Powder mixtures based on calcium hydroxyapatite (HAP) and sodium dihydrogen phosphate have been investigated. It was found that due to mechanochemical activation in these mixtures, calcium phosphates are formed with the ratio Ca: P = 1. When heated, each of the components of the mixture undergoes changes: HAP (Ca: P = 1.67) partially transforms into tricalcium phosphate (Ca: P = 1.5), low-temperature calcium phosphates brushite and monetite (Ca: P = 1) transform into calcium pyrophosphate , NaH 2 PO 4 becomes NaPO 3 , and Na 2 HPO 4 - in Na 4 P 2 O 7 . In this case, the components interact with each other to form double ortho- and metaphosphates of sodium calcium. Tab. 1, ill. 3, bibliography: 9 titles.
The effect of complex additives SB-FF + TPFN, S-3 + TPFN, rheotan + TPFN on the mobility of ceramic slip is considered. The effect of these complexes on the physical and mechanical properties of ceramic specimens after firing has been studied. It was revealed that the complex additive SB-FF + TPFN allows to increase the mobility of the ceramic slip and the rate of mass gain in comparison with additives based on C-3 and rheotane, as well as to improve the operational properties of finished products. Tab. 2, bibliography: 2 titles.
The results of the synthesis of composite materials based on silicon nitride, which were discussed from the standpoint of chemical and (or) thermal conjugation, are presented.
The synthesis of silicon nitride during the interaction of ferrosilicon in nitrogen in the combustion mode is considered as an inducing process. It is shown that due to the energy of self-propagating high-temperature synthesis in the process of nitriding ferrosilicon, it is possible to obtain composite ceramic materials based on silicon nitride: Si 3 N 4 - ZrO 2 - Si 2 N 2 O, Si 3 N 4 - TiN - Si 2 N 2 O, Si 3 N 4 - BN, Si 3 Al 3 O 3 N 5 and Si 3 N 4 - SiC. Il. 6, bibliography: 18 titles.
The compositions of single-fired ceramic tiles using phosphogypsum and waste from the production of acetate fiber - LiCl - have been developed and investigated. The mathematical planning of the experiment was carried out, as a result of which a system of mathematical equations was obtained that characterizes the dependence of the properties of ceramic tiles on the content of various components. The calculated results were checked.
Tab. 5, ill. 2, bibliography: 2 titles.
On the basis of red-burning clays, light ceramics with good decorative and technical characteristics were obtained by introducing into the ceramic mass CaCO 3 in the form of finely dispersed waste of sugar production. Tab. 1, bibliography: 2 titles.
Possibilities of obtaining building ceramics on the basis of "tailings" of concentration of vermiculite and apatite-nepheline ores have been investigated. Ceramic masses are proposed that are promising for the production of facing tiles, as well as solid and hollow bricks with improved physical and mechanical characteristics. Tab. 3, ill. 2, bibliography: 1 title.
Based on the calculations performed for various types of densest packings of spherical particles, it was concluded that it is possible to create in practice porous permeable ceramic materials with open porosity of more than 42 ±; 3%. The influence of the molding method (semi-dry pressing and slip casting), as well as the habit of crystals on the open porosity of ceramics, is shown. The assessment of the chemical resistance of the obtained porous ceramic materials in nitric acid and caustic soda is carried out. Tab. 4, ill. 4, bibliography: 7 titles.
The possibility of obtaining soft porcelain from ceramic masses based on unenriched kaolin from the Donetsk deposit is considered. The physical and mechanical properties and whiteness of the obtained samples were determined. The dependence of the reflection coefficient of individual porcelain phases on the Fe 2 O 3 content has been investigated. Tab. 4, ill. 1, bibliography: 4 titles.
The results of X-ray diffraction studies of two new modifications of aluminum oxide with tetragonal and hexagonal cells, synthesized by the explosion of a mixture of otktogen - aluminum hydride (90/10% by weight) are presented. Tetragonal cell parameters: a = 7.932 (6) & Aring ;, c = 9.142 (5) & Aring ;, c / a = 1.153, V = 575 & Aring; 3 ; hexagonal: a = 9.140 (3) & Aring ;, c = 3.980 (4) & Aring ;, c / a = 0.435, V = 288 & Aring; 3 . Conversion matrices of cell parameters are given. Tab. 1, bibliography: 3 titles.
The peculiarities of staining the glaze in blue with adjustable shades have been studied. The physicochemical properties of glazes with a given content of cobalt oxide and modifier oxides carrying active oxygen have been determined. A glaze of optimal composition with high aesthetic and performance characteristics has been synthesized. Tab. 2, ill. 3, bibliography: 1 title.
