On October 29, Vladimir Nikolaevich Sigaev celebrated his 75th birthday - Doctor of Chemical Sciences, Professor, Head of the Department of Chemical Technology of Glass and Sitalls of the Russian University of Chemical Technology. D. I. Mendeleeva (RCTU), honorary worker of higher professional education of the Russian Federation, member of the editorial board of the magazine & # 171; Glass and ceramics & # 187;.
The possibility of spatially selective crystallization of lithium-niobium germanate glasses with compositions (molar content, & # 37;) 25Li 2 O & middot; 30Nb 2 O 5 & middot; 45GeO has been demonstrated 2 and 30Li 2 O & middot; 25Nb 2 O 5 & middot; 45GeO 2 femtosecond laser beam with the formation of birefringent structures containing lithium niobate. A correlation has been established between the orientation of the fast axis of birefringence of crystallized tracks and the plane of polarization of the laser beam.
In the system Me 2 O & mdash; Ga 2 O 3 & mdash; GeO 2 & mdash; SiO 2 < / sub> (Me = Li, Na) a glass was obtained that meets the requirements of GOST in terms of impossibility for optical glass of the first category. Subsequent heat treatment results in the release of & # 947; -Ga 2 O 3 nanocrystals in it and the initiation of luminescence, excited only by UV radiation of the solar-blind range. The integral light transmission in the visible region and the luminescence intensity of the developed material are comparable with the same characteristics of glass-crystalline samples, the glass for which was obtained by melt quenching.
The effect of the addition of Al 2 O 3 and the heat treatment mode on the luminescence spectra of gallate glass ceramics has been investigated. The possibility of increasing the efficiency of its luminescence by
changing the submicron inhomogeneous structure of the initial glasses is shown.
Nanoporous glass is a universal matrix in which, by impregnating various substances, it is possible to initiate the appearance of properties uncharacteristic of glass. In this case, the porosity of glass can be controlled by heat treatment, creating a material with a given structure and properties. In this work, we studied the effect of heat treatment on the structure of porous glass impregnated with gold, and revealed the potential of this material as active substrates for Raman spectroscopy.
The effect of Nd 2 O 3 (0.1 - 3.0 & # 37;, molar content) oxide additives on the synthesis conditions, crystallization and spectral properties of heat-resistant sitall of the Li system was studied 2 O & ndash; Al 2 O 3 & ndash; SiO 2 (LAS). Introducing it to 1 & # 37; molar content of Nd 2 O 3 does not affect the crystallization properties and precipitation of the main crystalline phase of & # 946; -eucryptite-like solid solutions Li x Al x Si l & ndash; x O 2 , while an increase in the molar content of Nd 2 O 3 to 3 & # 37; significantly changes the character of crystallization of LAS glass. The results obtained show that an optical sitall with a near-zero LTEC value, activated by neodymium ions up to the N N d 3 + & # 8776; 4 & middot; 10 2 0 cm & ndash; 3 , can be considered as a basis for creating new light-emitting thermostable optical media
Reliable protection of the screens of new generation mobile devices requires the use of transparent materials that are stronger than glass. In this work, the influence of sitallization conditions on the structure and properties of sitall based on the ZnO - MgO - Al 2 O 3 - SiO 2 system is studied and is shown the prospects of its application for these purposes. Optimization of the sitallization mode allows increasing the microhardness of the material to values ??of more than 900 HV while maintaining transparency
The prospects of using recycled carbon fiber extracted from aviation carbon fiber waste for reinforcing composite materials based on blast-furnace slag activated with sodium silicate solution are evaluated. The influence of the concentration and length of the secondary carbon fiber on the structure, physical and mechanical properties and the nature of the destruction of dispersed-reinforced composites has been investigated.
The possibility of obtaining lightweight porous proppants based on metallurgical slags has been investigated. The structure, phase composition and some operational and physical properties of the obtained spheroidized bodies have been studied.
The possibilities of strong local bonding of glasses and metals with close thermal expansion coefficients by means of welding with a femtosecond laser beam have been investigated. For the first time, measurements of the shear strength of a welded joint of quartz glass with an Invar alloy, which amounted to about 26 MPa
