Abstract. Creating a functionally oriented, including nanostructured, anti-friction materials and coatings with qualitatively new complex of service properties is an important scientific and practical problem. In particular, for the cable industry it is urgent task of ensuring the high performance properties of fast deteriorating stretching and supporting rollers. Working surfaces of these parts operate under practically dry friction conditions with constantly updated material of stretching wire. Plasma spraying is one of the widely used methods of surface engineering to create wear resistant coatings and which is characterized with process flexibility and the ability to create coatings using various materials and alloys including composite ones. The installation UPU-3D with the PP-25 plasma torch was used for plasma spraying. The thickness of the sprayed layer was 0.8-1.1 mm. As a material for the deposition of composite coatings a powder mixture of self-fluxing nickel alloy PG-HN80SR4 (system Ni-Fe-Cr-Si-B-C) and a neutral oxide ceramics Al 2 O 3 was used. The amount of ceramics varied from 15 to 33 %. This ceramic oxide was selected due to the desire to reduce coatings' costs while providing high durability. Carried out phase and microstructural studies have shown when ceramics was added in an amount more than 20 % a formation of conglomerates formed by not melted alumina particles often was observed. These conglomerates serve as crack formation centers in the coating. The phase composition of the coatings practically does not depend on the content of ceramics compounds. Tribological tests have shown that the best results were obtained when the content of the oxide ceramic in the coating was in the range from 15 to 20 %. Реферат. Создание функционально ориентированных, в том числе наноструктурированных, антифрикционных мате-риалов и покрытий, обладающих качественно новым комплексом служебных свойств, является важной научной и практической задачей. В частности, для кабельного производства актуальна задача обеспечения высоких эксплуа-тационных свойств быстроизнашивающихся протягивающих и поддерживающих роликов кабельного производства. Рабочие поверхности этих деталей работают в условиях практически сухого трения при постоянно обновляющемся материале протягиваемой проволоки. Один из широко применяемых методов инженерии поверхности для создания износостойких покрытий -плазменное напыление, которое характеризуется гибкостью процесса и возможностью создавать покрытия из различных материалов и сплавов, включая композиционные покрытия. Для плазменного напыления использовали установку УПУ-3Д с плазмотроном ПП-25. Толщина напыленного слоя составила 0,8-1,1 мм. В качестве материала для создания композиционных покрытий применяли смесь порошков самофлюсующегося нике- и Машиностроение левого сплава ПГ-ХН80СР4 (системы Ni-Fe-Cr-Si-B-C) и нейтральной оксидной керамики Al 2 O 3 . Количество вво-димой керамики изменялось от 15 до 33 %. Выбор данной оксидной керамики обусловлен стремлением снизить сто-имость покрытия при обеспе...

The paper describes investigations on wear-resistant coatings from diffusion-alloyed austenitic steel obtained while using plasma spraying and subsequent laser processing. It is common knowledge that majority of machine parts and equipment has been out of service due to wear of surface layer. Application of diffusion-alloyed powder ПР-Х18Н9 based on austenitic steel while using combined technology including plasma spraying and laser infusion makes it possible to obtain qualitative coatings with high operational characteristics. The coating has a homogeneous structure with characteristic dispersive finely-dendrite formation. While using various powder boronizing modes and laser processing it is possible to control a porosity  (0,23–4,70 %) because the given factor is considered as an inherited parameter and it is influenced not only by laser processing characteristics but by powder boronizing time. It has been established that  the least deformations and internal stresses are formed in the coating in the case when self-fluxing diffusion-alloyed powder has been applied for 3 hours.  It has been revealed that there is a sharp increase in micro-hardness at the depth of 150-400 µm from the surface for a specific energy of 100-300 J/mm2 regardless of boronizing time. Coatings can be successfully applied in industry because after laser infusion the required mechanical processing of parts will not worsen operational characteristics when less hard coating layer is removed. Tests of parts under conditions of dry sliding friction without lubrication  have shown an increase of wear-resistance by 3.0-3.2-fold while preserving corrosion-resistance.

Формирование и исследование многослойных композиционных плазменных оксидных покрытий на элементах экранной противометеорной защиты Канд. техн. наук В. А. Оковитый 1) , докт. техн. наук, проф., чл.-кор. НАН Беларуси Ф. И. Пантелеенко 1) , докт. техн. наук, проф. О. Г. Девойно 1) , асп. В. В. Оковитый 1) , докт. физ.-мат. наук, проф., чл.-кор. НАН Беларуси В. М. Асташинский 2) , докт. физ.-мат. наук П. П. Храмцов 2) , канд. физ.-мат. наук М. Ю. Черник 2) , докт. физ.-мат. наук, проф. В. В. Углов 3) , канд. техн. наук С. Б. Соболевский 4) 1) Белорусский национальный технический университет (Минск, Республика Беларусь), 2) Институт тепло-и массообмена имени А. В. Лыкова НАН Беларуси (Минск, Республика Беларусь), 3) Белорусский государственный университет (Минск, Республика Беларусь), 4) РУП «БелНИИТ «Транстехника» (Минск, Республика Беларусь)

No abstract

Over the past few years, a group of new processes was developed for high-temperature, including plasma electric arc spraying (at ambient pressure) and spheroidizing of some ceramic and metal powder materials with the use of gaseous hydrocarbons in the heat carriers as well as with feeding of organic additions into a high-temperature jet, in particular, polymeric ones, to control porosity of sprayed metallic functional coatings. The paper considers the possibility to modify such technological processes by introducing solid fuel additions of a polymer type into the operating fluid of an apparatus for gasthermal (plasma or other) treatment, which provides melting of metal or oxide powders. For this, with the help of thermodynamic analysis, the processes have been evaluated at temperatures (300–3000) K for the set of such reacting five component systems as C–H–O–N–Me (at ambient pressure 0.101 MPa) with five variants of Ме – aluminum, titanium, chrome, copper, nickel. This makes it possible to consider these systems as simulants for potential technologies for the treatment of oxide powders (Al2O3, TiO2, Cr2O3) as well as metallic ones (Cu, Ni and their alloys). In order to obtain high exothermic contribution to the heating of powders, the combination “air + polymeric addition (polyethylene) of LDPE grade” was chosen as mixed heat carrier (operating fluid) for the basic version of simulated process. During the analysis of equilibria for the considered multicomponent systems (17 variants), a set of following parameters has been used to characterize the energy intensity of the target powder heating process: the equivalence ratio for reacting mixture and its adiabatic temperature; the energy efficiency of material heating with and without taking into account the effect of fuel addition; specific energy consumption for the powder melting; autothermicity degree of the process during the combined heating (electrothermal heating by the arc of plasma torch and heat flux from the “air + solid fuel additions” mixture) of refractory powders. As a result of the assessment, the preferred (from thermodynamic standpoint) regimes of the considered processes have been found and the possibility to realize an energy-efficient heating of these oxide and metal materials (without oxidation of the latter to CuOx, NiO) with a reduced part of the electric channel of energy transfer, resulted from the carrying out of appreciable effect of the fuel-initiated mechanism of heating in the analyzed C–H–O–N–Mesystems, has been shown in the paper.