O. V. Kaz’mina

Structure and strength of foam-glass-crystalline materials produced from a glass granulate

The microstructure of foam-glass-crystalline materials has been investigated using the energy-dispersive X-ray analysis, Auger electron and infrared spectroscopy, high-resolution scanning electron microscopy, and X-ray diffraction analysis. The strength of the materials is determined and proves to be higher than that for the foam glass prepared from a glass cullet. This is a consequence of the structural effect associated with the formation of nanostructural units in the glassy matrix.

Fractal Analysis in Assessing the Porous Structure of Foam Glass

It is shown that fractal analysis can be used to describe the structure of foam glass. It is proposed that the fractal dimension be used for quantitative assessment of foam-glass structure with fixed action of different technological factors. The interrelation of between the fractal dimension and the main technical characteristics of foam glass is determined.

Physicochemical modeling of composition of foam glass-crystal materials

The principles of the choice of compositions applicable for the low-temperature granulate production lay the foundation of physicochemical modeling of the composition of foam glass-crystal material in Na2O-CaO-SiO2 and Na2O-Al2O3-SiO2 systems. The model composition of granulate should provide the amount of melt formed at the temperatures below 950°C, at least 75%. The amount of crystalline phase in granulate should not exceed 20%; this provides the viscosity of the system in the foaming range (800–850°C) at 103–106 Pa s. To achieve the given viscosity of melt, the foaming temperature should be increased up to 950°C. During the formation of the nanosized crystalline phase in interpore partition, the strength of the material amounts to 3 MPa. In the course of the foaming process of the crystallizing granulate, the amount of the crystalline phase achieves 50%; this provides the strength of the foam material up to 10 MPa.

Effect of a Coating Deposited on Foam Glass on the Ability to Absorb High-Frequency Electromagnetic Radiation

The effect of a modified coating, deposited on the surface of foam glass, on the ability to absorb electromagnetic radiation in the high frequency range was studied. It was established that a coating obtained on the basis of a liquid glass composition with ilmenite with 3 μm particles improves the radio absorption characteristics of the foam glass. For 1.5% ilmenite concentration in the coating composition the absorption coefficient of foam glass increases four-fold at 120 GHz and two-fold at 260 GHz compared with uncoated foam glass.

Properties of Foam Glass Material Modified by Nanosize Zirconium Dioxide

The effect of small additions of zirconium concentrate with average particle size 30 nm on the physical and mechanical properties of foam glass is examined. It is found that the introduction of zirconium dioxide into the foaming mixture changes the macrostructure of foam glass and increases the average pore size to 2.5 mm. Nanosize ZrO2 decreases the viscosity of melt upon foaming. The optimal weight content of zirconium dioxide from the standpoint of mechanical properties is 0.3 wt.%. The strength of foam glass increases in the presence of nanosize particles to 1.4 MPa compared with the strength of the initial material 1.1 MPa. Subsequent increase of the zirconium dioxide content to 1.1 wt.% decreases the strength to 0.5 MPa.