Аннотация. Задача создания технологии упрочнения эпоксидной смолы (ЭС) и углепластика актуальна для многих разделов техники: космической, авиационной, оборонной, автомобильной и др. Вопрос решается многочисленными приемами модификации ЭС, компонентов углепластика. Модификация ЭС осуществляется путем ввода различных химических соединений. Одним из методов упрочнения углепластика является модификация пластификаторами (трикрезилфосфат, олеиновая кислота) или термопластами (полисульфон, поликарбонат, полистирол, ударопрочный полистирол). В работе собраны имеющиеся в литературе экспериментальные данные по влиянию различных видов модификаторов на прочность ЭС и углепластика. Проанализирован механизм модифицирования ЭС и углепластика пластификаторами и термопластами. Введение пластификаторов в качестве модификаторов ЭС приводит к улучшению ударной вязкости в 2 раза. Оптимальный ввод пластификаторов в ЭС составляет 15 % и зависит от полноты растворимости в связующем, дальнейшее увеличение ввода пластификатора приводит к снижению прочности материала. Модификация термопластами углепластика может привести к улучшению прочности на сжатие на 20% и ударной вязкости в 2 раза. При введении термопластов свыше 20% в углепластик показатели прочности снижаются. Полученные данные необходимы для разработки отечественной технологии производства ударопрочных углепластиков. Ключевые слова: эпоксидная смола, модификаторы, пластификаторы, термопласты, термообработка, ударная вязкость, прочность.Мустафа Л.М. -Ph.D. студент, старший научный сотрудник в АО «Национальном центре космических исследований и технологий», Алматы, Казахстан. ORCID ID: 0000-0002-9779-0007.

View the article online for updates and enhancements. Abstract. In this work crystallographic texture for a set of rail wheel steel samples with different regimes of thermo-mechanical treatment and with and without modification by system Al-Mg-SiFe-C-Ca-Ti-Ce was measured by neutron diffraction. The texture measurements were carried out by using time-of-flight technique at SKAT diffractometer situated at IBR-2 reactor (Dubna, JINR, Russia). The three complete pole figures (110), (200), (211) of α-Fe phase in 5˚×5˚grid were extracted from a set of 1368 spectra measured for each sample. The samples were cut from rail wheel rim and from transitional zone (between rail wheel hub and wheel disk). It was concluded that the steel modification and some changes in the heat treatment modes of the rail wheels from the experimental (modified) and the conventional (non-modified) steel lead to reorientation of texture component. IntroductionSolid-rolled wheels for railway rolling stock are being currently produced by about fifteen industrial enterprises in different countries (Belgium, the Czech Republic, France, Russia, Ukraine, etc.). According to Railway Wheels and Wheelsets Committee (ERWA), global demand for wheels is about 4.8 million units per year. Passenger rolling stock market in Europe increases annually by 3% (according to the International Union of Railways). It is need about 500 kg of steel to make one rail wheel. The price of a steel increased since 2004 to 2010 by 100 -120%. The rising of a steel price leads to increasing of wheels price. Therefore, the important task for operating companies becomes to prolong life of wheels, and for producers of wheels is to use the most efficient ways of high-quality metal production. That is why the study of a rail wheel steel quality is urgent from both scientific and practical sides. One way to improve the quality of the wheels is a modification of the molten steel. The modification is admixture of small amounts of additives to modify the properties of alloy through a change its microstructure (grains size, grains shape) and prefered orientations, i.e. texture. The modifiers admixture result in grain refinement. Besides, the additional atoms incorporated into crystal lattice leads to its distortion. This process could result in the blocking of dislocations and consequently to alloy hardening. The final operational properties of the wheels depend on several factors, namely the chemical composition, the macro-and microstructure and also the crystallographic texture of the steel. The production technology of the rail wheels includes such operations as forging, press forming and rolling that can result in texture formation. The subsequent temperature treatment (annealing, quenching and tempering for rim) can also influence texture changing. The crystallographic texture can result in brittle cracking in steel products [1][2][3], so it can be one of the rail wheels damage reasons. The aim of this work is to study the impact of the modification and the thermo-mechanical treatmen...

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stuDy on the effect of plAstIcIZers AnD therMoplAstIcs on the strenGth AnD touGhness of epoxy resIns purpose. To increase the strength and toughness of epoxy resins of "cold hardening" and "hot hardening" by using modified plasticizers and thermoplastic polymers. Methodology. Epoxy resins of "cold hardening" of ED20 and "hot hardening" of Etal InjectT, modified with three types of plasticizers and four types of thermoplastic polymers, were investigated. The toughness and compressive strength of unmodified and modified resins were determined with the help of the Charpy impact test at various modifier contents. findings. Among all studied plasticizers, tricresyl phosphate has the most significant effect on the strength and toughness of both types of resins. The best combination of strength and toughness of ED20 resin is obtained with 5 % tricresyl phosphate con tent, whereas its higher content reduces the strength of the material. For Etal InjectT, high values of these properties are obtained with 15 % tricresyl phosphate content, whereas adding a smaller amount of a modifier does not change the material strength. The modification with thermoplastic polymers has a less obvious effect on the properties of epoxy resins than the modification with plasticizers does. The most effective additives to ED20 are hightemperature polycarbonate (5 %) and polysulfone (10 and 15 %), the addition of which causes a simultaneous increase in both properties. A significant increase in the toughness of Etal InjectT is observed by adding 5-15 % polycarbonate, but the strength of the resin hardly changes. The complex modification of resins with a mixture of plasticizer and thermoplastic leads to a decrease in the toughness and compressive strength of both types of resins. originality. When the polymer mixture hardens, plasticizer molecules dispersed into the environment of epoxy macromole cules weaken the rigid spatial crosslinking of macromolecules and make them more active. As a result, toughness increases; in certain cases so does resistance due to directed reorientation of macromolecules under deformation. The change in mechanical properties of epoxy resin when modified with thermoplastics is defined by the bonding strength of the resin and dispersed particles of thermoplastic polymer as well as by the degree of heterophase of the produced mixture. practical value. The results of changing the mechanical properties of epoxy resin while being modified with plasticizers and thermoplastics can be used to produce impactresistant composite materials for structural purposes, including those for aviation and spacerocket technology.