[en] Metallic glass-forming liquids (MGFLs) exhibit a quite unusual pattern in the temperature dependence of the viscosity when plotted in a wide range of temperature. Among the fragile liquids, the MGFLs have the propensity that at high temperature the viscosity exhibits a very low activation energy, while at low temperature a straight-line viscosity behavior appears in the Arrhenius representation. This unusual pattern hinders a theoretical description over a wide temperature range and the understanding of its microscopic mechanism. In the present study, we show that the modified BSCNF model describes well the temperature dependence of the viscosity of MGFLs. The relevance of the result to the fragile-to-strong transition that can occur in the supercooled regime is discussed briefly.

[en] Glass forming ability (GFA) is one of the key factors hindering the application of bulk metallic glasses (BMGs). Microalloying has shown beneficial effects on GFA. However, the mechanism is still unclear. A new guidance via clusters was applied to understand and quickly choose beneficial microalloying elements for enhancing GFA which might help build a foundation for further quantitative analysis of minor alloying via clusters. Under the guidance, a series of beneficial microalloying elements could be quickly discovered, verified and understood. The results show that the beneficial microalloying elements for enhancing GFA should be chosen under the condition of bringing in new types of topologically efficiently packed clusters. (paper)

No abstract available

[en] Cold-rolled Zr₅₅Cu₃₀Ni₅Al₁₀ bulk metallic glasses (BMGs) exhibited volume dilatation across the entire range of thickness reduction fractions from 5.7% to 63%. The dilatation was dominantly attributed to the free volume generated during cold-rolling, together with any open volumes, like the voids or microcracks, or both, which survived even after sufficiently annealing the rolled sample at the temperature in the supercooled liquid region. The relaxation of free volume formed during cold-rolling resulted in more heat evolution per unit volume than that of as-cast glass. The structural change during cold-rolling could be ascribed to the increased fluctuation of atomic-level hydrostatic stress, 〈p²〉, in the glass

[en] As part of their research into the basic optical properties of laser glasses, the authors measured the two-photon absorption (2PA) coefficient β of some highly transparent oxide glasses. The authors tested several alkali silicate compositions (LG-650, LG-660, LG-670, and LSG-91H), several borosilicates (BK-3, BK-7, and BK-10), and one phosphate (LG-750)

[en] Two main by-products or waste from the production of glass fibre are following: sewage sludge containing montmorillonite clay as sorbent material and ca 50 % of organic matter as well as waste glass from aluminium borosilicate glass fibre with relatively high softening temperature (> 600 degree centigrade). In order to elaborate different new ceramic products (porous or dense composites) the mentioned by-products and illicit clay from two different layers of Apriki deposit (Latvia) with illite content in clay fraction up to 80-90 % was used as a matrix. The raw materials were investigated by differential-thermal (DTA) and XRD analysis. Ternary compositions were prepared from mixtures of 15 - 35 wt % of sludge, 20 wt % of waste glass and 45 - 65 wt % of clay and the pressed green bodies were thermally treated in sintering temperature range from 1080 to 1120 degree centigrade in different treatment conditions. Materials produced in temperature range 1090 - 1100 degree centigrade with the most optimal properties - porosity 38 - 52 %, water absorption 39 - 47 % and bulk density 1.35 - 1.67 g/cm³ were selected for production of porous ceramics and materials showing porosity 0.35 - 1.1 %, water absorption 0.7 - 2.6 % and bulk density 2.1 - 2.3 g/cm³ - for dense ceramic composites. Obtained results indicated that incorporation up to 25 wt % of sewage sludge is beneficial for production of both ceramic products and glass-ceramic composites according to the technological properties. Structural analysis of elaborated composite materials was performed by scanning electron microscopy(SEM). By X-ray diffraction analysis (XRD) the quartz, diopside and anorthite crystalline phases were detected. (Author) 16 refs.

No abstract available

[en] In the present work, a mass spectrometric Knudsen effusion method has been used to study the chemical forms of vapors with Na, B and Te over a borosilicate glass with simple composition 1Na₂O-1B₂O₃-3SiO₂-0.15TeO₂. (orig./RK)

[en] In the present article we discuss a new class of scintillation materials that are prospective for application in high energy physics experiments and for detection of neutrons in a wide energy range.(authors)

[en] The influence of global interactions between the static atomic structure and the valence electrons on structure formation in binary Al-(Ni,Cu,Zr), Zr-(Ni,Cu) and ternary Al-(Ni,Cu)-Zr metallic glasses is investigated over wide concentration ranges and discussed in terms of a Hume-Rothery-like theory by analysing and comparing data available in the literature. The results suggest that global interactions lead to an improvement of thermal stability and glass-forming ability. A complete understanding of structure formation in the considered alloys is assumed to be possible only by taking into account both local and global effects.