ZIRCONIA FIBERS AS A COMPONENT OF HIGH TEMPERATURE THERMAL INSULATION (review)

Based on the analysis of recent publications of scientific and technical literature, data on the production of zirconium oxide fibers used for the manufacture of high-temperature thermal insulation materials are presented. Information is provided on various methods of obtaining zirconium oxide fibers (methods of impregnation of the template and molding of the mixture, sol-gel method of spinning a fiber-forming precursor solution), as well as on the technique of fiber molding (manual pulling, dry and wet spinning, blowing and electrospinning). The use of such fibers for the production of thermal insulation materials (felts, cords and blocks) instead of currently existing materials made of aluminum oxide-based fibers can significantly increase the operating temperatures of the thermal protection systems.

STUDY OF THE INFLUENCE OF NON-COVALENT MODIFIERS ON THE STRUCTURE AND PROPERTIES OF POLYMER FILAMENTS FOR FDM-PRINTING BASED ON ABS-PLASTIC AND CARBON NANOPARTICLES

The paper presents the results of a study of the effect of non-covalent modifiers on the structure and properties of polymer filaments for FDM-printing based on ABS-plastic and carbon nanoparticles. The dependences of the characteristics of nanocomposites and filaments based on them to the type of functionalization have been established. The effect of the concentration of CNTs on the hardness, water absorption, electrical resistance, and shear strength for modified polymer filament has been investigated. The optimal formulations and technological parameters of FDM-printing of templates have been determined.

STUDY OF THE SHELF LIFE OF SEALANTS BASED ON LIQUID THIOKOL IN A STRESS-FREE STATE

The work carried out studies of the physicomechanical properties of polysulfide sealants of brands of U-30M and UT-31 after thermal, light aging, and the assessment of mushrooms. The data on the resistance of sealants of brands U-30M and UT-31 are investigated and summarized after the impact of accelerated climatic tests and aggressive environments. The optimal time and conditions for the storage of vulcanized sealants in the unattended state and components of sealants in warehouse conditions are determined, as well as the causes of different storage of sealing pastes based on liquid thiocola.

FEATURES OF THE MAGNETIC STATE IN AMORPHOUS RE–TM AND RE–TM–B MAGNETS (review)

Provides an overview of the magnetism features of amorphous magnets of the RE–TM and RE–TM–B alloys (RE – rare earth metal, TM – transition metal, B – boron). Magnetic states in amorphous alloys, the effect of the single-ionic anisotropy of heavy rare-earth metals on local disorder and spin frustrations in an amorphous body, and some spin-reorientation transitions observed in such compounds are presented. It is shown that the identification of the spin-glass state can be achieved by detecting specific features on the field and temperature dependences of the magnetic moment and magnetic susceptibility of the sample.

CERAMICS BASED ON ORGANOSILICON POLYMERS-PRECURSORS: MICROSTRUCTURE AND PROPERTIES (review). Part 2

Shows the scientific approaches of various authors to the study of the microstructure of ceramics, the purpose of which is to elucidate its structural organization at the micro- and nanoscale, as well as the influence of the microstructure on the complex of material properties. Various instrumental methods for studying ceramics (NMR spectroscopy, electron microscopy, х-ray structural analysis, etc.) are considered, the permissible capabilities of research methods and analysis of the results obtained with their correct interpretation are shown. The special role of theoretical modeling in understanding the structure of the considered ceramic materials is noted.

THE PROSPECTS OF USING CARBON NANOTUBES TO IMPART FUNCTIONAL PROPERTIES TO THE SURFACE OF POLYMER MATERIALS (review)

Presents a review of the scientific literature on various methods for producing electrically conductive polymer materials and coatings. The prospects of using carbon nanotubes (CNT) to impart high electrical properties to the surface of materials are shown. The mechanism of formation of the structured surface of polymer materials with CNT is described. It is shown that the use of CNT is a promising way to impart electrically conductive and superhydrophobic properties to the surface.

DESTRUCTIVE METHODS FOR DETERMINING RESIDUAL STRESSES (review)

The paper presents an overview of methods for determining residual stresses. Methods such as splitting and segmentation, layer-by-layer removal, slitting (cutting, pliability), profiling, drilling holes (including a «deep» hole) are considered. The description of the methods for mea-suring the deformation used in the determination of residual stresses is given. The most common contact method using strain gauges, as well as non-contact methods: polarization-optical (photo-elasticity), optical speckle interferometry, digital image correlation.

A DEVICE AND TOOL FOR MAKING SAMPLE FROM POLYMER COMPOSITE MATERIALS ON A CNC MACHINE (review)

The article discusses devices for fixing sheet metal blanks from PCM: a perforated vacuum table, its design features, advantages and disadvantages. Based on these data, the upper part of the vacuum table was made for cutting samples for Iosipescu tests and dielectric tests. The article describes various types of tools for PCM processing and an experiment on the wear resistance of a diamond-like coated rasp cutter when milling carbon fiber reinforced plastic, carried out by foreign researchers.

APPLICATION OF CYANATE ESTER MATERIALS (review) Part 1. Aviation and space structures

The review concerns the major application of materials based on cyanate ester resins in various branches of technology, indicating examples of implementation in modern devices. This article being the first part of the review highlights the cyanate esters implementation in the development of materials for aviation and space technology. The paper presents the most significant properties of polycyanurates in relation to their application. Information about the development of new cyanate ester resin-based composite materials for aircrafts and space shuttles is provided.

IMPROVEMENT OF THE CHEMICAL COMPOSITION AND STRUCTURE OF CASTABLE NICKEL-BASED SUPERALLOY WITH LOW DENSITY. Part 2

Results of design and experimental studies of a nickel-based superalloy VZhL20 with a density of 8.04 g/cm3 for the manufacture of turbine blades with a columnar granular structure and a single-crystal structure are presented. It is shown that alloy VZHL20 with a single-crystal structure of the crystallographic orientation [001] in the heat-treated state possesses high phase stability, and enhanced short-term strength ( = 950 MPa, = 1130 MPa), and long-term strength ( = 340 MPa, = 185 MPa).