Magnetic Laminates for Motor Slot Wedges and Other Applications

We have examined the properties of G-10-Fe, a commercially manufactured fiber-reinforced epoxy with a 70 wt% inclusion of Fe powder, and the advantages of this material in motor slot wedges are presented. The microstructure of G-10-Fe was observed by SEM/EDS and its magnetic properties were measured in terms of magnetization, saturation magnetization and AC loss. The saturation magnetization was 150 Am²/kg, as determined by vibrating sample magnetometry (VSM). Core losses were measured by spinning magnet calorimetry (SMC). In loss measurements made at applied field frequencies of 10 to 120 Hz essentially only hysteretic loss was present, the per cycle loss was ≅ 19 mJ/cm³. The absence of eddy current loss made G-10-Fe more suitable than bulk Fe for use as motor slot wedge material.