PSI - Issue 20

A.A. Kychkin et al. / Procedia Structural Integrity 20 (2019) 185–189 A.A.Kychkin et al / Structural Integrity Procedia 00 (2019) 000–000

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1. Introduction Progress in development of composite materials industry provides for designing, implementing and production of new materials in high- technology industries. Emergence of new materials implies necessity of research and applied studies on refining of technological solutions in the production of goods and constructions. Possibility of creation of new materials with a necessary set of properties is attributable to the rational choice of components and technology, which having specified components of a composite material guarantees to establish the structure, providing the required level of properties. However rationally a product may be designed, none of the materials in its composition can keep its properties indefinitely. This is owing to emergence and development of inner damage of the material in the process of its production and exploitation. Destruction of composite materials generally starts with accumulation of independent micro- defects, continues in growth and merging into main cracks in the matrix material. Therefore the period of the material working capacity will be determined by speed of emergence and development of cracks in the matrix material under the influence of operational factors. Consequently, the enhancing of crack resistance of polymer resin, used as matrix for reinforced KM, is a relevant practical task. 2. Results and discussion There is a great number of ways to adjust the properties of composites. Nowadays, introduction of ultrafine additives of different nature to the resin amount in order to modify its properties by Putilov (2002), is of practical interest. Therefore, introduction of little amount (to1 %) of nanodiamonds to epoxy resin makes it possible to enhance its impact strength of 25-30% in the solidified condition, as well as to increase the temperature of vitrification by Anan'eva (2013). Zheng and others (2003) showed in their research, that addition of 3% nanoparticles of silica to epoxy matrix increases tensile strength of 115%, whereas impact resistance capability increases of 56%. Rosso (2006) determined the increase of modulus of elastic in bending due to introduction of nanoparticles of silicon dioxide. Implementation of carbon nanotubes by Moniruzzaman (2006), Chen (2009), Akatenkov (2008) is relatively new. In recent years there has been a great effort to explore possibilities of application of silicon carbide (SiC) in the form of micro- and nano-sized powders, whose unique properties result in their application as fillers and polymers' modifiers. Combination of high thermal conductivity and low coefficient of thermal expansion allows to keep resistance at high heating rate under fixed thermal conditions. Influence of properties of fine disperse silicon carbide on polymer morphology in composition is expected. Distribution SiC over fine fractions gives opportunity to use silicon carbide powders directly in the manufacture of polymer and other composite materials without their prior fragmentation and distribution over fractions. In order to value effectiveness and technological feasibility of use of silicon carbide as a modifying addition, a resin based on epoxy oligomer ED- 20 was chosen as a subject of research and isomethyl-tetrahydrohthalic anhydride (iso-MTGFA) was chosen as a solidifying agent. The choice of resin stems from the prevalence of its application in the production of reinforced composite materials for different purposes. The modifying addition of silicon carbide was used in a powder form, where SiC content was no less than 94% with the average particle size form 80 to 110 nm and the maximum agglomerate size to 15 mkm. An important point while forming the mixture of resin with dispersed particles is achievement of relatively equal distribution of particles in the resin amount, size distribution, absence of large agglomerates and sediment sustainability of disperse system. To that end, introduction of dispersions to the most viscous part of resin was carried out – resin part (ED-20) with the following ultrasonic dispersing when the impact time varies within 60,120 and 240 minutes. In the process of dispersion the change of colour of resin part was observed, that is the evidence of change of particle concentration in the amount due to distraction of agglomerates (Fig.1).