Instytut Podstawowych Problemów Techniki

UMO-2023/51/D/ST8/02370

2024-09-02 / 2026-09-01

jedyny wykonawca

NCN

SONATA

19

In-situ monitoring of strain field evolution and dissipative effects by means of optical techniques at liquid helium (4K) or liquid nitrogen (77K) represents a significant breakthrough in identifying thermo-mechanical behaviour of advanced materials, such as: (i) Rutherford cable from high-field superconducting accelerator magnets in Large Hadron Collider and the Future Circular Collider, or (ii) additively manufactured (AM) austenitic stainless steels (ASS), used in liquid hydrogen storage. Until now, no one has successfully conducted 3D full-field strain measurements on macro-specimens and structural specimens at liquid helium (4K) or even at liquid nitrogen (77K) temperatures, coupled with multi-detector identification of dissipative effects. In the course of the project, we will assemble the DIC-enhanced experimental platform with a multi-detector array for tensile, fracture and fatigue tests of advanced materials at temperature near to 0K. The unique research tool will be equipped with: (i) 4-thermistors system to measure temperature distribution, (ii) a force link mounted just behind the specimen to measure applied force, and (iii) the acoustic emission system to measure the acoustic effects during tests at liquid nitrogen (77K) or even liquid helium (4K). The tested specimen will be immersed in a glass cryostat with an active and passive insulation system to maintain thermal stability during tests at 4K. The signals from multi-detector system will be simultaneously recorded together with strain field evolution background, during tension, fracture or fatigue tests at 77K and 4K. Based on the test carried out on the experimental setup: (i) the origin of dissipative effects, such as plastic flow instability, will be experimentally recognized, (ii) mechanical parameters of advanced materials will be obtained, (iii) the dissipative effect, such as plastic flow instability, deformation induced phase transformation or micro-damage evolution will be correlated with increment of plastic strain during tensile, fracture or fatigue tests, moreover, (iv) coupled effects (e.g. damage affected discontinuous plastic flow) will be identified, and finally, (v) constitutive models of advanced materials deformed at 4K will be experimentally validated. Presently, the in-situ monitoring of strain field evolution and dissipative effects in advanced materials at liquid helium (4K) or nitrogen (77K) is of heightened importance in CERN. The European Organization for Nuclear Research has been assigned the task of conducting a technical feasibility study for the Future Circular Collider (FCC) in preparation for the anticipated update of the strategy in 2027. It is worth pointing out that the superconducting dipole magnets developed at CERN for the FCC or HL-LHC, are equipped with coils manufactured from Nb3Sn Rutherford cables. The utilization of cutting-edge, DIC-enhanced experimental platform with a multi-detector array, sets the stage for unprecedented insights into the strain field evolution of advanced materials during deformation at cryogenic temperatures, even at 4K. In essence, the project's outcomes not only deepen our understanding of material behaviour in extreme cryogenic environments but also hold the key to transformative advancements in critical areas such as hydrogen storage and superconducting technologies.