Vol 74, No 9-10 (2018)

Different methods of molding glass and their physical-chemical and technological particulars are examined. The structural and deformation characteristics of glass-forming melts, forehearth characteristics of glass, and the molding conditions in isothermal and non-isothermal regimes are noted. An expanded classification of molding processes is presented

The sequence of formation of the crystalline phases during heat-treatment of composite glass mixtures 0.5MgO · 0.2BaO · 0.3B₂O₃ – kaolin is determined by means of thermodynamic calculations. It is shown that celsian is the primary crystalline phase and cordierite the secondary phase.

The possibility of formation and the thermal stability of nano-disperse bicomponent materials in the system SnO₂–CeO₂ were studied. The samples were identified by means of XPA, TEM-HTXPA, and low-temperature adsorption of nitrogen.

The possibility of increasing the strength of ceramic by introducing the ceramic-forming polymer polydimethylsilane into the batch is examined. Upon the introduction of polydimethylsilane into the mix a transition of polydimethylsilane into polycarbosilane is observed in the presence of the catalyst molybdenum chloride and is followed by a transition of polycarbosilane into silicon carbide. It is shown that the introduction of this additive with weight content > 4% increases strength and decreases open porosity.

The mass-operational characteristics of magnetic control of iron impurities in raw materials (silica sand, feldspar, gypsum), following an exponential law both fully and partially (tail section), when an experimental-computational model of control of iron impurities is possible taking account of the appropriate corrections, are analyzed. It is shown for different sources of the field that the results of magnetic control performed with a limited number of operations differ considerably between one another while for an unlimited number of operations (operational-computational method) they remain practically identical even though the form of the mass-operational characteristic changes.

The results of investigations of the stability of VOK-60 cutting ceramic during machining of hardened steel blanks made of No. 45 steel of different hardness 45 HRC and 54 HRC are presented. The stability of the cutting ceramic plate during machining of a harder blank is 41% higher than in machining of a less-hard blank. A microstructural analysis of the damage to the working surface was performed and the mechanism of wear of the cutting plate was determined. The reasons for the more rapid wear of the plate during machining of a less-hard blank were determined.

Coatings on glass witness samples, making it possible to set the process regimes for deposition, as well as the operational parameters of the setup — working current, voltage, limit and working vacuum as well as the required number of coating layers — were investigated. The measurement of the resistance of metallized coatings on nonwoven materials in definite regimes showed a value from 32 to 11 Ω/cm², as set by the experimental conditions.

A method for producing porous ceramic biocompatible with living tissues owing to the introduction of calcium phosphates in the interior of the ceramic was developed on the basis of zirconium, titanium, and aluminum oxides. A bioactive coating is formed directly during the fabrication of the sample. The resulting two-phase ceramic is characterized by developed microrelief. The samples meet the mechanical requirements of implants to be used as bone tissue replacements.

Different designs of hopper assemblies for glass batch mixers are examined. The factors affecting the shape, volume, and number of receiving hoppers for mixers are determined. It is shown that buckets as well as vibratory, auger, and ribbon feeders can be used to unload a batch from the mixing apparatus. Certain variants of rotary vibratory mechanisms used for unloading a mixture of raw materials from the receiving hoppers of batch mixers are presented.