11 February 2019In January 2019, Dmitriy Serebrennikov, a researcher from the Immanuel Kant Baltic Federal University, took out a patent on his invention in physics Composite Invar materials of a new type. Materials, which have both Invar and functional properties, are highly demanded in instrumentation engineering, radio-electronic equipment, aviation and aerospace industry.
The researcher explains that most metals expand when heated but there are alloys that hardly change their size in a certain temperature range. Such alloy is called Invar. In 1920, Charles Edouard Guillaume, a Swiss-French scientist, got the Nobel Prize for the Invar invention. Later, it became widely used for the manufacturing of high-precision mechanical watches. Invar does not possess other unique physical properties though. Meanwhile, functional materials often have a very high thermal expansion, which is a significant problem for a number of technical devices.
However, it is possible to manage the problem by making an alloy that is consisted of functional material and particles of another substance with a significantly lower coefficient of thermal expansion. The patent is unique due to the proposed materials that were designed to compensate the thermal expansion of the functional material. They are valence-unstable compounds with a negative thermal expansion. Unlike simple metals, these compounds are compressed when heated. Therefore they are perfectly suitable for creating composite Invar materials.
The research has been conducted for four years. It was led by Dmitriy Serebrennikov, junior research associate at IKBFU, in collaboration with Dr Evgeny Clementyev, Head of the Laboratory for Strongly Correlated Electron Systems at IKBFU, and Dr Pavel Alekseev, a researcher from National Research Nuclear University MEPhI.
Dmitriy Serebrennikov, junior research associate (IKBFU):
Today, the research group of the Immanuel Kant Baltic Federal University sets several goals and they are to synthesize various composites, to find out how to produce a necessary alloy and how to optimize this process. Next step is to study the thermodynamic properties of the obtained alloys, as well as to continue this study in the framework of fundamental research.
The results of the research were partly reported in the Journal of Magnetism and Magnetic Materials.