 2 O 3 –20CaO (x = 5, 10, 15, 20 and 25mol%) and 60P 2 O 5 -(40-y)Bi 2 O 3 -yCaO (y = 5, 10, 15, 20 and 25 mol%) lead-free glasses were prepared by traditional high temperature melting method. The formation region of P 2 O 5 –Bi 2 O 3 –CaO glass system is determined. The X-Ray diffraction verified the amorphous of the glass samples in a certain composition range, and analyzed the crystal structure and crystal chemistry of BiPO 4 and Bi 2 P 4 O 13 in the crystallization glass. The effect of different chemical compositions on the vibration of Q elements in phosphobismuth glass structure was studied by Fourier Transform Infrared and Raman spectroscopy. It was found through chemical durability evaluation that the dissolution rate of glass in water continued to decrease with time, and the decreasing trend continued to be stable. Through the research on the structure and performance of P 2 O 5 –Bi 2 O 3 –CaO ternary glass, a lead-free low-melting phosphate glass with excellent comprehensive performance was obtained, and the best composition of glass sample was determined. The P 2 O 5 –Bi 2 O 3 –CaO glass system is a potential lead-free candidate for sealing material. [ABSTRACT FROM AUTHOR]

The Fraunhofer Institute for Silicon Technology in Itzehoe has developed vacuum encapsulated dual-axis scanning micro-mirrors, for high-resolution laser projections [1]. Sinceparallel orientation of the glass cover to the micro-mirror results in a bright laser spot in the projected image, a wafer level packaging with an inclined glass lid was developed to eliminate the reflex in the image. To determine the quality requirements and the design specifications of the new package, optical simulations were performed in Zemax®. For this purpose, the influence of the surface curvatures on the laser beam was examined. A further study was focused on the avoidance of secondary reflections, resulting in a disturbing ghost images superimposing the projected image. [ABSTRACT FROM AUTHOR]

In this study, a bulk crystalline glass forming alloy with the composition of Al 87.4 Co 7.9 Ce 4.7 (at.%) was rapidly solidified by large area electron beam (LAEB) surface melting of an as-cast starting material. Glancing angle XRD results show that, providing appropriate processing parameters are selected, a predominantly amorphous layer ∼5 μm thick can be produced. However, under non-optimum processing conditions treated layers are compositionally inhomogeneous and comprise, in the main, crystalline regions. LAEB treated layers also exhibit a degree of surface cracking as well as micron-sized localised craters and ejected particles formed during electron beam irradiation. Potentiodynamic polarisation tests show that treated layers exhibit enhanced corrosion resistance compared to the as-cast bulk alloy; with the predominantly amorphous layer having the lowest current density. Examination of corroded samples following potentiodynamic tests reveals that cracks limit the effectiveness of the treated layer as a barrier to corrosion. [ABSTRACT FROM AUTHOR]

Abstract: Glass sagging is used to process glass industrial products such as windscreens, mirrors or lenses. A 2D glass sagging process, simulated with the Finite Element Method (FEM), is presented in this work. Different thermal cases are reviewed with special care brought to radiative transfer model, with an optimized reciprocity Monte Carlo method used as the reference. Results show that ignoring radiative transfer is a too rough hypothesis. This leads to large errors on the glass temperature distribution, on the forming process and on the final shape in case of glass sagging without mold. However, predefining glass temperature or using Rosseland approximation give acceptable results, less accurate than Monte Carlo simulations especially for a fine prediction of the transfer as a function of time, but with smaller CPU times. [Copyright &y& Elsevier]

Abstract: MEMS mirrors are gaining considerable interest for consumer applications like embedded pico projectors in smartphones. The use of micro mirrors in mobile systems demands for a robust package that prevents the system from contamination by particles, gases or fluids. Appropriate optical packaging so far has been neglected in most published MEMS mirror developments. This paper describes a unique technology to fabricate glass packages on 8 inch wafers with inclined optical windows for MOEMS on wafer scale which avoids the occurrence of highly intense reflections of the incident laser beam in the projected images. The new viscous glass forming process enables the fabrication of glass devices with optical windows with oblique surfaces using bonded silicon-glass wafers. [Copyright &y& Elsevier]

Abstract: Novel chalcogenide glasses based on GeS2–In2S3–Sb2S3 system were prepared by conventional melt-quenching method and their physicochemical properties, e.g. glass transition temperature, density, and Vickers micro-hardness, were studied in detail. The results show that the thermal, mechanical, and optical properties depend largely on four-coordinated Ge or In entities and are sensitive to the variation of the connectivity in the GeS2–In2S3–Sb2S3 glass network. It is a promising chalcogenide glass system suitable for rare earth doping or crystallization of rare earth doped crystals, which aims at optical applications of IR optical amplifier or efficient solid state laser. [Copyright &y& Elsevier]

Abstract: A predictive model for metallic glass compositional design was constructed based upon the calculated liquidus temperatures. Furthermore, a parameter, termed α, was defined in order to quantify the relative depth of a eutectic in an alloy system. Large α parameters signify higher glass-forming ability. Comparisons of this theory and experimental results given in literature from varied sources and alloy types show that compositions containing relatively high α values correspond to successfully produced bulk metallic glasses. Specifically, an α parameter value in excess of 1 suggests a slight tendency for glass formation, while α values greater than 1.5 suggest a very strong tendency. Thus, the α parameter can serve as a tool for quantifying potential bulk metallic glass alloys in terms of limiting their requirement for rapid quenching. This technique is appropriate for both constituent element selection and composition optimization. [Copyright &y& Elsevier]

Abstract: The temperature dependence of the optical non-linear response of dye molecules dissolved in a glass-forming liquid over a temperature range that includes the glass transition is investigated. Cooling down to temperatures below the glass transition dramatically slows the diffusive motion of the solvent molecules, while the bath retains its strong amorphous character. The results of ultrafast experiments such as echo-peak shift and heterodyne-detected echo are presented. The temperature dependence of the optical response is discussed within the context of the multimode Brownian oscillator model that is commonly used to describe dynamics in liquids. Freezing out a large part of the bath fluctuations allows for testing of the physical interpretation associated with this model. A temperature-dependent spectral density is proposed that can describe the results at all temperatures over the explored temperature range. The temperature dependence follows readily from the physical processes that are associated with the various parts of the density of states, with the exception of the fastest modes. The temperature dependence of these modes is inspected closely and the spectral shape is reinterpreted. [Copyright &y& Elsevier]

Numerical models may play an important role in the optimization of the quality of hollow-ware glass articles in glass industry. Due to the complexity of the phenomena involved a coupling between thermal and mechanical aspects is crucial. One of the key aspects required is a deep knowledge of the heat transfer at the glass/mould interface, a factor that may influence dramatically the final product. In this work an interface element developed to deal with heat transfer between glass and moulds in glass forming processes was introduced in a commercial code as a user element. The initial purpose was to make it possible to consider the dependence of the interface heat transfer resistance on process parameters like glass temperature and viscosity, mould temperature and contact pressure. In addition its implementation also proved to be an efficient tool to eliminate some perturbations introduced by the penalised form adopted in the commercial code to deal with non-matching meshes. A press and blow forming simulation of a Champagne flute was performed to assess the element performance on a real case study. [Copyright &y& Elsevier]

Abstract: The simulation of glass forming is a complex thermo-mechanical problem. For high temperatures, the mechanical glass behaviour is assumed to be as a viscous incompressible material. Its viscosity is strongly temperature dependent and the process involves large displacements and large strains. Therefore, the finite element modelling of such a process needs to take account of large geometrical transformations. From the numerical point of view, this problem can be studied by means of a solid approach where the degrees of freedom are displacements. This modelling is highly non-linear. Moreover, the numerical convergence can be affected on account of the mechanical contact between the mould and the glass. The aim of this paper is to propose a linear finite element formulation for 3D glass forming where the degrees of freedom are velocity and hydrostatic pressure. The mechanical contact is taken into account by means of an explicit algorithm related to the time integration scheme. The thermal coupling is not considered. The results are discussed and compared to a non-linear formulation where the degrees of freedom are displacements. [Copyright &y& Elsevier]

Abstract: Some optical surfaces are formed by gravity sagging of molten glass. A glass sheet supported on a ceramic former is heated; the glass becomes a very viscous fluid and sags under its own weight until the lower surface is in full contact with the former. The smooth upper free surface is the required optical surface. Its shape is dependent on the initial geometry and, in optical terms, differs significantly from the former shape. The inverse problem is to determine the shape of the former that produces a prescribed upper surface. This is a difficult, nonlinear problem. A finite element algorithm has been developed to compute gravity sagging for any given initial axisymmetric geometry (the forward problem). The present work describes a successful iterative method, which uses the output from a number of forward problems to determine the required (axisymmetric) former shape. [Copyright &y& Elsevier]

[Display omitted] From molecular dynamics simulations and the capillary fluctuation method, the solid-liquid interfacial free energy (γ 0) has been computed for the B2-liquid interface in the Cu-Zr system. Consistent with previous results for the FCC-liquid interface in Cu-Zr and Al-Sm but atypical of most alloys, γ 0 was found to increase as the temperature is lowered. In addition, the temperature dependence was obtained for model Lennard-Jones B2-liquid alloys. In all cases the unusual temperature dependence of γ 0 is correlated with an atomic structure of the interfacial region characterized by a misalignment of the number density peaks between solvents and solutes. In cases where the number density peaks are aligned, the typical temperature dependence is observed. The results are discussed in terms of the Gibbs theory of the thermodynamics of interfaces. It is proposed that the unique interfacial structure and the atypical temperature dependence of γ 0 are hallmarks of an easy glass forming alloy. [ABSTRACT FROM AUTHOR]