Glass and Ceramics

It is shown by direct methods that under the action of the surfactants present in polishing compositions the deformational-strength properties of a thin surface layer of solid bodies change in fine abrasive machining processes. Ruby and quartz were used as examples.

A physico-chemical analysis is performed of technologies for producing quartz grit and making glass from it. Experimental production of glass from grit was performed. The conditions of melting made it possible to form microgranular inhomogeneity with a volumetric network of boundaries in a glass ingot decorated with impurities. Optical, electron microscopic, and mass spectroscopic studies confirm the new hypothesis of microgranular heterogeneity appearing in quartz glass. The results of these studies can be taken into account when making high-quality ultrapure quartz glass for science-intensive industries.

The results of mechanoluminescence (ML) and acoustic emission (AE) studies of the response of the ceramic materials ZnS and ZnSe to impact damage to the surface are presented. The experiment simulates the process of dust erosion of optical components made from these materials and installed on high-speed mobile carriers. A comparison of a time series of light and sound emissions showed that ML manifests two peaks approximately 50 – 200 and 150 – 200 μsec after impact, while AE occurs in a single peak near 200 μsec. This result is explained by plastic deformation of the material at the first stage of fracture and subsequent formation of microcracks.

Mathematical models of the dynamics of mechanical stress fields in glass articles with complex configuration of the cylindrical-conical and prismatic-cylindrical type were developed. Finite difference equations making possible computer modeling of the process of change of the stress state in a glass article during firing are derived, using the obtained models of the dynamics of temperature fields, on the basis of a relaxation theory of vitrification. The results of a computer experiment on models of the dynamics of the mechanical stress field in glass articles are presented.

The results of calculations of thermal processes occurring in a bonded diamond tool during grinding of different materials on the surface in the contact zone with the machined material and in the interior of the diamond tool are presented. Amathematical model of the heating of the binder of the diamond tool as a result of friction in the grinding zone and cooling by a cutting liquid (CL) is described.

Aspects of the digitization of the economics of glass production are examined. The effect of digitization on the appearance of new and change an existing business models is shown. Owing to the modernization of glass production on the basis of Industry 4.0 technology it is possible to optimize and automate the basic production and control processes of a business, increase equipment utilization efficiency, and improve the planning of raw-materials consumption and finished-goods production schedules.

The results of the synthesis and analysis of diamond crystals with heavy boron doping (about 2%), which were obtained from mixtures of gas black with m-carborane at 8 GPa and 1873 K, are presented. A high boron concentration in the diamond lattice was confirmed by x-ray data and the characteristic Raman scattering spectra, which correspond to diamond with metallic conductivity. Thermobaric treatment of the diamond-like dl-BC₃ phase (1100 K, 25 GPa) results in the formation of BC₃-heteronanodiamond.

The synthesis of ceramic matrices, based on zirconium-enriched pyrochlore for the immobilization of high-level waste (HLW), by means of self-propagating high-temperature synthesis (SHS) under the pressure of argon and compressed air in a SHS-reactor was investigated. The dependences of the phase composition and characteristics of the crystalline phases of the material on the gas pressure were determined. It is shown that all rare-earth elements (REE) (Ce⁴⁺, La³⁺) from the model mixture of the HLW are incorporated into the structure of the ceramic. It is established based on evidence derived from elemental analysis that lanthanides are concentrated in the perovskite and pyrochlore structures.

The effect of different methods of processing quartz accessories for the purpose of completely removing hardly soluble films of borosilicate and phosphosilicate glasses is investigated. It is shown that the methods developed for processing quartz accessories make it possible to increase cleaning efficiency substantially. The optimal processing regimes for quartz accessories are presented.

The results of chemical and x-ray phase analysis of non-metalliferous raw materials resources are presented: diabase from Arvaten-Karakiiskoe, andesibasalt from the Karakhtaiskoe, and basalts from the Asmansaiskoe deposits, which are characterized as igneous rocks, and gabbro from the Akchinskoe deposit, which are characterized as intrusion rock. It was determined that the investigated magmatic rocks are promising raw materials for obtaining heat-insulating materials for various purposes.