Characterization of commercial corona resistant magnet wire enamels using nanoindentation techniques

Corona resistant magnet wire has become an important focus in motor designs for low voltage, inverter duty applications. While the electrical properties of these materials are under study by motor and wire manufacturers, a better understanding of the mechanical properties of these wires will help reduce defects and product loss due to poor manufacturability. A number of commercially available corona resistant magnet wire coatings were compared using nanoindentation techniques; hardness and modulus of elasticity were measured. The wire enamels were examined in cross-section and differences in the topcoat and basecoat observed.