International Scientific Journals
of Scientific Technical Union of Mechanical Engineering "Industry 4.0"

A general overview of a number of thermal insulation materials and products made on the basis of inorganic binders (mainly Portland cement) is presented. The technological methods of production, the main operational indicators and the application in construction of various heat-insulating and structural-heat-insulating lightweight concretes are examined. The structure of various cellular concretes (foam concretes and aerated concretes), composite materials and lightweight aggregate concrete was analyzed. The role of the origin, technological processing, characteristics and composition of different types of light additive materials for the formation of the final operational properties of the products has been traced.

The aim of this paper is to review the cleaning of solar photovoltaic (PV) systems and applied coatings that eliminates costly automated cleaning systems by using nano-sized TiO2 combined with various organic binders.

An innovative collapsible frame hive was developed, consisting of structural elements made of technical ceramics containing thermal insulation air chambers. Experimental prototypes were prepared using the slip casting method and based on modified recipe compositions, prepared casting molding masses, original gypsum matrices and optimal heat treatment mode. A comparison was performed between the main operational characteristics of the experimental samples and the traditional non-separable hives which have existed throughout history and made primarily of various plant materials and natural plastic raw materials (clays).

In summary form, some trends in the production and application of foamed silicate materials obtained from recycled waste materials are presented. The existing possibilities for the use of different fractions of foam glass granules for the preparation of various products (lightweight concrete, colored decorative panels, etc.) are considered. Experimental samples are prepared in which the average value of the thermal conductivity coefficient =0.24±0.13 W/m. K was established. The main technological factors determining the operational characteristics of the material and the existing potential prospects for their optimization are analyzed.

Experimental ceramic samples were obtained in which the presence of CaMgSi2O6 (predominant phase), MgCr2O4, CaAl2Si2O8 and quartz was detected by X-ray diffraction analysis. During the microscopic examination of the prepared sections, two mineral phases were established: main – clinopyroxene and secondary – green spinel. The presence of prismatic-granular and skeletal structure was found. In the formed dominant diopside phase the presence of numerous inclusions of magnesium-chromium spinel with green color (sizes up to 0,05 mm) was observed evenly distributed in the sections determining the characteristic green color of the samples.

In this paper we present the results of atomic force microscopy (AFM) characterization of the surface morphology of the nanostructured titanium oxide films featuring with Sm2O3 by the sol-gel method in order to increase the corrosion resistance of stainless steel. Two types of titanium precursors were applied – titanium (IV) isopropoxide Ti[OCH(CH3)2]4 and titanium(IV) butoxide Ti(OCH2CH2CH2CH3)4.

Different corrosion-resistant coatings based on various SiO2, TiO2, ZrO2 and CeO2oxides have been applied to various steels by the sol-gel method and spray pyrolysis. The obtained experimental coatings were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM) and weight loss measurements in 3.5% NaCl medium. TiO2 / SiO2 and CeO2/SiO2 coatings treated at lower temperatures (500oC) have been shown to exhibit higher corrosion resistance than ZrO2/SiO2 samples. Increasing the treatment temperature decreases the protective properties of the invesitgated coatings. The enhanced protective properties of TiO2/SiO2 are probably due to their low crystallized fine grained structure and relatively dense surface without visible cracks.

Sol gel TiO2-ZrO2 composite films were dip coated on stainless steel substrates and treated at 300, 400 and 500oC. The morphology and surface features were examined by Scanning electron microscopy (SEM) and X ray photoelectron spectroscopy (XPS). Xray diffraction analyses (XRD) was applied to investigate the phase composition. The corrosion resistances of the coatings were studied by evaluation of the weight loss in NaCl medium. According to XRD while the Zr-Ti composites are amorphous after treatment even at 500oC. The surfaces of the coatings possess typical island structure. The coatings, treated at 500oC ehxibit higher corrosion resistance than the other two type of samples. This could be explained by the amorphous structure of the composites, which lowers ion and electron conduction, high hydrophobicity and lower oxygen content.