Metal Matrix Composite Permanent Magnets Produced by Cold Spray

Alternative propulsion technologies such as hybrid, plug-in and electric vehicles play an increasing role to alleviate the effects of our transportation needs on the environment.  Permanent magnets are a key component of electric motors and represent a significant proportion of their total cost. We report on the fabrication of metal-NdFeB composite permanent magnets made from commercially available powders using industrial cold spray processes. Magnets were prepared using several metal matrices to optimize the composite thermo-mechanical properties. In order to control the magnetic properties, coatings’ microstructure was varied using different powders with various compositions, size distributions and morphologies. The coatings’ microstructure was correlated to the spray parameters using SEM imaging, EDS and XRD. Magnetic properties (remanence, saturation and coercitive field) were measured using a vibrating sample magnetometer. Magnets thermal diffusivity was measured using the laser flash method.