Measuring thermal and electrical performances of additively manufactured magnetic shielding material: an active thermography approach

The thermal and electrical responses of additive manufactured specimens were analysed for a additive manufactured steel magnetic shield as a case study. The analysis was based on the evidence that variations in the thermal properties of a material can be measured as a phase delay in thermal diffusion through the material bulk. The signal post-processing was performed, and the results were presented in a phase diagram. The results showed that after heat treatment, the slope of the phase diagram changed to less steep, indicating an increase in thermal diffusivity and hence thermal conductivity. The electrical conductivity was predicted using the thermal conductivity and the Weidemann-Franz law and validated by experimental measurements of the electrical conductivity. The same approach was applied to predict the electrical conductivity in the magnetic shielding, taking into consideration the scaling of the density due to porosity. The results showed that the thermographic non-destructive full field non-contact approach can be used to evaluate the electrical properties of a component and that the heat-treated specimens show better thermal diffusivity and hence thermal and electrical conductivity.