№5 2021
-
1
An overview of traditional methods for cleaning the surface of gas turbine engine (GTE) blades from products of gas corrosion and spent coating, methods for restoring the structure and properties of the material of blades using hot isostatic pressing and heat treatment, as well as methods for applying coatings on the inner and outer surfaces of the blades is presented. The main disadvantages of these methods are described, taking into account which the state-of-the-art technology for repairing gas-turbine engine nozzle blades made of ZhS6U alloy has been developed in FSUE «VIAM», which ensures an increase in their resource and a reduction in repair costs.
-
2
In the work, the development of technologies for the manufacture and production of standard samples of heat-resistant nickel-based alloys: SDP-1, SDP-2, VSPD-9, VZhL-2, AZh-8. Developed and certified by MI 1.2.027–2011 «Method of measuring alloying elements by x-ray fluorescence method in heat-resistant alloys» establishes the measurement of the dimensions of alloying elements in heat-resistant nickel-based alloys by x-ray fluorescence method. The registration of the RSA of heat-resistant nickel-based alloys SDP-1, SDP-2, VSPD-9, VZhL-2, AZh-8 in the System of voluntary certification of standard samples of materials and materials.
-
3
The Al2Ti intermetallic compound is a promising material for the development of heat-resistant alloys used for the manufacture of shaped parts for ground and aircraft power plants. Considers the features of the structure of two-phase alloys, evaluates the casting properties and technological characteristics in comparison with various AlTi alloys, as applied to the production of ingots and cast products. It is necessary to use technologies developed for titanium alloys in the production of cast products from such alloys.
-
4
A technology for the manufacture and production of reference material (CRM) of the composition of magnesium alloys of the VML20 and VMD16 grades has been developed. In FSUE «VNIIOFI» tests of CRM material were carried out in order to approve their type, as well as metrological examination. Conclusions were drawn up on checking the results of CRM testing for the composition of the indicated alloys and certificates of type approval of reference materials were issued. CRM sets of the approved type of state standard samples of high-strength magnesium alloys of VML20 and VMD16 grades have a relative error of the certified values of the mass fraction of elements in the range from 0.5 to 5% (by weight) no more than 5% rel.
-
5
The properties of the adhesive VKR-85 recommended for gluing rubbers, rubber fabric materials bands together and gluing them to metals during the vulcanization process are given. It is shown for which types of rubbers the adhesive can be used, performance of adhesive joints under the influence of various factors. A comparison of the properties of the adhesive joints based on adhesive VKR-85 with adhesives of a similar purpose – Leuconate and Desmodur RE is given. Adhesive joints strength made with adhesive VKR-85 is higher than strength of the bonded rubber.
-
6
An overview of polymeric materials of various structures used as antifriction materials is given. The experience of using various polymeric materials for the manufacture of antifriction coatings is considered. The advantages of thermosetting and thermoplastic polymers in comparison with metallic materials are revealed. Some compositions of carbon and organoplastics developed for plain bearings are described. A conclusion is made about the direction of research in the development of new binders for antifriction materials.
-
7Part 1
Data on the use of various types of silver filler in electrically conductive adhesive compositions are presented. The influence of form and size particles of silver filler on the conductive properties of adhesive bondline.
The effect of surface treatment of conductive particles with surfactants, the component composition of the resin part and the curing conditions of conductive adhesive compositions on their microstructure and conductive properties is shown.An overview of the results of studies of the microstructure of conductive silver-containing adhesive compositions is given.
-
8
The properties of heat-resistant polymer fibers (Arimid, PFBT) and samples of organoplastics based on them have been investigated. It has been established that polyimide and polybenzazole fibers can be used as a reinforcing filler to create organoplastics at operating temperatures up to 350‒400 °C. The level of retention of the elastic modulus in bending of organoplastics based on PFBT fiber and IP-5 heterocyclic binder is 90 %. Heat-resistant organoplastics are promising for use in the aerospace industry and mechanical engineering.
-
9
Experimental compositions of coatings based on SiO2–Al2O3–MgO matrix glass and modifying additives are considered. A number of refractory metal oxides were selected as modifying additives. The influence of these additives on the properties of the coating melt, such as the spreadability and the wetting edge angle, as well as the oxidability of the resulting compositions, is studied. It was found that the experimental coating modified with aluminum oxide has the best protective properties. The introduction of modifying additives in quantities of more than 5 % is considered inappropriate.
-
10
Considers possibility of corrosion damage evaluation using eddy current method implemented with surface probe. Comparative analysis of amplitude-phase and phase suppression methods implementation has been conducted. Finite-element model for calculating probe signal response to defects of different corrosion type was designed. Experimental research has been conducted that allowed to verify the designed model and to confirm results gained with mathematical simulation.
-
11
The question of the quality of samples made of polymer composite materials and its verification by x-ray computed tomography is considered. The capabilities of North Star Imaging X5000 tomograph were studied and the samples from PCM were examined for detection and evaluation of the porosity volume fraction. The factors influencing the accuracy of the estimation of the porosity volume fraction are investigated. Namely the size voxel, a filter material, quantity of projections. On the other hand, the size вокселя defines resolution of the digital image, the relation depends on a material of the applied filter a signal/noise, productivity of control worsens with growth of quantity of projections. The choice of optimum values of the listed parametres is necessary for satisfactory quality received tomographic images.
-
12
In this work has been investigated the climatic resistance of carbon and fiberglass polymers for aviation purposes based on solvent-free binders VST-1208, VSE-1212, VSR-3M after 3 years of exposure of these materials in the moderate cold climate of Moscow and the moderate warm climate of Gelendzhik. The effect of destruction, post curing, plasticization of binders on the compressive and flexural strengths of carbon plastics VKU-27L, VKU-39, VKU-46 and fiberglass plastics VPS-47/7781, VPS-48/778 was determined using the methods of profilometry, moisture transfer and dynamic mechanical analysis. It is shown that while determining the state of PCM after climatic exposure, it is necessary to take into account the effects of the reversible plasticizing action of moisture. A comparison is made of the climatic resistance of the investigated materials.
