MOSCOW, 19 Jun. Scientists of Tomsk Polytechnic University have proposed an inexpensive and energy-efficient method for controlling the structure of composite materials based on nitrides for use in electronics, aviation and automotive industries. The results are published in Materials Letters.
In recent years, composite materials based on nitrides have been widely used in electronics, aviation and automotive industries, construction, mechanical engineering and other industries due to the unique combination of electrical, thermal and mechanical properties.
Scientists of Tomsk Polytechnic University noted that the most promising method for obtaining such substances is the method of self-propagating high-temperature synthesis (SHS-synthesis) — air combustion of mixtures of aluminum nanopowder with metal oxides. This method is promising due to its low energy consumption, short processing time, and low cost. en/20230614/nauka-1877778658.html» data->
By controlling the pressure or adjusting the composition of the gas atmosphere in a chemical reactor, scientists can control the composition of SHS synthesis products. However, it has not yet been possible to control the morphology («shape» or «appearance») of the obtained structures until now. .
“We have experimentally proved that the introduction of a small amount of additives into the reaction mixture with simultaneous exposure to a magnetic field makes it possible to practically “control” the morphology, or, to put it simply, the “appearance” of the resulting structures,” said Andrey Mostovshchikov, professor at the Department of Natural Sciences of the Tomsk Polytechnic University.< br />
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According to him, this is due to the interaction of additives (and their reaction products during SHS synthesis) with a magnetic field and their drift under the action of the field, which leads to the crystallization of the reaction products in a certain form.
According to scientists, in the future it will be possible to obtain products of SHS synthesis of a given morphology by introducing a small amount of additives into the system and simultaneously exposing them to physical fields, in this case magnetic fields.
«Materials obtained using the crystal structures we have created can have additional improved properties — increased thermal conductivity, wear resistance, less combustibility, better magnetic properties. The use of such products in composites will help improve the performance of existing materials,» Andrey Mostovshchikov emphasized.
He noted that when obtaining materials by SHS synthesis, a problem often arises associated with the formation of sintered reaction products, which must be further crushed. And the synthesis according to the proposed method makes it possible to obtain, among other things, looser structures, which will facilitate their subsequent processing, the researcher said. url=»https://ria.ru/20220905/samarskiy_universitet-1813931367.html» data->
In the future, scientists plan to continue research on products obtained by the developed technology, as part of composite materials (ceramics, filled with polymers) and abrasive materials.
TPU is a member of the Priority-2030 State University Support Program.