Materials and structures applied at extremely low temperatures

by Błażej Skoczeń (Cracow University of Technology)

Thursday 1 Feb 2024, 11:00 → 13:00 Europe/Warsaw

Extremely low temperatures play a key role in the modern world due to the possibility of using the phenomenon of superconductivity in such devices like the particle accelerators, the superconducting magnets for nuclear magnetic resonance, the superconducting links or the magnetic cushion railways. In all cases, the properties of engineering materials operating at cryogenic temperatures, such as the austenitic steels, copper, aluminium or the composite materials, are crucial for safe operation of cryogenic devices. Research dedicated to the phenomena occurring in the materials at extremely low temperatures leads to the conclusion, that their behavior differs significantly from what is observed at room or at elevated temperatures. When designing the structures operating at the temperature of liquid or superfluid helium, it is necessary to take into account the evolution of the material microstructure, corresponding to such dissipative phenomena like the intermittent plastic flow, the plastic strain induced fcc-bcc phase transformation or the evolution of micro-damage caused by straining or by the particle flux. Of key importance for the above phenomena is the thermodynamic background related to weakly excited crystal lattice, as well as the thermodynamic instability, which results from the third law of thermodynamics. Mathematical description of the above coupled phenomena, and assessment of their impact on the behavior of structures operating at cryogenic temperatures, are objective of research conducted in cooperation with such institutions, like the European Organization for Nuclear Research, CERN. The research, supported by the National Science Centre, contributed to the implementation of such instruments like the Large Hadron Collider (LHC) or the International Thermonuclear Experimental Reactor (ITER).