Thermal diffusivity of corrosion-resistant coating SDP-1

In the present work, the thermal diffusivity of the SDP-1 grade nickel alloy was investigated in the wide temperature range of 300-1476 K. The SDP-1 alloy (Ni-Co-Cr-Al-Y) is the heat-resistant coating for blades of gas turbine plants, providing protection against sulfide-oxide corrosion in the temperature range of 1070-1220 K. The measurements were performed by laser flash method using LFA-427 apparatus. The estimated errors of the obtained data were 2-5% depending on temperature. The thermal diffusivity approximation equations and a table of reference values for various scientific and practical applications were obtained.

On the protective layer boundary determining error in the thermal conductivity inverse problem

The article studies the problem of determining the error introduced by the inaccuracy of determining the thickness of a protective heat-resistant coating for composite materials. The mathematical problem is the heat conduction equation on an inhomogeneous half-line. The temperature on the outer side of the half-line (x = 0) is considered unknown on an infinite time interval. To find it, the temperature is measured at the media section at the point x = x0. An analytical study of the direct problem is carried out in the work. It made it possible to formulate the inverse problem mathematically rigorously and to define functional spaces in which it is convenient to solve the inverse problem. The main difficulty to be solved in the article is to obtain an estimate of the approximate solution error. The projection regularization method is used to estimate the modulus of conditional correctness, with the help of which order-exact estimates are obtained.

Optimization of laser cladding parameters of nickel-based metal powder for creation a heat-resistant coating

Optimization of laser deposition of nickel aluminide was carried out to obtain a single track of high quality. The structure of single tracks was investigated. Based on the data obtained, a multilayer structure was deposited and a study of the distribution of elements was carried out.

Preparation of the heat-resistant superhydrophobic coating with a nanostructured finish layer based on a suspension of silicon dioxide in a fluorinated film-former and its properties

The processes of obtaining compositions based on organosilicon resin for a heat-resistant coating of accelerated drying, as well as its hydrophobization by creating an isotropic nano-microstructure on the surface, are studied. It is shown that the chemical nature, the content of the ingredients and the thickness of the coatings have the greatest influence on the physicochemical properties of heat-resistant coatings. The methods of obtaining a composition for heat-resistant coatings using a dissolver and a bead mill in various modes of operation were studied, which allowed us to develop a technological process for manufacturing heat-resistant paint and varnish material. The composition and technology of obtaining a final hydrophobic layer based on a suspension of aerosil HDK 12H and carbon nanoparticles in a fluorine-containing varnish LF 32LN was developed in order to obtain a complex heat-resistant, superhydrophobic and anticorrosive coating for the protection of metal products and its properties were investigated.

Ensuring flat heat transfer in heat units of food production

Предлагается способ модификации тепловых блоков пищевых производств с точечным источником генерации теплоты, позволяющий обеспечить плоскостной принцип его передачи на стенки варочного сосуда. Способ обеспечивает повышенную износостойкость и жаропрочность стенок варочного сосуда и теплового блока за счет применения газодинамического напыления запатентованного состава специального покрытия, включающего коллоидный графит, оксид меди, каолин, металлические порошки и мелкодисперсную керамику. Раскрыт порядок нанесения покрытия на стенки теплового блока и варочного сосуда, приводятся физико-химические свойства исходных компонентов керамического жаростойкого покрытия, наносимого на внутренние стенки теплового блока. Предложены образцы теплового оборудования для подготовки исходных компонентов изготовления противоизносного жаростойкого защитного покрытия. Обоснованы условия реализации технических и технологических операций по нанесению покрытий. Исследованы зависимости и получены закономерности изменения теплопередачи и теплопотерь в тепловых блоках пищевых производств в зависимости от состава покрытия и его толщины. A method is proposed for modifying the thermal blocks of food production with a point source of heat generation, which allows to ensure the plane principle of its transfer to the walls of the cooking vessel. The method provides increased wear resistance and heat resistance of the walls of the cooking vessel and the heat block due to the use of gas-dynamic spraying of a patented composition of a special coating including colloidal graphite, copper oxide, kaolin, metal powders and fine ceramics. The procedure for coating the walls of the heating block and the cooking vessel is disclosed, and the physicochemical properties of the initial components of the ceramic heat-resistant coating applied to the inner walls of the heating block are presented. Samples of thermal equipment for the preparation of the initial components for the manufacture of antiwear heat-resistant protective coating are proposed. The conditions for the implementation of technical and technological operations for coating are substantiated. The dependences are investigated and the regularities of changes in heat transfer and heat losses in the thermal blocks of food production are obtained depending on the composition of the coating and its thickness.

Development of organosilicon decorative coating with craquelure effect

The article analyzes coatings based on organosilicon compounds and presents the results of research on the selection components of compositions that provide protection of painted products from corrosive environments, mechanical and thermal effects. Defects of paint and varnish coatings are investigated. The expediency of modifying organosilicon film-forming compositions with solutions bead polymers of polymethyl methacrylate and polybutyl methacrylate has been substantiated. To obtain a heat-resistant coating, two compositions were developed for the lower and upper layers. The bottom layer was KO-85 organosilicon varnish modified with solutions of bead polymers and PF-060 alkyd varnish. To regulate the wetting and spreading, surfactants were introduced into the bottom layer, which could improve the structural, mechanical and decorative properties of the coatings. The top layer of the coating with the craquelure effect was KO-868 silicone enamel modified with functional additives that increase the surface tension and reduce the spreadability of the resulting composition. Research has been carried out on the physica-mechanical (adhesion, impact strength, elasticity of the film during bending), decorative (change in gloss, color, dirt retention, chalking) and protective (cracking, peeling, weathering, bubble formation, corrosion of metaln, wrinkling, dissolution) properties of a two-layer coating, as well as its resistance to water, gasoline, mineral oil and temperature.

A BLOCK OF THERMAL INSULATION MATERIALS WITH PROTECTIVE AND DECORATIVE COATINGS

scientific and technological principles of alternative plasma technology for the production of two-layer heat-resistant glass-like decorative coating were developed. The compositions of the intermediate heat-resistant layer and the technology of its application to the surface of the enclosing block of foam glass are proposed. The optimal parameters of plasma melting of heat-resistant and decorative coating layers were determined. The influence of high-speed characteristics of plasma jet thermal melting on the formation of texture and performance of two-layer heat-resistant coating is established. The features of the formation of amorphous vitreous and glass-crystalline phases of a two-layer heat-resistant coating are presented. Using x-ray phase analysis, the features of the phase composition of different layers of heat-resistant coating, as well as the laws of formation of its structural elements are studied. Based on the analysis of significant experimental material, it was concluded that the formation of the upper amorphous layer with liquating regions and minor gas inclusions. The conducted researches allowed to reveal and justify the features of the structure of the layers lying under the amorphous liquating. It was found that the two-layer protective and decorative coating had high physico-chemical and physico-mechanical properties: adhesion strength to the matrix of the foam glass block-1.25 ± 0.05 MPa, microhardness-785 HV, heat resistance-122°C, acid resistance – 98.5%, alkali resistance – 95.4%.

Block Foam Glass with Plasma Protective and Decorative Coatings

An innovative energy-saving technology for producing block foam glass with a protective decorative coating has been developed, including the preliminary application of an intermediate heat resistant coating followed by the application of the main coating and the plasma jet melting. The optimal composition of the intermediate heat resistant coating, its preparation technology and laying on the front surface of the foam glass block are determined. It is shown that the main factor shaping the quality of the foam glass insulating block with a protective decorative coating is the speed of the plasma burner movement with a plasma jet on the front surface of the foam block glass with a preliminary applied two-layer heat resistant protective decorative coating. The formation regularity of the front layer texture of a protective and decorative coating on the plasma jet speed to the enclosing foam glass block has been established. It is shown that at the optimum plasma processing speed of 10 mm/s, a continuous, high-quality protective and decorative coating is formed. The features of the phase composition and microstructure of a multilayer heat resistant protective decorative coating are investigated. It is established that the surface layer is represented by an amorphous vitreous phase.