Electroplating of Indium-Cadmium and Tin-Cadmium Alloy Coatings

Technological parameters for electroplating cadmium alloy (Cd (24)-In and Cd (33)-Sn) coatings from low toxic solutions have been proposed. Since the fabricated alloy coatings possess low internal stress and microhardness, good adhesion property, high corrosion and wear resistance, they can be used as protective coatings for machine building products to enhance reliability and operability thereof. The presence of good solderability and low values of transient electric resistance in climatic testing favor these coatings to be applied in hetero-structured contact systems of instrument making products for increasing their reliability and operability in a tropical marine climate.

Estimating transmission line mismatch under thermal exposure conditions

The paper introduces a methodology for and the results of estimating transmission line mismatch when carrying out measurements of frequency-dependent parameters of radio and electronic equipment of military-purpose complexes and systems under climatic testing conditions.

THE INFLUENCE OF CLIMATIC FACTORS ON RESIDUAL STRESSES IN NANOMODIFIED CYANATE ESTER-BASED CFRP

The residual stresses in carbon fiber reinforced plastic (CFRP), based on VTkU-2.200 carbon fiber and VSC-14 cyanate ester resin, modified by nanoscale additives (astralen) were studied. Natural exposure was performed in a moderately cold climate. The influence of nanoadditives on mechanical and physical CFRP’s properties after 9 months of climatic testing was studied using the following properties: three-point bending strength, compression strength, coefficient of linear thermal expansion, glass transition temperature and residual stresses parameters. The increase of residual stresses after climatic testing was revealed.

Accelerated climatic testing of composite coatings on AMg3 aluminum alloy in salt spray medium

Представлены результаты ускоренных климатических испытаний композиционных полимерсодержащих покрытий на сплаве алюминия АМг3. Выявлено положительное влияние импрегнированного в поры ПЭО-покрытия композиционного материала на смачиваемость и коррозионную стойкость исследуемых образцов в условиях долговременного воздействия соляного тумана. Наиболее высокую коррозионную стойкость продемонстрировали образцы с четырехкратным нанесением ультрадисперсного политетрафторэтилена. The results of accelerated climatic tests of composite polymer-containing coatings on the AMg3 aluminum alloy are presented in the paper. According to the results of the studies carried out, a positive effect of the penetrated composite material into the pores of a PEO-coating on the wettability and corrosion resistance of the test samples under conditions of long-term exposure to salt fog has been revealed. The highest corrosion resistance was demonstrated by samples with a fourfold (СС-4x) application of superdispersed polytetrafluoroethylene.

Methodology for conducting climatic tests in cabins and habitable compartments of wheeled and tracked vehicles

In the course of many years of climate research and analysis of research works by other authors, a number of methodological errors were identified that did not allow obtaining objective and reliable research results in some cases. As a result of evaluating a number of research materials of domestic and foreign researchers, it was revealed that the real temperature and humidity characteristics are hidden inside the habitable compartments. This was done, most likely due to a commercial interest in distorted research results. Since the beginning of the 90s of the twentieth century, the author often had to take part in works of improving the climatic characteristics inside the inhabited compartments of special wheeled and tracked vehicles, but the vehicles were completely unsuitable for installing climate control systems by their design and did not have free power to ensure their mechanical and electrical drive. It is especially difficult to provide the required climatic characteris-tics in the habitable compartments at high temperatures. This is due to the fact that the cost of cold in the habitable compartment is 5−7 times higher than the cost of heat, besides, the units used to generate cold require greater precision and quality of manufacture compared to other units, and large vibration and shock loads lead to damage system parts and assemblies and refrigerant leaks. The studies were carried out to objectively assess the heat fluxes entering the cabins and habitable compartments. The results were compared with previous methodological developments. In the pro-cess of research it was determined that the main heat load of the cabins and habitable compartments is borne by solar radiation, penetrating into the habitable compartment through transparent fences. The recommendations for climatic testing of full-size vehicles and cabin prototypes based on the results of field studies were given. Full-scale climatic tests are inherently the most difficult, since they depend on changeable weather, and in many cases cannot be objectively reproduced in a cli-matic chamber.

Proposals to improve the durability assessment after ageing tests for wood-based sandwich panels

This work deals with the durability assessment, after ageing, of wood-based sandwich panels, carried out according to the European guideline ETAG 016, Annex C7 Climatic testing cycles. ETAG 016-2 is a guideline to assess the wood-based sandwich panels for roofs. It has tests and criteria for evaluating the results of these tests. As regards durability and performance under the weather, it proposes to choose one of three different climatic cycles. The choice depends on the material of the core. Each climate cycle has assessment criteria to measure whether the cycle has been successfully overcome or not. This assessment is related to the standard EN 14509, paragraph 5.2.3.1 that contains the same climatic test cycles. In this work we subjected several types of non-metallic sandwich panels to this test and criteria. Then, a critical review of these acceptance criteria was done. As a result, some recommendations are proposed regarding the acceptance criteria and testing procedure.

Autonomous Solar-Wind Power Forecasting Systems

The paper reports on the results of climatic testing of silicon photovoltaic modules and photovoltaic power systems conducted in Russia (Siberia and the Far East). The monitoring system to control the power system work was developed. Testing over 17 years and a large amount of experimental studies enabled us to develop a precise mathematical model of the photovoltaic module in natural environment taking into account climatic and hardware factors.