Induced Thermal Stresses in Core Shell Magnetic Particles

In this paper, the induced thermal stresses that appear during the cooling process from the room temperature to a lower temperature for core shell magnetic particles are analyzed. Using a finite element method for solving the Fourier heat transport equation, the thermal stresses in the system were calculated taking into account of the temperature dependence of thermal conductivity, heat capacity and different thermal expansion coefficients of the two materials (iron core + alumina shell) in contact. The thermal stresses depend on the particle's radius and the thickness of the alumina shell, having negative values due to the thermal contraction. It was estimated the influence of shell thickness on thermal stresses and on the speed of reaching the mechanical and thermal equilibrium state.