Impact of porosity on trapped magnetic field and mechanical stresses in HTS bulks during PFM
Résumé
During pulsed-field magnetization (PFM) processes, high-temperature superconducting (HTS) bulks are subjected to significant mechanical deformations due to rapid changes in magnetic flux (Lorentz force) and temperature (thermal stress), potentially leading to fracture. Furthermore, fabricationinduced defects, such as cracks, pores, and grain boundaries, can strongly impact the HTS performance, often resulting in non-uniform trapped magnetic fields and promoting mechanical failure. The present study assesses the impact of porosity on the trapped magnetic field, temperature, and mechanical stresses through a 2D multiphysics PFM numerical model using COMSOL Multiphysics. The results show that the porosity highly influences both local stresses and the temperature rise by affecting the distribution of induced currents, which leads to an non-uniform and reduced trapped magnetic field.