Development of a new measurement method for soft magnetic materials under thermal and mechanical load

Metals are widely used in aerospace applications, where the mechanical and thermal loads can change rapidly and very dramatically. For the best operational performance every part gets analyzed and every load case simulated. Simulations work only properly if the input variables reflect reality in an accurate way. Literature shows, that the mentioned loads have an impact on the magnetic properties of ferromagnetic materials, which needs to be verified for each material and geometry. Mechanical stress in the metal elongates the grains and aligns therefore the Weiss domains with the force path. If this is the same direction as an outer magnetic field, the required magnetization energy is lowered. A rise in temperature leads to a faster oscillation of the atoms in the lattice, which counteracts the alignment of the magnetic moments.There is currently no measurement device which can observe both effects at once, and therefore existing set ups were investigated and a new design was developed. A spring combined with a lever arm induces up to 100 MPa of stress in the specimen and the whole set up is placed in a climate chamber, to observe the effects at a temperature range from $-50^\circ $C till $120^\circ $C. A Vacoflux\textsuperscript{\textregistered} 50 Yoke closes the magnetic circle around the specimen and holds the primary and secondary coils.Hysteresis loops were measured at various frequencies, temperatures and stresses in three different materials. Algorithms were developed to find the loops of interest and make the data comparable. The effects were measurable, but different for each material and not always consistent with literature. After implementing the initial magnetization curves into a finite element model, realistic results were calculated. *****Metals are widely used in aerospace applications, where the mechanical and thermal loads can change rapidly and very dramatically. For the best operational performance every part gets analyzed and every load case si