VOL 74, No. 8 (2001)

The shapes and types of stress zones at the tops of edge cracks are investigated depending on the size of the crack, the presence of a propping fluid in it, and the presence of post-annealing stresses in the glass. The mechanism of glass surface protection from damage by exposure to post-annealing stresses is explained. Tab. 1, ill. 4, bibliography: 7 titles.

The results of research on the production of glass microspheres by the method of plasma spraying are presented. The influence of the parameters of the plasmatron operation on the grain size composition of the microspheres has been studied. Tab. 1, ill. 3, bibliography: 5 titles.

The drying properties of kaolins of the Southern Urals and the molding properties of porcelain masses based on them have been studied. Practical recommendations are given. Tab. 3.

Formation of silicon carbide products by freezing water slips is considered. Freezing mode developed. The composition of the slip is selected. Firing in a nitrogen-hydrogen atmosphere at a temperature of 1850 ° C made it possible to obtain samples, the properties of which are characteristic of this material. Tab. 1, ill. 1, bibliography: 6 titles.

The processes of silicate and glass formation in iron-containing glass mixtures based on technical raw materials (oxides and carbonates) and with the use of igneous rocks - metadiabases are investigated. The distinctive features of their course are revealed depending on the chemical composition of the glass. It has been established that the crystalline phases that have appeared in the process of silicate formation in the form of structural groups in the glass melt are preserved. The possibility of lowering the synthesis temperature of glaze frits using metadiabases is shown. Tab. 2, ill. 3, bibliography: 7 titles.

The results of the indexing of the X-ray diffraction pattern of a new modification of ZnO, previously obtained by the hydrothermal method, are presented. It has been suggested that this is a new high-density modification of zinc oxide, which crystallizes in a tetragonal body-centered lattice with a = 8.572 A and c = 7.186 A, z = 24. Its calculated density is 6.215 g / cm ³... Tab. 2, bibliography: 7 titles.

The optimal compositions of titanium-containing lead-free glasses have been determined for obtaining low-melting white coatings on sheet glass. The properties of glasses and coatings, their structure and phase composition have been investigated. The optimal modes of coating formation have been determined. Tab. 1, ill. 2, bibliography: 8 titles.

The effect of aluminum and cadmium oxides on glasses of an alkali-containing lead borosilicate system with a small amount of boron and lead has been studied. The influence of the ratio of aluminum and cadmium oxides on the color of the enamel, as well as on some physicochemical and technological parameters of the enamel is shown. It has been established that, on the basis of this system, it is possible to obtain a low-melting (780 - 800 ° C) corrosion-resistant blue enamel for copper and its alloys. Tab. 1, ill. 1, bibliography: 9 titles.

The results of a study of the dispersed composition of muscovite micas and wollastonite, the shape of the particles of which are characterized by significant anisometry, are presented. A simple method of sedimentation analysis is proposed, which makes it possible to quickly, and most importantly, with high accuracy, determine the distribution of particles by their sedimentation diameters. Dependences have been obtained, with the help of which it is possible to calculate the geometric dimensions of the particles of the materials under study. Il. 4, bibliography: 5 titles.