VOL 91, No. 3 (2018)

A review of technologies for laser welding of glass is carried out. The technologies of welding with continuous CO ₂ -laser radiation in the mode of surface heating and in the mode of deep penetration are presented. The technology of glass microwelding by lasers with ultrashort pulses and high pulse repetition rate is considered.

The phase composition, structure and distribution of elements and hydrolytic stability of quenched and annealed sodium aluminum phosphate (NAF) and sodium aluminum iron phosphate (NAIP) glass materials containing over 100 & # 37; 10 & # 37; (mass content) oxides of rare earth elements (REE). It was shown that all materials obtained by quenching the melts, except for La-containing ones, were X-ray amorphous, while slowly cooled (annealed) materials partially or completely crystallized with the precipitation of various phases of orthophosphates. The leaching rate of elements from annealed NAF glasses, determined at 90 ° C, is approximately 1 - 2 orders of magnitude higher than from tempered ones, and the leaching rates of elements from tempered NAF glasses are lower than from tempered NAF glasses.

A comprehensive assessment of the state of the glazed porcelain surface by mechanical and optical means has been carried out. It is shown that both of these tools can be used to assess the quality of the glazed surface, but in combination they are more informative. It was determined that the brilliance of the surface is more influenced not by the depth of irregularities, but by their width. In terms of the surface quality of the feldspar glaze, the hard porcelain specimens are inferior to the bone porcelain specimen.

The results of studying the properties of heat-efficient ceramic materials from substandard clay raw materials and microgranules of foam glass as a porous, emaciated component are presented. Foam glass micro-granules shorten the drying process and reduce the firing temperature. The structural and textural features of the obtained heat-efficient materials and their influence on the physical and mechanical properties have been investigated.

9th INTERNATIONAL CONFERENCE & # 171; STEKLOPROGRESS-XXI & # 187;
22 - 25 May 2018, JSC & # 171; Saratov Institute of Glass & # 187;, Saratov
The purpose of the conference is to analyze the current state and the development of the glass industry, science, international business cooperation, training for the industry.
We invite you to take part in the 9th International Conference & # 171; Glass-progress-XXI & # 187;, which will be held on May 22 - 25, 2018 in JSC & # 171; Saratov Institute of Glass & # 187;, Saratov.

A study of the properties of lightweight geopolymer materials (GM) based on refractory technogenic waste of aluminosilicates has been carried out. The effect of the ratio of oxides SiO ₂ and Al ₂ O ₃ in the compositions of GM on the physical and mechanical properties of GM has been investigated. It was found that a decrease in the ratio SiO ₂ / Al ₂ O ₃ in the composition of GM leads to an increase in density and strength, and a decrease in water absorption of samples after exposure. After firing at temperatures of 800 and 1000 & # 176; C, the strength of the samples is the higher, the lower the ratio of SiO ₂ / Al ₂ O ₃ in the composition... The heat resistance of samples with a high ratio SiO ₂ / Al ₂ O ₃ is four thermal cycles, and with a low ratio, more than seven cycles

On the basis of liquid glass modified with sodium chloride and salt waste of aluminum production, a heat-insulating material was obtained without the use of natural traditional materials. The presence of isometric and oval pores in the test samples gives them mechanical strength. The X-ray phase composition showed the presence of mullite and anorthite in the samples, which provide strength to heat-insulating materials. The formation of mullite is facilitated by an increased content of alkalis and iron, which reduce the temperature of its crystallization to 1100 ° C

The loss of stability of the wetting water films on the quartz surface with increasing temperature was found. It is assumed that this is due to the temperature dependence of the structure of water in the wall layer. Based on the results of measuring the contact angle of wetting, the calculation of the parameter characterizing the magnitude of the structural forces was carried out. The inversion of the parameter sign is associated with the predominance of the forces of hydrophobic attraction over the forces of hydrophilic repulsion in a certain temperature range. The results of deferrization of glass quartz sands by flotation under temperature action on wetting water films are presented.

From an aqueous solution of calcium acetate and a mixed-anionic (HPO ₄ ^2- / CO ₃ ^2-) aqueous solution containing ammonium hydrogen phosphate and ammonium carbonate, an X-ray amorphous powder was synthesized at room temperature without pH adjustment. Powders synthesized from a mixed-anionic (HPO ₄ ^2- / CO ₃ ^2-) solution can be recommended for the manufacture of composite materials with a polymer matrix or for the production of ceramics containing tricalcium-phosphate and calcite phases at a firing temperature of no more than 600 ° C